Eager load node and way details when processing a map call.

[rails.git] / app / controllers / amf_controller.rb

diff --git a/app/controllers/amf_controller.rb b/app/controllers/amf_controller.rb
index b318e3eefc060a87dd837197c266ba083996bc80..9004397218ddcbc47e2e8a43b5761c6266a35ab8 100644 (file)
--- a/app/controllers/amf_controller.rb
+++ b/app/controllers/amf_controller.rb
@@ -1,844 +1,945 @@
+# amf_controller is a semi-standalone API for Flash clients, particularly 
+# Potlatch. All interaction between Potlatch (as a .SWF application) and the 
+# OSM database takes place using this controller. Messages are 
+# encoded in the Actionscript Message Format (AMF).
+#
+# Helper functions are in /lib/potlatch.rb
+#
+# Author::     editions Systeme D / Richard Fairhurst 2004-2008
+# Licence::    public domain.
+#
+# == General structure
+#
+# Apart from the amf_read and amf_write methods (which distribute the requests
+# from the AMF message), each method generally takes arguments in the order 
+# they were sent by the Potlatch SWF. Do not assume typing has been preserved. 
+# Methods all return an array to the SWF.
+#
+# == API 0.6
+#
+# Note that this requires a patched version of composite_primary_keys 1.1.0
+# (see http://groups.google.com/group/compositekeys/t/a00e7562b677e193) 
+# if you are to run with POTLATCH_USE_SQL=false .
+# 
+# == Debugging
+# 
+# Any method that returns a status code (0 for ok) can also send:
+#      return(-1,"message")            <-- just puts up a dialogue
+#      return(-2,"message")            <-- also asks the user to e-mail me
+# 
+# To write to the Rails log, use logger.info("message").
+
+# Remaining issues:
+# * version conflict when POIs and ways are reverted
+

 class AmfController < ApplicationController
   require 'stringio'
 
 class AmfController < ApplicationController
   require 'stringio'
 

-  # to log:
-  # RAILS_DEFAULT_LOGGER.error("Args: #{args[0]}, #{args[1]}, #{args[2]}, #{args[3]}")
-
-  # ====================================================================
-  # Main AMF handler
-
-  # ---- talk  process AMF request
+  include Potlatch

 
 

-  def talk
-    req=StringIO.new(request.raw_post) # Get POST data as request
-    req.read(2)                                                        # Skip version indicator and client ID
-    results={}                                                 # Results of each body
+  # Help methods for checking boundary sanity and area size
+  include MapBoundary

 
 

-    # -------------
-    # Parse request
+  session :off
+  before_filter :check_api_writable

 
 

-    headers=getint(req)                                        # Read number of headers
-
-    headers.times do                               # Read each header
-      name=getstring(req)                              #  |
-      req.getc                                         #  | skip boolean
-      value=getvalue(req)                              #  |
-      header["name"]=value                             #  |
-    end
+  # Main AMF handlers: process the raw AMF string (using AMF library) and
+  # calls each action (private method) accordingly.
+  # ** FIXME: refactor to reduce duplication of code across read/write
+  
+  def amf_read
+    if request.post?
+      req=StringIO.new(request.raw_post+0.chr)# Get POST data as request
+                                # (cf http://www.ruby-forum.com/topic/122163)
+      req.read(2)                                                              # Skip version indicator and client ID
+      results={}                                                               # Results of each body
+
+      # Parse request
+
+      headers=AMF.getint(req)                          # Read number of headers
+
+      headers.times do                                 # Read each header
+        name=AMF.getstring(req)                                #  |
+        req.getc                                       #  | skip boolean
+        value=AMF.getvalue(req)                                #  |
+        header["name"]=value                           #  |
+      end

 
 

-    bodies=getint(req)                                 # Read number of bodies
-    bodies.times do                                    # Read each body
-      message=getstring(req)                   #  | get message name
-      index=getstring(req)                             #  | get index in response sequence
-      bytes=getlong(req)                               #  | get total size in bytes
-      args=getvalue(req)                               #  | get response (probably an array)
-
-      case message
-                 when 'getpresets';    results[index]=putdata(index,getpresets)
-                 when 'whichways';             results[index]=putdata(index,whichways(args))
-                 when 'getway';                results[index]=putdata(index,getway(args))
-                 when 'putway';                results[index]=putdata(index,putway(args))
-                 when 'deleteway';             results[index]=putdata(index,deleteway(args))
-                 when 'makeway';               results[index]=putdata(index,makeway(args))
+      bodies=AMF.getint(req)                           # Read number of bodies
+      bodies.times do                                  # Read each body
+        message=AMF.getstring(req)                     #  | get message name
+        index=AMF.getstring(req)                       #  | get index in response sequence
+        bytes=AMF.getlong(req)                         #  | get total size in bytes
+        args=AMF.getvalue(req)                         #  | get response (probably an array)
+        logger.info("Executing AMF #{message}:#{index}")
+
+        case message
+          when 'getpresets';           results[index]=AMF.putdata(index,getpresets())
+          when 'whichways';            results[index]=AMF.putdata(index,whichways(*args))
+          when 'whichways_deleted';    results[index]=AMF.putdata(index,whichways_deleted(*args))
+          when 'getway';               r=AMF.putdata(index,getway(args[0].to_i))
+                                        results[index]=r
+          when 'getrelation';          results[index]=AMF.putdata(index,getrelation(args[0].to_i))
+          when 'getway_old';           results[index]=AMF.putdata(index,getway_old(args[0].to_i,args[1]))
+          when 'getway_history';       results[index]=AMF.putdata(index,getway_history(args[0].to_i))
+          when 'getnode_history';      results[index]=AMF.putdata(index,getnode_history(args[0].to_i))
+          when 'findgpx';              results[index]=AMF.putdata(index,findgpx(*args))
+          when 'findrelations';                results[index]=AMF.putdata(index,findrelations(*args))
+          when 'getpoi';               results[index]=AMF.putdata(index,getpoi(*args))
+        end

       end
       end

+      logger.info("encoding AMF results")
+      sendresponse(results)
+    else
+      render :nothing => true, :status => :method_not_allowed

     end
     end

-
-    # ------------------
-    # Write out response
-
-    RAILS_DEFAULT_LOGGER.info("  Response: start")
-    a,b=results.length.divmod(256)
-       render :content_type => "application/x-amf", :text => proc { |response, output| 
-        output.write 0.chr+0.chr+0.chr+0.chr+a.chr+b.chr
-               results.each do |k,v|
-                 output.write(v)
-               end
-       }
-    RAILS_DEFAULT_LOGGER.info("  Response: end")
-

   end
 
   end
 

-  private
+  def amf_write
+    if request.post?
+      req=StringIO.new(request.raw_post+0.chr)
+      req.read(2)
+      results={}
+      renumberednodes={}                               # Shared across repeated putways
+      renumberedways={}                                        # Shared across repeated putways
+
+      headers=AMF.getint(req)                          # Read number of headers
+      headers.times do                                 # Read each header
+        name=AMF.getstring(req)                                #  |
+        req.getc                                       #  | skip boolean
+        value=AMF.getvalue(req)                                #  |
+        header["name"]=value                           #  |
+      end

 
 

-  # ====================================================================
-  # Remote calls
-
-  # ----- getpresets
-  #          return presets,presetmenus and presetnames arrays
-
-  def getpresets
-    presets={}
-    presetmenus={}; presetmenus['point']=[]; presetmenus['way']=[]
-    presetnames={}; presetnames['point']={}; presetnames['way']={}
-    presettype=''
-    presetcategory=''
-
-    RAILS_DEFAULT_LOGGER.info("  Message: getpresets")
-
-    #          File.open("config/potlatch/presets.txt") do |file|
-
-    # Temporary patch to get around filepath problem
-    # To remove this patch and make the code nice again:
-    # 1. uncomment above line
-    # 2. fix the path in the above line
-    # 3. delete this here document, and the following line (StringIO....)
-
-    txt=<<-EOF
-way/road
-motorway: highway=motorway,ref=(type road number)
-trunk road: highway=trunk,ref=(type road number),name=(type road name)
-primary road: highway=primary,ref=(type road number),name=(type road name)
-secondary road: highway=secondary,ref=(type road number),name=(type road name)
-residential road: highway=residential,name=(type road name)
-unclassified road: highway=unclassified,name=(type road name)
-
-way/footway
-footpath: highway=footway,foot=yes
-bridleway: highway=bridleway,foot=yes,horse=yes,bicycle=yes
-byway: highway=byway,foot=yes,horse=yes,bicycle=yes,motorcar=yes
-permissive path: highway=footway,foot=permissive
-
-way/cycleway
-cycle lane: highway=cycleway,cycleway=lane,ncn_ref=
-cycle track: highway=cycleway,cycleway=track,ncn_ref=
-cycle lane (NCN): highway=cycleway,cycleway=lane,name=(type name here),ncn_ref=(type route number)
-cycle track (NCN): highway=cycleway,cycleway=track,name=(type name here),ncn_ref=(type route number)
-
-way/waterway
-canal: waterway=canal,name=(type name here)
-navigable river: waterway=river,boat=yes,name=(type name here)
-navigable drain: waterway=drain,boat=yes,name=(type name here)
-derelict canal: waterway=derelict_canal,name=(type name here)
-unnavigable river: waterway=river,boat=no,name=(type name here)
-unnavigable drain: waterway=drain,boat=no,name=(type name here)
-
-way/railway
-railway: railway=rail
-tramway: railway=tram
-light railway: railway=light_rail
-preserved railway: railway=preserved
-disused railway tracks: railway=disused
-course of old railway: railway=abandoned
-
-point/road
-mini roundabout: highway=mini_roundabout
-traffic lights: highway=traffic_signals
-
-point/footway
-bridge: highway=bridge
-gate: highway=gate
-stile: highway=stile
-cattle grid: highway=cattle_grid
-
-point/cycleway
-gate: highway=gate
-
-point/waterway
-lock gate: waterway=lock_gate
-weir: waterway=weir
-aqueduct: waterway=aqueduct
-winding hole: waterway=turning_point
-mooring: waterway=mooring
-
-point/railway
-station: railway=station
-viaduct: railway=viaduct
-level crossing: railway=crossing
-EOF
-
-    StringIO.open(txt) do |file|
-      file.each_line {|line|
-        t=line.chomp
-        if (t=~/(\w+)\/(\w+)/) then
-          presettype=$1
-          presetcategory=$2
-          presetmenus[presettype].push(presetcategory)
-          presetnames[presettype][presetcategory]=["(no preset)"]
-        elsif (t=~/^(.+):\s?(.+)$/) then
-          pre=$1; kv=$2
-          presetnames[presettype][presetcategory].push(pre)
-          presets[pre]={}
-          kv.split(',').each {|a|
-            if (a=~/^(.+)=(.*)$/) then presets[pre][$1]=$2 end
-          }
+      bodies=AMF.getint(req)                           # Read number of bodies
+      bodies.times do                                  # Read each body
+        message=AMF.getstring(req)                     #  | get message name
+        index=AMF.getstring(req)                       #  | get index in response sequence
+        bytes=AMF.getlong(req)                         #  | get total size in bytes
+        args=AMF.getvalue(req)                         #  | get response (probably an array)
+
+        logger.info("Executing AMF #{message}:#{index}")
+        case message
+          when 'putway';                       r=putway(renumberednodes,*args)
+                                               renumberednodes=r[3]
+                                               if r[1] != r[2] then renumberedways[r[1]] = r[2] end
+                                               results[index]=AMF.putdata(index,r)
+          when 'putrelation';                  results[index]=AMF.putdata(index,putrelation(renumberednodes, renumberedways, *args))
+          when 'deleteway';                    results[index]=AMF.putdata(index,deleteway(*args))
+          when 'putpoi';                       r=putpoi(*args)
+                                               if r[1] != r[2] then renumberednodes[r[1]] = r[2] end
+                                               results[index]=AMF.putdata(index,r)
+          when 'startchangeset';               results[index]=AMF.putdata(index,startchangeset(*args))

         end
         end

-      }
+      end
+      logger.info("encoding AMF results")
+      sendresponse(results)
+    else
+      render :nothing => true, :status => :method_not_allowed

     end
     end

-    return [presets,presetmenus,presetnames]

   end
 
   end
 

-  # ----- whichways(left,bottom,right,top)
-  #              return array of ways in current bounding box
-  #              at present, instead of using correct (=more complex) SQL to find
-  #              corner-crossing ways, it simply enlarges the bounding box by +/- 0.01
-
-  def whichways(args)
-    xmin = args[0].to_f-0.01
-    ymin = args[1].to_f-0.01
-    xmax = args[2].to_f+0.01
-    ymax = args[3].to_f+0.01
-
-    RAILS_DEFAULT_LOGGER.info("  Message: whichways, bbox=#{xmin},#{ymin},#{xmax},#{ymax}")
-
-    waylist=WaySegment.find_by_sql("SELECT DISTINCT current_way_segments.id AS wayid"+
-       "  FROM current_way_segments,current_segments,current_nodes,current_ways "+
-       " WHERE segment_id=current_segments.id "+
-       "   AND current_segments.visible=1 "+
-       "   AND node_a=current_nodes.id "+
-          "   AND current_ways.id=current_way_segments.id "+
-          "   AND current_ways.visible=1 "+
-       "   AND (latitude  BETWEEN "+ymin.to_s+" AND "+ymax.to_s+") "+
-       "   AND (longitude BETWEEN "+xmin.to_s+" AND "+xmax.to_s+")")
-
-       ways = waylist.collect {|a| a.wayid.to_i } # get an array of way id's
-
-       pointlist =ActiveRecord::Base.connection.select_all("SELECT current_nodes.id,current_nodes.tags "+
-       "  FROM current_nodes "+
-       "  LEFT OUTER JOIN current_segments cs1 ON cs1.node_a=current_nodes.id "+
-       "  LEFT OUTER JOIN current_segments cs2 ON cs2.node_b=current_nodes.id "+
-       " WHERE (latitude  BETWEEN "+ymin.to_s+" AND "+ymax.to_s+") "+
-       "   AND (longitude BETWEEN "+xmin.to_s+" AND "+xmax.to_s+") "+
-       "   AND cs1.id IS NULL AND cs2.id IS NULL "+
-       "   AND current_nodes.visible=1")
-
-           points = pointlist.collect {|a| [a['id'],tag2array(a['tags'])]      } # get a list of node ids and their tags
-
-    return [ways,points]
-  end
+  private

 
 

-  # ----- getway (objectname, way, baselong, basey, masterscale)
-  #              returns objectname, array of co-ordinates, attributes,
-  #                              xmin,xmax,ymin,ymax
-
-  def getway(args)
-    objname,wayid,baselong,basey,masterscale=args
-    wayid = wayid.to_i
-    points = []
-    lastid = -1
-    xmin = ymin = 999999
-    xmax = ymax = -999999
-
-    RAILS_DEFAULT_LOGGER.info("  Message: getway, id=#{wayid}")
-
-    readwayquery(wayid).each {|row|
-      xs1=long2coord(row['long1'].to_f,baselong,masterscale); ys1=lat2coord(row['lat1'].to_f,basey,masterscale)
-      xs2=long2coord(row['long2'].to_f,baselong,masterscale); ys2=lat2coord(row['lat2'].to_f,basey,masterscale)
-      points << [xs1,ys1,row['id1'].to_i,0,tag2array(row['tags1']),0] if (row['id1'].to_i!=lastid)
-      lastid = row['id2'].to_i
-      points << [xs2,ys2,row['id2'].to_i,1,tag2array(row['tags2']),row['segment_id'].to_i]
-      xmin = [xmin,row['long1'].to_f,row['long2'].to_f].min
-      xmax = [xmax,row['long1'].to_f,row['long2'].to_f].max
-      ymin = [ymin,row['lat1'].to_f,row['lat2'].to_f].min
-      ymax = [ymax,row['lat1'].to_f,row['lat2'].to_f].max
-    }
+  # Start new changeset
+  
+  def startchangeset(usertoken, cstags, closeid, closecomment)
+    user = getuser(usertoken)
+    if !user then return -1,"You are not logged in, so Potlatch can't write any changes to the database." end
+
+    # close previous changeset and add comment
+    if closeid
+      cs = Changeset.find(closeid)
+      cs.set_closed_time_now
+      if cs.user_id!=user.id
+        return -2,"You cannot close that changeset because you're not the person who opened it."
+      elsif closecomment.empty?
+        cs.save!
+      else
+        cs.tags['comment']=closecomment
+        cs.save_with_tags!
+      end
+    end
+       
+    # open a new changeset
+    cs = Changeset.new
+    cs.tags = cstags
+    cs.user_id = user.id
+    # smsm1 doesn't like the next two lines and thinks they need to be abstracted to the model more/better
+    cs.created_at = Time.now.getutc
+    cs.closed_at = cs.created_at + Changeset::IDLE_TIMEOUT
+    cs.save_with_tags!
+    return [0,cs.id]
+  end

 
 

-    attributes={}
-    attrlist=ActiveRecord::Base.connection.select_all "SELECT k,v FROM current_way_tags WHERE id=#{wayid}"
-    attrlist.each {|a| attributes[a['k']]=a['v'] }
+  # Return presets (default tags, localisation etc.):
+  # uses POTLATCH_PRESETS global, set up in OSM::Potlatch.

 
 

-    [objname,points,attributes,xmin,xmax,ymin,ymax]
+  def getpresets() #:doc:
+    return POTLATCH_PRESETS

   end
 
   end
 

-  # -----      putway (user token, way, array of co-ordinates, array of attributes,
-  #                                    baselong, basey, masterscale)
-  #                    returns current way ID, new way ID, hash of renumbered nodes,
-  #                                    xmin,xmax,ymin,ymax
-
-  def putway(args)
-    usertoken,originalway,points,attributes,baselong,basey,masterscale=args
-    uid=getuserid(usertoken)
-    return if !uid
-    db_uqs='uniq'+uid.to_s+originalway.to_i.abs.to_s+Time.new.to_i.to_s        # temp uniquesegments table name, typically 51 chars
-    db_uqn='unin'+uid.to_s+originalway.to_i.abs.to_s+Time.new.to_i.to_s        # temp uniquenodes table name, typically 51 chars
-    db_now='@now'+uid.to_s+originalway.to_i.abs.to_s+Time.new.to_i.to_s        # 'now' variable name, typically 51 chars
-    ActiveRecord::Base.connection.execute("SET #{db_now}=NOW()")
-    originalway=originalway.to_i
-
-    RAILS_DEFAULT_LOGGER.info("  Message: putway, id=#{originalway}")
-
-    # -- 3.    read original way into memory
-
-    xc={}; yc={}; tagc={}; seg={}
-    if originalway>0
-      way=originalway
-      readwayquery(way).each { |row|
-        id1=row['id1'].to_i; xc[id1]=row['long1'].to_f; yc[id1]=row['lat1'].to_f; tagc[id1]=row['tags1']
-        id2=row['id2'].to_i; xc[id2]=row['long2'].to_f; yc[id2]=row['lat2'].to_f; tagc[id2]=row['tags2']
-        seg[row['segment_id'].to_i]=id1.to_s+'-'+id2.to_s
-      }
-         ActiveRecord::Base.connection.update("UPDATE current_ways SET timestamp=#{db_now},user_id=#{uid},visible=1 WHERE id=#{way}")
+  ##
+  # Find all the ways, POI nodes (i.e. not part of ways), and relations
+  # in a given bounding box. Nodes are returned in full; ways and relations 
+  # are IDs only. 
+  #
+  # return is of the form: 
+  # [error_code, 
+  #  [[way_id, way_version], ...],
+  #  [[node_id, lat, lon, [tags, ...], node_version], ...],
+  #  [[rel_id, rel_version], ...]]
+  # where the ways are any visible ways which refer to any visible
+  # nodes in the bbox, nodes are any visible nodes in the bbox but not
+  # used in any way, rel is any relation which refers to either a way
+  # or node that we're returning.
+  def whichways(xmin, ymin, xmax, ymax) #:doc:
+    enlarge = [(xmax-xmin)/8,0.01].min
+    xmin -= enlarge; ymin -= enlarge
+    xmax += enlarge; ymax += enlarge
+    
+    # check boundary is sane and area within defined
+    # see /config/application.yml
+    check_boundaries(xmin, ymin, xmax, ymax)
+
+    if POTLATCH_USE_SQL then
+      ways = sql_find_ways_in_area(xmin, ymin, xmax, ymax)
+      points = sql_find_pois_in_area(xmin, ymin, xmax, ymax)
+      relations = sql_find_relations_in_area_and_ways(xmin, ymin, xmax, ymax, ways.collect {|x| x[0]})

     else
     else

-      way=ActiveRecord::Base.connection.insert("INSERT INTO current_ways (user_id,timestamp,visible) VALUES (#{uid},#{db_now},1)")
+      # find the way ids in an area
+      nodes_in_area = Node.find_by_area(ymin, xmin, ymax, xmax, :conditions => ["current_nodes.visible = ?", true], :include => :ways)
+      ways = nodes_in_area.inject([]) { |sum, node| 
+        visible_ways = node.ways.select { |w| w.visible? }
+        sum + visible_ways.collect { |w| [w.id,w.version] }
+      }.uniq
+      ways.delete([])
+
+      # find the node ids in an area that aren't part of ways
+      nodes_not_used_in_area = nodes_in_area.select { |node| node.ways.empty? }
+      points = nodes_not_used_in_area.collect { |n| [n.id, n.lon, n.lat, n.tags, n.version] }.uniq
+
+      # find the relations used by those nodes and ways
+      relations = Relation.find_for_nodes(nodes_in_area.collect { |n| n.id }, :conditions => {:visible => true}) +
+                  Relation.find_for_ways(ways.collect { |w| w[0] }, :conditions => {:visible => true})
+      relations = relations.collect { |relation| [relation.id,relation.version] }.uniq

     end
 
     end
 

-    # -- 4.    get version by inserting new row into ways
-
-    version=ActiveRecord::Base.connection.insert("INSERT INTO ways (id,user_id,timestamp,visible) VALUES (#{way},#{uid},#{db_now},1)")
-
-    # -- 5. compare nodes and update xmin,xmax,ymin,ymax
-
-    xmin = ymin = 999999
-    xmax = ymax = -999999
-    insertsql = ''
-    renumberednodes={}
-
-    points.each_index do |i|
-      xs=coord2long(points[i][0],masterscale,baselong)
-      ys=coord2lat(points[i][1],masterscale,basey)
-      xmin=[xs,xmin].min; xmax=[xs,xmax].max
-      ymin=[ys,ymin].min; ymax=[ys,ymax].max
-      node=points[i][2].to_i
-      tagstr=array2tag(points[i][4])
-         tagstr=tagstr.gsub(/[\000-\037]/,"")
-      tagsql="'"+sqlescape(tagstr)+"'"
-
-      # compare node
-      if node<0
-        # new node - create
-        newnode=ActiveRecord::Base.connection.insert("INSERT INTO current_nodes (   latitude,longitude,timestamp,user_id,visible,tags) VALUES (           #{ys},#{xs},#{db_now},#{uid},1,#{tagsql})")
-                       ActiveRecord::Base.connection.insert("INSERT INTO nodes         (id,latitude,longitude,timestamp,user_id,visible,tags) VALUES (#{newnode},#{ys},#{xs},#{db_now},#{uid},1,#{tagsql})")
-        points[i][2]=newnode
-        renumberednodes[node.to_s]=newnode.to_s
-
-      elsif xc.has_key?(node)
-        # old node from original way - update
-        if (xs!=xc[node] or (ys/0.0000001).round!=(yc[node]/0.0000001).round or tagstr!=tagc[node])
-          ActiveRecord::Base.connection.insert("INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible,tags) VALUES (#{node},#{ys},#{xs},#{db_now},#{uid},1,#{tagsql})")
-          ActiveRecord::Base.connection.update("UPDATE current_nodes SET latitude=#{ys},longitude=#{xs},timestamp=#{db_now},user_id=#{uid},tags=#{tagsql},visible=1 WHERE id=#{node}")
-        end
-      else
-        # old node, created in another way and now added to this way
-      end
-
-    end
-
-
-    # -- 6.i compare segments
-
-    numberedsegments={}
-    seglist=''                         # list of existing segments that we want to keep
-    for i in (0..(points.length-2))
-      if (points[i+1][3].to_i==0) then next end
-      segid=points[i+1][5].to_i
-      from =points[i  ][2].to_i
-      to   =points[i+1][2].to_i
-      if seg.has_key?(segid)
-               # if segment exists, check it still refers to the same nodes
-        if seg[segid]=="#{from}-#{to}" then 
-          if (seglist!='') then seglist+=',' end; seglist+=segid.to_s
-          next
-        end
-         elsif segid>0
-               # not in previous version of way, but supplied, so assume
-               # that it's come from makeway (i.e. unwayed segments)
-               if (seglist!='') then seglist+=',' end; seglist+=segid.to_s
-               next
-      end
-      segid=ActiveRecord::Base.connection.insert("INSERT INTO current_segments (   node_a,node_b,timestamp,user_id,visible,tags) VALUES (         #{from},#{to},#{db_now},#{uid},1,'')")
-               ActiveRecord::Base.connection.insert("INSERT INTO segments         (id,node_a,node_b,timestamp,user_id,visible,tags) VALUES (#{segid},#{from},#{to},#{db_now},#{uid},1,'')")
-      points[i+1][5]=segid
-      numberedsegments[(i+1).to_s]=segid.to_s
-    end
+    [0, ways, points, relations]

 
 

+  rescue Exception => err
+    [-2,"Sorry - I can't get the map for that area. The server said: #{err}"]
+  end

 
 

-    # -- 6.ii insert new way segments
+  # Find deleted ways in current bounding box (similar to whichways, but ways
+  # with a deleted node only - not POIs or relations).

 
 

-    createuniquesegments(way,db_uqs,seglist)   # segments which appear in this way but no other
+  def whichways_deleted(xmin, ymin, xmax, ymax) #:doc:
+    enlarge = [(xmax-xmin)/8,0.01].min
+    xmin -= enlarge; ymin -= enlarge
+    xmax += enlarge; ymax += enlarge

 
 

-    #          delete segments from uniquesegments (and not in modified way)
+    # check boundary is sane and area within defined
+    # see /config/application.yml
+    begin
+      check_boundaries(xmin, ymin, xmax, ymax)
+    rescue Exception => err
+      return [-2,"Sorry - I can't get the map for that area. The server said: #{err}"]
+    end

 
 

-    sql=<<-EOF
-      INSERT INTO segments (id,node_a,node_b,timestamp,user_id,visible) 
-      SELECT DISTINCT segment_id,node_a,node_b,#{db_now},#{uid},0
-        FROM current_segments AS cs, #{db_uqs} AS us
-       WHERE cs.id=us.segment_id AND cs.visible=1 
-    EOF
-    ActiveRecord::Base.connection.insert(sql)
+    nodes_in_area = Node.find_by_area(ymin, xmin, ymax, xmax, :conditions => ["current_ways.visible = ?", false], :include => :ways_via_history)
+    way_ids = nodes_in_area.collect { |node| node.ways_via_history_ids }.flatten.uniq

 
 

-    sql=<<-EOF
-         UPDATE current_segments AS cs, #{db_uqs} AS us
-          SET cs.timestamp=#{db_now},cs.visible=0,cs.user_id=#{uid} 
-        WHERE cs.id=us.segment_id AND cs.visible=1 
-    EOF
-    ActiveRecord::Base.connection.update(sql)
+    [0,way_ids]
+  end

 
 

-    #          delete nodes not in modified way or any other segments
+  # Get a way including nodes and tags.
+  # Returns the way id, a Potlatch-style array of points, a hash of tags, and the version number.

 
 

-    createuniquenodes(db_uqs,db_uqn)   # nodes which appear in this way but no other
+  def getway(wayid) #:doc:
+    if POTLATCH_USE_SQL then
+        points = sql_get_nodes_in_way(wayid)
+        tags = sql_get_tags_in_way(wayid)
+        version = sql_get_way_version(wayid)
+      else
+        # Ideally we would do ":include => :nodes" here but if we do that
+        # then rails only seems to return the first copy of a node when a
+        # way includes a node more than once
+        begin
+          way = Way.find(wayid, :include => { :nodes => :node_tags })
+        rescue ActiveRecord::RecordNotFound
+          return [wayid,[],{}]
+        end

 
 

-    sql=<<-EOF
-               INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible)  
-               SELECT DISTINCT cn.id,cn.latitude,cn.longitude,#{db_now},#{uid},0 
-                 FROM current_nodes AS cn,#{db_uqn}
-                WHERE cn.id=node_id
-    EOF
-    ActiveRecord::Base.connection.insert(sql)
+        # check case where way has been deleted or doesn't exist
+        return [wayid,[],{}] if way.nil? or !way.visible

 
 

-    sql=<<-EOF
-      UPDATE current_nodes AS cn, #{db_uqn}
-         SET cn.timestamp=#{db_now},cn.visible=0,cn.user_id=#{uid} 
-       WHERE cn.id=node_id
-    EOF
-    ActiveRecord::Base.connection.update(sql)
-
-    ActiveRecord::Base.connection.execute("DROP TABLE #{db_uqs}")
-    ActiveRecord::Base.connection.execute("DROP TABLE #{db_uqn}")
-
-    #          insert new version of route into way_segments
-
-    insertsql =''
-    currentsql=''
-    sequence  =1
-    for i in (0..(points.length-2))
-      if (points[i+1][3].to_i==0) then next end
-      if insertsql !='' then insertsql +=',' end
-      if currentsql!='' then currentsql+=',' end
-      insertsql +="(#{way},#{points[i+1][5]},#{version})"
-      currentsql+="(#{way},#{points[i+1][5]},#{sequence})"
-      sequence  +=1
+        points = way.nodes.collect do |node|
+        nodetags=node.tags
+        nodetags.delete('created_by')
+        [node.lon, node.lat, node.id, nodetags, node.version]
+      end
+      tags = way.tags
+      version = way.version

     end
 
     end
 

-    ActiveRecord::Base.connection.execute("DELETE FROM current_way_segments WHERE id=#{way}");
-    ActiveRecord::Base.connection.insert("INSERT INTO         way_segments (id,segment_id,version    ) VALUES #{insertsql}");
-    ActiveRecord::Base.connection.insert("INSERT INTO current_way_segments (id,segment_id,sequence_id) VALUES #{currentsql}");
-
-    # -- 7. insert new way tags
-
-    insertsql =''
-    currentsql=''
-    attributes.each do |k,v|
-      if v=='' or v.nil? then next end
-      if v[0,6]=='(type ' then next end
-      if insertsql !='' then insertsql +=',' end
-      if currentsql!='' then currentsql+=',' end
-         k=k.gsub(/[\000-\037]/,"")
-         v=v.gsub(/[\000-\037]/,"")
-      insertsql +="(#{way},'"+sqlescape(k)+"','"+sqlescape(v)+"',#{version})"
-      currentsql+="(#{way},'"+sqlescape(k)+"','"+sqlescape(v)+"')"
+    [wayid, points, tags, version]
+  end
+  
+  # Get an old version of a way, and all constituent nodes.
+  #
+  # For undelete (version<0), always uses the most recent version of each node, 
+  # even if it's moved.  For revert (version >= 0), uses the node in existence 
+  # at the time, generating a new id if it's still visible and has been moved/
+  # retagged.
+  #
+  # Returns:
+  # 0. success code, 
+  # 1. id, 
+  # 2. array of points, 
+  # 3. hash of tags, 
+  # 4. version, 
+  # 5. is this the current, visible version? (boolean)
+  
+  def getway_old(id, timestamp) #:doc:
+    if timestamp == ''
+      # undelete
+      old_way = OldWay.find(:first, :conditions => ['visible = ? AND id = ?', true, id], :order => 'version DESC')
+      points = old_way.get_nodes_undelete unless old_way.nil?
+    else
+      begin
+        # revert
+        timestamp = DateTime.strptime(timestamp.to_s, "%d %b %Y, %H:%M:%S")
+        old_way = OldWay.find(:first, :conditions => ['id = ? AND timestamp <= ?', id, timestamp], :order => 'timestamp DESC')
+        unless old_way.nil?
+          points = old_way.get_nodes_revert(timestamp)
+          if !old_way.visible
+            return [-1, "Sorry, the way was deleted at that time - please revert to a previous version."]
+          end
+        end
+      rescue ArgumentError
+        # thrown by date parsing method. leave old_way as nil for
+        # the superb error handler below.
+      end

     end
 
     end
 

-    ActiveRecord::Base.connection.execute("DELETE FROM current_way_tags WHERE id=#{way}")
-    if (insertsql !='') then ActiveRecord::Base.connection.insert("INSERT INTO way_tags (id,k,v,version) VALUES #{insertsql}" ) end
-    if (currentsql!='') then ActiveRecord::Base.connection.insert("INSERT INTO current_way_tags (id,k,v) VALUES #{currentsql}") end
-
-    [originalway,way,renumberednodes,numberedsegments,xmin,xmax,ymin,ymax]
+    if old_way.nil?
+      # *** FIXME: shouldn't this be returning an error?
+      return [-1, id, [], {}, -1,0]
+    else
+      curway=Way.find(id)
+      old_way.tags['history'] = "Retrieved from v#{old_way.version}"
+      return [0, id, points, old_way.tags, curway.version, (curway.version==old_way.version and curway.visible)]
+    end

   end
   end

+  
+  # Find history of a way.
+  # Returns 'way', id, and an array of previous versions:
+  # - formerly [old_way.version, old_way.timestamp.strftime("%d %b %Y, %H:%M"), old_way.visible ? 1 : 0, user, uid]
+  # - now [timestamp,user,uid]
+  #
+  # Heuristic: Find all nodes that have ever been part of the way; 
+  # get a list of their revision dates; add revision dates of the way;
+  # sort and collapse list (to within 2 seconds); trim all dates before the 
+  # start date of the way.
+
+  def getway_history(wayid) #:doc:
+
+    begin
+      # Find list of revision dates for way and all constituent nodes
+      revdates=[]
+      revusers={}
+      Way.find(wayid).old_ways.collect do |a|
+        revdates.push(a.timestamp)
+        unless revusers.has_key?(a.timestamp.to_i) then revusers[a.timestamp.to_i]=change_user(a) end
+        a.nds.each do |n|
+          Node.find(n).old_nodes.collect do |o|
+            revdates.push(o.timestamp)
+            unless revusers.has_key?(o.timestamp.to_i) then revusers[o.timestamp.to_i]=change_user(o) end
+          end
+        end
+      end
+      waycreated=revdates[0]
+      revdates.uniq!
+      revdates.sort!
+         revdates.reverse!
+
+      # Remove any dates (from nodes) before first revision date of way
+      revdates.delete_if { |d| d<waycreated }
+      # Remove any elements where 2 seconds doesn't elapse before next one
+      revdates.delete_if { |d| revdates.include?(d+1) or revdates.include?(d+2) }
+      # Collect all in one nested array
+      revdates.collect! {|d| [d.strftime("%d %b %Y, %H:%M:%S")] + revusers[d.to_i] }
+
+      return ['way',wayid,revdates]
+    rescue ActiveRecord::RecordNotFound
+      return ['way', wayid, []]
+    end
+  end
+  
+  # Find history of a node. Returns 'node', id, and an array of previous versions as above.

 
 

-  # -----      deleteway (user token, way)
-  #                    returns way ID only
-
-  def deleteway(args)
-    usertoken,way=args
-
-    RAILS_DEFAULT_LOGGER.info("  Message: deleteway, id=#{way}")
-
-    uid=getuserid(usertoken); if !uid then return end
-       way=way.to_i
-
-       db_uqs='uniq'+uid.to_s+way.to_i.abs.to_s+Time.new.to_i.to_s     # temp uniquesegments table name, typically 51 chars
-       db_uqn='unin'+uid.to_s+way.to_i.abs.to_s+Time.new.to_i.to_s     # temp uniquenodes table name, typically 51 chars
-       db_now='@now'+uid.to_s+way.to_i.abs.to_s+Time.new.to_i.to_s     # 'now' variable name, typically 51 chars
-       ActiveRecord::Base.connection.execute("SET #{db_now}=NOW()")
-       createuniquesegments(way,db_uqs,'')
-
-       # -     delete any otherwise unused segments
-
-       sql=<<-EOF
-      INSERT INTO segments (id,node_a,node_b,timestamp,user_id,visible) 
-      SELECT DISTINCT segment_id,node_a,node_b,#{db_now},#{uid},0 
-        FROM current_segments AS cs, #{db_uqs} AS us
-       WHERE cs.id=us.segment_id
-    EOF
-       ActiveRecord::Base.connection.insert(sql)
+  def getnode_history(nodeid) #:doc:
+    begin 
+      history = Node.find(nodeid).old_nodes.reverse.collect do |old_node|
+        [old_node.timestamp.strftime("%d %b %Y, %H:%M:%S")] + change_user(old_node)
+      end
+      return ['node', nodeid, history]
+    rescue ActiveRecord::RecordNotFound
+      return ['node', nodeid, []]
+    end
+  end

 
 

-       sql=<<-EOF
-      UPDATE current_segments AS cs, #{db_uqs} AS us
-         SET cs.timestamp=#{db_now},cs.visible=0,cs.user_id=#{uid} 
-       WHERE cs.id=us.segment_id
-    EOF
-       ActiveRecord::Base.connection.update(sql)
+  def change_user(obj)
+    user_object = obj.changeset.user
+    user = user_object.data_public? ? user_object.display_name : 'anonymous'
+    uid  = user_object.data_public? ? user_object.id : 0
+    [user,uid]
+  end

 
 

-       # - delete any unused nodes
+  # Find GPS traces with specified name/id.
+  # Returns array listing GPXs, each one comprising id, name and description.

   
   

-    createuniquenodes(db_uqs,db_uqn)
+  def findgpx(searchterm, usertoken)
+    user = getuser(usertoken)
+    if !uid then return -1,"You must be logged in to search for GPX traces." end
+
+    gpxs = []
+    if searchterm.to_i>0 then
+      gpx = Trace.find(searchterm.to_i, :conditions => ["visible=? AND (public=? OR user_id=?)",true,true,user.id] )
+      if gpx then
+        gpxs.push([gpx.id, gpx.name, gpx.description])
+      end
+    else
+      Trace.find(:all, :limit => 21, :conditions => ["visible=? AND (public=? OR user_id=?) AND MATCH(name) AGAINST (?)",true,true,user.id,searchterm] ).each do |gpx|
+      gpxs.push([gpx.id, gpx.name, gpx.description])
+         end
+       end
+    gpxs
+  end

 
 

-       sql=<<-EOF
-               INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible)  
-               SELECT DISTINCT cn.id,cn.latitude,cn.longitude,#{db_now},#{uid},0 
-                 FROM current_nodes AS cn,#{db_uqn}
-                WHERE cn.id=node_id
-    EOF
-       ActiveRecord::Base.connection.insert(sql)
+  # Get a relation with all tags and members.
+  # Returns:
+  # 0. relation id,
+  # 1. hash of tags,
+  # 2. list of members,
+  # 3. version.
+  
+  def getrelation(relid) #:doc:
+    begin
+      rel = Relation.find(relid)
+    rescue ActiveRecord::RecordNotFound
+      return [relid, {}, []]
+    end

 
 

-       sql=<<-EOF
-      UPDATE current_nodes AS cn, #{db_uqn}
-         SET cn.timestamp=#{db_now},cn.visible=0,cn.user_id=#{uid} 
-       WHERE cn.id=node_id
-    EOF
-       ActiveRecord::Base.connection.update(sql)
-       
-       ActiveRecord::Base.connection.execute("DROP TABLE #{db_uqs}")
-       ActiveRecord::Base.connection.execute("DROP TABLE #{db_uqn}")
+    return [relid, {}, [], nil] if rel.nil? or !rel.visible
+    [relid, rel.tags, rel.members, rel.version]
+  end

 
 

-       # - delete way
-       
-       ActiveRecord::Base.connection.insert("INSERT INTO ways (id,user_id,timestamp,visible) VALUES (#{way},#{uid},#{db_now},0)")
-       ActiveRecord::Base.connection.update("UPDATE current_ways SET user_id=#{uid},timestamp=#{db_now},visible=0 WHERE id=#{way}")
-       ActiveRecord::Base.connection.execute("DELETE FROM current_way_segments WHERE id=#{way}")
-       ActiveRecord::Base.connection.execute("DELETE FROM current_way_tags WHERE id=#{way}")
-       
-       way
-end
+  # Find relations with specified name/id.
+  # Returns array of relations, each in same form as getrelation.
+  
+  def findrelations(searchterm)
+    rels = []
+    if searchterm.to_i>0 then
+      rel = Relation.find(searchterm.to_i)
+      if rel and rel.visible then
+        rels.push([rel.id, rel.tags, rel.members, rel.version])
+      end
+    else
+      RelationTag.find(:all, :limit => 11, :conditions => ["match(v) against (?)", searchterm] ).each do |t|
+      if t.relation.visible then
+             rels.push([t.relation.id, t.relation.tags, t.relation.members, t.relation.version])
+           end
+         end
+       end
+    rels
+  end

 
 

-# ----- makeway(x,y,baselong,basey,masterscale)
-#              returns way made from unwayed segments
+  # Save a relation.
+  # Returns
+  # 0. 0 (success),
+  # 1. original relation id (unchanged),
+  # 2. new relation id,
+  # 3. version.
+
+  def putrelation(renumberednodes, renumberedways, usertoken, changeset_id, version, relid, tags, members, visible) #:doc:
+    user = getuser(usertoken)
+    if !user then return -1,"You are not logged in, so the relation could not be saved." end
+
+    relid = relid.to_i
+    visible = (visible.to_i != 0)
+
+    new_relation = nil
+    relation = nil
+    Relation.transaction do
+      # create a new relation, or find the existing one
+      if relid > 0
+        relation = Relation.find(relid)
+      end
+      # We always need a new node, based on the data that has been sent to us
+      new_relation = Relation.new
+
+      # check the members are all positive, and correctly type
+      typedmembers = []
+      members.each do |m|
+        mid = m[1].to_i
+        if mid < 0
+          mid = renumberednodes[mid] if m[0] == 'Node'
+          mid = renumberedways[mid] if m[0] == 'Way'
+        end
+        if mid
+          typedmembers << [m[0], mid, m[2]]
+        end
+      end

 
 

-def makeway(args)
-       x,y,baselong,basey,masterscale=args
-       points=[]
-       nodesused={}                            # so we don't go over the same node twice
+      # assign new contents
+      new_relation.members = typedmembers
+      new_relation.tags = tags
+      new_relation.visible = visible
+      new_relation.changeset_id = changeset_id
+      new_relation.version = version
+
+      if relid <= 0
+        # We're creating the node
+        new_relation.create_with_history(user)
+      elsif visible
+        # We're updating the node
+        relation.update_from(new_relation, user)
+      else
+        # We're deleting the node
+        relation.delete_with_history!(new_relation, user)
+      end
+    end # transaction
+      
+    if relid <= 0
+      return [0, relid, new_relation.id, new_relation.version]
+    else
+      return [0, relid, relid, relation.version]
+    end
+  rescue OSM::APIChangesetAlreadyClosedError => ex
+    return [-1, "The changeset #{ex.changeset.id} was closed at #{ex.changeset.closed_at}."]
+  rescue OSM::APIVersionMismatchError => ex
+    # Really need to check to see whether this is a server load issue, and the 
+    # last version was in the same changeset, or belongs to the same user, then
+    # we can return something different
+    return [-3, "Sorry, someone else has changed this relation since you started editing. Please click the 'Edit' tab to reload the area. The server said: #{ex}"]
+  rescue OSM::APIAlreadyDeletedError => ex
+    return [-1, "The relation has already been deleted."]
+  rescue OSM::APIError => ex
+    # Some error that we don't specifically catch
+    return [-2, "An unusual error happened (in 'putrelation' #{relid}). The server said: #{ex}"]
+  end

 
 

-       # - find start point near x
+  # Save a way to the database, including all nodes. Any nodes in the previous
+  # version and no longer used are deleted.
+  # 
+  # Parameters:
+  # 0. hash of renumbered nodes (added by amf_controller)
+  # 1. current user token (for authentication)
+  # 2. current changeset
+  # 3. new way version
+  # 4. way ID
+  # 5. list of nodes in way
+  # 6. hash of way tags
+  # 7. array of nodes to change (each one is [lon,lat,id,version,tags])
+  # 
+  # Returns:
+  # 0. '0' (code for success),
+  # 1. original way id (unchanged),
+  # 2. new way id,
+  # 3. hash of renumbered nodes (old id=>new id),
+  # 4. way version,
+  # 5. hash of node versions (node=>version)
+
+  def putway(renumberednodes, usertoken, changeset_id, wayversion, originalway, pointlist, attributes, nodes) #:doc:
+
+    # -- Initialise

        
        

-       xc=coord2long(x,masterscale,baselong)
-       yc=coord2lat(y,masterscale,basey)
-       xs1=xc-0.001; xs2=xc+0.001
-       ys1=yc-0.001; ys2=yc+0.001
-       
-       sql=<<-EOF
-               SELECT cn1.latitude AS lat1,cn1.longitude AS lon1,cn1.id AS id1,
-                      cn2.latitude AS lat2,cn2.longitude AS lon2,cn2.id AS id2, cs.id AS segid
-                 FROM current_nodes AS cn1,
-                      current_nodes AS cn2,
-                      current_segments AS cs 
-                      LEFT OUTER JOIN current_way_segments ON segment_id=cs.id 
-                WHERE (cn1.longitude BETWEEN #{xs1} AND #{xs2}) 
-                  AND (cn1.latitude  BETWEEN #{ys1} AND #{ys2}) 
-                  AND segment_id IS NULL 
-                  AND cn1.id=node_a AND cn1.visible=1 
-                  AND cn2.id=node_b AND cn2.visible=1 
-      ORDER BY SQRT(POW(cn1.longitude-#{xc},2)+
-                               POW(cn1.latitude -#{yc},2)) 
-        LIMIT 1
-       EOF
-       row=ActiveRecord::Base.connection.select_one sql
-       if row.nil? then return [0,0,0,0,0] end
-       xs1=long2coord(row['lon1'].to_f,baselong,masterscale); ys1=lat2coord(row['lat1'].to_f,basey,masterscale)
-       xs2=long2coord(row['lon2'].to_f,baselong,masterscale); ys2=lat2coord(row['lat2'].to_f,basey,masterscale)
-       xmin=[xs1,xs2].min; xmax=[xs1,xs2].max
-       ymin=[ys1,ys2].min; ymax=[ys1,ys2].max
-       nodesused[row['id1'].to_i]=true
-       nodesused[row['id2'].to_i]=true
-       points<<[xs1,ys1,row['id1'].to_i,1,{},0]
-       points<<[xs2,ys2,row['id2'].to_i,1,{},row['segid'].to_i]
-       
-       # - extend at start, then end
-       while (a,point,nodesused=findconnect(points[0][2],nodesused,'b',baselong,basey,masterscale))[0]
-               points[0][5]=point[5]; point[5]=0       # segment leads to next node
-               points.unshift(point)
-               xmin=[point[0],xmin].min; xmax=[point[0],xmax].max
-               ymin=[point[1],ymin].min; ymax=[point[1],ymax].max
-       end
-       while (a,point,nodesused=findconnect(points[-1][2],nodesused,'a',baselong,basey,masterscale))[0]
-               points.push(point)
-               xmin=[point[0],xmin].min; xmax=[point[0],xmax].max
-               ymin=[point[1],ymin].min; ymax=[point[1],ymax].max
-       end
-       points[0][3]=0  # start with a move
+    user = getuser(usertoken)
+    if !user then return -1,"You are not logged in, so the way could not be saved." end
+    if pointlist.length < 2 then return -2,"Server error - way is only #{points.length} points long." end

 
 

-       [points,xmin,xmax,ymin,ymax]
-end
+    originalway = originalway.to_i
+       pointlist.collect! {|a| a.to_i }

 
 

-def findconnect(id,nodesused,lookfor,baselong,basey,masterscale)
-       # get all segments with 'id' as a point
-       # (to look for both node_a and node_b, UNION is faster than node_a=id OR node_b=id)!
-       sql=<<-EOF
-               SELECT cn1.latitude AS lat1,cn1.longitude AS lon1,cn1.id AS id1,
-                      cn2.latitude AS lat2,cn2.longitude AS lon2,cn2.id AS id2, cs.id AS segid
-                 FROM current_nodes AS cn1,
-                      current_nodes AS cn2,
-                      current_segments AS cs 
-                      LEFT OUTER JOIN current_way_segments ON segment_id=cs.id 
-                WHERE segment_id IS NULL 
-                  AND cn1.id=node_a AND cn1.visible=1 
-                  AND cn2.id=node_b AND cn2.visible=1 
-                  AND node_a=#{id}
-       UNION
-               SELECT cn1.latitude AS lat1,cn1.longitude AS lon1,cn1.id AS id1,
-                      cn2.latitude AS lat2,cn2.longitude AS lon2,cn2.id AS id2, cs.id AS segid
-                 FROM current_nodes AS cn1,
-                      current_nodes AS cn2,
-                      current_segments AS cs 
-                      LEFT OUTER JOIN current_way_segments ON segment_id=cs.id 
-                WHERE segment_id IS NULL 
-                  AND cn1.id=node_a AND cn1.visible=1 
-                  AND cn2.id=node_b AND cn2.visible=1 
-                  AND node_b=#{id}
-       EOF
-       connectlist=ActiveRecord::Base.connection.select_all sql
-       
-       if lookfor=='b' then tocol='id1'; tolat='lat1'; tolon='lon1'; fromcol='id2'
-                                       else tocol='id2'; tolat='lat2'; tolon='lon2'; fromcol='id1'
-       end
-       
-       # eliminate those already in the hash
-       connex=0
-       point=nil
-       connectlist.each { |row|
-               tonode=row[tocol].to_i
-               fromnode=row[fromcol].to_i
-               if id==tonode and !nodesused.has_key?(fromnode)
-                       connex+=1
-                       nodesused[fromnode]=true
-               elsif id==fromnode and !nodesused.has_key?(tonode)
-                       connex+=1
-                       point=[long2coord(row[tolon].to_f,baselong,masterscale),lat2coord(row[tolat].to_f,basey,masterscale),tonode,1,{},row['segid'].to_i]
-                       nodesused[tonode]=true
-               end
-       }
-       
-       # if only one left, then add it; otherwise return false
-       if connex!=1 or point.nil? then
-               return [false,[],nodesused]
-       else
-               return [true,point,nodesused]
-       end
-end
+    way=nil    # this is returned, so scope it outside the transaction
+    nodeversions = {}
+    Way.transaction do

 
 

+      # -- Get unique nodes

 
 

-# ====================================================================
-# Support functions for remote calls
+      if originalway <= 0
+        uniques = []
+      else
+        way = Way.find(originalway)
+        uniques = way.unshared_node_ids
+      end

 
 

-def readwayquery(id)
-  ActiveRecord::Base.connection.select_all "SELECT n1.latitude AS lat1,n1.longitude AS long1,n1.id AS id1,n1.tags as tags1, "+
-      "                  n2.latitude AS lat2,n2.longitude AS long2,n2.id AS id2,n2.tags as tags2,segment_id "+
-      "    FROM current_way_segments,current_segments,current_nodes AS n1,current_nodes AS n2 "+
-      "   WHERE current_way_segments.id=#{id} "+
-      "     AND segment_id=current_segments.id "+
-         "     AND current_segments.visible=1 "+
-      "     AND n1.id=node_a and n2.id=node_b "+
-      "     AND n1.visible=1 AND n2.visible=1 "+
-      "   ORDER BY sequence_id"
-end
+      #-- Update each changed node
+
+      nodes.each do |a|
+        lon = a[0].to_f
+        lat = a[1].to_f
+        id = a[2].to_i
+        version = a[3].to_i
+        if id == 0  then return -2,"Server error - node with id 0 found in way #{originalway}." end
+        if lat== 90 then return -2,"Server error - node with latitude -90 found in way #{originalway}." end
+        if renumberednodes[id] then id = renumberednodes[id] end
+
+        node = Node.new
+        node.changeset_id = changeset_id
+        node.lat = lat
+        node.lon = lon
+        node.tags = a[4]
+        node.tags.delete('created_by')
+        node.version = version
+        if id <= 0
+          # We're creating the node
+          node.create_with_history(user)
+          renumberednodes[id] = node.id
+          nodeversions[node.id] = node.version
+        else
+          # We're updating an existing node
+          previous=Node.find(id)
+          previous.update_from(node, user)
+          nodeversions[previous.id] = previous.version
+        end
+      end

 
 

-def createuniquesegments(way,uqs_name,seglist)
-  # Finds segments which appear in (previous version of) this way and no other
-  sql=<<-EOF
-      CREATE TEMPORARY TABLE #{uqs_name}
-              SELECT a.segment_id
-                FROM (SELECT DISTINCT segment_id FROM current_way_segments 
-                  WHERE id = #{way}) a
-             LEFT JOIN current_way_segments b 
-                ON b.segment_id = a.segment_id
-                 AND b.id != #{way}
-               WHERE b.segment_id IS NULL
-    EOF
-  if (seglist!='') then sql+=" AND a.segment_id NOT IN (#{seglist})" end
-  ActiveRecord::Base.connection.execute(sql)
-end
+      # -- Save revised way
+
+         pointlist.collect! {|a|
+               renumberednodes[a] ? renumberednodes[a]:a
+         } # renumber nodes
+      new_way = Way.new
+      new_way.tags = attributes
+      new_way.nds = pointlist
+      new_way.changeset_id = changeset_id
+      new_way.version = wayversion
+      if originalway <= 0
+        new_way.create_with_history(user)
+        way=new_way    # so we can get way.id and way.version
+      elsif way.tags!=attributes or way.nds!=pointlist or !way.visible?
+        way.update_from(new_way, user)
+      end

 
 

-def createuniquenodes(uqs_name,uqn_name)
-       # Finds nodes which appear in uniquesegments but no other segments
-       sql=<<-EOF
-               CREATE TEMPORARY TABLE #{uqn_name}
-                          SELECT DISTINCT node_id
-                             FROM (SELECT cn.id AS node_id
-                                                 FROM current_nodes AS cn,
-                                                      current_segments AS cs,
-                                                      #{uqs_name} AS us
-                                                WHERE cs.id=us.segment_id
-                                                  AND (cn.id=cs.node_a OR cn.id=cs.node_b)) AS n
-                                        LEFT JOIN current_segments AS cs2 ON node_id=cs2.node_a AND cs2.visible=1
-                                        LEFT JOIN current_segments AS cs3 ON node_id=cs3.node_b AND cs3.visible=1
-                                            WHERE cs2.node_a IS NULL
-                                              AND cs3.node_b IS NULL
-       EOF
-       ActiveRecord::Base.connection.execute(sql)
-end
+      # -- Delete any unique nodes no longer used

 
 

-def sqlescape(a)
-  a.gsub("'","''").gsub(92.chr,92.chr+92.chr)
-end
+      uniques=uniques-pointlist
+      uniques.each do |n|
+        node = Node.find(n)
+        deleteitemrelations(user, changeset_id, id, 'Node', node.version)
+        new_node = Node.new
+        new_node.changeset_id = changeset_id
+        new_node.version = node.version
+        node.delete_with_history!(new_node, user)
+      end

 
 

-def tag2array(a)
-  tags={}
-  a.gsub(';;;','#%').split(';').each do |b|
-    b.gsub!('#%',';;;')
-    b.gsub!('===','#%')
-    k,v=b.split('=')
-    if k.nil? then k='' end
-    if v.nil? then v='' end
-    tags[k.gsub('#%','=')]=v.gsub('#%','=')
+    end # transaction
+
+    [0, originalway, way.id, renumberednodes, way.version, nodeversions]
+  rescue OSM::APIChangesetAlreadyClosedError => ex
+    return [-2, "Sorry, your changeset #{ex.changeset.id} has been closed (at #{ex.changeset.closed_at})."]
+  rescue OSM::APIVersionMismatchError => ex
+    # Really need to check to see whether this is a server load issue, and the 
+    # last version was in the same changeset, or belongs to the same user, then
+    # we can return something different
+    return [-3, "Sorry, someone else has changed this way since you started editing. Click the 'Edit' tab to reload the area. The server said: #{ex}"]
+  rescue OSM::APITooManyWayNodesError => ex
+    return [-1, "You have tried to upload a really long way with #{ex.provided} points: only #{ex.max} are allowed."]
+  rescue OSM::APIAlreadyDeletedError => ex
+    return [-1, "The point has already been deleted."]
+  rescue OSM::APIError => ex
+    # Some error that we don't specifically catch
+    return [-2, "An unusual error happened (in 'putway' #{originalway}). The server said: #{ex}"]

   end
   end

-  tags
-end

 
 

-def array2tag(a)
-  str=''
-  a.each do |k,v|
-    if v=='' then next end
-    if v[0,6]=='(type ' then next end
-    if str!='' then str+=';' end
-    str+=k.gsub(';',';;;').gsub('=','===')+'='+v.gsub(';',';;;').gsub('=','===')
-  end
-  str
-end
+  # Save POI to the database.
+  # Refuses save if the node has since become part of a way.
+  # Returns array with:
+  # 0. 0 (success),
+  # 1. original node id (unchanged),
+  # 2. new node id,
+  # 3. version.
+
+  def putpoi(usertoken, changeset_id, version, id, lon, lat, tags, visible) #:doc:
+    user = getuser(usertoken)
+    if !user then return -1,"You are not logged in, so the point could not be saved." end
+
+    id = id.to_i
+    visible = (visible.to_i == 1)
+    node = nil
+    new_node = nil
+    Node.transaction do
+      if id > 0 then
+        node = Node.find(id)
+
+        if !visible then
+          unless node.ways.empty? then return -1,"The point has since become part of a way, so you cannot save it as a POI." end
+        end
+      end
+      # We always need a new node, based on the data that has been sent to us
+      new_node = Node.new
+
+      new_node.changeset_id = changeset_id
+      new_node.version = version
+      new_node.lat = lat
+      new_node.lon = lon
+      new_node.tags = tags
+      if id <= 0 
+        # We're creating the node
+        new_node.create_with_history(user)
+      elsif visible
+        # We're updating the node
+        node.update_from(new_node, user)
+      else
+        # We're deleting the node
+        node.delete_with_history!(new_node, user)
+      end
+     end # transaction

 
 

-def getuserid(token)
-  token=sqlescape(token)
-  if (token=~/^(.+)\+(.+)$/) then
-    return ActiveRecord::Base.connection.select_value("SELECT id FROM users WHERE active=1 AND email='#{$1}' AND pass_crypt=MD5('#{$2}')")
-  else
-    return ActiveRecord::Base.connection.select_value("SELECT id FROM users WHERE active=1 AND token='#{token}'")
+    if id <= 0
+      return [0, id, new_node.id, new_node.version]
+    else
+      return [0, id, node.id, node.version]
+    end 
+  rescue OSM::APIChangesetAlreadyClosedError => ex
+    return [-1, "The changeset #{ex.changeset.id} was closed at #{ex.changeset.closed_at}"]
+  rescue OSM::APIVersionMismatchError => ex
+    # Really need to check to see whether this is a server load issue, and the 
+    # last version was in the same changeset, or belongs to the same user, then
+    # we can return something different
+    return [-3, "Sorry, someone else has changed this point since you started editing. Please click the 'Edit' tab to reload the area. The server said: #{ex}"]
+  rescue OSM::APIAlreadyDeletedError => ex
+    return [-1, "The point has already been deleted"]
+  rescue OSM::APIError => ex
+    # Some error that we don't specifically catch
+    return [-2, "An unusual error happened (in 'putpoi' #{id}). The server said: #{ex}"]

   end
   end

-end
-

 
 

+  # Read POI from database
+  # (only called on revert: POIs are usually read by whichways).
+  #
+  # Returns array of id, long, lat, hash of tags, (current) version.

 
 

-# ====================================================================
-# AMF read subroutines
-
-# -----        getint          return two-byte integer
-# -----        getlong         return four-byte long
-# -----        getstring       return string with two-byte length
-# ----- getdouble      return eight-byte double-precision float
-# ----- getobject      return object/hash
-# ----- getarray       return numeric array
-
-def getint(s)
-  s.getc*256+s.getc
-end
+  def getpoi(id,timestamp) #:doc:
+    n = Node.find(id)
+    v = n.version
+    unless timestamp == ''
+      n = OldNode.find(id, :conditions=>['timestamp=?',DateTime.strptime(timestamp, "%d %b %Y, %H:%M:%S")])
+    end

 
 

-def getlong(s)
-  ((s.getc*256+s.getc)*256+s.getc)*256+s.getc
-end
+    if n
+      return [n.id, n.lon, n.lat, n.tags, v]
+    else
+      return [nil, nil, nil, {}, nil]
+    end
+  end

 
 

-def getstring(s)
-  len=s.getc*256+s.getc
-  s.read(len)
-end
+  # Delete way and all constituent nodes. Also removes from any relations.
+  # Params:
+  # * The user token
+  # * the changeset id
+  # * the id of the way to change
+  # * the version of the way that was downloaded
+  # * a hash of the id and versions of all the nodes that are in the way, if any 
+  # of the nodes have been changed by someone else then, there is a problem!
+  # Returns 0 (success), unchanged way id.
+
+  def deleteway(usertoken, changeset_id, way_id, way_version, node_id_version) #:doc:
+    user = getuser(usertoken)
+    unless user then return -1,"You are not logged in, so the way could not be deleted." end
+      
+    way_id = way_id.to_i
+    # Need a transaction so that if one item fails to delete, the whole delete fails.
+    Way.transaction do
+
+      # delete the way
+      old_way = Way.find(way_id)
+      u = old_way.unshared_node_ids
+      delete_way = Way.new
+      delete_way.version = way_version
+      delete_way.changeset_id = changeset_id
+      old_way.delete_with_history!(delete_way, user)
+
+      u.each do |node_id|
+        # delete the node
+        node = Node.find(node_id)
+        delete_node = Node.new
+        delete_node.changeset_id = changeset_id
+        if node_id_version[node_id.to_s]
+          delete_node.version = node_id_version[node_id.to_s]
+        else
+          # in case the node wasn't passed (i.e. if it was previously removed
+          # from the way in Potlatch)
+          deleteitemrelations(user, changeset_id, node_id, 'Node', node.version)
+             delete_node.version = node.version
+           end
+        node.delete_with_history!(delete_node, user)
+      end
+    end # transaction
+    [0, way_id]
+  rescue OSM::APIChangesetAlreadyClosedError => ex
+    return [-1, "The changeset #{ex.changeset.id} was closed at #{ex.changeset.closed_at}"]
+  rescue OSM::APIVersionMismatchError => ex
+    # Really need to check to see whether this is a server load issue, and the 
+    # last version was in the same changeset, or belongs to the same user, then
+    # we can return something different
+    return [-3, "Sorry, someone else has changed this way since you started editing. Please click the 'Edit' tab to reload the area."]
+  rescue OSM::APIAlreadyDeletedError => ex
+    return [-1, "The way has already been deleted."]
+  rescue OSM::APIError => ex
+    # Some error that we don't specifically catch
+    return [-2, "An unusual error happened (in 'deleteway' #{way_id}). The server said: #{ex}"]
+  end

 
 

-def getdouble(s)
-  a=s.read(8).unpack('G')                      # G big-endian, E little-endian
-  a[0]
-end

 
 

-def getarray(s)
-  len=getlong(s)
-  arr=[]
-  for i in (0..len-1)
-    arr[i]=getvalue(s)
+  # ====================================================================
+  # Support functions
+
+  # Remove a node or way from all relations
+  # This is only used by putway and deleteway when deleting nodes removed 
+  # from a way (because Potlatch itself doesn't keep track of these - 
+  # possible FIXME).
+
+  def deleteitemrelations(user, changeset_id, objid, type, version) #:doc:
+    relations = RelationMember.find(:all, 
+                                                                       :conditions => ['member_type = ? and member_id = ?', type.classify, objid], 
+                                                                       :include => :relation).collect { |rm| rm.relation }.uniq
+
+    relations.each do |rel|
+      rel.members.delete_if { |x| x[0] == type and x[1] == objid }
+      new_rel = Relation.new
+      new_rel.tags = rel.tags
+      new_rel.visible = rel.visible
+      new_rel.version = rel.version
+      new_rel.members = rel.members
+      new_rel.changeset_id = changeset_id
+      rel.update_from(new_rel, user)
+    end

   end
   end

-  arr
-end

 
 

-def getobject(s)
-  arr={}
-  while (key=getstring(s))
-    if (key=='') then break end
-    arr[key]=getvalue(s)
-  end
-  s.getc               # skip the 9 'end of object' value
-  arr
-end
+  # Authenticate token
+  # (can also be of form user:pass)
+  # When we are writing to the api, we need the actual user model, 
+  # not just the id, hence this abstraction

 
 

-# -----        getvalue        parse and get value
-
-def getvalue(s)
-  case s.getc
-  when 0;      return getdouble(s)                     # number
-  when 1;      return s.getc                           # boolean
-  when 2;      return getstring(s)                     # string
-  when 3;      return getobject(s)                     # object/hash
-  when 5;      return nil                                      # null
-  when 6;      return nil                                      # undefined
-  when 8;      s.read(4)                                       # mixedArray
-                   return getobject(s)                 #  |
-  when 10;     return getarray(s)                      # array
-  else;                return nil                                      # error
+  def getuser(token) #:doc:
+    if (token =~ /^(.+)\:(.+)$/) then
+      user = User.authenticate(:username => $1, :password => $2)
+    else
+      user = User.authenticate(:token => token)
+    end
+    return user

   end
   end

-end

 
 

-# ====================================================================
-# AMF write subroutines
+  # Send AMF response
+  
+  def sendresponse(results)
+    a,b=results.length.divmod(256)
+    render :content_type => "application/x-amf", :text => proc { |response, output| 
+      # ** move amf writing loop into here - 
+      # basically we read the messages in first (into an array of some sort),
+      # then iterate through that array within here, and do all the AMF writing
+      output.write 0.chr+0.chr+0.chr+0.chr+a.chr+b.chr
+      results.each do |k,v|
+        output.write(v)
+      end
+    }
+  end

 
 

-# -----        putdata         envelope data into AMF writeable form
-# -----        encodevalue     pack variables as AMF

 
 

-def putdata(index,n)
-  d =encodestring(index+"/onResult")
-  d+=encodestring("null")
-  d+=[-1].pack("N")
-  d+=encodevalue(n)
-end
+  # ====================================================================
+  # Alternative SQL queries for getway/whichways

 
 

-def encodevalue(n)
-  case n.class.to_s
-  when 'Array'
-    a=10.chr+encodelong(n.length)
-    n.each do |b|
-      a+=encodevalue(b)
+  def sql_find_ways_in_area(xmin,ymin,xmax,ymax)
+    sql=<<-EOF
+    SELECT DISTINCT current_ways.id AS wayid,current_ways.version AS version
+      FROM current_way_nodes
+    INNER JOIN current_nodes ON current_nodes.id=current_way_nodes.node_id
+    INNER JOIN current_ways  ON current_ways.id =current_way_nodes.id
+       WHERE current_nodes.visible=TRUE 
+       AND current_ways.visible=TRUE 
+       AND #{OSM.sql_for_area(ymin, xmin, ymax, xmax, "current_nodes.")}
+    EOF
+    return ActiveRecord::Base.connection.select_all(sql).collect { |a| [a['wayid'].to_i,a['version'].to_i] }
+  end
+       
+  def sql_find_pois_in_area(xmin,ymin,xmax,ymax)
+    pois=[]
+    sql=<<-EOF
+                 SELECT current_nodes.id,current_nodes.latitude*0.0000001 AS lat,current_nodes.longitude*0.0000001 AS lon,current_nodes.version 
+                       FROM current_nodes 
+       LEFT OUTER JOIN current_way_nodes cwn ON cwn.node_id=current_nodes.id 
+                  WHERE current_nodes.visible=TRUE
+                        AND cwn.id IS NULL
+                        AND #{OSM.sql_for_area(ymin, xmin, ymax, xmax, "current_nodes.")}
+    EOF
+    ActiveRecord::Base.connection.select_all(sql).each do |row|
+      poitags={}
+      ActiveRecord::Base.connection.select_all("SELECT k,v FROM current_node_tags WHERE id=#{row['id']}").each do |n|
+        poitags[n['k']]=n['v']
+      end
+      pois << [row['id'].to_i, row['lon'].to_f, row['lat'].to_f, poitags, row['version'].to_i]

     end
     end

-    a
-  when 'Hash'
-    a=3.chr
-    n.each do |k,v|
-      a+=encodestring(k)+encodevalue(v)
+    pois
+  end
+       
+  def sql_find_relations_in_area_and_ways(xmin,ymin,xmax,ymax,way_ids)
+    # ** It would be more Potlatchy to get relations for nodes within ways
+    #    during 'getway', not here
+    sql=<<-EOF
+      SELECT DISTINCT cr.id AS relid,cr.version AS version 
+      FROM current_relations cr
+      INNER JOIN current_relation_members crm ON crm.id=cr.id 
+      INNER JOIN current_nodes cn ON crm.member_id=cn.id AND crm.member_type='Node' 
+       WHERE #{OSM.sql_for_area(ymin, xmin, ymax, xmax, "cn.")}
+      EOF
+    unless way_ids.empty?
+      sql+=<<-EOF
+       UNION
+        SELECT DISTINCT cr.id AS relid,cr.version AS version
+        FROM current_relations cr
+        INNER JOIN current_relation_members crm ON crm.id=cr.id
+         WHERE crm.member_type='Way' 
+         AND crm.member_id IN (#{way_ids.join(',')})
+        EOF

     end
     end

-    a+0.chr+0.chr+9.chr
-  when 'String'
-    2.chr+encodestring(n)
-  when 'Bignum','Fixnum','Float'
-    0.chr+encodedouble(n)
-  when 'NilClass'
-    5.chr
-  else
-    RAILS_DEFAULT_LOGGER.error("Unexpected Ruby type for AMF conversion: "+n.class.to_s)
+    ActiveRecord::Base.connection.select_all(sql).collect { |a| [a['relid'].to_i,a['version'].to_i] }
+  end
+       
+  def sql_get_nodes_in_way(wayid)
+    points=[]
+    sql=<<-EOF
+      SELECT latitude*0.0000001 AS lat,longitude*0.0000001 AS lon,current_nodes.id,current_nodes.version 
+      FROM current_way_nodes,current_nodes 
+       WHERE current_way_nodes.id=#{wayid.to_i} 
+                  AND current_way_nodes.node_id=current_nodes.id 
+                  AND current_nodes.visible=TRUE
+      ORDER BY sequence_id
+         EOF
+    ActiveRecord::Base.connection.select_all(sql).each do |row|
+      nodetags={}
+      ActiveRecord::Base.connection.select_all("SELECT k,v FROM current_node_tags WHERE id=#{row['id']}").each do |n|
+        nodetags[n['k']]=n['v']
+      end
+      nodetags.delete('created_by')
+      points << [row['lon'].to_f,row['lat'].to_f,row['id'].to_i,nodetags,row['version'].to_i]
+    end
+    points
+  end
+       
+  def sql_get_tags_in_way(wayid)
+    tags={}
+    ActiveRecord::Base.connection.select_all("SELECT k,v FROM current_way_tags WHERE id=#{wayid.to_i}").each do |row|
+      tags[row['k']]=row['v']
+    end
+    tags

   end
   end

-end
-
-# -----        encodestring    encode string with two-byte length
-# -----        encodedouble    encode number as eight-byte double precision float
-# -----        encodelong              encode number as four-byte long
-
-def encodestring(n)
-  a,b=n.size.divmod(256)
-  a.chr+b.chr+n
-end
-
-def encodedouble(n)
-  [n].pack('G')
-end
-
-def encodelong(n)
-  [n].pack('N')
-end
-
-# ====================================================================
-# Co-ordinate conversion
-
-def lat2coord(a,basey,masterscale)
-  -(lat2y(a)-basey)*masterscale+250
-end
-
-def long2coord(a,baselong,masterscale)
-  (a-baselong)*masterscale+350
-end
-
-def lat2y(a)
-  180/Math::PI * Math.log(Math.tan(Math::PI/4+a*(Math::PI/180)/2))
-end
-
-def coord2lat(a,masterscale,basey)
-  y2lat((a-250)/-masterscale+basey)
-end
-
-def coord2long(a,masterscale,baselong)
-  (a-350)/masterscale+baselong
-end

 
 

-def y2lat(a)
-  180/Math::PI * (2*Math.atan(Math.exp(a*Math::PI/180))-Math::PI/2)
+  def sql_get_way_version(wayid)
+    ActiveRecord::Base.connection.select_one("SELECT version FROM current_ways WHERE id=#{wayid.to_i}")
+  end

 end
 
 end
 

-end