Give the API error handler a generic rescue that returns 500 with

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

diff --git a/app/controllers/amf_controller.rb b/app/controllers/amf_controller.rb
index fd0296ae5ecbd4ce91bfd471077028e1bb73f89d..18ecb13231f8b36a561bc3c872aefaa7b36e050d 100644 (file)
--- a/app/controllers/amf_controller.rb
+++ b/app/controllers/amf_controller.rb
@@ -1,726 +1,958 @@
-# AMF Controller is a semi-standalone API for Flash clients, particularly Potlatch.
-# All interaction between Potlatch (as a .SWF application) and the 
+# 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).
 #
 # OSM database takes place using this controller. Messages are 
 # encoded in the Actionscript Message Format (AMF).
 #

-# See Also Potlatch::Potlatch and Potlatch::AMF
+# Helper functions are in /lib/potlatch.rb

 #
 #

-# Public domain.
-# editions Systeme D / Richard Fairhurst 2004-2008
+# Author::     editions Systeme D / Richard Fairhurst 2004-2008
+# Licence::    public domain.

 #
 #

-# All in/out parameters are floats unless explicitly stated.
+# == 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 .

 # 
 # 

-# to trap errors (getway_old,putway,putpoi,deleteway only):
-#   return(-1,"message")               <-- just puts up a dialogue
-#   return(-2,"message")               <-- also asks the user to e-mail me
-# to log:
-#   RAILS_DEFAULT_LOGGER.error("Args: #{args[0]}, #{args[1]}, #{args[2]}, #{args[3]}")
+# == 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
+# return(-3,["type",v],id)    <-- version conflict
+# return(-4,"type",id)        <-- object not found
+# -5 indicates the method wasn't called (due to a previous error)
+# 
+# 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'
 
   include Potlatch
 
 class AmfController < ApplicationController
   require 'stringio'
 
   include Potlatch
 

+  # Help methods for checking boundary sanity and area size
+  include MapBoundary
+

   session :off
   session :off

-  before_filter :check_write_availability
-
-  # Main AMF handler. Tha talk method takes in AMF, figures out what to do and dispatched to the appropriate private method
-  def talk
-    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
-    renumberednodes={}                                                 # Shared across repeated putways
-
-    # -------------
-    # 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
+  before_filter :check_api_writable
+  around_filter :api_call_timeout, :only => [:amf_read]
+
+  # 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=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)
-
-      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';                   results[index]=AMF.putdata(index,getway(args))
-      when 'getway_old';               results[index]=AMF.putdata(index,getway_old(args))
-      when 'getway_history';   results[index]=AMF.putdata(index,getway_history(args))
-      when 'putway';                   r=putway(args,renumberednodes)
-                                                               renumberednodes=r[3]
-                                                               results[index]=AMF.putdata(index,r)
-      when 'deleteway';                        results[index]=AMF.putdata(index,deleteway(args))
-      when 'putpoi';                   results[index]=AMF.putdata(index,putpoi(args))
-      when 'getpoi';                   results[index]=AMF.putdata(index,getpoi(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}(#{args.join(',')}):#{index}")
+
+        case message
+          when 'getpresets';             results[index]=AMF.putdata(index,getpresets(args[0]))
+          when 'whichways';                results[index]=AMF.putdata(index,whichways(*args))
+          when 'whichways_deleted';    results[index]=AMF.putdata(index,whichways_deleted(*args))
+          when 'getway';                 results[index]=AMF.putdata(index,getway(args[0].to_i))
+          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

+  end

 
 

-    # ------------------
-    # Write out response
+  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

 
 

-    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)
+      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)
+        err=false                   # Abort batch on error
+
+        logger.info("Executing AMF #{message}:#{index}")
+        if err
+          results[index]=[-5,nil]
+        else
+          case message
+            when 'putway';                       r=putway(renumberednodes,*args)
+                                                               renumberednodes=r[4]
+                                                               if r[2] != r[3] then renumberedways[r[2]] = r[3] 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[2] != r[3] then renumberednodes[r[2]] = r[3] end
+                                                       results[index]=AMF.putdata(index,r)
+            when 'startchangeset';results[index]=AMF.putdata(index,startchangeset(*args))
+          end
+          if results[index][0]==-3 then err=true end  # If a conflict is detected, don't execute any more writes
+        end

       end
       end

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

   end
 
   private
 
   end
 
   private
 

-  # Return presets (default tags and crap) to potlatch.
-  # Uses POTLATCH_PRESETS global, set up in OSM::Potlatch
-  def getpresets #:doc:
-    return POTLATCH_PRESETS
+  # Start new changeset
+  # Returns success_code,success_message,changeset id
+  
+  def startchangeset(usertoken, cstags, closeid, closecomment, opennew)
+    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.",nil
+      elsif closecomment.empty?
+        cs.save!
+      else
+        cs.tags['comment']=closecomment
+        cs.save_with_tags!
+      end
+    end
+       
+    # open a new changeset
+    if opennew!=0
+      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]
+    else
+      return [0,'',nil]
+    end

   end
 
   end
 

-  # ----- whichways
-  # Find all the way ids and nodes (including tags and projected lat/lng) which aren't part of those ways in an are
-  # 
-  # The argument is an array containing the following, in order:
-  # 0. minimum longitude
-  # 1. minimum latitude
-  # 2. maximum longitude
-  # 3. maximum latitude
-  # 4. baselong, 5. basey, 6. masterscale as above
-  def whichways(args) #:doc:
-    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
-    baselong    = args[4]
-    basey       = args[5]
-    masterscale = args[6]
-
-    RAILS_DEFAULT_LOGGER.info("  Message: whichways, bbox=#{xmin},#{ymin},#{xmax},#{ymax}")
-
-    # find the way ids in an area
-    nodes_in_area = Node.find_by_area(ymin, xmin, ymax, xmax, :conditions => "current_nodes.visible = 1", :include => :ways)
-    way_ids = nodes_in_area.collect { |node| node.way_ids }.flatten.uniq
-
-    # 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_potlatch(baselong,masterscale), n.lat_potlatch(basey,masterscale), n.tags_as_hash] }
-
-    [way_ids,points]
-  end
+  # Return presets (default tags, localisation etc.):
+  # uses POTLATCH_PRESETS global, set up in OSM::Potlatch.

 
 

-  # ----- whichways_deleted
-  #              return array of deleted ways in current bounding box
-  #              in:   as whichways
-  #              does: finds all deleted ways with a deleted node in bounding box
-  #              out:  [0] array of way ids
-  def whichways_deleted(args) #:doc:
-    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
-    baselong    = args[4]
-    basey       = args[5]
-    masterscale = args[6]
+  def getpresets(lang) #:doc:
+       lang.gsub!(/[^\w\-]/,'')

 
 

-    sql=<<-EOF
-     SELECT DISTINCT current_ways.id 
-       FROM current_nodes,way_nodes,current_ways 
-      WHERE #{OSM.sql_for_area(ymin, xmin, ymax, xmax, "current_nodes.")} 
-      AND way_nodes.node_id=current_nodes.id 
-      AND way_nodes.id=current_ways.id 
-      AND current_nodes.visible=0 
-      AND current_ways.visible=0 
-  EOF
-    waylist = ActiveRecord::Base.connection.select_all(sql)
-    ways = waylist.collect {|a| a['id'].to_i }
-    [ways]
-  end
+    begin
+      localised = YAML::load(File.open("#{RAILS_ROOT}/config/potlatch/localised/#{lang}/localised.yaml"))
+    rescue
+      localised = "" # guess we'll just have to use the hardcoded English text instead
+       end

 
 

-  # ----- getway
-  # Get a way with all of it's nodes and tags
-  # The input is an array with the following components, in order:
-  # 0. wayid - the ID of the way to get
-  # 1. baselong - origin of SWF map (longitude)
-  # 2. basey - origin of SWF map (latitude)
-  # 3. masterscale - SWF map scale
-  #
-  # The output is an array which contains all the nodes (with projected 
-  # latitude and longitude) and tags for a way (and all the nodes tags). 
-  # It also has the way's unprojected (WGS84) bbox.
-  #
-  # FIXME: The server really shouldn't be figuring out a ways bounding box and doing projection for potlatch
-  # FIXME: the argument splitting should be done in the 'talk' method, not here
-  def getway(args) #:doc:
-    wayid,baselong,basey,masterscale = args
-    wayid = wayid.to_i
-
-    RAILS_DEFAULT_LOGGER.info("  Message: getway, id=#{wayid}")
-
-    # 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
-    way = Way.find(wayid)
-
-    long_array = []
-    lat_array = []
-    points = []
-
-    way.nodes.each do |node|
-      projected_longitude = node.lon_potlatch(baselong,masterscale) # do projection for potlatch
-      projected_latitude = node.lat_potlatch(basey,masterscale)
-      id = node.id
-      tags_hash = node.tags_as_hash
-
-      points << [projected_longitude, projected_latitude, id, nil, tags_hash]
-      long_array << projected_longitude
-      lat_array << projected_latitude
+    begin
+      help = File.read("#{RAILS_ROOT}/config/potlatch/localised/#{lang}/help.html")
+    rescue
+      help = File.read("#{RAILS_ROOT}/config/potlatch/localised/en/help.html")

     end
     end

-
-    [wayid,points,way.tags,long_array.min,long_array.max,lat_array.min,lat_array.max]
+    return POTLATCH_PRESETS+[localised,help]

   end
 
   end
 

-  # ----- getway_old
-  #              returns old version of way
-  #              in:   [0] way id,
-  #                            [1] way version to get (or -1 for "last deleted version")
-  #                            [2] baselong, [3] basey, [4] masterscale
-  #              does: gets old version of way and all constituent nodes
-  #                            for undelete, always uses the most recent version of each node
-  #                              (even if it's moved)
-  #                            for revert, uses the historic version of each node, but if that node is
-  #                              still visible and has been changed since, generates a new node id
-  #              out:  [0] 0 (code for success), [1] SWF object name,
-  #                            [2] array of points (as getway _except_ [3] is node.visible?, 0 or 1),
-  #                            [4] xmin, [5] xmax, [6] ymin, [7] ymax (unprojected bbox),
-  #                            [8] way version
-  def getway_old(args) #:doc:
-    RAILS_DEFAULT_LOGGER.info("  Message: getway_old (server is #{SERVER_URL})")
-    #  if SERVER_URL=="www.openstreetmap.org" then return -1,"Revert is not currently enabled on the OpenStreetMap server." end
-
-    wayid,version,baselong,basey,masterscale=args
-    wayid = wayid.to_i
-    version = version.to_i
-    xmin = ymin =  999999
-    xmax = ymax = -999999
-    points=[]
-    if version<0
-      historic=false
-      version=getlastversion(wayid,version)
+  ##
+  # 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: 
+  # [success_code, success_message,
+  #  [[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

-      historic=true
+      # 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

-    readwayquery_old(wayid,version,historic).each { |row|
-      points<<[long2coord(row['longitude'].to_f,baselong,masterscale),lat2coord(row['latitude'].to_f,basey,masterscale),row['id'].to_i,row['visible'].to_i,tag2array(row['tags'].to_s)]
-      xmin=[xmin,row['longitude'].to_f].min
-      xmax=[xmax,row['longitude'].to_f].max
-      ymin=[ymin,row['latitude' ].to_f].min
-      ymax=[ymax,row['latitude' ].to_f].max
-    }

 
 

-    # get tags from this version
-    attributes={}
-    attrlist=ActiveRecord::Base.connection.select_all "SELECT k,v FROM way_tags WHERE id=#{wayid} AND version=#{version}"
-    attrlist.each {|a| attributes[a['k'].gsub(':','|')]=a['v'] }
-    attributes['history']="Retrieved from v"+version.to_s
+    [0, '', ways, points, relations]

 
 

-    [0,wayid,points,attributes,xmin,xmax,ymin,ymax,version]
-  end
-
-  # ----- getway_history
-  #              find history of a way
-  #              in:   [0] way id
-  #              does: finds history of a way
-  #              out:  [0] array of previous versions (where each is
-  #                                    [0] version, [1] db timestamp (string),
-  #                                    [2] visible 0 or 1,
-  #                                    [3] username or 'anonymous' (string))
-  def getway_history(args) #:doc:
-    wayid=args[0]
-    history=[]
-    sql=<<-EOF
-  SELECT version,timestamp,visible,display_name,data_public
-    FROM ways,users
-   WHERE ways.id=#{wayid}
-     AND ways.user_id=users.id
-     AND ways.visible=1
-   ORDER BY version DESC
-  EOF
-    histlist=ActiveRecord::Base.connection.select_all(sql)
-    histlist.each { |row|
-      if row['data_public'].to_i==1 then user=row['display_name'] else user='anonymous' end
-      history<<[row['version'],row['timestamp'],row['visible'],user]
-    }
-    [history]
+  rescue OSM::APITimeoutError => err
+    [-1,"Sorry, I can't get the map for that area - try zooming in further. The server said: #{err}"]
+  rescue Exception => err
+    [-2,"Sorry - I can't get the map for that area. The server said: #{err}",[],[],[] ]

   end
 
   end
 

-  # ----- putway
-  #              saves a way to the database
-  #              in:   [0] user token (string),
-  #                            [1] original way id (may be negative), 
-  #                            [2] array of points (as getway/getway_old),
-  #                            [3] hash of way tags,
-  #                            [4] original way version (0 if not a reverted/undeleted way),
-  #                            [5] baselong, [6] basey, [7] masterscale
-  #              does: saves way to the database
-  #                            all constituent nodes are created/updated as necessary
-  #                            (or deleted if they were in the old version and are otherwise unused)
-  #              out:  [0] 0 (code for success), [1] original way id (unchanged),
-  #                            [2] new way id, [3] hash of renumbered nodes (old id=>new id),
-  #                            [4] xmin, [5] xmax, [6] ymin, [7] ymax (unprojected bbox)
-  def putway(args,renumberednodes) #:doc:
-    RAILS_DEFAULT_LOGGER.info("  putway started")
-    usertoken,originalway,points,attributes,oldversion,baselong,basey,masterscale=args
-    uid=getuserid(usertoken)
-    if !uid then return -1,"You are not logged in, so the way could not be saved." end
-
-    RAILS_DEFAULT_LOGGER.info("  putway authenticated happily")
-    db_uqn='unin'+(rand*100).to_i.to_s+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'+(rand*100).to_i.to_s+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
-    oldversion=oldversion.to_i
-
-    RAILS_DEFAULT_LOGGER.info("  Message: putway, id=#{originalway}")
-
-    # -- Check for null IDs or short ways
-
-    points.each do |a|
-      if a[2]==0 or a[2].nil? then return -2,"Server error - node with id 0 found in way #{originalway}." end
-    end
-    
-    if points.length<2 then return -2,"Server error - way is only #{points.length} points long." end
-
-    # -- 3.    read original way into memory
-
-    xc={}; yc={}; tagc={}; vc={}
-    if originalway>0
-      way=originalway
-      if oldversion==0 then r=readwayquery(way,false)
-      else r=readwayquery_old(way,oldversion,true) end
-      r.each { |row|
-        id=row['id'].to_i
-        if (id>0) then
-          xc[id]=row['longitude'].to_f
-          yc[id]=row['latitude' ].to_f
-          tagc[id]=row['tags']
-          vc[id]=row['visible'].to_i
-        end
-      }
-      ActiveRecord::Base.connection.update("UPDATE current_ways SET timestamp=#{db_now},user_id=#{uid},visible=1 WHERE id=#{way}")
-    else
-      way=ActiveRecord::Base.connection.insert("INSERT INTO current_ways (user_id,timestamp,visible) VALUES (#{uid},#{db_now},1)")
-    end
+  # Find deleted ways in current bounding box (similar to whichways, but ways
+  # with a deleted node only - not POIs or relations).

 
 

-    # -- 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=''
-    nodelist=[]
-
-    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])
-      tagsql="'"+sqlescape(tagstr)+"'"
-      lat=(ys * 10000000).round
-      long=(xs * 10000000).round
-      tile=QuadTile.tile_for_point(ys, xs)
-
-      # compare node
-      if node<0
-        # new node - create
-        if renumberednodes[node.to_s].nil?
-          newnode=ActiveRecord::Base.connection.insert("INSERT INTO current_nodes (   latitude,longitude,timestamp,user_id,visible,tags,tile) VALUES (           #{lat},#{long},#{db_now},#{uid},1,#{tagsql},#{tile})")
-          ActiveRecord::Base.connection.insert("INSERT INTO nodes         (id,latitude,longitude,timestamp,user_id,visible,tags,tile) VALUES (#{newnode},#{lat},#{long},#{db_now},#{uid},1,#{tagsql},#{tile})")
-          points[i][2]=newnode
-          nodelist.push(newnode)
-          renumberednodes[node.to_s]=newnode.to_s
-        else
-          points[i][2]=renumberednodes[node.to_s].to_i
-        end
+  def whichways_deleted(xmin, ymin, xmax, ymax) #:doc:
+    enlarge = [(xmax-xmin)/8,0.01].min
+    xmin -= enlarge; ymin -= enlarge
+    xmax += enlarge; ymax += enlarge

 
 

-      elsif xc.has_key?(node)
-        nodelist.push(node)
-        # old node from original way - update
-        if ((xs/0.0000001).round!=(xc[node]/0.0000001).round or (ys/0.0000001).round!=(yc[node]/0.0000001).round or tagstr!=tagc[node] or vc[node]==0)
-          ActiveRecord::Base.connection.insert("INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible,tags,tile) VALUES (#{node},#{lat},#{long},#{db_now},#{uid},1,#{tagsql},#{tile})")
-          ActiveRecord::Base.connection.update("UPDATE current_nodes SET latitude=#{lat},longitude=#{long},timestamp=#{db_now},user_id=#{uid},tags=#{tagsql},visible=1,tile=#{tile} WHERE id=#{node}")
-        end
-      else
-        # old node, created in another way and now added to this way
-      end
+    # 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
 
     end
 

-    # -- 6a. delete any nodes not in modified way
+    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

 
 

-    createuniquenodes(way,db_uqn,nodelist)     # nodes which appear in this way but no other
+    [0,'',way_ids]
+  end

 
 

-    sql=<<-EOF
-  INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible,tile)  
-  SELECT DISTINCT cn.id,cn.latitude,cn.longitude,#{db_now},#{uid},0,cn.tile
-    FROM current_nodes AS cn,#{db_uqn}
-   WHERE cn.id=node_id
-    EOF
-    ActiveRecord::Base.connection.insert(sql)
+  # 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.

 
 

-    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)
-
-    deleteuniquenoderelations(db_uqn,uid,db_now)
-    ActiveRecord::Base.connection.execute("DROP TEMPORARY TABLE #{db_uqn}")
-
-    #  6b. insert new version of route into way_nodes
-
-    insertsql =''
-    currentsql=''
-    sequence  =1
-    points.each do |p|
-      if insertsql !='' then insertsql +=',' end
-      if currentsql!='' then currentsql+=',' end
-      insertsql +="(#{way},#{p[2]},#{sequence},#{version})"
-      currentsql+="(#{way},#{p[2]},#{sequence})"
-      sequence  +=1
-    end
+  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 [-4, 'way', wayid, [], {}, nil]
+        end

 
 

-    ActiveRecord::Base.connection.execute("DELETE FROM current_way_nodes WHERE id=#{way}");
-    ActiveRecord::Base.connection.insert( "INSERT INTO         way_nodes (id,node_id,sequence_id,version) VALUES #{insertsql}");
-    ActiveRecord::Base.connection.insert( "INSERT INTO current_way_nodes (id,node_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
-      insertsql +="(#{way},'"+sqlescape(k.gsub('|',':'))+"','"+sqlescape(v)+"',#{version})"
-      currentsql+="(#{way},'"+sqlescape(k.gsub('|',':'))+"','"+sqlescape(v)+"')"
-    end
+        # check case where way has been deleted or doesn't exist
+        return [-4, 'way', wayid, [], {}, nil] if way.nil? or !way.visible

 
 

-    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
+        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

 
 

-    [0,originalway,way,renumberednodes,xmin,xmax,ymin,ymax]
+    [0, '', wayid, points, tags, version]

   end
   end

-
-  # ----- putpoi
-  #              save POI to the database
-  #              in:   [0] user token (string),
-  #                            [1] original node id (may be negative),
-  #                            [2] projected longitude, [3] projected latitude,
-  #                            [4] hash of tags, [5] visible (0 to delete, 1 otherwise), 
-  #                            [6] baselong, [7] basey, [8] masterscale
-  #              does: saves POI node to the database
-  #                            refuses save if the node has since become part of a way
-  #              out:  [0] 0 (success), [1] original node id (unchanged),
-  #                            [2] new node id
-  def putpoi(args) #:doc:
-    usertoken,id,x,y,tags,visible,baselong,basey,masterscale=args
-    uid=getuserid(usertoken)
-    if !uid then return -1,"You are not logged in, so the point could not be saved." end
-
-    db_now='@now'+(rand*100).to_i.to_s+uid.to_s+id.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()")
-
-    id=id.to_i
-    visible=visible.to_i
-    if visible==0 then
-      # if deleting, check node hasn't become part of a way 
-      inway=ActiveRecord::Base.connection.select_one("SELECT cw.id FROM current_ways cw,current_way_nodes cwn WHERE cw.id=cwn.id AND cw.visible=1 AND cwn.node_id=#{id} LIMIT 1")
-      unless inway.nil? then return -1,"The point has since become part of a way, so you cannot save it as a POI." end
-      deleteitemrelations(id,'node',uid,db_now)
+  
+  # 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.", id, [], {}, nil, false]
+          end
+        end
+      rescue ArgumentError
+        # thrown by date parsing method. leave old_way as nil for
+        # the error handler below.
+      end

     end
 
     end
 

-    x=coord2long(x.to_f,masterscale,baselong)
-    y=coord2lat(y.to_f,masterscale,basey)
-    tagsql="'"+sqlescape(array2tag(tags))+"'"
-    lat=(y * 10000000).round
-    long=(x * 10000000).round
-    tile=QuadTile.tile_for_point(y, x)
-
-    if (id>0) then
-      ActiveRecord::Base.connection.insert("INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible,tags,tile) VALUES (#{id},#{lat},#{long},#{db_now},#{uid},#{visible},#{tagsql},#{tile})");
-      ActiveRecord::Base.connection.update("UPDATE current_nodes SET latitude=#{lat},longitude=#{long},timestamp=#{db_now},user_id=#{uid},visible=#{visible},tags=#{tagsql},tile=#{tile} WHERE id=#{id}");
-      newid=id
+    if old_way.nil?
+      return [-1, "Sorry, the server could not find a way at that time.", id, [], {}, nil, false]

     else
     else

-      newid=ActiveRecord::Base.connection.insert("INSERT INTO current_nodes (latitude,longitude,timestamp,user_id,visible,tags,tile) VALUES (#{lat},#{long},#{db_now},#{uid},#{visible},#{tagsql},#{tile})");
-      ActiveRecord::Base.connection.update("INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible,tags,tile) VALUES (#{newid},#{lat},#{long},#{db_now},#{uid},#{visible},#{tagsql},#{tile})");
+      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

-    [0,id,newid]

   end
   end

-
-  # ----- getpoi
-  # read POI from database
-  #              (only called on revert: POIs are usually read by whichways)
-  #              in:   [0] node id, [1] baselong, [2] basey, [3] masterscale
-  #              does: reads POI
-  #              out:  [0] id (unchanged), [1] projected long, [2] projected lat,
-  #                            [3] hash of tags
-  def getpoi(args) #:doc:
-    id,baselong,basey,masterscale = args
-    
-    n = Node.find(id.to_i)
-    if n
-      return [n.id, n.long_potlatch(baselong,masterscale), n.lat_potlatch(basey,masterscale), n.tags_as_hash]
-    else
-      return [nil,nil,nil,'']
+  
+  # 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
     end
   end

+  
+  # Find history of a node. Returns 'node', id, and an array of previous versions as above.

 
 

-  # ----- deleteway
-  #              delete way and constituent nodes from database
-  #              in:   [0] user token (string), [1] way id
-  #              does: deletes way from db and any constituent nodes not used elsewhere
-  #                            also removes ways/nodes from any relations they're in
-  #              out:  [0] 0 (success), [1] way id (unchanged)
-  def deleteway(args) #:doc:
-    usertoken,way_id=args
-    RAILS_DEFAULT_LOGGER.info("  Message: deleteway, id=#{way_id}")
-    uid=getuserid(usertoken)
-    if !uid then return -1,"You are not logged in, so the way could not be deleted." end
-
-    user = User.find(uid)
-
-    way = Way.find(way_id)
+  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

 
 

-    way.delete_with_relations_and_nodes_and_history(user)  
+  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

 
 

-    return [0,way_id]
+  # Find GPS traces with specified name/id.
+  # Returns array listing GPXs, each one comprising id, name and description.
+  
+  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
+    [0,'',gpxs]

   end
 
   end
 

-  def readwayquery(id,insistonvisible) #:doc:
-    sql=<<-EOF
-    SELECT latitude*0.0000001 AS latitude,longitude*0.0000001 AS longitude,current_nodes.id,tags,visible 
-      FROM current_way_nodes,current_nodes 
-     WHERE current_way_nodes.id=#{id} 
-       AND current_way_nodes.node_id=current_nodes.id 
-  EOF
-    if insistonvisible then sql+=" AND current_nodes.visible=1 " end
-    sql+=" ORDER BY sequence_id"
-    ActiveRecord::Base.connection.select_all(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 [-4, 'relation', relid, {}, [], nil]
+    end
+
+    return [-4, 'relation', relid, {}, [], nil] if rel.nil? or !rel.visible
+    [0, '', relid, rel.tags, rel.members, rel.version]

   end
 
   end
 

-  # Get the latest version id of a way
-  def getlastversion(id,version) #:doc:
-    old_way = OldWay.find(:first, :conditions => ['visible=1 AND id=?' , id], :order => 'version DESC')
-    old_way.version
+  # 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
 
   end
 

-  def readwayquery_old(id,version,historic) #:doc:
-    # Node handling on undelete (historic=false):
-    # - always use the node specified, even if it's moved
+  # 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

 
 

-    # Node handling on revert (historic=true):
-    # - if it's a visible node, use a new node id (i.e. not mucking up the old one)
-    #   which means the SWF needs to allocate new ids
-    # - if it's an invisible node, we can reuse the old node id
+      # 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 relation
+        new_relation.create_with_history(user)
+      elsif visible
+        # We're updating the relation
+        new_relation.id = relid
+        relation.update_from(new_relation, user)
+      else
+        # We're deleting the relation
+        new_relation.id = relid
+        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}.", relid, relid, nil]
+  rescue OSM::APIVersionMismatchError => ex
+    a=ex.to_s.match(/(\d+) of (\w+) (\d+)$/)
+    return [-3, ['relation', a[1]], relid, relid, nil]
+  rescue OSM::APIAlreadyDeletedError => ex
+    return [-1, "The relation has already been deleted.", relid, relid, nil]
+  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}", relid, relid, nil]
+  end

 
 

-    # get node list from specified version of way,
-    # and the _current_ lat/long/tags of each node
+  # 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]),
+  # 8. hash of nodes to delete (id->version).
+  # 
+  # 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, deletednodes) #:doc:
+
+    # -- Initialise
+       
+    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
+
+    originalway = originalway.to_i
+logger.info("received #{pointlist} for #{originalway}")
+       pointlist.collect! {|a| a.to_i }
+logger.info("converted to #{pointlist}")
+
+    way=nil    # this is returned, so scope it outside the transaction
+    nodeversions = {}
+    Way.transaction do
+
+      # -- 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)
+          node.id=id
+          previous.update_from(node, user)
+          nodeversions[previous.id] = previous.version
+        end
+      end

 
 

-    row=ActiveRecord::Base.connection.select_one("SELECT timestamp FROM ways WHERE version=#{version} AND id=#{id}")
-    waytime=row['timestamp']
+      # -- Save revised way
+
+logger.info("renumberednodes is #{renumberednodes.inspect}")
+         pointlist.collect! {|a|
+             renumberednodes[a] ? renumberednodes[a]:a
+         } # renumber nodes
+logger.info("saving with #{pointlist}")
+      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
+      else
+             way = Way.find(originalway)
+                 if way.tags!=attributes or way.nds!=pointlist or !way.visible?
+                   new_way.id=originalway
+          way.update_from(new_way, user)
+        end
+      end

 
 

-    sql=<<-EOF
-  SELECT cn.id,visible,latitude*0.0000001 AS latitude,longitude*0.0000001 AS longitude,tags 
-    FROM way_nodes wn,current_nodes cn 
-   WHERE wn.version=#{version} 
-     AND wn.id=#{id} 
-     AND wn.node_id=cn.id 
-   ORDER BY sequence_id
-  EOF
-    rows=ActiveRecord::Base.connection.select_all(sql)
-
-    # if historic (full revert), get the old version of each node
-    # - if it's in another way now, generate a new id
-    # - if it's not in another way, use the old ID
-    if historic then
-      rows.each_index do |i|
-        sql=<<-EOF
-    SELECT latitude*0.0000001 AS latitude,longitude*0.0000001 AS longitude,tags,cwn.id AS currentway 
-      FROM nodes n
-   LEFT JOIN current_way_nodes cwn
-      ON cwn.node_id=n.id
-     WHERE n.id=#{rows[i]['id']} 
-       AND n.timestamp<="#{waytime}" 
-     AND cwn.id!=#{id} 
-     ORDER BY n.timestamp DESC 
-     LIMIT 1
-    EOF
-        row=ActiveRecord::Base.connection.select_one(sql)
-        unless row.nil? then
-          nx=row['longitude'].to_f
-          ny=row['latitude'].to_f
-          if (row['currentway'] && (nx!=rows[i]['longitude'].to_f or ny!=rows[i]['latitude'].to_f or row['tags']!=rows[i]['tags'])) then rows[i]['id']=-1 end
-          rows[i]['longitude']=nx
-          rows[i]['latitude' ]=ny
-          rows[i]['tags'     ]=row['tags']
+      # -- Delete unwanted nodes
+
+      deletednodes.each do |id,v|
+        node = Node.find(id.to_i)
+        new_node = Node.new
+        new_node.changeset_id = changeset_id
+        new_node.version = v.to_i
+        new_node.id = id.to_i
+        begin
+          node.delete_with_history!(new_node, user)
+        rescue OSM::APIPreconditionFailedError => ex
+          # We don't do anything here as the node is being used elsewhere
+          # and we don't want to delete it

         end
       end
         end
       end

-    end
-    rows
-  end

 
 

-  def createuniquenodes(way,uqn_name,nodelist) #:doc:
-    # Find nodes which appear in this way but no others
-    sql=<<-EOF
-  CREATE TEMPORARY TABLE #{uqn_name}
-          SELECT a.node_id
-            FROM (SELECT DISTINCT node_id FROM current_way_nodes
-              WHERE id=#{way}) a
-         LEFT JOIN current_way_nodes b
-            ON b.node_id=a.node_id
-             AND b.id!=#{way}
-           WHERE b.node_id IS NULL
-  EOF
-    unless nodelist.empty? then
-      sql+="AND a.node_id NOT IN ("+nodelist.join(',')+")"
-    end
-    ActiveRecord::Base.connection.execute(sql)
+    end # transaction
+
+    [0, '', originalway, way.id, renumberednodes, way.version, nodeversions, deletednodes]
+  rescue OSM::APIChangesetAlreadyClosedError => ex
+    return [-1, "Sorry, your changeset #{ex.changeset.id} was closed (at #{ex.changeset.closed_at}).", originalway, originalway, renumberednodes, wayversion, nodeversions, deletednodes]
+  rescue OSM::APIVersionMismatchError => ex
+    a=ex.to_s.match(/(\d+) of (\w+) (\d+)$/)
+    return [-3, ['way', a[1], a[2].downcase, a[3]], originalway, originalway, renumberednodes, wayversion, nodeversions, deletednodes]
+  rescue OSM::APITooManyWayNodesError => ex
+    return [-1, "You have tried to upload a really long way with #{ex.provided} points: only #{ex.max} are allowed.", originalway, originalway, renumberednodes, wayversion, nodeversions, deletednodes]
+  rescue OSM::APIAlreadyDeletedError => ex
+    return [-1, "The point has already been deleted.", originalway, originalway, renumberednodes, wayversion, nodeversions, deletednodes]
+  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}", originalway, originalway, renumberednodes, wayversion, nodeversions, deletednodes]

   end
 
   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.",id,id,version 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
+        new_node.id=id
+        node.update_from(new_node, user)
+      else
+        # We're deleting the node
+        new_node.id=id
+        node.delete_with_history!(new_node, user)
+      end

 
 

+    end # transaction

 
 

-  # ====================================================================
-  # Relations handling
-  # deleteuniquenoderelations(uqn_name,uid,db_now)
-  # deleteitemrelations(way|node,'way'|'node',uid,db_now)
+    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}",id,id,version]
+  rescue OSM::APIVersionMismatchError => ex
+    a=ex.to_s.match(/(\d+) of (\w+) (\d+)$/)
+    return [-3, ['node', a[1]], id,id,version]
+  rescue OSM::APIAlreadyDeletedError => ex
+    return [-1, "The point has already been deleted",id,id,version]
+  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}",id,id,version]
+  end

 
 

-  def deleteuniquenoderelations(uqn_name,uid,db_now) #:doc:
-    sql=<<-EOF
-  SELECT node_id,cr.id FROM #{uqn_name},current_relation_members crm,current_relations cr 
-   WHERE crm.member_id=node_id 
-     AND crm.member_type='node' 
-     AND crm.id=cr.id 
-     AND cr.visible=1
-  EOF
-
-    relnodes=ActiveRecord::Base.connection.select_all(sql)
-    relnodes.each do |a|
-      removefromrelation(a['node_id'],'node',a['id'],uid,db_now)
+  # 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.
+
+  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
     end

-  end

 
 

-  def deleteitemrelations(objid,type,uid,db_now) #:doc:
-    sql=<<-EOF
-  SELECT cr.id FROM current_relation_members crm,current_relations cr 
-   WHERE crm.member_id=#{objid} 
-     AND crm.member_type='#{type}' 
-     AND crm.id=cr.id 
-     AND cr.visible=1
-  EOF
-
-    relways=ActiveRecord::Base.connection.select_all(sql)
-    relways.each do |a|
-      removefromrelation(objid,type,a['id'],uid,db_now)
+    if n
+      return [0, '', n.id, n.lon, n.lat, n.tags, v]
+    else
+      return [-4, 'node', id, nil, nil, {}, nil]

     end
   end
 
     end
   end
 

-  def removefromrelation(objid,type,relation,uid,db_now) #:doc:
-    rver=ActiveRecord::Base.connection.insert("INSERT INTO relations (id,user_id,timestamp,visible) VALUES (#{relation},#{uid},#{db_now},1)")
-
-    tagsql=<<-EOF
-  INSERT INTO relation_tags (id,k,v,version) 
-  SELECT id,k,v,#{rver} FROM current_relation_tags 
-   WHERE id=#{relation} 
-  EOF
-    ActiveRecord::Base.connection.insert(tagsql)
-
-    membersql=<<-EOF
-  INSERT INTO relation_members (id,member_type,member_id,member_role,version) 
-  SELECT id,member_type,member_id,member_role,#{rver} FROM current_relation_members 
-   WHERE id=#{relation} 
-     AND (member_id!=#{objid} OR member_type!='#{type}')
-  EOF
-    ActiveRecord::Base.connection.insert(membersql)
-
-    ActiveRecord::Base.connection.update("UPDATE current_relations SET user_id=#{uid},timestamp=#{db_now} WHERE id=#{relation}")
-    ActiveRecord::Base.connection.execute("DELETE FROM current_relation_members WHERE id=#{relation} AND member_type='#{type}' AND member_id=#{objid}")
-  end
+  # Delete way and all constituent nodes.
+  # 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, new way version, new node versions.
+
+  def deleteway(usertoken, changeset_id, way_id, way_version, deletednodes) #: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
+    nodeversions = {}
+    old_way=nil # returned, so scope it outside the transaction
+    # 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)
+      delete_way = Way.new
+      delete_way.version = way_version
+      delete_way.changeset_id = changeset_id
+      delete_way.id = way_id
+      old_way.delete_with_history!(delete_way, user)
+
+      # -- Delete unwanted nodes
+
+      deletednodes.each do |id,v|
+        node = Node.find(id.to_i)
+        new_node = Node.new
+        new_node.changeset_id = changeset_id
+        new_node.version = v.to_i
+        new_node.id = id.to_i
+        begin
+          node.delete_with_history!(new_node, user)
+          nodeversions[node.id]=node.version
+        rescue OSM::APIPreconditionFailedError => ex
+          # We don't do anything with the exception as the node is in use
+          # elsewhere and we don't want to delete it
+        end
+      end

 
 

-  def sqlescape(a) #:doc:
-    a.gsub(/[\000-\037]/,"").gsub("'","''").gsub(92.chr) {92.chr+92.chr}
+    end # transaction
+    [0, '', way_id, old_way.version, nodeversions]
+  rescue OSM::APIChangesetAlreadyClosedError => ex
+    return [-1, "The changeset #{ex.changeset.id} was closed at #{ex.changeset.closed_at}",way_id,way_version,nodeversions]
+  rescue OSM::APIVersionMismatchError => ex
+    a=ex.to_s.match(/(\d+) of (\w+) (\d+)$/)
+    return [-3, ['way', a[1]],way_id,way_version,nodeversions]
+  rescue OSM::APIAlreadyDeletedError => ex
+    return [-1, "The way has already been deleted.",way_id,way_version,nodeversions]
+  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}",way_id,way_version,nodeversions]

   end
 
   end
 

-  def tag2array(a) #:doc:
-    tags={}
-    Tags.split(a) do |k, v|
-      tags[k.gsub(':','|')]=v
-    end
-    tags
-  end

 
 

-  def array2tag(a) #:doc:
-    tags = []
-    a.each do |k,v|
-      if v=='' then next end
-      if v[0,6]=='(type ' then next end
-      tags << [k.gsub('|',':'), v]
-    end
-    return Tags.join(tags)
-  end
+  # ====================================================================
+  # Support functions
+
+  # 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

 
 

-  def getuserid(token) #:doc:
-    if (token =~ /^(.+)\+(.+)$/) then
+  def getuser(token) #:doc:
+    if (token =~ /^(.+)\:(.+)$/) then

       user = User.authenticate(:username => $1, :password => $2)
     else
       user = User.authenticate(:token => token)
     end
       user = User.authenticate(:username => $1, :password => $2)
     else
       user = User.authenticate(:token => token)
     end

+    return user
+  end

 
 

-    return user ? user.id : nil;
+  # 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
 
   end
 

+

   # ====================================================================
   # ====================================================================

-  # Co-ordinate conversion
+  # Alternative SQL queries for getway/whichways

 
 

-  def lat2coord(a,basey,masterscale) #:doc:
-    -(lat2y(a)-basey)*masterscale
+  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
   end

-
-  def long2coord(a,baselong,masterscale) #:doc:
-    (a-baselong)*masterscale
+       
+  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
+    pois

   end
   end

-
-  def lat2y(a) #:doc:
-    180/Math::PI * Math.log(Math.tan(Math::PI/4+a*(Math::PI/180)/2))
+       
+  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
+    ActiveRecord::Base.connection.select_all(sql).collect { |a| [a['relid'].to_i,a['version'].to_i] }

   end
   end

-
-  def coord2lat(a,masterscale,basey) #:doc:
-    y2lat(a/-masterscale+basey)
+       
+  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
   end

-
-  def coord2long(a,masterscale,baselong) #:doc:
-    a/masterscale+baselong
+       
+  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
 

-  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

+