]> git.openstreetmap.org Git - rails.git/blobdiff - app/controllers/amf_controller.rb
Added methods to strip those non-XML control characters from tags in AMF controller...
[rails.git] / app / controllers / amf_controller.rb
index 38c567734ff6a5905ef2e23bfeee7d5828cc0308..20053644d8635177a32ffd3c175328bb496ee29c 100644 (file)
+# 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
+# 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'
 
-  # Still to do:
-  # - all db interaction
-  # - user authentication
-  # - (also pass lat/lon through from view tab to edit tab)
+  include Potlatch
 
-# to log:
-# RAILS_DEFAULT_LOGGER.error("Args: #{args[0]}, #{args[1]}, #{args[2]}, #{args[3]}")
+  # Help methods for checking boundary sanity and area size
+  include MapBoundary
 
+  before_filter :check_api_writable
 
-  # ====================================================================
-  # Main AMF handler
+  # 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
   
-  # ---- talk  process AMF request
-
-  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
-
-       # -------------
-       # Parse request
-
-       headers=getint(req)                                     # Read number of headers
-       for i in (1..headers)                           # Read each header
-               name=getstring(req)                             #  |
-               req.getc                                                #  | skip boolean
-               value=getvalue(req)                             #  |
-               header["name"]=value                    #  |
-       end
-
-       bodies=getint(req)                                      # Read number of bodies
-       for i in (1..bodies)                            # 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))
-               end
-       end
-
-       # ------------------
-       # Write out response
-
-       response.headers["Content-Type"]="application/x-amf"
-       a,b=results.length.divmod(256)
-       ans=0.chr+0.chr+0.chr+0.chr+a.chr+b.chr
-       results.each do |k,v|
-               ans+=v
-       end
-       render :text=>ans
-
-  end
-
-
-       # ====================================================================
-       # Remote calls
-
-       def getpresets
-               presets={}
-               presetmenus={}; presetmenus['point']=[]; presetmenus['way']=[]
-               presetnames={}; presetnames['point']={}; presetnames['way']={}
-               presettype=''
-               presetcategory=''
-               
-               File.open("config/potlatch/presets.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]=$2 end
-                                       }
-                               end
-                       }
-               end
-               [presets,presetmenus,presetnames]
-       end
-
-       def whichways(args)
-               waylist=WaySegment.find_by_sql("SELECT DISTINCT current_way_segments.id AS wayid"+
-                        "  FROM current_way_segments,current_segments,current_nodes "+
-                        " WHERE segment_id=current_segments.id "+
-                        "   AND node_a=current_nodes.id "+
-                        "   AND (latitude  BETWEEN "+(args[1].to_f-0.01).to_s+" AND "+(args[3].to_f+0.01).to_s+") "+
-                        "   AND (longitude BETWEEN "+(args[0].to_f-0.01).to_s+" AND "+(args[2].to_f+0.01).to_s+")")
-               ways=[]
-               waylist.each {|a|
-                       ways<<a.wayid.to_i
-RAILS_DEFAULT_LOGGER.error("Found #{a.wayid.to_i}")
-               }
-               ways
-       end
-       
-       def getway(args)
-               objname,wayid,$baselong,$basey,$masterscale=args
-               wayid=wayid.to_i
-               points=[]
-               lastid=-1
-               xmin=999999; xmax=-999999
-               ymin=999999; ymax=-999999
-
-RAILS_DEFAULT_LOGGER.error("Looking for way #{wayid}")
-               nodelist=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=#{wayid} "+
-                       "     AND segment_id=current_segments.id "+
-                       "     AND n1.id=node_a and n2.id=node_b "+
-                       "   ORDER BY sequence_id"
-               nodelist.each {|row|
-                       xs1=long2coord(row['long1'].to_f); ys1=lat2coord(row['lat1'].to_f)
-                       xs2=long2coord(row['long2'].to_f); ys2=lat2coord(row['lat2'].to_f)
-                       if (row['id1'].to_i!=lastid)
-                               points<<[xs1,ys1,row['id1'].to_i,0,tag2array(row['tags1']),0]
-                       end
-                       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
-               }
-                       
-               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'] }
-
-RAILS_DEFAULT_LOGGER.error("Way #{wayid} #{xmin},#{xmax},#{ymin},#{ymax}")
-               [objname,points,attributes,xmin,xmax,ymin,ymax]
-       end
-       
-       def putway(args)
-               # to do
-       end
-       
-       def deleteway(args)
-               # to do
-       end
-       
-       # need support functions here too:
-       #       database support functions (readwayquery, createuniquesegments)
-       #       tag2array, array2tag
-       #       getuserid
-
-       def tag2array(a)
-               tags={}
-               a.gsub('\;','#%').split(';').each do |b|
-                       b.gsub!('#%',';')
-                       k,v=b.split('=')
-                       tags[k]=v
-               end
-               tags
-       end
-       
+  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
 
-       # ====================================================================
-       # 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 getlong(s)
-               ((s.getc*256+s.getc)*256+s.getc)*256+s.getc
-       end
-       
-       def getstring(s)
-               len=s.getc*256+s.getc
-               s.read(len)
-       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)
-               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
-       
-       # ----- 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
-               end
-       end
-
-       # ====================================================================
-       # AMF write subroutines
-       
-       # ----- 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
-       
-       def encodevalue(n)
-               case n.class.to_s
-                       when 'Array'
-                               a=10.chr+encodelong(n.length)
-                               n.each do |b|
-                                       a+=encodevalue(b)
-                               end
-                               a
-                       when 'Hash'
-                               a=3.chr
-                               n.each do |k,v|
-                                       a+=encodestring(k)+encodevalue(v)
-                               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)
-               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
+      # 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)
+        logger.info("Executing AMF #{message}(#{args.join(',')}):#{index}")
+
+        case message
+          when 'getpresets';        results[index]=AMF.putdata(index,getpresets(*args))
+          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
+      logger.info("Encoding AMF results")
+      sendresponse(results)
+    else
+      render :nothing => true, :status => :method_not_allowed
+    end
+  end
+
+  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
+
+      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';         orn=renumberednodes.dup
+                                   r=putway(renumberednodes,*args)
+                                   r[4]=renumberednodes.reject { |k,v| orn.has_key?(k) }
+                                   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
+      logger.info("Encoding AMF results")
+      sendresponse(results)
+    else
+      render :nothing => true, :status => :method_not_allowed
+    end
+  end
+
+  private
+
+  def amf_handle_error(call)
+    yield
+  rescue OSM::APIVersionMismatchError => ex
+    return [-3, [ex.type.downcase, ex.latest, ex.id]]
+  rescue OSM::APIUserChangesetMismatchError => ex
+    return [-2, ex.to_s]
+  rescue OSM::APIBadBoundingBox => ex
+    return [-2, "Sorry - I can't get the map for that area. The server said: #{ex.to_s}"]
+  rescue OSM::APIError => ex
+    return [-1, ex.to_s]
+  rescue Exception => ex
+    return [-2, "An unusual error happened (in #{call}). The server said: #{ex.to_s}"]
+  end
+
+  def amf_handle_error_with_timeout(call)
+    amf_handle_error(call) do
+      Timeout::timeout(APP_CONFIG['api_timeout'], OSM::APITimeoutError) do
+        yield
+      end
+    end
+  end
+
+  # Start new changeset
+  # Returns success_code,success_message,changeset id
+  
+  def startchangeset(usertoken, cstags, closeid, closecomment, opennew)
+    amf_handle_error("'startchangeset'") do
+      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
+          raise OSM::APIUserChangesetMismatchError.new
+        elsif closecomment.empty?
+          cs.save!
+        else
+          cs.tags['comment']=closecomment
+          cs.save_with_tags!
+        end
+      end
        
-       def lat2coord(a)
-               -(lat2y(a)-$basey)*$masterscale+250
-       end
+      # open a new changeset
+      if opennew!=0
+        cs = Changeset.new
+        cs.tags = cstags
+        cs.user_id = user.id
+        if !closecomment.empty? then cs.tags['comment']=closecomment end
+        # 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
+
+  # Return presets (default tags, localisation etc.):
+  # uses POTLATCH_PRESETS global, set up in OSM::Potlatch.
+
+  def getpresets(usertoken,lang) #:doc:
+    user = getuser(usertoken)
+
+    if user && !user.languages.empty?
+      request.user_preferred_languages = user.languages
+    end
+
+    lang = request.compatible_language_from(getlocales)
+
+    begin
+      # if not, try the browser language
+      localised = YAML::load(File.open("#{RAILS_ROOT}/config/potlatch/localised/#{lang}/localised.yaml"))
+    rescue
+      # fall back to hardcoded English text
+      localised = ""
+    end
+
+    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
+    return POTLATCH_PRESETS+[localised,help]
+  end
+
+  ##
+  # 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:
+    amf_handle_error_with_timeout("'whichways'") do
+      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
+        # 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
+
+      [0, '', ways, points, relations]
+    end
+  end
+
+  # Find deleted ways in current bounding box (similar to whichways, but ways
+  # with a deleted node only - not POIs or relations).
+
+  def whichways_deleted(xmin, ymin, xmax, ymax) #:doc:
+    amf_handle_error_with_timeout("'whichways_deleted'") do
+      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)
+
+      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
+
+      [0,'',way_ids]
+    end
+  end
+
+  # Get a way including nodes and tags.
+  # Returns the way id, a Potlatch-style array of points, a hash of tags, the version number, and the user ID.
+
+  def getway(wayid) #:doc:
+    amf_handle_error_with_timeout("'getway' #{wayid}") do
+      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)
+        uid = sql_get_way_user(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
+        way = Way.find(:first, :conditions => { :id => wayid }, :include => { :nodes => :node_tags })
+
+        # check case where way has been deleted or doesn't exist
+        return [-4, 'way', wayid, [], {}, nil] if way.nil? or !way.visible
+
+        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
+        uid = way.changeset.user.id
+      end
+
+      [0, '', wayid, points, tags, version, uid]
+    end
+  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:
+    amf_handle_error_with_timeout("'getway_old' #{id}, #{timestamp}") do
+      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
+
+      if old_way.nil?
+        return [-1, "Sorry, the server could not find a way at that time.", id, [], {}, nil, false]
+      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.succ.strftime("%d %b %Y, %H:%M:%S")] + revusers[d.to_i] }
+      revdates.uniq!
+
+      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.
+
+  def getnode_history(nodeid) #:doc:
+    begin 
+      history = Node.find(nodeid).old_nodes.reverse.collect do |old_node|
+        [old_node.timestamp.succ.strftime("%d %b %Y, %H:%M:%S")] + change_user(old_node)
+      end
+      return ['node', nodeid, history]
+    rescue ActiveRecord::RecordNotFound
+      return ['node', nodeid, []]
+    end
+  end
+
+  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
+
+  # Find GPS traces with specified name/id.
+  # Returns array listing GPXs, each one comprising id, name and description.
+  
+  def findgpx(searchterm, usertoken)
+    amf_handle_error_with_timeout("'findgpx'") do
+      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
+
+  # Get a relation with all tags and members.
+  # Returns:
+  # 0. success code?
+  # 1. object type?
+  # 2. relation id,
+  # 3. hash of tags,
+  # 4. list of members,
+  # 5. version.
+  
+  def getrelation(relid) #:doc:
+    amf_handle_error("'getrelation' #{relid}") do
+      rel = Relation.find(:first, :conditions => { :id => relid })
+
+      return [-4, 'relation', relid, {}, [], nil] if rel.nil? or !rel.visible
+      [0, '', relid, rel.tags, rel.members, rel.version]
+    end
+  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 => ["v like ?", "%#{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
+
+  # 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:
+    amf_handle_error("'putrelation' #{relid}")  do
+      user = getuser(usertoken)
+      if !user then return -1,"You are not logged in, so the relation could not be saved." end
+      if !tags_ok(tags) then return -1,"One of the tags is invalid. Please pester Adobe to fix Flash on Linux." end
+      tags = strip_non_xml_chars tags
+
+      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
+
+        # 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
+   end
+  end
+
+  # 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. message,
+  # 2. original way id (unchanged),
+  # 3. new way id,
+  # 4. hash of renumbered nodes (old id=>new id),
+  # 5. way version,
+  # 6. hash of node versions (node=>version)
+
+  def putway(renumberednodes, usertoken, changeset_id, wayversion, originalway, pointlist, attributes, nodes, deletednodes) #:doc:
+    amf_handle_error("'putway' #{originalway}") do
+      # -- Initialise
        
-       def long2coord(a)
-               (a-$baselong)*$masterscale+350
-       end
+      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
+      if !tags_ok(tags) then return -1,"One of the tags is invalid. Please pester Adobe to fix Flash on Linux." end
+      tags = strip_non_xml_chars tags
+
+      originalway = originalway.to_i
+      pointlist.collect! {|a| a.to_i }
+
+      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
+
+        # -- 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
+        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
+
+        # -- 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 # transaction
+
+      [0, '', originalway, way.id, renumberednodes, way.version, 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. success message,
+  # 2. original node id (unchanged),
+  # 3. new node id,
+  # 4. version.
+
+  def putpoi(usertoken, changeset_id, version, id, lon, lat, tags, visible) #:doc:
+    amf_handle_error("'putpoi' #{id}") do
+      user = getuser(usertoken)
+      if !user then return -1,"You are not logged in, so the point could not be saved." end
+      if !tags_ok(tags) then return -1,"One of the tags is invalid. Please pester Adobe to fix Flash on Linux." end
+      tags = strip_non_xml_chars tags
+
+      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
+
+      if id <= 0
+        return [0, '', id, new_node.id, new_node.version]
+      else
+        return [0, '', id, node.id, node.version]
+      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.
+
+  def getpoi(id,timestamp) #:doc:
+    amf_handle_error("'getpoi' #{id}") do
+      id = id.to_i
+      n = Node.find(id)
+      v = n.version
+      unless timestamp == ''
+        n = OldNode.find(:first, :conditions => ['id = ? AND timestamp <= ?', id, timestamp], :order => 'timestamp DESC')
+      end
+
+      if n
+        return [0, '', n.id, n.lon, n.lat, n.tags, v]
+      else
+        return [-4, 'node', id, nil, nil, {}, nil]
+      end
+    end
+  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:
+    amf_handle_error("'deleteway' #{way_id}") do
+      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
+
+      end # transaction
+      [0, '', way_id, old_way.version, nodeversions]
+    end
+  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 getuser(token) #:doc:
+    if (token =~ /^(.+)\:(.+)$/) then
+      user = User.authenticate(:username => $1, :password => $2)
+    else
+      user = User.authenticate(:token => token)
+    end
+    return user
+  end
+
+  # 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
+
+  def getlocales
+    Dir.glob("#{RAILS_ROOT}/config/potlatch/localised/*").collect { |f| File.basename(f) }
+  end
+  
+  ##
+  # check that all key-value pairs are valid UTF-8.
+  def tags_ok(tags)
+    tags.each do |k, v|
+      return false unless UTF8.valid? k
+      return false unless UTF8.valid? v
+    end
+    return true
+  end
+
+  ##
+  # strip characters which are invalid in XML documents from the strings
+  # in the +tags+ hash.
+  def strip_non_xml_chars(tags)
+    new_tags = Hash.new
+    unless tags.nil?
+      tags.each do |k, v|
+        new_k = k.delete "\000-\037", "^\011\012\015"
+        new_v = v.delete "\000-\037", "^\011\012\015"
+        new_tags[new_k] = new_v
+      end
+    end
+    return new_tags
+  end
+
+  # ====================================================================
+  # Alternative SQL queries for getway/whichways
+
+  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 lat2y(a)
-               180/Math::PI * Math.log(Math.tan(Math::PI/4+a*(Math::PI/180)/2))
-       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
+    pois
+  end
        
-       def coord2lat(a)
-               y2lat((a-250)/-$masterscale+$basey)
-       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
+    ActiveRecord::Base.connection.select_all(sql).collect { |a| [a['relid'].to_i,a['version'].to_i] }
+  end
        
-       def coord2long(a)
-               (a-350)/$masterscale+$baselong
-       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 y2lat(a)
-               180/Math::PI * (2*Math.atan(Math.exp(a*Math::PI/180))-Math::PI/2)
-       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
 
+  def sql_get_way_version(wayid)
+    ActiveRecord::Base.connection.select_one("SELECT version FROM current_ways WHERE id=#{wayid.to_i}")['version']
+  end
 
+  def sql_get_way_user(wayid)
+    ActiveRecord::Base.connection.select_one("SELECT user FROM current_ways,changesets WHERE current_ways.id=#{wayid.to_i} AND current_ways.changeset=changesets.id")['user']
+  end
 end
+