]> git.openstreetmap.org Git - rails.git/blobdiff - app/controllers/amf_controller.rb
more madness
[rails.git] / app / controllers / amf_controller.rb
index bffff484e23a7d7223bf897c4f86097906683b9a..4afba1484fd58fd9f39ff6dca1b7f6b3d7bf4afe 100644 (file)
@@ -1,65 +1,74 @@
+# 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).
+#
+# See Also Potlatch::Potlatch and Potlatch::AMF
+#
+# Public domain.
+# editions Systeme D / Richard Fairhurst 2004-2008
+#
+# All in/out parameters are floats unless explicitly stated.
+# 
+# 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]}")
 class AmfController < ApplicationController
   require 'stringio'
 
+  include Potlatch
+
   session :off
   before_filter :check_write_availability
 
-  # AMF controller for 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).
-  #
-  # Public domain. Set your tab width to 4 to read this document. :)
-  # editions Systeme D / Richard Fairhurst 2004-2007
-  
-  # 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]}")
-
-  # ====================================================================
-  # Main AMF handler
-
-  # ---- talk  process AMF request
-
+  # 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)
+    # (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
+    renumberedways={}                                                  # Shared across repeated putways
 
     # -------------
     # Parse request
 
-    headers=getint(req)                                        # Read number of headers
+    headers=AMF.getint(req)                                    # Read number of headers
 
     headers.times do                               # Read each header
-      name=getstring(req)                              #  |
+      name=AMF.getstring(req)                          #  |
       req.getc                                         #  | skip boolean
-      value=getvalue(req)                              #  |
+      value=AMF.getvalue(req)                          #  |
       header["name"]=value                             #  |
     end
 
-    bodies=getint(req)                                 # Read number of bodies
+    bodies=AMF.getint(req)                                     # Read number of bodies
     bodies.times do                                    # Read each body
-      message=getstring(req)                   #  | get message name
-      index=getstring(req)                             #  | get index in response sequence
-      bytes=getlong(req)                               #  | get total size in bytes
-      args=getvalue(req)                               #  | get response (probably an array)
+      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]=putdata(index,getpresets)
-                 when 'whichways';                     results[index]=putdata(index,whichways(args))
-                 when 'whichways_deleted';     results[index]=putdata(index,whichways_deleted(args))
-                 when 'getway';                        results[index]=putdata(index,getway(args))
-                 when 'getway_old';            results[index]=putdata(index,getway_old(args))
-                 when 'getway_history';        results[index]=putdata(index,getway_history(args))
-                 when 'putway';                        results[index]=putdata(index,putway(args))
-                 when 'deleteway';                     results[index]=putdata(index,deleteway(args))
-                 when 'putpoi';                        results[index]=putdata(index,putpoi(args))
-                 when 'getpoi';                        results[index]=putdata(index,getpoi(args))
+      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 'getrelation';              results[index]=AMF.putdata(index,getrelation(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]
+                                                               if r[1] != r[2]
+                                                                       renumberedways[r[1]] = r[2]
+                                                               end
+                                                               results[index]=AMF.putdata(index,r)
+      when 'putrelation';              results[index]=AMF.putdata(index,putrelation(args, renumberednodes, renumberedways))
+      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))
       end
     end
 
@@ -68,165 +77,33 @@ class AmfController < ApplicationController
 
     RAILS_DEFAULT_LOGGER.info("  Response: start")
     a,b=results.length.divmod(256)
-       render :content_type => "application/x-amf", :text => proc { |response, output| 
-        output.write 0.chr+0.chr+0.chr+0.chr+a.chr+b.chr
-               results.each do |k,v|
-                 output.write(v)
-               end
-       }
+    render :content_type => "application/x-amf", :text => proc { |response, output| 
+      output.write 0.chr+0.chr+0.chr+0.chr+a.chr+b.chr
+      results.each do |k,v|
+        output.write(v)
+      end
+    }
     RAILS_DEFAULT_LOGGER.info("  Response: end")
-
   end
 
   private
 
-  # ====================================================================
-  # Remote calls
-
-  # ----- getpresets
-  #          return presets,presetmenus and presetnames arrays
-
-  def getpresets
-    presets={}
-    presetmenus={}; presetmenus['point']=[]; presetmenus['way']=[]; presetmenus['POI']=[]
-    presetnames={}; presetnames['point']={}; presetnames['way']={}; presetnames['POI']={}
-    presettype=''
-    presetcategory=''
-
-    RAILS_DEFAULT_LOGGER.info("  Message: getpresets")
-
-    #          File.open("config/potlatch/presets.txt") do |file|
-
-    # Temporary patch to get around filepath problem
-    # To remove this patch and make the code nice again:
-    # 1. uncomment above line
-    # 2. fix the path in the above line
-    # 3. delete this here document, and the following line (StringIO....)
-
-    txt=<<-EOF
-way/road
-motorway: highway=motorway,ref=(type road number)
-trunk road: highway=trunk,ref=(type road number),name=(type road name)
-primary road: highway=primary,ref=(type road number),name=(type road name)
-secondary road: highway=secondary,ref=(type road number),name=(type road name)
-tertiary road: highway=tertiary,ref=,name=(type road name)
-residential road: highway=residential,ref=,name=(type road name)
-unclassified road: highway=unclassified,ref=,name=(type road name)
-
-way/footway
-footpath: highway=footway,foot=yes
-bridleway: highway=bridleway,foot=yes
-byway: highway=unsurfaced,foot=yes
-permissive path: highway=footway,foot=permissive
-
-way/cycleway
-cycle lane: highway=cycleway,cycleway=lane,ncn_ref=
-cycle track: highway=cycleway,cycleway=track,ncn_ref=
-cycle lane (NCN): highway=cycleway,cycleway=lane,name=(type name here),ncn_ref=(type route number)
-cycle track (NCN): highway=cycleway,cycleway=track,name=(type name here),ncn_ref=(type route number)
-
-way/waterway
-canal: waterway=canal,name=(type name here)
-navigable river: waterway=river,boat=yes,name=(type name here)
-navigable drain: waterway=drain,boat=yes,name=(type name here)
-derelict canal: waterway=derelict_canal,name=(type name here)
-unnavigable river: waterway=river,boat=no,name=(type name here)
-unnavigable drain: waterway=drain,boat=no,name=(type name here)
-
-way/railway
-railway: railway=rail
-tramway: railway=tram
-light railway: railway=light_rail
-preserved railway: railway=preserved
-disused railway tracks: railway=disused
-course of old railway: railway=abandoned
-
-way/natural
-lake: natural=water,landuse=
-forest: landuse=forest,natural=
-
-point/road
-mini roundabout: highway=mini_roundabout
-traffic lights: highway=traffic_signals
-
-point/footway
-bridge: highway=bridge
-gate: highway=gate
-stile: highway=stile
-cattle grid: highway=cattle_grid
-
-point/cycleway
-gate: highway=gate
-
-point/waterway
-lock gate: waterway=lock_gate
-weir: waterway=weir
-aqueduct: waterway=aqueduct
-winding hole: waterway=turning_point
-mooring: waterway=mooring
-
-point/railway
-station: railway=station
-viaduct: railway=viaduct
-level crossing: railway=crossing
-
-point/natural
-peak: natural=peak
-
-POI/road
-car park: amenity=parking
-petrol station: amenity=fuel
-
-POI/cycleway
-bike park: amenity=bicycle_parking
-
-POI/place
-city: place=city,name=(type name here),is_in=(type region or county)
-town: place=town,name=(type name here),is_in=(type region or county)
-suburb: place=suburb,name=(type name here),is_in=(type region or county)
-village: place=village,name=(type name here),is_in=(type region or county)
-hamlet: place=hamlet,name=(type name here),is_in=(type region or county)
-
-POI/tourism
-attraction: tourism=attraction,amenity=,religion=,denomination=
-church: tourism=,amenity=place_of_worship,name=(type name here),religion=christian,denomination=(type denomination here)
-hotel: tourism=hotel,amenity=,religion=,denomination=
-other religious: tourism=,amenity=place_of_worship,name=(type name here),religion=(type religion),denomination=
-post box: amenity=post_box,tourism=,name=,religion=,denomination=
-post office: amenity=post_office,tourism=,name=,religion=,denomination=
-pub: tourism=,amenity=pub,name=(type name here),religion=,denomination=
-
-POI/natural
-peak: point=peak
-EOF
-
-    StringIO.open(txt) do |file|
-      file.each_line {|line|
-        t=line.chomp
-        if (t=~/(\w+)\/(\w+)/) then
-          presettype=$1
-          presetcategory=$2
-          presetmenus[presettype].push(presetcategory)
-          presetnames[presettype][presetcategory]=["(no preset)"]
-        elsif (t=~/^(.+):\s?(.+)$/) then
-          pre=$1; kv=$2
-          presetnames[presettype][presetcategory].push(pre)
-          presets[pre]={}
-          kv.split(',').each {|a|
-            if (a=~/^(.+)=(.*)$/) then presets[pre][$1]=$2 end
-          }
-        end
-      }
-    end
-    [presets,presetmenus,presetnames]
+  # Return presets (default tags and crap) to potlatch.
+  # Uses POTLATCH_PRESETS global, set up in OSM::Potlatch
+  def getpresets #:doc:
+    return POTLATCH_PRESETS
   end
 
-  # ----- whichways(left,bottom,right,top)
-  #              return array of ways in current bounding box
-  #              at present, instead of using correct (=more complex) SQL to find
-  #              corner-crossing ways, it simply enlarges the bounding box by +/- 0.01
-
-  def whichways(args)
+  # ----- 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
@@ -237,32 +114,26 @@ EOF
 
     RAILS_DEFAULT_LOGGER.info("  Message: whichways, bbox=#{xmin},#{ymin},#{xmax},#{ymax}")
 
-    waylist = ActiveRecord::Base.connection.select_all("SELECT DISTINCT current_way_nodes.id AS wayid"+
-       "  FROM current_way_nodes,current_nodes,current_ways "+
-       " WHERE current_nodes.id=current_way_nodes.node_id "+
-       "   AND current_nodes.visible=1 "+
-       "   AND current_ways.id=current_way_nodes.id "+
-       "   AND current_ways.visible=1 "+
-       "   AND "+OSM.sql_for_area(ymin, xmin, ymax, xmax, "current_nodes."))
+    # 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
 
-    ways = waylist.collect {|a| a['wayid'].to_i } # get an array of way IDs
+    # 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] }
 
-    pointlist = ActiveRecord::Base.connection.select_all("SELECT current_nodes.id,current_nodes.latitude*0.0000001 AS lat,current_nodes.longitude*0.0000001 AS lng,current_nodes.tags "+
-       "  FROM current_nodes "+
-       "  LEFT OUTER JOIN current_way_nodes cwn ON cwn.node_id=current_nodes.id "+
-       " WHERE "+OSM.sql_for_area(ymin, xmin, ymax, xmax, "current_nodes.")+
-       "   AND cwn.id IS NULL "+
-       "   AND current_nodes.visible=1")
+    # find the relations used by those nodes and ways
+    relation_ids = (Relation.find_for_nodes_and_ways(nodes_in_area.collect {|n| n.id}, way_ids)).collect {|n| n.id}.uniq
 
-    points = pointlist.collect {|a| [a['id'],long2coord(a['lng'].to_f,baselong,masterscale),lat2coord(a['lat'].to_f,basey,masterscale),tag2array(a['tags'])]   } # get a list of node ids and their tags
-
-    [ways,points]
+    [way_ids,points,relation_ids]
   end
 
-  # ----- whichways_deleted(left,bottom,right,top)
+  # ----- whichways_deleted
   #              return array of deleted ways in current bounding box
-  
-  def whichways_deleted(args)
+  #              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
@@ -271,111 +142,226 @@ EOF
     basey       = args[5]
     masterscale = args[6]
 
-       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
+    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]
+    [ways]
   end
-  
-  # ----- getway (objectname, way, baselong, basey, masterscale)
-  #              returns objectname, array of co-ordinates, attributes,
-  #                              xmin,xmax,ymin,ymax
 
-  def getway(args)
-    objname,wayid,baselong,basey,masterscale=args
+  # ----- 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
-    points = []
-    xmin = ymin =  999999
-    xmax = ymax = -999999
 
     RAILS_DEFAULT_LOGGER.info("  Message: getway, id=#{wayid}")
 
-    readwayquery(wayid).each {|row|
-      points<<[long2coord(row['longitude'].to_f,baselong,masterscale),lat2coord(row['latitude'].to_f,basey,masterscale),row['id'].to_i,nil,tag2array(row['tags'])]
-      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
-    }
+    # 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)
 
-    attributes={}
-    attrlist=ActiveRecord::Base.connection.select_all "SELECT k,v FROM current_way_tags WHERE id=#{wayid}"
-    attrlist.each {|a| attributes[a['k'].gsub(':','|')]=a['v'] }
+    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
 
-    [objname,points,attributes,xmin,xmax,ymin,ymax]
+      points << [projected_longitude, projected_latitude, id, nil, tags_hash]
+      long_array << projected_longitude
+      lat_array << projected_latitude
+    end
+
+    [wayid,points,way.tags,long_array.min,long_array.max,lat_array.min,lat_array.max]
   end
-  
-  # -----      getway_old (objectname, way, version, baselong, basey, masterscale)
-  #                    returns old version of way
 
-  def getway_old(args)
+  # ----- 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
-       
-    objname,wayid,version,baselong,basey,masterscale=args
+    #  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)
-       else
-         historic=true
-       end
-       readwayquery_old(wayid,version,historic).each { |row|
+    points=[]
+    if version<0
+      historic=false
+      version=getlastversion(wayid,version)
+    else
+      historic=true
+    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
+    # 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
+    attributes['history']="Retrieved from v"+version.to_s
+
+    [0,wayid,points,attributes,xmin,xmax,ymin,ymax,version]
+  end
 
-    [0,objname,points,attributes,xmin,xmax,ymin,ymax,version]
+  # ----- 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]
   end
 
-  # -----      getway_history (way)
-  #                    returns array of previous versions (version,timestamp,visible,user)
-  #                    should also show 'created_by'
-
-  def getway_history(wayid)
-       history=[]
-       sql=<<-EOF
-       SELECT version,timestamp,visible,display_name,data_public
-         FROM ways,users
-        WHERE ways.id=#{wayid}
-          AND ways.user_id=users.id
-        ORDER BY version DESC
-       EOF
-       histlist=ActiveRecord::Base.connection.select_all(sql)
-       histlist.each { |row|
-               if row['data_public'] then user=row['display_name'] else user='anonymous' end
-               history<<[row['version'],row['timestamp'],row['visible'],user]
-       }
-       [history]
+  # ----- getrelation
+  # Get a relation with all of it's tags, and member IDs
+  # The input is an array with the following components, in order:
+  # 0. relid - the ID of the relation to get
+  #
+  # The output is an array which contains:
+  # [0] relation id, [1] hash of tags, [2] list of members
+  def getrelation(args) #:doc:
+    relid = args[0]
+    relid = relid.to_i
+
+    RAILS_DEFAULT_LOGGER.info("  Message: getrel, id=#{relid}")
+
+    rel = Relation.find(relid)
+
+    [relid,rel.tags,rel.members]#nodes,ways]
   end
 
-  # -----      putway (user token, way, array of co-ordinates, array of attributes,
-  #                                    baselong, basey, masterscale)
-  #                    returns current way ID, new way ID, hash of renumbered nodes,
-  #                                    xmin,xmax,ymin,ymax
+  # ----- getrelation
+  #              save relation to the database
+  #              in:   [0] user token (string),
+  #                            [1] original relation id (may be negative),
+  #                            [2] hash of tags, [3] list of members,
+  #                            [4] visible
+  #              out:  [0] 0 (success), [1] original relation id (unchanged),
+  #                            [2] new relation id
+  def putrelation(args, renumberednodes, renumberedways) #:doc:
+    usertoken,relid,tags,members,visible=args
+    uid=getuserid(usertoken)
+    if !uid then return -1,"You are not logged in, so the point could not be saved." end
+
+    relid = relid.to_i
+       visible = visible.to_i
+
+       # create a new relation, or find the existing one
+    if relid <= 0
+      rel = Relation.new
+    else
+      rel = Relation.find(relid)
+    end
+
+    # 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'
+        if mid < 0
+          return -2, "Negative ID unresolved"
+        end
+      end
+      typedmembers << [m[0], mid, m[2]]
+    end
+
+       # assign new contents
+       rel.members = typedmembers
+       rel.tags = tags
+       rel.visible = visible
+       rel.user_id = uid
 
-  def putway(args)
+    # check it then save it
+    # BUG: the following is commented out because it always fails on my
+    #  install. I think it's a Rails bug.
+
+    #if !rel.preconditions_ok?
+    #  return -2, "Relation preconditions failed"
+    #else
+      rel.save_with_history!
+    #end
+
+    [0,relid,rel.id]
+  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)
@@ -386,40 +372,34 @@ EOF
     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
-       
+    oldversion=oldversion.to_i
+
     RAILS_DEFAULT_LOGGER.info("  Message: putway, id=#{originalway}")
 
-       # -- Temporary check for null IDs
-       
-       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
+    # -- 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
-           readwayquery(way).each { |row|
-                 id=row['id'].to_i
-                 xc[id]=row['longitude'].to_f
-                 yc[id]=row['latitude' ].to_f
-                 tagc[id]=row['tags']
-                 vc[id]=1
-               }
-         else
-           readwayquery_old(way,oldversion,true).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
-               }
-         end
+      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)")
@@ -434,8 +414,7 @@ EOF
     xmin=ymin= 999999
     xmax=ymax=-999999
     insertsql=''
-    renumberednodes={}
-       nodelist=[]
+    nodelist=[]
 
     points.each_index do |i|
       xs=coord2long(points[i][0],masterscale,baselong)
@@ -443,7 +422,7 @@ EOF
       xmin=[xs,xmin].min; xmax=[xs,xmax].max
       ymin=[ys,ymin].min; ymax=[ys,ymax].max
       node=points[i][2].to_i
-         tagstr=array2tag(points[i][4])
+      tagstr=array2tag(points[i][4])
       tagsql="'"+sqlescape(tagstr)+"'"
       lat=(ys * 10000000).round
       long=(xs * 10000000).round
@@ -452,20 +431,20 @@ EOF
       # compare node
       if node<0
         # new node - create
-               if renumberednodes[node.to_s].nil?
+        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})")
+          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
+        else
           points[i][2]=renumberednodes[node.to_s].to_i
-               end
+        end
 
       elsif xc.has_key?(node)
-               nodelist.push(node)
+        nodelist.push(node)
         # old node from original way - update
-        if (xs!=xc[node] or (ys/0.0000001).round!=(yc[node]/0.0000001).round or tagstr!=tagc[node] or vc[node]==0)
+        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
@@ -474,16 +453,15 @@ EOF
       end
     end
 
-
-       # -- 6a. delete any nodes not in modified way
+    # -- 6a. delete any nodes not in modified way
 
     createuniquenodes(way,db_uqn,nodelist)     # nodes which appear in this way but no other
 
     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
+  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)
 
@@ -494,10 +472,10 @@ EOF
     EOF
     ActiveRecord::Base.connection.update(sql)
 
-       deleteuniquenoderelations(db_uqn,uid,db_now)
-    ActiveRecord::Base.connection.execute("DROP TABLE #{db_uqn}")
+    deleteuniquenoderelations(db_uqn,uid,db_now)
+    ActiveRecord::Base.connection.execute("DROP TEMPORARY TABLE #{db_uqn}")
 
-       #       6b. insert new version of route into way_nodes
+    #  6b. insert new version of route into way_nodes
 
     insertsql =''
     currentsql=''
@@ -534,12 +512,18 @@ EOF
     [0,originalway,way,renumberednodes,xmin,xmax,ymin,ymax]
   end
 
-  # -----      putpoi (user token, id, x,y,tag array,visible,baselong,basey,masterscale)
-  #                    returns current id, new id
-  #                    if new: add new row to current_nodes and nodes
-  #                    if old: add new row to nodes, update current_nodes
-
-  def putpoi(args)
+  # ----- 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
@@ -549,12 +533,12 @@ EOF
 
     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)
-       end
+    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)
+    end
 
     x=coord2long(x.to_f,masterscale,baselong)
     y=coord2lat(y.to_f,masterscale,basey)
@@ -562,420 +546,278 @@ EOF
     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
+      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
     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})");
+      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})");
     end
     [0,id,newid]
   end
 
-  # -----      getpoi (id,baselong,basey,masterscale)
-  #                    returns id,x,y,tag array
-  
-  def getpoi(args)
-       id,baselong,basey,masterscale=args; id=id.to_i
-       poi=ActiveRecord::Base.connection.select_one("SELECT latitude*0.0000001 AS lat,longitude*0.0000001 AS lng,tags "+
-               "FROM current_nodes WHERE visible=1 AND id=#{id}")
-       if poi.nil? then return [nil,nil,nil,''] end
-       [id,
-        long2coord(poi['lng'].to_f,baselong,masterscale),
-        lat2coord(poi['lat'].to_f,basey,masterscale),
-        tag2array(poi['tags'])]
+  # ----- 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.lon_potlatch(baselong,masterscale), n.lat_potlatch(basey,masterscale), n.tags_as_hash]
+    else
+      return [nil,nil,nil,'']
+    end
   end
 
-  # -----      deleteway (user token, way, nodes to keep)
-  #                    returns way ID only
-
-  def deleteway(args)
-    usertoken,way=args
+  # ----- 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)
 
-    RAILS_DEFAULT_LOGGER.info("  Message: deleteway, id=#{way}")
+  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
 
-    way=way.to_i
-    db_uqn='unin'+(rand*100).to_i.to_s+uid.to_s+way.to_i.abs.to_s+Time.new.to_i.to_s   # temp uniquenodes table name, typically 51 chars
-    db_now='@now'+(rand*100).to_i.to_s+uid.to_s+way.to_i.abs.to_s+Time.new.to_i.to_s   # 'now' variable name, typically 51 chars
+       # FIXME
+       # the next bit removes the way from any relations
+       # the delete_with_relations_and_nodes_and_history method should do this,
+       #   but at present it just throws a 'precondition failed'
+    way=way.to_i 
+    db_now='@now'+(rand*100).to_i.to_s+uid.to_s+id.to_i.abs.to_s+Time.new.to_i.to_s
+       db_uqn='unin'+(rand*100).to_i.to_s+uid.to_s+way.to_i.abs.to_s+Time.new.to_i.to_s
     ActiveRecord::Base.connection.execute("SET #{db_now}=NOW()")
+       createuniquenodes(way,db_uqn,[])
+       deleteuniquenoderelations(db_uqn,uid,db_now)
+    deleteitemrelations(way_id,'way',uid,db_now)
+    ActiveRecord::Base.connection.execute("DROP TEMPORARY TABLE #{db_uqn}")
+       # end of FIXME
+
+       # now delete the way
+    user = User.find(uid)
+    way = Way.find(way_id)
+    way.delete_with_relations_and_nodes_and_history(user)  
+    return [0,way_id]
+  end
 
-    # - delete any otherwise unused nodes
-  
-    createuniquenodes(way,db_uqn,[])
-
-#      unless (preserve.empty?) then
-#              ActiveRecord::Base.connection.execute("DELETE FROM #{db_uqn} WHERE node_id IN ("+preserve.join(',')+")")
-#      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)
 
+  def readwayquery(id,insistonvisible) #:doc:
     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 TABLE #{db_uqn}")
-
-    # - delete way
-       
-    ActiveRecord::Base.connection.insert("INSERT INTO ways (id,user_id,timestamp,visible) VALUES (#{way},#{uid},#{db_now},0)")
-    ActiveRecord::Base.connection.update("UPDATE current_ways SET user_id=#{uid},timestamp=#{db_now},visible=0 WHERE id=#{way}")
-    ActiveRecord::Base.connection.execute("DELETE FROM current_way_nodes WHERE id=#{way}")
-    ActiveRecord::Base.connection.execute("DELETE FROM current_way_tags WHERE id=#{way}")
-       deleteitemrelations(way,'way',uid,db_now)
-    [0,way]
-end
+    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)
+  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
+  end
 
+  def readwayquery_old(id,version,historic) #:doc:
+    # Node handling on undelete (historic=false):
+    # - always use the node specified, even if it's moved
 
-# ====================================================================
-# Support functions for remote calls
+    # 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
 
-def readwayquery(id)
-  ActiveRecord::Base.connection.select_all "SELECT latitude*0.0000001 AS latitude,longitude*0.0000001 AS longitude,current_nodes.id,tags "+
-      "    FROM current_way_nodes,current_nodes "+
-      "   WHERE current_way_nodes.id=#{id} "+
-      "     AND current_way_nodes.node_id=current_nodes.id "+
-      "     AND current_nodes.visible=1 "+
-      "   ORDER BY sequence_id"
-end
+    # get node list from specified version of way,
+    # and the _current_ lat/long/tags of each node
 
-def getlastversion(id,version)
-  row=ActiveRecord::Base.connection.select_one("SELECT version FROM ways WHERE id=#{id} AND visible=1 ORDER BY version DESC LIMIT 1")
-  row['version']
-end
+    row=ActiveRecord::Base.connection.select_one("SELECT timestamp FROM ways WHERE version=#{version} AND id=#{id}")
+    waytime=row['timestamp']
 
-def readwayquery_old(id,version,historic)
-  # Node handling on undelete (historic=false):
-  # - always use the node specified, even if it's moved
-  
-  # 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
-
-  # get node list from specified version of way,
-  # and the _current_ lat/long/tags of each node
-
-  row=ActiveRecord::Base.connection.select_one("SELECT timestamp FROM ways WHERE version=#{version} AND id=#{id}")
-  waytime=row['timestamp']
-
-  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
+    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,
-  # and use this (though with a new id) if it differs from the current one
-  if historic then
-       rows.each_index do |i|
-         sql=<<-EOF
-         SELECT latitude*0.0000001 AS latitude,longitude*0.0000001 AS longitude,tags 
-           FROM nodes 
-          WHERE id=#{rows[i]['id']} 
-            AND timestamp<="#{waytime}" 
-          ORDER BY 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 (nx!=rows[i]['longitude'].to_f or ny!=rows[i]['latitude'].to_f or row['tags']!=rows[i]['tags']) then
-                 rows[i]['id']=-1
-                 # This generates a new node id if x/y/tags differ from current node.
-                 # Strictly speaking, it need only do this for uniquenodes, but we're
-                 # not generating uniquenodes for historic ways (yet!).
-           end
-               rows[i]['longitude']=nx
-               rows[i]['latitude' ]=ny
-               rows[i]['tags'     ]=row['tags']
-         end
+    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']
+        end
+      end
     end
+    rows
   end
-  rows
-end
-
-def createuniquenodes(way,uqn_name,nodelist)
-       # 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
 
+  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
 
 
-# ====================================================================
-# Relations handling
-# deleteuniquenoderelations(uqn_name,uid,db_now)
-# deleteitemrelations(way|node,'way'|'node',uid,db_now)
-
-def deleteuniquenoderelations(uqn_name,uid,db_now)
-       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)
-       end
-end
-
-def deleteitemrelations(objid,type,uid,db_now)
-       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)
-       end
-end
-
-def removefromrelation(objid,type,relation,uid,db_now)
-       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
 
+  # ====================================================================
+  # Relations handling
+  # deleteuniquenoderelations(uqn_name,uid,db_now)
+  # deleteitemrelations(way|node,'way'|'node',uid,db_now)
 
-def sqlescape(a)
-  a.gsub(/[\000-\037]/,"").gsub("'","''").gsub(92.chr,92.chr+92.chr)
-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
 
-def tag2array(a)
-  tags={}
-  a.gsub(';;;','#%').split(';').each do |b|
-    b.gsub!('#%',';;;')
-    b.gsub!('===','#%')
-    k,v=b.split('=')
-    if k.nil? then k='' end
-    if v.nil? then v='' end
-    tags[k.gsub('#%','=').gsub(':','|')]=v.gsub('#%','=')
+    relnodes=ActiveRecord::Base.connection.select_all(sql)
+    relnodes.each do |a|
+      removefromrelation(a['node_id'],'node',a['id'],uid,db_now)
+    end
   end
-  tags
-end
 
-def array2tag(a)
-  str=''
-  a.each do |k,v|
-    if v=='' then next end
-    if v[0,6]=='(type ' then next end
-    if str!='' then str+=';' end
-    str+=k.gsub(';',';;;').gsub('=','===').gsub('|',':')+'='+v.gsub(';',';;;').gsub('=','===')
-  end
-  str
-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
 
-def getuserid(token)
-  if (token =~ /^(.+)\+(.+)$/) then
-    user = User.authenticate(:username => $1, :password => $2)
-  else
-    user = User.authenticate(:token => token)
+    relways=ActiveRecord::Base.connection.select_all(sql)
+    relways.each do |a|
+      removefromrelation(objid,type,a['id'],uid,db_now)
+    end
   end
 
-  return user ? user.id : nil;
-end
-
-
-
-# ====================================================================
-# AMF read subroutines
+  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)")
 
-# -----        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
+    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)
 
-def getdouble(s)
-  a=s.read(8).unpack('G')                      # G big-endian, E little-endian
-  a[0]
-end
+    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)
 
-def getarray(s)
-  len=getlong(s)
-  arr=[]
-  for i in (0..len-1)
-    arr[i]=getvalue(s)
+    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
-  arr
-end
 
-def getobject(s)
-  arr={}
-  while (key=getstring(s))
-    if (key=='') then break end
-    arr[key]=getvalue(s)
+  def sqlescape(a) #:doc:
+    a.gsub(/[\000-\037]/,"").gsub("'","''").gsub(92.chr) {92.chr+92.chr}
   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
+  def tag2array(a) #:doc:
+    tags={}
+    Tags.split(a) do |k, v|
+      tags[k.gsub(':','|')]=v
+    end
+    tags
   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)
+  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
-    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)
+    return Tags.join(tags)
   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 getuserid(token) #:doc:
+    if (token =~ /^(.+)\+(.+)$/) then
+      user = User.authenticate(:username => $1, :password => $2)
+    else
+      user = User.authenticate(:token => token)
+    end
 
-def encodelong(n)
-  [n].pack('N')
-end
+    return user ? user.id : nil;
+  end
 
-# ====================================================================
-# Co-ordinate conversion
+  # ====================================================================
+  # Co-ordinate conversion
 
-def lat2coord(a,basey,masterscale)
-  -(lat2y(a)-basey)*masterscale+250
-end
+  def lat2coord(a,basey,masterscale) #:doc:
+    -(lat2y(a)-basey)*masterscale
+  end
 
-def long2coord(a,baselong,masterscale)
-  (a-baselong)*masterscale+350
-end
+  def long2coord(a,baselong,masterscale) #:doc:
+    (a-baselong)*masterscale
+  end
 
-def lat2y(a)
-  180/Math::PI * Math.log(Math.tan(Math::PI/4+a*(Math::PI/180)/2))
-end
+  def lat2y(a) #:doc:
+    180/Math::PI * Math.log(Math.tan(Math::PI/4+a*(Math::PI/180)/2))
+  end
 
-def coord2lat(a,masterscale,basey)
-  y2lat((a-250)/-masterscale+basey)
-end
+  def coord2lat(a,masterscale,basey) #:doc:
+    y2lat(a/-masterscale+basey)
+  end
 
-def coord2long(a,masterscale,baselong)
-  (a-350)/masterscale+baselong
-end
+  def coord2long(a,masterscale,baselong) #:doc:
+    a/masterscale+baselong
+  end
 
-def y2lat(a)
-  180/Math::PI * (2*Math.atan(Math.exp(a*Math::PI/180))-Math::PI/2)
-end
+  def y2lat(a)
+    180/Math::PI * (2*Math.atan(Math.exp(a*Math::PI/180))-Math::PI/2)
+  end
 
 end