X-Git-Url: https://git.openstreetmap.org./rails.git/blobdiff_plain/ecefee485b8dc033d020bd6b67d9ae4559ec796a..231bdf66cdc8239c37e1536be4fb52ce275219e3:/app/controllers/amf_controller.rb

diff --git a/app/controllers/amf_controller.rb b/app/controllers/amf_controller.rb
index 43bec41a1..331487a93 100644
--- a/app/controllers/amf_controller.rb
+++ b/app/controllers/amf_controller.rb
@@ -3,7 +3,7 @@
 # OSM database takes place using this controller. Messages are 
 # encoded in the Actionscript Message Format (AMF).
 #
-# Helper functions are in /lib/potlatch.
+# Helper functions are in /lib/potlatch.rb
 #
 # Author::	editions Systeme D / Richard Fairhurst 2004-2008
 # Licence::	public domain.
@@ -27,7 +27,10 @@
 #	return(-1,"message")		<-- just puts up a dialogue
 #	return(-2,"message")		<-- also asks the user to e-mail me
 # 
-# To write to the Rails log, use RAILS_DEFAULT_LOGGER.info("message").
+# 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'
@@ -67,7 +70,7 @@ class AmfController < ApplicationController
       index=AMF.getstring(req)				#  | get index in response sequence
       bytes=AMF.getlong(req)				#  | get total size in bytes
       args=AMF.getvalue(req)				#  | get response (probably an array)
-      logger.info "Executing AMF #{message}:#{index}"
+      logger.info("Executing AMF #{message}:#{index}")
 
       case message
         when 'getpresets';			results[index]=AMF.putdata(index,getpresets())
@@ -75,7 +78,7 @@ class AmfController < ApplicationController
         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].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))
@@ -109,6 +112,7 @@ class AmfController < ApplicationController
       bytes=AMF.getlong(req)				#  | get total size in bytes
       args=AMF.getvalue(req)				#  | get response (probably an array)
 
+      logger.info("Executing AMF #{message}:#{index}")
       case message
         when 'putway';				r=putway(renumberednodes,*args)
 									renumberednodes=r[3]
@@ -122,6 +126,7 @@ class AmfController < ApplicationController
         when 'startchangeset';		results[index]=AMF.putdata(index,startchangeset(*args))
       end
     end
+    logger.info("encoding AMF results")
     sendresponse(results)
   end
 
@@ -130,14 +135,16 @@ class AmfController < ApplicationController
   # Start new changeset
   
   def startchangeset(usertoken, cstags, closeid, closecomment)
-    uid = getuserid(usertoken)
-    if !uid then return -1,"You are not logged in, so Potlatch can't write any changes to the database." end
+    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 closecomment.empty?
+      if cs.user_id!=user.id
+        return -2,"You cannot close that changeset because you're not the person who opened it."
+      elsif closecomment.empty?
         cs.save!
       else
         cs.tags['comment']=closecomment
@@ -148,10 +155,10 @@ class AmfController < ApplicationController
     # open a new changeset
     cs = Changeset.new
     cs.tags = cstags
-    cs.user_id = uid
-    # Don't like the next two lines. These need to be abstracted to the model more/better
+    cs.user_id = user.id
+    # smsm1 doesn't like the next two lines and thinks they need to be abstracted to the model more/better
     cs.created_at = Time.now
-    cs.closed_at = Time.new + Changeset::IDLE_TIMEOUT
+    cs.closed_at = cs.created_at + Changeset::IDLE_TIMEOUT
     cs.save_with_tags!
     return [0,cs.id]
   end
@@ -163,21 +170,28 @@ class AmfController < ApplicationController
     return POTLATCH_PRESETS
   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: 
+  # [error_code, 
+  #  [[way_id, way_version], ...],
+  #  [[node_id, lat, lon, [tags, ...], node_version], ...],
+  #  [[rel_id, rel_version], ...]]
+  # where the ways are any visible ways which refer to any visible
+  # nodes in the bbox, nodes are any visible nodes in the bbox but not
+  # used in any way, rel is any relation which refers to either a way
+  # or node that we're returning.
   def whichways(xmin, ymin, xmax, ymax) #:doc:
-    xmin -= 0.01; ymin -= 0.01
-    xmax += 0.01; ymax += 0.01
+    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
-    begin
-      check_boundaries(xmin, ymin, xmax, ymax)
-    rescue Exception => err
-      return [-2,"Sorry - I can't get the map for that area."]
-    end
+    check_boundaries(xmin, ymin, xmax, ymax)
 
     if POTLATCH_USE_SQL then
       ways = sql_find_ways_in_area(xmin, ymin, xmax, ymax)
@@ -186,14 +200,15 @@ class AmfController < ApplicationController
     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.collect { |node| 
-        node.ways.collect { |w| [w.id,w.version] }.flatten
+      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] }
+      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}) +
@@ -201,15 +216,19 @@ class AmfController < ApplicationController
       relations = relations.collect { |relation| [relation.id,relation.version] }.uniq
     end
 
-    [0,ways, points, relations]
+    [0, ways, points, relations]
+
+  rescue Exception => err
+    [-2,"Sorry - I can't get the map for that area."]
   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:
-    xmin -= 0.01; ymin -= 0.01
-    xmax += 0.01; ymax += 0.01
+    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
@@ -230,9 +249,9 @@ class AmfController < ApplicationController
 
   def getway(wayid) #:doc:
     if POTLATCH_USE_SQL then
-      points = sql_get_nodes_in_way(wayid)
-      tags = sql_get_tags_in_way(wayid)
-      version = sql_get_way_version(wayid)
+        points = sql_get_nodes_in_way(wayid)
+        tags = sql_get_tags_in_way(wayid)
+        version = sql_get_way_version(wayid)
       else
         # Ideally we would do ":include => :nodes" here but if we do that
         # then rails only seems to return the first copy of a node when a
@@ -249,7 +268,7 @@ class AmfController < ApplicationController
         points = way.nodes.collect do |node|
         nodetags=node.tags
         nodetags.delete('created_by')
-        [node.lon, node.lat, node.id, nodetags]
+        [node.lon, node.lat, node.id, nodetags, node.version]
       end
       tags = way.tags
       version = way.version
@@ -272,76 +291,111 @@ class AmfController < ApplicationController
   # 3. hash of tags, 
   # 4. version, 
   # 5. is this the current, visible version? (boolean)
-
-  def getway_old(id, version) #:doc:
-    if version < 0
+  
+  def getway_old(id, timestamp) #:doc:
+    if timestamp == ''
+      # undelete
       old_way = OldWay.find(:first, :conditions => ['visible = ? AND id = ?', true, id], :order => 'version DESC')
       points = old_way.get_nodes_undelete unless old_way.nil?
     else
-      old_way = OldWay.find(:first, :conditions => ['id = ? AND version = ?', id, version])
-      points = old_way.get_nodes_revert unless old_way.nil?
+      # revert
+      timestamp = DateTime.strptime(timestamp, "%d %b %Y, %H:%M:%S")
+      old_way = OldWay.find(:first, :conditions => ['id = ? AND timestamp <= ?', id, timestamp], :order => 'timestamp DESC')
+      points = old_way.get_nodes_revert(timestamp) unless old_way.nil?
+      if !old_way.visible
+        return [-1, "Sorry, the way was deleted at that time - please revert to a previous version."]
+      end
     end
 
     if old_way.nil?
+      # *** FIXME: shouldn't this be returning an error?
       return [-1, id, [], {}, -1,0]
     else
       curway=Way.find(id)
       old_way.tags['history'] = "Retrieved from v#{old_way.version}"
-      return [0, id, points, old_way.tags, old_way.version, (curway.version==old_way.version and curway.visible)]
+      return [0, id, points, old_way.tags, curway.version, (curway.version==old_way.version and curway.visible)]
     end
   end
   
-  # Find history of a way. Returns 'way', id, and 
-  # an array of previous versions.
+  # 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
-      history = Way.find(wayid).old_ways.reverse.collect do |old_way|
-        user_object = old_way.changeset.user
-        user = user_object.data_public? ? user_object.display_name : 'anonymous'
-        uid  = user_object.data_public? ? user_object.id : 0
-        [old_way.version, old_way.timestamp.strftime("%d %b %Y, %H:%M"), old_way.visible ? 1 : 0, user, uid]
+      # 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
-
-      return ['way',wayid,history]
+      waycreated=revdates[0]
+      revdates.uniq!
+      revdates.sort!
+	  revdates.reverse!
+
+      # Remove any dates (from nodes) before first revision date of way
+      revdates.delete_if { |d| d<waycreated }
+      # Remove any elements where 2 seconds doesn't elapse before next one
+      revdates.delete_if { |d| revdates.include?(d+1) or revdates.include?(d+2) }
+      # Collect all in one nested array
+      revdates.collect! {|d| [d.strftime("%d %b %Y, %H:%M:%S")] + revusers[d.to_i] }
+
+      return ['way',wayid,revdates]
     rescue ActiveRecord::RecordNotFound
       return ['way', wayid, []]
     end
   end
-
-  # Find history of a node. Returns 'node', id, and 
-  # an array of previous versions.
+  
+  # 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|
-        user_object = old_node.changeset.user
-        user = user_object.data_public? ? user_object.display_name : 'anonymous'
-        uid  = user_object.data_public? ? user_object.id : 0
-        [old_node.version, old_node.timestamp.strftime("%d %b %Y, %H:%M"), old_node.visible ? 1 : 0, user, uid]
+    begin 
+      history = Node.find(nodeid).old_nodes.reverse.collect do |old_node|
+        [old_node.timestamp.strftime("%d %b %Y, %H:%M:%S")] + change_user(old_node)
       end
-
-      return ['node',nodeid,history]
+      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)
-    uid = getuserid(usertoken)
+    user = getuser(usertoken)
     if !uid then return -1,"You must be logged in to search for GPX traces." end
 
     gpxs = []
     if searchterm.to_i>0 then
-      gpx = Trace.find(searchterm.to_i, :conditions => ["visible=? AND (public=? OR user_id=?)",true,true,uid] )
+      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,uid,searchterm] ).each do |gpx|
+      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
@@ -392,194 +446,260 @@ class AmfController < ApplicationController
   # 1. original relation id (unchanged),
   # 2. new relation id.
 
-  def putrelation(renumberednodes, renumberedways, usertoken, changeset, relid, tags, members, visible) #:doc:
-    uid = getuserid(usertoken)
-    if !uid then return -1,"You are not logged in, so the relation could not be saved." end
+  def putrelation(renumberednodes, renumberedways, usertoken, changeset_id, version, relid, tags, members, visible) #:doc:
+    user = getuser(usertoken)
+    if !user then return -1,"You are not logged in, so the relation could not be saved." end
 
     relid = relid.to_i
     visible = (visible.to_i != 0)
 
-    # create a new relation, or find the existing one
-    if relid <= 0
-      rel = Relation.new
-      rel.version = 0
-    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'
+    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
-      if mid
-        typedmembers << [m[0], mid, m[2]]
+      # 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
-    end
-
-    # assign new contents
-    rel.members = typedmembers
-    rel.tags = tags
-    rel.visible = visible
-    rel.changeset_id = changeset
 
-    # 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.
+      # 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 !rel.preconditions_ok?
-    #  return -2, "Relation preconditions failed"
-    #else
-    rel.save_with_history!
-    #end
 
-    [0, relid, rel.id]
+      if id <= 0
+        # We're creating the node
+        new_relation.create_with_history(user)
+      elsif visible
+        # We're updating the node
+        relation.update_from(new_relation, user)
+      else
+        # We're deleting the node
+        relation.delete_with_history!(new_relation, user)
+      end
+    end # transaction
+      
+    if id <= 0
+      return [0, relid, new_relation.id, new_relation.version]
+    else
+      return [0, relid, relation.id, relation.version]
+    end
+  rescue OSM::APIChangesetAlreadyClosedError => ex
+    return [-1, "The changeset #{ex.changeset.id} was closed at #{ex.changeset.closed_at}."]
+  rescue OSM::APIVersionMismatchError => ex
+    # Really need to check to see whether this is a server load issue, and the 
+    # last version was in the same changeset, or belongs to the same user, then
+    # we can return something different
+    return [-3, "Sorry, someone else has changed this relation since you started editing. Please click the 'Edit' tab to reload the area."]
+  rescue OSM::APIAlreadyDeletedError => ex
+    return [-1, "The relation has already been deleted."]
+  rescue OSM::APIError => ex
+    # Some error that we don't specifically catch
+    return [-2, "Something really bad happened :-( ."]
   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])
+  # 
   # Returns:
   # 0. '0' (code for success),
   # 1. original way id (unchanged),
   # 2. new way id,
   # 3. hash of renumbered nodes (old id=>new id),
-  # 4. version
+  # 4. way version,
+  # 5. hash of node versions (node=>version)
 
-  def putway(renumberednodes, usertoken, changeset, originalway, points, attributes) #:doc:
+  def putway(renumberednodes, usertoken, changeset_id, wayversion, originalway, pointlist, attributes, nodes) #:doc:
 
-    # -- Initialise and carry out checks
+    # -- Initialise
 	
-    uid = getuserid(usertoken)
-    if !uid then return -1,"You are not logged in, so the way could not be saved." 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
 
     originalway = originalway.to_i
+	pointlist.collect! {|a| a.to_i }
 
-    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
-      if a[1] == 90 then return -2,"Server error - node with lat -90 found in way #{originalway}." end
-    end
-
-    if points.length < 2 then return -2,"Server error - way is only #{points.length} points long." end
+    way=nil	# this is returned, so scope it outside the transaction
+    nodeversions = {}
+    Way.transaction do
 
-    # -- Get unique nodes
+      # -- Get unique nodes
 
-    if originalway < 0
-      way = Way.new
-      way.version = 0	# otherwise +=1 breaks
-      uniques = []
-    else
-      way = Way.find(originalway)
-      uniques = way.unshared_node_ids
-    end
-
-    # -- Compare nodes and save changes to any that have changed
+      if originalway <= 0
+        uniques = []
+      else
+        way = Way.find(originalway)
+        uniques = way.unshared_node_ids
+      end
 
-    nodes = []
+      #-- Update each changed node
 
-    points.each do |n|
-      lon = n[0].to_f
-      lat = n[1].to_f
-      id = n[2].to_i
-      savenode = false
+      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
 
-      if renumberednodes[id]
-        id = renumberednodes[id]
-      elsif id < 0
-        # Create new node
         node = Node.new
-        node.version = 0	# otherwise +=1 breaks
-        savenode = true
-      else
-        node = Node.find(id)
-        nodetags=node.tags
-        nodetags.delete('created_by')
-        if !fpcomp(lat, node.lat) or !fpcomp(lon, node.lon) or
-           n[4] != nodetags or !node.visible?
-          savenode = true
-        end
-      end
-
-      if savenode
-        node.changeset_id = changeset
+        node.changeset_id = changeset_id
         node.lat = lat
         node.lon = lon
-        node.tags = n[4]
-        node.visible = true
-        node.save_with_history!
-
-        if id != node.id
+        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
-          id = node.id
+          nodeversions[node.id] = node.version
+        else
+          # We're updating an existing node
+          previous=Node.find(id)
+          previous.update_from(node, user)
+          nodeversions[previous.id] = previous.version
         end
       end
 
-      uniques = uniques - [id]
-      nodes.push(id)
-    end
-
-    # -- Delete any unique nodes
-	
-    uniques.each do |n|
-      deleteitemrelations(n, 'node')
-
-      node = Node.find(n)
-      node.changeset_id = changeset
-      node.visible = false
-      node.save_with_history!
-    end
+      # -- Save revised way
+
+	  pointlist.collect! {|a|
+		renumberednodes[a] ? renumberednodes[a]:a
+	  } # renumber nodes
+      new_way = Way.new
+      new_way.tags = attributes
+      new_way.nds = pointlist
+      new_way.changeset_id = changeset_id
+      new_way.version = wayversion
+      if originalway <= 0
+        new_way.create_with_history(user)
+        way=new_way	# so we can get way.id and way.version
+      elsif way.tags!=attributes or way.nds!=pointlist or !way.visible?
+        way.update_from(new_way, user)
+      end
 
-    # -- Save revised way
+      # -- Delete any unique nodes no longer used
 
-    if way.tags!=attributes or way.nds!=nodes or !way.visible?
-      way.tags = attributes
-      way.nds = nodes
-      way.changeset_id = changeset
-      way.visible = true
-      way.save_with_history!
-    end
+      uniques=uniques-pointlist
+      uniques.each do |n|
+        node = Node.find(n)
+        deleteitemrelations(user, changeset_id, id, 'node', node.version)
+        new_node = Node.new
+        new_node.changeset_id = changeset_id
+        new_node.version = node.version
+        node.delete_with_history!(new_node, user)
+      end
 
-    [0, originalway, way.id, renumberednodes, way.version]
+    end # transaction
+
+    [0, originalway, way.id, renumberednodes, way.version, nodeversions]
+  rescue OSM::APIChangesetAlreadyClosedError => ex
+    return [-2, "Sorry, your changeset #{ex.changeset.id} has been closed (at #{ex.changeset.closed_at})."]
+  rescue OSM::APIVersionMismatchError => ex
+    # Really need to check to see whether this is a server load issue, and the 
+    # last version was in the same changeset, or belongs to the same user, then
+    # we can return something different
+    return [-3, "Sorry, someone else has changed this way since you started editing. Please click the 'Edit' tab to reload the area."]
+  rescue OSM::APITooManyWayNodesError => ex
+    return [-1, "You have tried to upload a really long way with #{ex.provided} points: only #{ex.max} are allowed."]
+  rescue OSM::APIAlreadyDeletedError => ex
+    return [-1, "The point has already been deleted."]
+  rescue OSM::APIError => ex
+    # Some error that we don't specifically catch
+    return [-2, "Something really bad happened :-(."]
   end
 
   # Save POI to the database.
   # Refuses save if the node has since become part of a way.
-  # Returns:
+  # Returns array with:
   # 0. 0 (success),
   # 1. original node id (unchanged),
   # 2. new node id,
   # 3. version.
 
-  def putpoi(usertoken, changeset, id, lon, lat, tags, visible) #:doc:
-    uid = getuserid(usertoken)
-    if !uid then return -1,"You are not logged in, so the point could not be saved." end
+  def putpoi(usertoken, changeset_id, version, id, lon, lat, tags, visible) #:doc:
+    user = getuser(usertoken)
+    if !user then return -1,"You are not logged in, so the point could not be saved." end
 
     id = id.to_i
     visible = (visible.to_i == 1)
+    node = nil
+    new_node = nil
+    Node.transaction do
+      if id > 0 then
+        node = Node.find(id)
 
-    if id > 0 then
-      node = Node.find(id)
-
-      if !visible then
-        unless node.ways.empty? then return -1,"The point has since become part of a way, so you cannot save it as a POI." end
-        deleteitemrelations(id, 'node')
+        if !visible then
+          unless node.ways.empty? then return -1,"The point has since become part of a way, so you cannot save it as a POI." end
+        end
       end
-    else
-      node = Node.new
-      node.version = 0
-    end
-
-    node.changeset_id = changeset
-    node.lat = lat
-    node.lon = lon
-    node.tags = tags
-    node.visible = visible
-    node.save_with_history!
+      # We always need a new node, based on the data that has been sent to us
+      new_node = Node.new
+
+      new_node.changeset_id = changeset_id
+      new_node.version = version
+      new_node.lat = lat
+      new_node.lon = lon
+      new_node.tags = tags
+      if id <= 0 
+        # We're creating the node
+        new_node.create_with_history(user)
+      elsif visible
+        # We're updating the node
+        node.update_from(new_node, user)
+      else
+        # We're deleting the node
+        node.delete_with_history!(new_node, user)
+      end
+     end # transaction
 
-    [0, id, node.id, node.version]
+    if id <= 0
+      return [0, id, new_node.id, new_node.version]
+    else
+      return [0, id, node.id, node.version]
+    end 
+  rescue OSM::APIChangesetAlreadyClosedError => ex
+    return [-1, "The changeset #{ex.changeset.id} was closed at #{ex.changeset.closed_at}"]
+  rescue OSM::APIVersionMismatchError => ex
+    # Really need to check to see whether this is a server load issue, and the 
+    # last version was in the same changeset, or belongs to the same user, then
+    # we can return something different
+    return [-3, "Sorry, someone else has changed this point since you started editing. Please click the 'Edit' tab to reload the area."]
+  rescue OSM::APIAlreadyDeletedError => ex
+    return [-1, "The point has already been deleted"]
+  rescue OSM::APIError => ex
+    # Some error that we don't specifically catch
+    return [-2, "Something really bad happened :-()"]
   end
 
   # Read POI from database
@@ -587,11 +707,11 @@ class AmfController < ApplicationController
   #
   # Returns array of id, long, lat, hash of tags, version.
 
-  def getpoi(id,version) #:doc:
-    if version>0 then
-        n = OldNode.find(id, :conditions=>['version=?',version])
-    else
+  def getpoi(id,timestamp) #:doc:
+    if timestamp == '' then
       n = Node.find(id)
+    else
+      n = OldNode.find(id, :conditions=>['timestamp=?',DateTime.strptime(timestamp, "%d %b %Y, %H:%M:%S")])
     end
 
     if n
@@ -602,24 +722,59 @@ class AmfController < ApplicationController
   end
 
   # Delete way and all constituent nodes. Also removes from any relations.
+  # Params:
+  # * The user token
+  # * the changeset id
+  # * the id of the way to change
+  # * the version of the way that was downloaded
+  # * a hash of the id and versions of all the nodes that are in the way, if any 
+  # of the nodes have been changed by someone else then, there is a problem!
   # Returns 0 (success), unchanged way id.
 
-  def deleteway(usertoken, changeset_id, way_id) #:doc:
-    if !getuserid(usertoken) then return -1,"You are not logged in, so the way could not be deleted." end
-
+  def deleteway(usertoken, changeset_id, way_id, way_version, node_id_version) #:doc:
+    user = getuser(usertoken)
+    unless user then return -1,"You are not logged in, so the way could not be deleted." end
+      
     way_id = way_id.to_i
-
-    # FIXME: would be good not to make two history entries when removing
-    #		 two nodes from the same relation
-    way = Way.find(way_id)
-    way.unshared_node_ids.each do |n|
-      deleteitemrelations(n, 'node')
-    end
-    deleteitemrelations(way_id, 'way')
-
-    way.delete_with_relations_and_nodes_and_history(changeset_id.to_i)
-
+    # Need a transaction so that if one item fails to delete, the whole delete fails.
+    Way.transaction do
+
+      # delete the way
+      old_way = Way.find(way_id)
+      delete_way = Way.new
+      delete_way.version = way_version
+      delete_way.changeset_id = changeset_id
+      old_way.delete_with_history!(delete_way, user)
+
+      old_way.unshared_node_ids.each do |node_id|
+        # delete the node
+        node = Node.find(node_id)
+        delete_node = Node.new
+        delete_node.changeset_id = changeset_id
+        if node_id_version[node_id.to_s]
+          delete_node.version = node_id_version[node_id.to_s]
+        else
+          # in case the node wasn't passed (i.e. if it was previously removed
+          # from the way in Potlatch)
+          deleteitemrelations(user, changeset_id, node_id, 'node', node.version)
+	      delete_node.version = node.version
+	    end
+        node.delete_with_history!(delete_node, user)
+      end
+    end # transaction
     [0, way_id]
+  rescue OSM::APIChangesetAlreadyClosedError => ex
+    return [-1, "The changeset #{ex.changeset.id} was closed at #{ex.changeset.closed_at}"]
+  rescue OSM::APIVersionMismatchError => ex
+    # Really need to check to see whether this is a server load issue, and the 
+    # last version was in the same changeset, or belongs to the same user, then
+    # we can return something different
+    return [-3, "Sorry, someone else has changed this way since you started editing. Please click the 'Edit' tab to reload the area."]
+  rescue OSM::APIAlreadyDeletedError => ex
+    return [-1, "The way has already been deleted."]
+  rescue OSM::APIError => ex
+    # Some error that we don't specifically catch
+    return [-2, "Something really bad happened :-( ."]
   end
 
 
@@ -627,46 +782,39 @@ class AmfController < ApplicationController
   # Support functions
 
   # Remove a node or way from all relations
+  # This is only used by putway and deleteway when deleting nodes removed 
+  # from a way (because Potlatch itself doesn't keep track of these - 
+  # possible FIXME).
 
-  def deleteitemrelations(objid, type) #:doc:
+  def deleteitemrelations(user, changeset_id, objid, type, version) #:doc:
     relations = RelationMember.find(:all, 
 									:conditions => ['member_type = ? and member_id = ?', type, objid], 
 									:include => :relation).collect { |rm| rm.relation }.uniq
 
     relations.each do |rel|
       rel.members.delete_if { |x| x[0] == type and x[1] == objid }
-      rel.save_with_history!
+      new_rel = Relation.new
+      new_rel.tags = rel.tags
+      new_rel.visible = rel.visible
+      new_rel.version = rel.version
+      new_rel.members = rel.members
+      new_rel.changeset_id = changeset_id
+      rel.update_from(new_rel, user)
     end
   end
 
-  # Break out node tags into a hash
-  # (should become obsolete as of API 0.6)
-
-  def tagstring_to_hash(a) #:doc:
-    tags={}
-    Tags.split(a) do |k, v|
-      tags[k]=v
-    end
-    tags
-  end
-
   # Authenticate token
   # (can also be of form user:pass)
+  # When we are writing to the api, we need the actual user model, 
+  # not just the id, hence this abstraction
 
-  def getuserid(token) #:doc:
+  def getuser(token) #:doc:
     if (token =~ /^(.+)\:(.+)$/) then
       user = User.authenticate(:username => $1, :password => $2)
     else
       user = User.authenticate(:token => token)
     end
-
-    return user ? user.id : nil;
-  end
-
-  # Compare two floating-point numbers to within 0.0000001
-
-  def fpcomp(a,b) #:doc:
-    return ((a/0.0000001).round==(b/0.0000001).round)
+    return user
   end
 
   # Send AMF response