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

# amf_controller is a semi-standalone API for Flash clients, particularly 
# Potlatch. All interaction between Potlatch (as a .SWF application) and the 
# OSM database takes place using this controller. Messages are 
# encoded in the Actionscript Message Format (AMF).
#
# Helper functions are in /lib/potlatch.
#
# Author::      editions Systeme D / Richard Fairhurst 2004-2008
# Licence::     public domain.
#
# == General structure
#
# Apart from the talk method (which distributes the requests from the
# AMF message), each method generally takes arguments in the order they were 
# sent by the Potlatch SWF. Do not assume typing has been preserved. Methods 
# all return an array to the SWF.
# 
# == Debugging
# 
# Any method that returns a status code (0 for ok) can also send:
#       return(-1,"message")            <-- just puts up a dialogue
#       return(-2,"message")            <-- also asks the user to e-mail me
# 
# To write to the Rails log, use RAILS_DEFAULT_LOGGER.info("message").
#
# == To do
# 
# - Check authentication
# - Check the right things are being written to the database!

class AmfController < ApplicationController
  require 'stringio'

  include Potlatch

  session :off
  before_filter :check_write_availability

  # Main AMF handler: processes the raw AMF string (using AMF library) and
  # calls each action (private method) accordingly.
  
  def talk
        req=StringIO.new(request.raw_post+0.chr)        # Get POST data as request
                                                                                                # (cf http://www.ruby-forum.com/topic/122163)
        req.read(2)                                                                     # Skip version indicator and client ID
        results={}                                                                      # Results of each body
        renumberednodes={}                                                      # Shared across repeated putways
        renumberedways={}                                                       # Shared across repeated putways

        # Parse request

        headers=AMF.getint(req)                                 # Read number of headers

        headers.times do                                                # Read each header
          name=AMF.getstring(req)                               #  |
          req.getc                                                              #  | skip boolean
          value=AMF.getvalue(req)                               #  |
          header["name"]=value                                  #  |
        end

        bodies=AMF.getint(req)                                  # Read number of bodies
        bodies.times do                                                 # Read each body
          message=AMF.getstring(req)                    #  | get message name
          index=AMF.getstring(req)                              #  | get index in response sequence
          bytes=AMF.getlong(req)                                #  | get total size in bytes
          args=AMF.getvalue(req)                                #  | get response (probably an array)

          case message
                when 'getpresets';                      results[index]=AMF.putdata(index,getpresets())
                when 'whichways';                       results[index]=AMF.putdata(index,whichways(*args))
                when 'whichways_deleted';       results[index]=AMF.putdata(index,whichways_deleted(*args))
                when 'getway';                          results[index]=AMF.putdata(index,getway(args[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_history';          results[index]=AMF.putdata(index,getway_history(args[0].to_i))
                when 'putway';                          r=putway(renumberednodes,*args)
                                                                        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(renumberednodes, renumberedways, *args))
                when 'deleteway';                       results[index]=AMF.putdata(index,deleteway(args[0],args[1].to_i))
                when 'putpoi';                          results[index]=AMF.putdata(index,putpoi(*args))
                when 'getpoi';                          results[index]=AMF.putdata(index,getpoi(args[0].to_i))
          end
        end

        # Write out response

        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
        }
  end

  private

  # Return presets (default tags, localisation etc.):
  # uses POTLATCH_PRESETS global, set up in OSM::Potlatch.

  def getpresets() #:doc:
        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. 

  def whichways(xmin, ymin, xmax, ymax) #:doc:
        xmin -= 0.01; ymin -= 0.01
        xmax += 0.01; ymax += 0.01

        if POTLATCH_USE_SQL then
          way_ids = sql_find_way_ids_in_area(xmin, ymin, xmax, ymax)
          points = sql_find_pois_in_area(xmin, ymin, xmax, ymax)
          relation_ids = sql_find_relations_in_area_and_ways(xmin, ymin, xmax, ymax, way_ids)
        else
          # find the way ids in an area
          nodes_in_area = Node.find_by_area(ymin, xmin, ymax, xmax, :conditions => "current_nodes.visible = 1", :include => :ways)
          way_ids = nodes_in_area.collect { |node| node.way_ids }.flatten.uniq

          # find the node ids in an area that aren't part of ways
          nodes_not_used_in_area = nodes_in_area.select { |node| node.ways.empty? }
          points = nodes_not_used_in_area.collect { |n| [n.id, n.lon, n.lat, n.tags_as_hash] }

          # find the relations used by those nodes and ways
          relations = Relation.find_for_nodes(nodes_in_area.collect { |n| n.id }, :conditions => "visible = 1") +
                  Relation.find_for_ways(way_ids, :conditions => "visible = 1")
          relation_ids = relations.collect { |relation| relation.id }.uniq
        end

        [way_ids, points, relation_ids]
  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

        nodes_in_area = Node.find_by_area(ymin, xmin, ymax, xmax, :conditions => "current_nodes.visible = 0 AND current_ways.visible = 0", :include => :ways_via_history)
        way_ids = nodes_in_area.collect { |node| node.ways_via_history_ids }.flatten.uniq

        [way_ids]
  end

  # Get a way including nodes and tags.
  # Returns 0 (success), a Potlatch-style array of points, and a hash of tags.

  def getway(wayid) #:doc:
        if POTLATCH_USE_SQL then
          points = sql_get_nodes_in_way(wayid)
          tags = sql_get_tags_in_way(wayid)
        else
          # Ideally we would do ":include => :nodes" here but if we do that
          # then rails only seems to return the first copy of a node when a
          # way includes a node more than once
          way = Way.find(wayid)
          points = way.nodes.collect do |node|
                [node.lon, node.lat, node.id, nil, node.tags_as_hash]
          end
          tags = way.tags
        end

        [wayid, points, tags]
  end

  # Get an old version of a way, and all constituent nodes.
  #
  # For undelete (version=0), always uses the most recent version of each node, 
  # even if it's moved.  For revert (version=1+), uses the node in existence 
  # at the time, generating a new id if it's still visible and has been moved/
  # retagged.

  def getway_old(id, version) #:doc:
        if version < 0
          old_way = OldWay.find(:first, :conditions => ['visible = 1 AND id = ?', id], :order => 'version DESC')
          points = old_way.get_nodes_undelete
        else
          old_way = OldWay.find(:first, :conditions => ['id = ? AND version = ?', id, version])
          points = old_way.get_nodes_revert
        end

        old_way.tags['history'] = "Retrieved from v#{old_way.version}"

        [0, id, points, old_way.tags, old_way.version]
  end
  
  # Find history of a way. Returns an array of previous versions.

  def getway_history(wayid) #:doc:
        history = Way.find(wayid).old_ways.collect do |old_way|
          user = old_way.user.data_public? ? old_way.user.display_name : 'anonymous'
          [old_way.version, old_way.timestamp.strftime("%d %b %Y, %H:%M"), old_way.visible ? 1 : 0, user]
        end

        [history]
  end

  # Get a relation with all tags and members.
  # Returns:
  # 0. relation id,
  # 1. hash of tags,
  # 2. list of members.
  
  def getrelation(relid) #:doc:
        rel = Relation.find(relid)

        [relid, rel.tags, rel.members]
  end

  # Save a relation.
  # Returns
  # 0. 0 (success),
  # 1. original relation id (unchanged),
  # 2. new relation id.

  def putrelation(renumberednodes, renumberedways, usertoken, 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

        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

        # 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

  # Save a way to the database, including all nodes. Any nodes in the previous
  # version and no longer used are deleted.
  # 
  # Returns:
  # 0. '0' (code for success),
  # 1. original way id (unchanged),
  # 2. new way id,
  # 3. hash of renumbered nodes (old id=>new id)

  def putway(renumberednodes, usertoken, originalway, points, attributes) #:doc:

        # -- Initialise and carry out checks
        
        uid = getuserid(usertoken)
        if !uid then return -1,"You are not logged in, so the way could not be saved." end

        originalway = originalway.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

        # -- Get unique nodes

        if originalway < 0
          way = Way.new
          uniques = []
        else
          way = Way.find(originalway)
          uniques = way.unshared_node_ids
        end

        # -- Compare nodes and save changes to any that have changed

        nodes = []

        points.each do |n|
          lon = n[0].to_f
          lat = n[1].to_f
          id = n[2].to_i
          savenode = false

          if renumberednodes[id]
            id = renumberednodes[id]
          elsif id < 0
                # Create new node
                node = Node.new
                savenode = true
          else
                node = Node.find(id)
                if !fpcomp(lat, node.lat) or !fpcomp(lon, node.lon) or
                   Tags.join(n[4]) != node.tags or !node.visible?
                  savenode = true
                end
          end

          if savenode
                node.user_id = uid
            node.lat = lat
        node.lon = lon
            node.tags = Tags.join(n[4])
            node.visible = true
            node.save_with_history!

                if id != node.id
                  renumberednodes[id] = node.id
                  id = node.id
            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.user_id = uid
          node.visible = false
          node.save_with_history!
        end

        # -- Save revised way

        way.tags = attributes
        way.nds = nodes
        way.user_id = uid
        way.visible = true
        way.save_with_history!

        [0, originalway, way.id, renumberednodes]
  end

  # Save POI to the database.
  # Refuses save if the node has since become part of a way.
  # Returns:
  # 0. 0 (success),
  # 1. original node id (unchanged),
  # 2. new node id.

  def putpoi(usertoken, 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

        id = id.to_i
        visible = (visible.to_i == 1)

        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')
          end
        else
          node = Node.new
        end

        node.user_id = uid
        node.lat = lat
        node.lon = lon
        node.tags = Tags.join(tags)
        node.visible = visible
        node.save_with_history!

        [0, id, node.id]
  end

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

  def getpoi(id) #:doc:
        n = Node.find(id)

        if n
          return [n.id, n.lon, n.lat, n.tags_as_hash]
        else
          return [nil, nil, nil, '']
        end
  end

  # Delete way and all constituent nodes. Also removes from any relations.
  # Returns 0 (success), unchanged way id.

  def deleteway(usertoken, way_id) #:doc:
        uid = getuserid(usertoken)
        if !uid then return -1,"You are not logged in, so the way could not be deleted." end

        # FIXME: would be good not to make two history entries when removing
        #                two nodes from the same relation
        user = User.find(uid)
        way = Way.find(way_id)
        way.unshared_node_ids.each do |n|
          deleteitemrelations(n, 'node')
        end

        way.delete_with_relations_and_nodes_and_history(user)  

        [0, way_id]
  end


  # ====================================================================
  # Support functions

  # Remove a node or way from all relations

  def deleteitemrelations(objid, type) #: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!
        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
  # (could be removed if no-one uses the username+password form)

  def getuserid(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)
  end


  # ====================================================================
  # Alternative SQL queries for getway/whichways

  def sql_find_way_ids_in_area(xmin,ymin,xmax,ymax)
        sql=<<-EOF
  SELECT DISTINCT current_way_nodes.id AS wayid
                FROM current_way_nodes
  INNER JOIN current_nodes ON current_nodes.id=current_way_nodes.node_id
  INNER JOIN current_ways  ON current_ways.id =current_way_nodes.id
           WHERE current_nodes.visible=1 
                 AND current_ways.visible=1 
                 AND #{OSM.sql_for_area(ymin, xmin, ymax, xmax, "current_nodes.")}
        EOF
        return ActiveRecord::Base.connection.select_all(sql).collect { |a| a['wayid'].to_i }
  end
        
  def sql_find_pois_in_area(xmin,ymin,xmax,ymax)
        sql=<<-EOF
                  SELECT current_nodes.id,current_nodes.latitude*0.0000001 AS lat,current_nodes.longitude*0.0000001 AS lon,current_nodes.tags 
                        FROM current_nodes 
 LEFT OUTER JOIN current_way_nodes cwn ON cwn.node_id=current_nodes.id 
                   WHERE current_nodes.visible=1
                         AND cwn.id IS NULL
                         AND #{OSM.sql_for_area(ymin, xmin, ymax, xmax, "current_nodes.")}
        EOF
        return ActiveRecord::Base.connection.select_all(sql).collect { |n| [n['id'].to_i,n['lon'].to_f,n['lat'].to_f,tagstring_to_hash(n['tags'])] }
  end
        
  def sql_find_relations_in_area_and_ways(xmin,ymin,xmax,ymax,way_ids)
        # ** It would be more Potlatchy to get relations for nodes within ways
        #    during 'getway', not here
        sql=<<-EOF
          SELECT DISTINCT cr.id AS relid 
                FROM current_relations cr
  INNER JOIN current_relation_members crm ON crm.id=cr.id 
  INNER JOIN current_nodes cn ON crm.member_id=cn.id AND crm.member_type='node' 
           WHERE #{OSM.sql_for_area(ymin, xmin, ymax, xmax, "cn.")}
        EOF
        unless way_ids.empty?
          sql+=<<-EOF
           UNION
          SELECT DISTINCT cr.id AS relid
                FROM current_relations cr
  INNER JOIN current_relation_members crm ON crm.id=cr.id
           WHERE crm.member_type='way' 
                 AND crm.member_id IN (#{way_ids.join(',')})
          EOF
        end
        return ActiveRecord::Base.connection.select_all(sql).collect { |a| a['relid'].to_i }.uniq
  end
        
  def sql_get_nodes_in_way(wayid)
        points=[]
        sql=<<-EOF
                SELECT latitude*0.0000001 AS lat,longitude*0.0000001 AS lon,current_nodes.id,tags 
                  FROM current_way_nodes,current_nodes 
                 WHERE current_way_nodes.id=#{wayid.to_i} 
                   AND current_way_nodes.node_id=current_nodes.id 
                   AND current_nodes.visible=1
          ORDER BY sequence_id
          EOF
        ActiveRecord::Base.connection.select_all(sql).each do |row|
          points << [row['lon'].to_f,row['lat'].to_f,row['id'].to_i,nil,tagstring_to_hash(row['tags'])]
        end
        points
  end
        
  def sql_get_tags_in_way(wayid)
        tags={}
        ActiveRecord::Base.connection.select_all("SELECT k,v FROM current_way_tags WHERE id=#{wayid.to_i}").each do |row|
          tags[row['k']]=row['v']
        end
        tags
  end

end

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