Potlatch 0.10
[rails.git] / app / controllers / amf_controller.rb
1 # amf_controller is a semi-standalone API for Flash clients, particularly 
2 # Potlatch. All interaction between Potlatch (as a .SWF application) and the 
3 # OSM database takes place using this controller. Messages are 
4 # encoded in the Actionscript Message Format (AMF).
5 #
6 # Helper functions are in /lib/potlatch.
7 #
8 # Author::      editions Systeme D / Richard Fairhurst 2004-2008
9 # Licence::     public domain.
10 #
11 # == General structure
12 #
13 # Apart from the talk method (which distributes the requests from the
14 # AMF message), each method generally takes arguments in the order they were 
15 # sent by the Potlatch SWF. Do not assume typing has been preserved. Methods 
16 # all return an array to the SWF.
17
18 # == Debugging
19
20 # Any method that returns a status code (0 for ok) can also send:
21 #       return(-1,"message")            <-- just puts up a dialogue
22 #       return(-2,"message")            <-- also asks the user to e-mail me
23
24 # To write to the Rails log, use RAILS_DEFAULT_LOGGER.info("message").
25 #
26 # == To do
27
28 # - Check authentication
29 # - Check the right things are being written to the database!
30
31 class AmfController < ApplicationController
32   require 'stringio'
33
34   include Potlatch
35
36   session :off
37   before_filter :check_write_availability
38
39   # Main AMF handler: processes the raw AMF string (using AMF library) and
40   # calls each action (private method) accordingly.
41   
42   def talk
43         req=StringIO.new(request.raw_post+0.chr)        # Get POST data as request
44                                                                                                 # (cf http://www.ruby-forum.com/topic/122163)
45         req.read(2)                                                                     # Skip version indicator and client ID
46         results={}                                                                      # Results of each body
47         renumberednodes={}                                                      # Shared across repeated putways
48         renumberedways={}                                                       # Shared across repeated putways
49
50         # Parse request
51
52         headers=AMF.getint(req)                                 # Read number of headers
53
54         headers.times do                                                # Read each header
55           name=AMF.getstring(req)                               #  |
56           req.getc                                                              #  | skip boolean
57           value=AMF.getvalue(req)                               #  |
58           header["name"]=value                                  #  |
59         end
60
61         bodies=AMF.getint(req)                                  # Read number of bodies
62         bodies.times do                                                 # Read each body
63           message=AMF.getstring(req)                    #  | get message name
64           index=AMF.getstring(req)                              #  | get index in response sequence
65           bytes=AMF.getlong(req)                                #  | get total size in bytes
66           args=AMF.getvalue(req)                                #  | get response (probably an array)
67
68           case message
69                 when 'getpresets';                      results[index]=AMF.putdata(index,getpresets())
70                 when 'whichways';                       results[index]=AMF.putdata(index,whichways(*args))
71                 when 'whichways_deleted';       results[index]=AMF.putdata(index,whichways_deleted(*args))
72                 when 'getway';                          results[index]=AMF.putdata(index,getway(args[0].to_i))
73                 when 'getrelation';                     results[index]=AMF.putdata(index,getrelation(args[0].to_i))
74                 when 'getway_old';                      results[index]=AMF.putdata(index,getway_old(args[0].to_i,args[1].to_i))
75                 when 'getway_history';          results[index]=AMF.putdata(index,getway_history(args[0].to_i))
76                 when 'putway';                          r=putway(renumberednodes,*args)
77                                                                         renumberednodes=r[3]
78                                                                         if r[1] != r[2]
79                                                                           renumberedways[r[1]] = r[2]
80                                                                         end
81                                                                         results[index]=AMF.putdata(index,r)
82                 when 'putrelation';                     results[index]=AMF.putdata(index,putrelation(renumberednodes, renumberedways, *args))
83                 when 'deleteway';                       results[index]=AMF.putdata(index,deleteway(args[0],args[1].to_i))
84                 when 'putpoi';                          results[index]=AMF.putdata(index,putpoi(*args))
85                 when 'getpoi';                          results[index]=AMF.putdata(index,getpoi(args[0].to_i))
86           end
87         end
88
89         # Write out response
90
91         a,b=results.length.divmod(256)
92         render :content_type => "application/x-amf", :text => proc { |response, output| 
93           output.write 0.chr+0.chr+0.chr+0.chr+a.chr+b.chr
94           results.each do |k,v|
95                 output.write(v)
96           end
97         }
98   end
99
100   private
101
102   # Return presets (default tags, localisation etc.):
103   # uses POTLATCH_PRESETS global, set up in OSM::Potlatch.
104
105   def getpresets() #:doc:
106         return POTLATCH_PRESETS
107   end
108
109   # Find all the ways, POI nodes (i.e. not part of ways), and relations
110   # in a given bounding box. Nodes are returned in full; ways and relations 
111   # are IDs only. 
112
113   def whichways(xmin,ymin,xmax,ymax) #:doc:
114         xmin-=0.01; ymin-=0.01
115         xmax+=0.01; ymax+=0.01
116
117         if POTLATCH_USE_SQL then
118           way_ids=sql_find_way_ids_in_area(xmin,ymin,xmax,ymax)
119           points=sql_find_pois_in_area(xmin,ymin,xmax,ymax)
120           relation_ids=sql_find_relations_in_area_and_ways(xmin,ymin,xmax,ymax,way_ids)
121         else
122           # find the way ids in an area
123           nodes_in_area = Node.find_by_area(ymin, xmin, ymax, xmax, :conditions => "current_nodes.visible = 1", :include => :ways)
124           way_ids = nodes_in_area.collect { |node| node.way_ids }.flatten.uniq
125
126           # find the node ids in an area that aren't part of ways
127           nodes_not_used_in_area = nodes_in_area.select { |node| node.ways.empty? }
128           points = nodes_not_used_in_area.collect { |n| [n.id, n.lon, n.lat, n.tags_as_hash] }
129
130           # find the relations used by those nodes and ways
131           relations = nodes_in_area.collect { |node| node.containing_relations.visible }.flatten +
132                       way_ids.collect { |id| Way.find(id).containing_relations.visible }.flatten
133           relation_ids = relations.collect { |relation| relation.id }.uniq
134         end
135
136         [way_ids,points,relation_ids]
137   end
138
139   # Find deleted ways in current bounding box (similar to whichways, but ways
140   # with a deleted node only - not POIs or relations).
141
142   def whichways_deleted(xmin,ymin,xmax,ymax) #:doc:
143         xmin-=0.01; ymin-=0.01
144         xmax+=0.01; ymax+=0.01
145
146         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 )
147         way_ids = nodes_in_area.collect { |node| node.ways_via_history_ids }.flatten.uniq
148         [way_ids]
149   end
150
151   # Get a way including nodes and tags.
152   # Returns 0 (success), a Potlatch-style array of points, and a hash of tags.
153
154   def getway(wayid) #:doc:
155         if POTLATCH_USE_SQL then
156           points=sql_get_nodes_in_way(wayid)
157           tags=sql_get_tags_in_way(wayid)
158         else
159           # Ideally we would do ":include => :nodes" here but if we do that
160           # then rails only seems to return the first copy of a node when a
161           # way includes a node more than once
162           points = []
163           way = Way.find(wayid)
164           way.nodes.each do |node|
165             points << [node.lon, node.lat, node.id, nil, node.tags_as_hash]
166           end
167           tags=way.tags
168         end
169         [wayid,points,tags]
170   end
171
172   # Get an old version of a way, and all constituent nodes.
173   #
174   # For undelete (version=0), always uses the most recent version of each node, 
175   # even if it's moved.  For revert (version=1+), uses the node in existence 
176   # at the time, generating a new id if it's still visible and has been moved/
177   # retagged.
178
179   def getway_old(id,version) #:doc:
180         if version<0
181           old_way = OldWay.find(:first, :conditions => ['visible=1 AND id=?', id], :order => 'version DESC')
182           points = old_way.get_nodes_undelete
183         else
184           old_way = OldWay.find(:first, :conditions => ['id=? AND version=?', id, version])
185           points = old_way.get_nodes_revert
186         end
187         old_way.tags['history']="Retrieved from v#{old_way.version}"
188         [0,id,points,old_way.tags,old_way.version]
189   end
190   
191   # Find history of a way. Returns an array of previous versions.
192
193   def getway_history(wayid) #:doc:
194         history=[]
195         way=Way.find(wayid)
196         way.old_ways.each do |old_way|
197           if old_way.user.data_public then user=old_way.user.display_name else user='anonymous' end
198           history<<[old_way.version,old_way.timestamp.strftime("%d %b %Y, %H:%M"),old_way.visible ? 1 : 0,user]
199         end
200         [history]
201   end
202
203   # Get a relation with all tags and members.
204   # Returns:
205   # 0. relation id,
206   # 1. hash of tags,
207   # 2. list of members.
208   
209   def getrelation(relid) #:doc:
210         rel = Relation.find(relid)
211         [relid,rel.tags,rel.members]
212   end
213
214   # Save a relation.
215   # Returns
216   # 0. 0 (success),
217   # 1. original relation id (unchanged),
218   # 2. new relation id.
219
220   def putrelation(renumberednodes, renumberedways, usertoken,relid,tags,members,visible) #:doc:
221         uid=getuserid(usertoken)
222         if !uid then return -1,"You are not logged in, so the point could not be saved." end
223
224         relid = relid.to_i
225         visible = visible.to_i
226
227         # create a new relation, or find the existing one
228         if relid <= 0
229           rel = Relation.new
230         else
231           rel = Relation.find(relid)
232         end
233
234         # check the members are all positive, and correctly type
235         typedmembers = []
236         members.each do |m|
237           mid = m[1].to_i
238           if mid < 0
239                 mid = renumberednodes[mid] if m[0] == 'node'
240                 mid = renumberedways[mid] if m[0] == 'way'
241                 if mid < 0
242                   return -2, "Negative ID unresolved"
243                 end
244           end
245           typedmembers << [m[0], mid, m[2]]
246         end
247
248         # assign new contents
249         rel.members = typedmembers
250         rel.tags = tags
251         rel.visible = visible
252         rel.user_id = uid
253
254         # check it then save it
255         # BUG: the following is commented out because it always fails on my
256         #  install. I think it's a Rails bug.
257
258         #if !rel.preconditions_ok?
259         #  return -2, "Relation preconditions failed"
260         #else
261           rel.save_with_history!
262         #end
263
264         [0,relid,rel.id]
265   end
266
267   # Save a way to the database, including all nodes. Any nodes in the previous
268   # version and no longer used are deleted.
269   # 
270   # Returns:
271   # 0. '0' (code for success),
272   # 1. original way id (unchanged),
273   # 2. new way id,
274   # 3. hash of renumbered nodes (old id=>new id)
275
276   def putway(renumberednodes,usertoken,originalway,points,attributes) #:doc:
277
278         # -- Initialise and carry out checks
279         
280         uid=getuserid(usertoken)
281         if !uid then return -1,"You are not logged in, so the way could not be saved." end
282         originalway=originalway.to_i
283
284         points.each do |a|
285           if a[2]==0 or a[2].nil? then return -2,"Server error - node with id 0 found in way #{originalway}." end
286           if a[1]==90 then return -2,"Server error - node with lat -90 found in way #{originalway}." end
287         end
288
289         if points.length<2 then return -2,"Server error - way is only #{points.length} points long." end
290
291         # -- Get unique nodes
292
293         if originalway<0
294           way=Way.new
295           uniques=[]
296         else
297           way=Way.find(originalway)
298           uniques=way.unique_nodes
299         end
300
301         # -- Compare nodes and save changes to any that have changed
302
303         nodes=[]
304
305         points.each do |n|
306           lon=n[0].to_f
307           lat=n[1].to_f
308           id =n[2].to_i
309           savenode=false
310           if renumberednodes[id]
311             id=renumberednodes[id]
312           elsif id<0
313                 # Create new node
314                 node=Node.new
315                 savenode=true
316           else
317                 node=Node.find(id)
318                 if (!fpcomp(lat,node.lat) or !fpcomp(lon,node.lon) or \
319                         Tags.join(n[4])!=node.tags or node.visible==0)
320                   savenode=true
321                 end
322           end
323           if savenode
324                 node.user_id=uid
325             node.lat=lat; node.lon=lon
326             node.tags=Tags.join(n[4])
327             node.visible=true
328             node.save_with_history!
329                 if id!=node.id
330                   renumberednodes[id]=node.id
331                   id=node.id
332             end
333           end
334           uniques=uniques-[id]
335           nodes.push(id)
336         end
337
338         # -- Delete any unique nodes
339         
340         uniques.each do |n|
341           deleteitemrelations(n,'node')
342           node=Node.find(n)
343           node.user_id=uid
344           node.visible=false
345           node.save_with_history!
346         end
347
348         # -- Save revised way
349
350         way.tags=attributes
351         way.nds=nodes
352         way.user_id=uid
353         way.visible=true
354         way.save_with_history!
355
356         [0,originalway,way.id,renumberednodes]
357   end
358
359   # Save POI to the database.
360   # Refuses save if the node has since become part of a way.
361   # Returns:
362   # 0. 0 (success),
363   # 1. original node id (unchanged),
364   # 2. new node id.
365
366   def putpoi(usertoken,id,lon,lat,tags,visible) #:doc:
367         uid=getuserid(usertoken)
368         if !uid then return -1,"You are not logged in, so the point could not be saved." end
369
370         id=id.to_i
371         visible=(visible.to_i==1)
372
373         if (id>0) then
374           node=Node.find(id)
375           if !visible then
376             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
377             deleteitemrelations(id,'node')
378           end
379         else
380           node=Node.new
381         end
382
383         node.user_id = uid
384         node.latitude = (lat*10000000).round
385         node.longitude = (lon*10000000).round
386         node.tags = Tags.join(tags)
387         node.visible=visible
388         node.save_with_history!
389         newid=node.id
390         [0,id,newid]
391   end
392
393   # Read POI from database
394   # (only called on revert: POIs are usually read by whichways).
395   #
396   # Returns array of id, long, lat, hash of tags.
397
398   def getpoi(id) #:doc:
399         n = Node.find(id)
400         if n
401           return [n.id, n.lon, n.lat, n.tags_as_hash]
402         else
403           return [nil,nil,nil,'']
404         end
405   end
406
407   # Delete way and all constituent nodes. Also removes from any relations.
408   # Returns 0 (success), unchanged way id.
409
410   def deleteway(usertoken,way_id) #:doc:
411         uid=getuserid(usertoken)
412         if !uid then return -1,"You are not logged in, so the way could not be deleted." end
413
414         # FIXME: would be good not to make two history entries when removing
415         #                two nodes from the same relation
416         user = User.find(uid)
417         way = Way.find(way_id)
418         way.unique_nodes.each do |n|
419           deleteitemrelations(n,'node')
420         end
421
422         way.delete_with_relations_and_nodes_and_history(user)  
423         return [0,way_id]
424   end
425
426
427   # ====================================================================
428   # Support functions
429
430   # Remove a node or way from all relations
431
432   def deleteitemrelations(objid,type) #:doc:
433         relationids = RelationMember.find(:all, :conditions => ['member_type=? and member_id=?', type, objid]).collect { |ws| ws.id }.uniq
434         relationids.each do |relid|
435           rel=Relation.find(relid)
436           rel.members.delete_if {|x| x[0]==type and x[1]==objid}
437           rel.save_with_history!
438         end
439   end
440
441   # Break out node tags into a hash
442   # (should become obsolete as of API 0.6)
443
444   def tagstring_to_hash(a) #:doc:
445         tags={}
446         Tags.split(a) do |k, v|
447           tags[k]=v
448         end
449         tags
450   end
451
452   # Authenticate token
453   # (could be removed if no-one uses the username+password form)
454
455   def getuserid(token) #:doc:
456         if (token =~ /^(.+)\+(.+)$/) then
457           user = User.authenticate(:username => $1, :password => $2)
458         else
459           user = User.authenticate(:token => token)
460         end
461
462         return user ? user.id : nil;
463   end
464
465   # Compare two floating-point numbers to within 0.0000001
466
467   def fpcomp(a,b) #:doc:
468         return ((a/0.0000001).round==(b/0.0000001).round)
469   end
470
471
472   # ====================================================================
473   # Alternative SQL queries for getway/whichways
474
475   def sql_find_way_ids_in_area(xmin,ymin,xmax,ymax)
476         sql=<<-EOF
477   SELECT DISTINCT current_way_nodes.id AS wayid
478                 FROM current_way_nodes
479   INNER JOIN current_nodes ON current_nodes.id=current_way_nodes.node_id
480   INNER JOIN current_ways  ON current_ways.id =current_way_nodes.id
481            WHERE current_nodes.visible=1 
482                  AND current_ways.visible=1 
483                  AND #{OSM.sql_for_area(ymin, xmin, ymax, xmax, "current_nodes.")}
484         EOF
485         return ActiveRecord::Base.connection.select_all(sql).collect { |a| a['wayid'].to_i }
486   end
487         
488   def sql_find_pois_in_area(xmin,ymin,xmax,ymax)
489         sql=<<-EOF
490                   SELECT current_nodes.id,current_nodes.latitude*0.0000001 AS lat,current_nodes.longitude*0.0000001 AS lon,current_nodes.tags 
491                         FROM current_nodes 
492  LEFT OUTER JOIN current_way_nodes cwn ON cwn.node_id=current_nodes.id 
493                    WHERE current_nodes.visible=1
494                          AND cwn.id IS NULL
495                          AND #{OSM.sql_for_area(ymin, xmin, ymax, xmax, "current_nodes.")}
496         EOF
497         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'])] }
498   end
499         
500   def sql_find_relations_in_area_and_ways(xmin,ymin,xmax,ymax,way_ids)
501         # ** It would be more Potlatchy to get relations for nodes within ways
502         #    during 'getway', not here
503         sql=<<-EOF
504           SELECT DISTINCT cr.id AS relid 
505                 FROM current_relations cr
506   INNER JOIN current_relation_members crm ON crm.id=cr.id 
507   INNER JOIN current_nodes cn ON crm.member_id=cn.id AND crm.member_type='node' 
508            WHERE #{OSM.sql_for_area(ymin, xmin, ymax, xmax, "cn.")}
509         EOF
510         unless way_ids.empty?
511           sql+=<<-EOF
512            UNION
513           SELECT DISTINCT cr.id AS relid
514                 FROM current_relations cr
515   INNER JOIN current_relation_members crm ON crm.id=cr.id
516            WHERE crm.member_type='way' 
517                  AND crm.member_id IN (#{way_ids.join(',')})
518           EOF
519         end
520         return ActiveRecord::Base.connection.select_all(sql).collect { |a| a['relid'].to_i }.uniq
521   end
522         
523   def sql_get_nodes_in_way(wayid)
524         points=[]
525         sql=<<-EOF
526                 SELECT latitude*0.0000001 AS lat,longitude*0.0000001 AS lon,current_nodes.id,tags 
527                   FROM current_way_nodes,current_nodes 
528                  WHERE current_way_nodes.id=#{wayid.to_i} 
529                    AND current_way_nodes.node_id=current_nodes.id 
530                    AND current_nodes.visible=1
531           ORDER BY sequence_id
532           EOF
533         ActiveRecord::Base.connection.select_all(sql).each do |row|
534           points << [row['lon'].to_f,row['lat'].to_f,row['id'].to_i,nil,tagstring_to_hash(row['tags'])]
535         end
536         points
537   end
538         
539   def sql_get_tags_in_way(wayid)
540         tags={}
541         ActiveRecord::Base.connection.select_all("SELECT k,v FROM current_way_tags WHERE id=#{wayid.to_i}").each do |row|
542           tags[row['k']]=row['v']
543         end
544         tags
545   end
546
547 end