Support unwrapped bbox values in changeset history queries

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

diff --git a/app/controllers/changesets_controller.rb b/app/controllers/changesets_controller.rb
index 5e79f4da62a70ac42bc4e75203c60a70d073de24..07e7a365f0d1a3884e62a99f3cdb61fc82e64bad 100644 (file)
--- a/app/controllers/changesets_controller.rb
+++ b/app/controllers/changesets_controller.rb
@@ -54,7 +54,10 @@ class ChangesetsController < ApplicationController
                        changesets.where("false")
                      end
       elsif @params[:bbox]
-        changesets = conditions_bbox(changesets, BoundingBox.from_bbox_params(params))
+        bbox_array = @params[:bbox].split(",").map(&:to_f)
+        raise OSM::APIBadUserInput, "The parameter bbox must be of the form min_lon,min_lat,max_lon,max_lat" unless bbox_array.count == 4
+
+        changesets = conditions_bbox(changesets, *bbox_array)
       elsif @params[:friends] && current_user
         changesets = changesets.where(:user => current_user.followings.identifiable)
       elsif @params[:nearby] && current_user
@@ -113,21 +116,37 @@ class ChangesetsController < ApplicationController
   #------------------------------------------------------------
 
   ##
-  # if a bounding box was specified do some sanity checks.
   # restrict changesets to those enclosed by a bounding box
-  def conditions_bbox(changesets, bbox)
-    if bbox
-      bbox.check_boundaries
-      bbox = bbox.to_scaled
-
-      changesets.where("min_lon < ? and max_lon > ? and min_lat < ? and max_lat > ?",
-                       bbox.max_lon.to_i, bbox.min_lon.to_i,
-                       bbox.max_lat.to_i, bbox.min_lat.to_i)
-    else
+  def conditions_bbox(changesets, min_lon, min_lat, max_lon, max_lat)
+    db_min_lat = (min_lat * GeoRecord::SCALE).to_i
+    db_max_lat = (max_lat * GeoRecord::SCALE).to_i
+    db_min_lon = (wrap_lon(min_lon) * GeoRecord::SCALE).to_i
+    db_max_lon = (wrap_lon(max_lon) * GeoRecord::SCALE).to_i
+
+    changesets = changesets.where("min_lat < ? and max_lat > ?", db_max_lat, db_min_lat)
+
+    if max_lon - min_lon >= 360
+      # the query bbox spans the entire world, therefore no lon checks are necessary
       changesets
+    elsif db_min_lon <= db_max_lon
+      # the normal case when the query bbox doesn't include the antimeridian
+      changesets.where("min_lon < ? and max_lon > ?", db_max_lon, db_min_lon)
+    else
+      # the query bbox includes the antimeridian
+      # this case works as if there are two query bboxes:
+      #   [-180*SCALE .. db_max_lon], [db_min_lon .. 180*SCALE]
+      # it would be necessary to check if changeset bboxes intersect with either of the query bboxes:
+      #   (changesets.min_lon < db_max_lon and changesets.max_lon > -180*SCALE) or (changesets.min_lon < 180*SCALE and changesets.max_lon > db_min_lon)
+      # but the comparisons with -180*SCALE and 180*SCALE are unnecessary:
+      #   (changesets.min_lon < db_max_lon) or (changesets.max_lon > db_min_lon)
+      changesets.where("min_lon < ? or max_lon > ?", db_max_lon, db_min_lon)
     end
   end
 
+  def wrap_lon(lon)
+    ((lon + 180) % 360) - 180
+  end
+
   ##
   # eliminate empty changesets (where the bbox has not been set)
   # this should be applied to all changeset list displays