From f86e4d33113f462092fe23263721cccd599c3303 Mon Sep 17 00:00:00 2001
From: Ilya Zverev <zverik@textual.ru>
Date: Mon, 9 Sep 2013 23:48:40 +0100
Subject: [PATCH] Single changeset query

---
 .../controllers/changeset_api_controller.rb   | 28 +++++++++++++++++++
 rails/config/routes.rb                        |  4 +++
 2 files changed, 32 insertions(+)

diff --git a/rails/app/controllers/changeset_api_controller.rb b/rails/app/controllers/changeset_api_controller.rb
index a36c995..94ce4ff 100644
--- a/rails/app/controllers/changeset_api_controller.rb
+++ b/rails/app/controllers/changeset_api_controller.rb
@@ -47,6 +47,16 @@ def summary_tilerange
     render :json => @summary_list.as_json, :callback => params[:callback]
   end
 
+  def changeset_json
+    @changesets = find_changeset('json')
+    render :json => JSON[@changesets.map(&:generate_json)], :callback => params[:callback]
+  end
+
+  def changeset_geojson
+    @changesets = find_changeset('geojson')
+    render :json => changesets_to_geojson(@changesets, @x, @y, @zoom), :callback => params[:callback]
+  end
+
 private
   def find_changesets_by_tile(format)
     @x, @y, @zoom = get_xyz(params)
@@ -97,6 +107,24 @@ def find_changesets_by_range(format)
     changesets
   end
 
+  def find_changeset(format)
+    @id = params[:id].to_i
+    changesets = ActiveRecord::Base.connection.select_all("
+      SELECT cs.*,
+        #{format == 'geojson' ? '(SELECT array_agg(ST_AsGeoJSON(g)) FROM unnest(t.geom) AS g) AS geom_geojson,' : ''}
+        #{format == 'geojson' ? '(SELECT array_agg(ST_AsGeoJSON(g)) FROM unnest(t.prev_geom) AS g) AS prev_geom_geojson,' : ''}
+        (SELECT ST_Extent(g) FROM unnest(t.geom) AS g)::text AS bboxes,
+        cs.bbox::box2d::text AS total_bbox,
+        (SELECT array_agg(g) FROM unnest(t.changes) AS g) AS change_ids
+      FROM changeset_tiles t
+      INNER JOIN changesets cs ON (cs.id = t.changeset_id)
+      WHERE cs.id = #{@id}
+      GROUP BY t.geom, t.prev_geom, t.changes
+      ").collect {|row| Changeset.new(row)}
+    load_changes(changesets)
+    changesets
+  end
+
   def generate_summary_tile
     @x, @y, @zoom = get_xyz(params)
     rows = ActiveRecord::Base.connection.select_all("WITH agg AS (
diff --git a/rails/config/routes.rb b/rails/config/routes.rb
index 4b619ef..c4cb313 100644
--- a/rails/config/routes.rb
+++ b/rails/config/routes.rb
@@ -18,6 +18,10 @@
   match 'api/0.1/summary/:zoom/:x/:y' => 'changeset_api#summary_tile', :constraints => @xyz_constrains
   match 'api/0.1/summary/:zoom/:x1/:y1/:x2/:y2' => 'changeset_api#summary_tilerange', :constraints => @range_constrains, :format => 'json'
 
+  # Single changeset operations
+  match 'api/0.1/changeset/:id.geojson' => 'changeset_api#changeset_geojson', :constraints => { :id => /\d+/ }, :format => 'json'
+  match 'api/0.1/changeset/:id.json' => 'changeset_api#changeset_json', :constraints => { :id => /\d+/ }, :format => 'json'
+
   # Map API
   match 'api/0.1/kothic/:zoom/:x/:y.js' => 'map_api#kothic', :constraints => @xyz_constrains
 end