opengis: add tile endpoint (calls GetMap) (#19603)

debian/control

@@ -25,7 +25,8 @@ Depends: ${python:Depends},
     python-suds,
     python-cmislib (>= 0.5), python-cmislib (< 0.6),
     python-lxml,
-    python-dateutil
+    python-dateutil,
+    python-pyproj
 Recommends: python-soappy, python-phpserialize
 Suggests: python-sqlalchemy, python-mako
 Description: Uniform access to multiple data sources and services (Python module)

passerelle/apps/opengis/models.py

@@ -14,10 +14,14 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import math
 import xml.etree.ElementTree as ET
-from django.utils.text import slugify
+
+import pyproj
 
 from django.db import models
+from django.http import HttpResponse
+from django.utils.text import slugify
 from django.utils.translation import ugettext_lazy as _
 
 from passerelle.base.models import BaseResource
@@ -70,3 +74,48 @@ class OpenGIS(BaseResource):
         response = self.requests.get(self.service_root_url, params=params)
         element = ET.fromstring(response.content)
         return {'err': 0, 'data': build_dict_from_xml(element)}
+
+    # https://carton.entrouvert.org/hydda-tiles/16/33650/23378.pn
+    @endpoint(name='tile', pattern=r'^(?P<zoom>\d+)/(?P<tile_x>\d+)/(?P<tile_y>\d+).png',
+              example_pattern='{zoom}/{tile_x}/{tile_y}.png',
+              parameters={
+                  'zoom': {'description': _('Zoom Level'), 'example_value': '16'},
+                  'tile_x': {'description': _('X Coordinate'), 'example_value': '33650'},
+                  'tile_y': {'description': _('Y Coordinate'), 'example_value': '23378'},
+              })
+    def tile(self, request, zoom, tile_x, tile_y):
+        zoom = int(zoom)
+
+        tile_x = int(tile_x)
+        tile_y = int(tile_y) + 1
+
+        def num2deg(xtile, ytile, zoom):
+            # http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#Python
+            n = 2.0 ** zoom
+            lon_deg = xtile / n * 360.0 - 180.0
+            lat_rad = math.atan(math.sinh(math.pi * (1 - 2 * ytile / n)))
+            lat_deg = math.degrees(lat_rad)
+            return (lon_deg, lat_deg)
+
+        wgs84 = pyproj.Proj(init='epsg:4326')
+        epsg3857 = pyproj.Proj(init='epsg:3857')
+        tl_lon, tl_lat = pyproj.transform(wgs84, epsg3857, *num2deg(tile_x, tile_y, zoom))
+        br_lon, br_lat = pyproj.transform(wgs84, epsg3857, *num2deg(tile_x+1, tile_y+1, zoom))
+        bbox = '%s,%s,%s,%s' % (tl_lon, tl_lat, br_lon, br_lat)
+
+        params = {
+            'VERSION': '1.1.1',
+            'SERVICE': 'WMS',
+            'REQUEST': 'GetMap',
+            'LAYERS': self.query_layer,
+            'STYLES': '',
+            'FORMAT': 'image/png',
+            'TRANSPARENT': 'false',
+            'HEIGHT': '256',
+            'WIDTH': '256',
+            'SRS': 'EPSG:3857',
+            'BBOX': bbox,
+        }
+        return HttpResponse(
+                self.requests.get(self.service_root_url, params=params).content,
+                content_type='image/png')

requirements.txt

@@ -6,4 +6,5 @@ requests
 -e git+http://repos.entrouvert.org/gadjo.git/#egg=gadjo
 SOAPpy
 phpserialize
+pyproj
 suds

setup.py

@@ -97,6 +97,7 @@ setup(name='passerelle',
             'pyexcel-ods >= 0.4, <0.5',
             'pyexcel-xls >= 0.4, <0.5',
             'cmislib >= 0.5, <0.6',
+            'pyproj',
             'feedparser',
             'lxml',
             'python-dateutil',

tests/test_opengis.py

@@ -42,3 +42,11 @@ def test_feature_info(mocked_get, app, connector):
     mocked_get.return_value = utils.FakedResponse(content=FAKE_FEATURE_INFO, status_code=200)
     resp = app.get(endpoint, params={'lat': '45.796890', 'lon': '4.784140'})
     assert resp.json['data']['cad_cadastrecadparcelle_layer']['cad_cadastrecadparcelle_feature']['natureproprietaire'] == 'Particulier'
+
+@mock.patch('passerelle.utils.LoggedRequest.get')
+def test_tile(mocked_get, app, connector):
+    endpoint = utils.generic_endpoint_url('opengis', 'tile', slug=connector.slug)
+    assert endpoint == '/opengis/test/tile'
+    mocked_get.return_value = utils.FakedResponse(content='\x89PNG\r\n\x1a\n\x00\x00...', status_code=200)
+    resp = app.get(endpoint + '/16/33650/23378.png')
+    assert resp.content == '\x89PNG\r\n\x1a\n\x00\x00...'