Alpha endpoint to correctly split path into selection parts

fixes #253

TODO: altitude, see #256

backend/promis/backend_api/serializer.py

@@ -16,6 +16,7 @@
 from backend_api import helpers
 import parsers
 import unix_time
+import math
 
 
 class LookupById:
@@ -78,19 +79,8 @@ def get_geo_line(self, obj):
         # Just in case for the future
         #return obj.geo_line.wkb.hex()
 
-        poly = self.context['request'].query_params.get('polygon')
-
-        # Convert polygon to GEOS object as intersection doesn't auto-convert
-        if poly:
-            try:
-                poly = GEOSGeometry(poly, srid = 4326)
-            except ValueError:
-                raise NotFound("Invalid WKT for polygon selection")
-
-        geo_line = obj.geo_line if not poly else obj.geo_line.intersection(poly)
-
         # TODO: study whether pre-building the list or JSON would speed up things
-        return parsers.wkb(geo_line.wkb) # <- Generator
+        return parsers.wkb(obj.geo_line.wkb) # <- Generator
 
     def get_timelapse(self, obj):
         # TODO: change to time_start in model for consistency
@@ -260,3 +250,67 @@ def update(self, instance, validated_data):
             password = validated_data.pop('password')
             instance.set_password(password)
         return super().update(instance, validated_data)
+
+# TODO: REFACTOR, alpha code below
+class DataSerializer(serializers.ModelSerializer):
+    session = SwaggerHyperlinkedRelatedField(many = False, view_name = 'session-detail', read_only = True)
+    channel = SwaggerHyperlinkedRelatedField(many = False, view_name = 'channel-detail', read_only = True)
+    parameter = SwaggerHyperlinkedRelatedField(many = False, view_name = 'parameter-detail', read_only = True)
+    selection = serializers.SerializerMethodField()
+
+
+    class Meta(LookupById):
+        # TODO: add 'url' here, currently it's broken, see #196
+        fields = ('id', 'session', 'parameter', 'channel', 'sampling_frequency', 'min_frequency', 'max_frequency', 'selection')
+        model = models.Measurement
+
+    def get_selection(self, obj):
+        def gen_selection():
+            # Extracting request information
+            poly = self.context['request'].query_params.get('polygon')
+            time_begin = self.context['request'].query_params.get('time_begin')
+            time_end = self.context['request'].query_params.get('time_end')
+
+            # Agreeing on time boundaries
+            session_start = unix_time.datetime_to_utc(obj.session.time_begin)
+            session_end = unix_time.datetime_to_utc(obj.session.time_end)
+            time_begin = int(time_begin) if time_begin else session_start
+            time_end = int(time_end) if time_end else session_end
+
+            # Convert polygon to GEOS object as intersection doesn't auto-convert
+            if poly:
+                try:
+                    poly = GEOSGeometry(poly, srid = 4326)
+
+                    # FIXME: Django's GEOS implementation
+                    # doesn't support 4D linestrings
+                    # TODO: patch upstream, it's horrible!
+
+                    # Intersection of search polygon and the orbit
+                    for sect in obj.session.geo_line.intersection(poly):
+                        # NOTE: taking the first and last point within the selection
+                        sect_start = math.ceil(sect[0][2]) + session_start
+                        sect_end = math.floor(sect[-1][2]) + session_start
+
+                        # TODO: if you ever catch this assert, call me
+                        assert sect_end >= sect_start
+
+                        print(sect_start, sect_end)
+                        print(time_begin, time_end)
+
+                        # If the data not within time selection, skip completely
+                        if sect_end < time_begin or sect_start > time_end:
+                            continue
+
+                        yield { 'start': max(time_begin, sect_start), 'end': min(time_end, sect_end) }
+
+
+                except ValueError:
+                    raise NotFound("Invalid WKT for polygon selection")
+            # Otherwise take the whole session, just make sure to trim the time values
+            else:
+                yield { 'start': max(time_begin, session_start),
+                        'end': min(time_end, session_end) }
+
+        # TODO: data links
+        return [ x for x in gen_selection() ]

backend/promis/backend_api/views.py

@@ -26,8 +26,6 @@
 from rest_framework.exceptions import NotAuthenticated, NotFound, MethodNotAllowed
 from rest_framework.renderers import JSONRenderer, BrowsableAPIRenderer
 
-from django.contrib.gis.geos import GEOSGeometry
-
 import unix_time
 
 import datetime
@@ -264,7 +262,7 @@ def UserUpdate(request):
 # TODO: create a proper filterset
 # TODO: make use of Q() to help django understand the request
 class DataView(PromisViewSet):
-    serializer_class = serializer.MeasurementsSerializer
+    serializer_class = serializer.DataSerializer
     # TODO: only to prevent Django from asking for base_name
     queryset = models.Measurement.objects.all()
 
@@ -274,13 +272,14 @@ def get_queryset(self):
         # Composing the filter
         filter_opts = {}
 
+        # Begin-End's are reversed: we are looking for session that overlap the time selection
         time_begin = self.request.query_params.get('time_begin')
         if time_begin:
-            filter_opts['session__time_begin__gte'] = unix_time.maketime(int(time_begin))
+            filter_opts['session__time_end__gte'] = unix_time.maketime(int(time_begin))
 
         time_end = self.request.query_params.get('time_end')
         if time_end:
-            filter_opts['session__time_end__lte'] = unix_time.maketime(int(time_end))
+            filter_opts['session__time_begin__lte'] = unix_time.maketime(int(time_end))
 
         # NOTE: channels and filters are combined as *AND* not *OR* at the moment
         # so they are mutually exclusive in a sense, but this won't be a problem for alpha
@@ -296,15 +295,11 @@ def get_queryset(self):
 
         poly = self.request.query_params.get('polygon')
 
-        # Convert polygon to GEOS object as intersection doesn't auto-convert
         if poly:
             try:
-                poly = GEOSGeometry(poly, srid = 4326)
                 filter_opts['session__geo_line__intersects'] = poly
             except ValueError:
                 raise NotFound("Invalid WKT for polygon selection")
 
         # Applying the filter
-        qs = models.Measurement.objects.filter(**filter_opts)
-
-        return qs
+        return models.Measurement.objects.filter(**filter_opts)

backend/promis/classes/potential.py

@@ -132,7 +132,7 @@ def fetch(self, daydir):
                                 ez_time_end = time_end
 
                                 # Generator for the orbit
-                                line_gen = ( (y.lon, y.lat, y.alt) for _, y, _ in orbit.generate_orbit(orbit_path, time_start, time_end) )
+                                line_gen = ( (y.lon, y.lat, t) for t, y, _ in orbit.generate_orbit(orbit_path, time_start, time_end) )
                                 # Converting time to python objects for convenience
                                 # This is the point where onboard time gets converted to the UTC
                                 time_start = unix_time.maketime(time_start)

backend/promis/classes/test_set.py

@@ -35,7 +35,7 @@ def general_fetch(path, satellite_object):
             timemark = int(sess_name)
             ftp.cwd(sess_name)
             with ftp.xopen("orbit.csv") as fp:
-                line_gen = [ pt for pt in parsers.csv(fp) ]
+                line_gen = [ (pt[0],pt[1],t) for t, pt in enumerate(parsers.csv(fp)) ]
                 time_start = unix_time.maketime(timemark)
                 time_end = unix_time.maketime(timemark + len(line_gen)) # Orbit points are 1 per second
                 time_dur = time_end - time_start

backend/promis/orbit.py

@@ -126,4 +126,4 @@ def predict(t):
             res_vals[0] = ( res_vals[0] + 180 ) % 360 - 180
             return OrbitPoint(*res_vals)
 
-        yield j, datapoints[j] if j in datapoints else predict(j), False if j in datapoints else True
+        yield j - orbit_start, datapoints[j] if j in datapoints else predict(j), False if j in datapoints else True

frontend/app/components/CesiumMap.js

@@ -458,8 +458,8 @@ export default class CesiumContainer extends Component {
         let cartesians = new Array();
 
         /* data is [lat, lon, hgt] */
-        data.forEach(function(point) {
-            cartesians.push(Cartesian3.fromDegrees(point[1], point[0], point[2] ? point[2] : 250000));
+        data.forEach(function(point) { // TODO temporary disabling altitude because it stores time temporarily
+            cartesians.push(Cartesian3.fromDegrees(point[1], point[0], /*point[2] ? point[2] :*/ 250000));
         });
 
         return this.viewer.entities.add({