front end issue #74_location endpoint for mapping

api/src/resources/locations.py

@@ -1,6 +1,10 @@
+from functools import partial, reduce
+from collections import defaultdict, namedtuple
+
 from flask import Blueprint, request, jsonify
 from flask_restful import Api, Resource, fields
 from geoalchemy2 import functions
+from sqlalchemy import func
 
 from .base import BaseAPI, BaseListAPI
 from models import db, Project, ProjectType, Location
@@ -76,3 +80,118 @@ def get(self, id):
 
 
 api.add_resource(LocationProjectAPI, '/locations/<int:id>/project', endpoint='location_project')
+
+
+def build_project_year_query(min_year, max_year):
+    min_year_query = (Project.year >= min_year) if min_year else None
+    max_year_query = (Project.year <= max_year) if max_year else None
+
+    if min_year is not None and max_year is not None:
+        year_query = min_year_query & max_year_query
+    elif max_year is not None:
+        year_query = max_year_query
+    elif min_year is not None:
+        year_query = min_year_query
+    else:
+        year_query = None
+
+    return year_query
+
+
+def format_map_component_output(location, project):
+    return {
+        'points': LatLongArray,
+        'project_name': thisProject.name,
+        'center': LatLongCenter,
+        'project_id': location.project_id,
+        'project_type': thisProjectType.type_name
+    }
+
+def query_projects(min_year, max_year, project_types):
+    if project_types is None:
+        project_types = []
+    project_types = list(map(lambda type: type.lower(), project_types))
+    project_types = ProjectType.query.filter(
+        func.lower(ProjectType.type_name).in_(project_types)).all()
+    project_type_ids = [type.id for type in project_types]
+
+    year_query = build_project_year_query(min_year, max_year)
+
+    project_type_query = (Project.project_type_id.in_(project_type_ids))
+
+    projects = Project.query
+    if year_query is not None:
+        projects = projects.filter(year_query)
+
+    projects = projects.filter(project_type_query)
+
+    projects = projects.all()
+
+    return projects
+
+
+def compute_centroid(points):
+    points = list(points)
+    if len(points) == 0:
+        return points
+    try:
+        lat = sum(p.get('lat') for p in points if p.get('lat') is not None)
+        lat /= len([p for p in points if p.get('lat') is not None])
+        lng = sum(p.get('lng') for p in points if p.get('lng') is not None)
+        lng /= len([p for p in points if p.get('lng') is not None])
+        return {'lat': lat, 'lng': lng}
+    except ZeroDivisionError as e:
+        return points[0]
+
+Coord = namedtuple('Coord', ['lat', 'lng'])
+
+def aggregate_projects(projects):
+    grouped_by_name = defaultdict(list)
+    for project in projects:
+        grouped_by_name[project.name.lower()].append(project)
+    aggregates = []
+    for project_name, group in grouped_by_name.items():
+        locations = [project.locations for project in group]
+        coords = [[loc.coords for loc in loc_group] for loc_group in locations]
+        coords_nt = [list(map(lambda c: Coord(c.get('latitude'), c.get('longitude')), coord_group)) for coord_group in coords]
+        points_nt = reduce(
+            lambda agg, next: agg | set(next),
+            coords_nt,
+            set([])
+        )
+        points = [p._asdict() for p in points_nt]
+        center = compute_centroid(points)
+        project_ids = [project.id for project in group]
+        project_types = list(set(project.type.type_name.lower() for project in group))
+        gge_reduced = sum(proj.gge_reduced for proj in group if proj.gge_reduced is not None)
+        ghg_reduced = sum(proj.ghg_reduced for proj in group if proj.ghg_reduced is not None)
+        aggregates.append({
+            'points': points,
+            'project_name': project_name,
+            'center': center,
+            'project_ids': project_ids,
+            'project_types': project_types,
+            'ghg_reduced': ghg_reduced,
+            'gge_reduced': gge_reduced
+        })
+    return aggregates
+
+
+class LocationMapComponent(BaseListAPI):
+    base = LocationAPI()
+
+    def get(self):
+        min_year = request.args.get('minYear')
+        if min_year is not None:
+            min_year = int(min_year)
+        max_year = request.args.get('maxYear')
+        if max_year is not None:
+            max_year = int(max_year)
+        project_types = request.args.getlist('projectType')
+        # format project types
+        projects = query_projects(min_year, max_year, project_types)
+        projects_agg = aggregate_projects(projects)
+        return jsonify(projects_agg)
+
+
+api.add_resource(LocationMapComponent, '/locationMap', '/locationMap/')