Validate broadcast against schema

This commit adds a JSONSchema which can validate the fields in an API
call to create a broadcast. It takes the CAP XML schema as a starting
point.

app/v2/broadcast/broadcast_schemas.py

@@ -0,0 +1,97 @@
+post_broadcast_schema = {
+    "$schema": "http://json-schema.org/draft-07/schema",
+    "type": "object",
+    "required": [
+        "reference",
+        "category",
+        "content",
+        "areas",
+    ],
+    "additionalProperties": False,
+    "properties": {
+        "reference": {
+            "type": [
+                "string",
+                "null",
+            ],
+        },
+        "category": {
+            "type": "string",
+            "enum": [
+                "Geo",
+                "Met",
+                "Safety",
+                "Security",
+                "Rescue",
+                "Fire",
+                "Health",
+                "Env",
+                "Transport",
+                "Infra",
+                "CBRNE",
+                "Other",
+            ],
+        },
+        "expires": {
+            "type": "string",
+            "format": "date-time",
+        },
+        "content": {
+            "type": "string",
+            "minLength": 1,
+            "maxLength": 1395,
+        },
+        "web": {
+            "type": "string",
+            "format": "uri",
+        },
+        "areas": {
+            "type": "array",
+            "minItems": 1,
+            "items": {
+                "$ref": "#/definitions/area",
+            },
+        },
+    },
+    "definitions": {
+        "area": {
+            "type": "object",
+            "required": [
+                "name",
+                "polygons",
+            ],
+            "additionalProperties": False,
+            "properties": {
+                "name": {
+                    "type": "string",
+                },
+                "polygons": {
+                    "type": "array",
+                    "minItems": 1,
+                    "items": {
+                        "oneOf": [
+                            {
+                                "$ref": "#/definitions/polygon",
+                            },
+                        ],
+                    },
+                },
+            },
+        },
+        "polygon": {
+            "type": "array",
+            "minItems": 4,
+            "items": {
+                "$ref": "#/definitions/coordinatePair",
+            },
+        },
+        "coordinatePair": {
+            "type": "array",
+            "items": {
+                "type": "number"
+            },
+            "minItems": 2,
+            "maxItems": 2,
+        },
+    },
+}

app/v2/broadcast/post_broadcast.py

@@ -1,9 +1,12 @@
+from itertools import chain
 from flask import jsonify, request
 from app import authenticated_service, api_user
 from app.dao.dao_utils import dao_save_object
 from app.notifications.validators import check_service_has_permission
 from app.models import BROADCAST_TYPE, BroadcastMessage, BroadcastStatusType
+from app.schema_validation import validate
 from app.v2.broadcast import v2_broadcast_blueprint
+from app.v2.broadcast.broadcast_schemas import post_broadcast_schema
 
 
 @v2_broadcast_blueprint.route("", methods=['POST'])
@@ -14,15 +17,19 @@ def create_broadcast():
         authenticated_service.permissions,
     )
 
-    request_json = request.get_json()
+    broadcast_json = validate(request.get_json(), post_broadcast_schema)
 
     broadcast_message = BroadcastMessage(
         service_id=authenticated_service.id,
-        content=request_json['content'],
-        reference=request_json['reference'],
+        content=broadcast_json['content'],
+        reference=broadcast_json['reference'],
         areas={
-            "areas": [],
-            "simple_polygons": request_json['polygons'],
+            'areas': [
+                area['name'] for area in broadcast_json['areas']
+            ],
+            'simple_polygons': list(chain.from_iterable((
+                area['polygons'] for area in broadcast_json['areas']
+            )))
         },
         status=BroadcastStatusType.PENDING_APPROVAL,
         api_key_id=api_user.id,