Add support for json queries for recordings

app/api/blueprint.py

@@ -18,6 +18,7 @@ def add_resources():
     from .resources.token import TokenResource, ValidateTokenResource
     from .resources.device import (DeviceResource,
                                    DeviceRecordingResource,
+                                   DeviceRecordingQueryResource,
                                    DeviceListResource,
                                    DeviceTypeResource,
                                    DeviceTypeListResource,
@@ -42,6 +43,8 @@ def add_resources():
     api.add_resource(DeviceResource, '/v1/devices/<int:device_id>')
     api.add_resource(DeviceRecordingResource,
                      '/v1/devices/<int:device_id>/recordings')
+    api.add_resource(DeviceRecordingQueryResource,
+                     '/v1/devices/<int:device_id>/recordings/jsonql')
     api.add_resource(DeviceListResource, '/v1/devices')
     api.add_resource(DeviceTypeResource,
                      '/v1/devices/types/<int:device_type_id>')

app/api/resources/device.py

@@ -31,7 +31,13 @@ class DeviceWithConfigurationSchema(DeviceSchema):
 class RecordingsSchema(BaseResourceSchema):
     recorded_at = fields.DateTime()
     record_type = fields.Integer()
-    record_value = fields.String()
+    record_value = fields.Float()
+
+
+class RecordingsQuerySchema(Schema):
+    selections = fields.Raw()
+    filters = fields.Raw()
+    groups = fields.Raw()
 
 
 class DeviceSecretSchema(BaseResourceSchema):
@@ -103,6 +109,17 @@ class DeviceRecordingResource(ProtectedResource):
         return RecordingsSchema().dump(created_recording), 201
 
 
+class DeviceRecordingQueryResource(ProtectedResource):
+    @use_args(RecordingsQuerySchema(), locations=('json',))
+    @swag_from('swagger/create_device_recording_query_spec.yaml')
+    def post(self, args, device_id):
+        validate_device_ownership(device_id)
+        try:
+            return devices.run_custom_query(device_id, args), 200
+        except ValueError as e:
+            abort(400, message=str(e), status='error')
+
+
 class DeviceListResource(ProtectedResource):
     @use_args(DeviceSchema(), locations=('json',))
     @swag_from('swagger/create_device_spec.yaml')

app/devices/api.py

@@ -3,6 +3,7 @@ import hmac
 import urllib.parse
 from .models import Device, Recording, DeviceAssociation, DeviceType
 from app.core import app
+from app.jsonql import api as jsonql
 
 
 # Private helpers
@@ -260,3 +261,30 @@ def create_recording(device_id, raw_json):
     recording = parse_raw_json_recording(device_id, raw_json)
     with app.app_context():
         recording.save()
+
+
+def run_custom_query(device_id, request):
+    """
+    """
+    if not Device.exists(id=device_id):
+        raise ValueError("Device does not exist!")
+
+    def recording_field_provider(name):
+        if name == 'record_value':
+            return Recording.record_value
+        if name == 'record_type':
+            return Recording.record_type
+        if name == 'device_id':
+            return Recording.device_id
+        if name == 'recorded_at':
+            return Recording.recorded_at
+        if name == 'received_at':
+            return Recording.received_at
+
+    resulting_query = jsonql.run_query_on(Recording.query.with_entities(),
+                                          recording_field_provider,
+                                          **request)
+    print("Resulting query: " + str(resulting_query))
+    result = resulting_query.filter(Recording.device_id == device_id).all()
+    print("RESULT: " + str(result))
+    return result

app/devices/models.py

@@ -16,14 +16,14 @@ class Recording(db.Model):
                             default=db.func.current_timestamp())
     device_id = db.Column(db.Integer, db.ForeignKey('devices.id'))
     record_type = db.Column(db.Integer, nullable=False)
-    record_value = db.Column(db.String, nullable=False)
+    record_value = db.Column(db.Float, nullable=False)
     raw_record = db.Column(JSON, nullable=True)
 
     def __init__(self, device_id, record_type,
                  record_value, recorded_at, raw_json):
         self.device_id = int(device_id)
         self.record_type = int(record_type)
-        self.record_value = str(record_value)
+        self.record_value = float(record_value)
         self.recorded_at = datetime.fromtimestamp(int(recorded_at))
         self.received_at = datetime.utcnow()
         self.raw_record = raw_json

app/jsonql/api.py

@@ -0,0 +1,93 @@
+from app.core import db
+
+GROUPS = ['sum', 'avg', 'count']
+FILTERS = ['$gt', '$lt', '$eq']
+PERIODS = ['year', 'month', 'week', 'day']
+
+
+def run_query_on(query_object, field_provider, **kwargs):
+    selections, filters, groups = validate_selections(**kwargs)
+    entities = []
+
+    print('Starting with args: ' + str(kwargs))
+
+    if selections is not None:
+        for selection in selections.keys():
+            entities.append(get_column(selections[selection],
+                            field_provider(selection)))
+
+        print('New entities: ' + str(entities))
+        query_object = query_object.with_entities(*entities)
+
+    if filters is not None:
+        for filtered_column in filters.keys():
+            for actual_filter in filters[filtered_column].keys():
+                query_object = query_object.filter(
+                        get_filter(field_provider(filtered_column),
+                                   actual_filter,
+                                   filters[filtered_column][actual_filter]))
+
+    if groups is not None:
+        for group in groups.keys():
+            query_object = query_object.group_by(
+                    get_group(field_provider(group), groups[group]))
+
+    return query_object
+
+
+def get_column(selection_name, field):
+    if selection_name == 'value':
+        return field
+    if selection_name == 'sum':
+        return db.func.sum(field)
+    if selection_name == 'avg':
+        return db.func.avg(field)
+    if selection_name == 'count':
+        return db.func.count(field)
+
+
+def get_filter(filter_column, filter_key, filter_value):
+    if filter_key == '$gt':
+        return filter_column > filter_value
+    if filter_key == '$lt':
+        return filter_column < filter_value
+    if filter_key == '$eq':
+        return filter_column == filter_value
+
+
+def get_group(group_column, group_value):
+    if group_value == 'value':
+        return group_column
+    if group_value in PERIODS:
+        return db.func.date_part(group_value, group_column)
+    # We now expect a date format
+    return db.func.to_char(group_column, group_value)
+
+
+def is_group(**kwargs):
+    if kwargs.get('group') is not None:
+        return True
+
+
+def validate_selections(**kwargs):
+    selections = kwargs.get('selections')
+    filters = kwargs.get('filters')
+    groups = kwargs.get('groups')
+
+    if selections is None:
+        raise ValueError("Missing selections!")
+
+    if is_group(**kwargs):
+        for key in selections.keys():
+            if selections[key] not in GROUPS:
+                raise ValueError("Can only use sum, avg and count when\
+                                 grouping!")
+
+    if filters is not None:
+        for key in filters.keys():
+            for inner_key in filters[key].keys():
+                if inner_key not in FILTERS:
+                    raise ValueError("Unknown filter: " + str(
+                        inner_key))
+
+    return selections, filters, groups

app/jsonql/example_query.json

@@ -0,0 +1,16 @@
+{
+    "target": "Recording",
+    "selection": {
+        "record_value": "sum",
+        "record_type": "count",
+        "record_type": "avg"
+    },
+    "filter": {
+        "date": {
+            "$gt": "12-12-02"
+        }
+    },
+    "group": {
+        "date": "month"
+    }
+}

app/swagger/template.yaml

@@ -157,9 +157,9 @@ definitions:
       record_type:
         $ref: '#/definitions/id'
       record_value:
-        type: string
+        type: float
         description: Value of the recording
-        example: '25 degrees'
+        example: 25.0
 
   RecordingCreation:
     type: object
@@ -173,9 +173,9 @@ definitions:
       record_type:
         $ref: '#/definitions/id'
       record_value:
-        type: string
+        type: float
         description: Value of the recording
-        example: '25 degrees'
+        example: 25.0
 
   DeviceType:
     type: object

migrations/versions/c09252c2c547_.py

@@ -0,0 +1,34 @@
+"""empty message
+
+Revision ID: c09252c2c547
+Revises: dad1f9b4eec2
+Create Date: 2018-10-30 19:33:17.778301
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'c09252c2c547'
+down_revision = 'dad1f9b4eec2'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.alter_column('recordings', 'record_value',
+               existing_type=sa.String(),
+               type_=sa.Float(),
+               postgresql_using='record_value::double precision')
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.alter_column('recordings', 'record_value',
+               existing_type=sa.Float(),
+               type_=sa.String(),
+               nullable=False)
+    # ### end Alembic commands ###