import falcon
import simplejson as json
import mysql.connector
import config
import uuid
from core.userlogger import user_logger


class SensorCollection:
    @staticmethod
    def __init__():
        """"Initializes SensorCollection"""
        pass

    @staticmethod
    def on_options(req, resp):
        resp.status = falcon.HTTP_200

    @staticmethod
    def on_get(req, resp):
        cnx = mysql.connector.connect(**config.myems_system_db)
        cursor = cnx.cursor(dictionary=True)

        query = (" SELECT id, name, uuid, description "
                 " FROM tbl_sensors "
                 " ORDER BY id ")
        cursor.execute(query)
        rows_sensors = cursor.fetchall()

        result = list()
        if rows_sensors is not None and len(rows_sensors) > 0:
            for row in rows_sensors:
                meta_result = {"id": row['id'],
                               "name": row['name'],
                               "uuid": row['uuid'],
                               "description": row['description']}
                result.append(meta_result)

        cursor.close()
        cnx.disconnect()
        resp.text = json.dumps(result)

    @staticmethod
    @user_logger
    def on_post(req, resp):
        """Handles POST requests"""
        try:
            raw_json = req.stream.read().decode('utf-8')
        except Exception as ex:
            raise falcon.HTTPError(falcon.HTTP_400, title='API.ERROR', description=ex)

        new_values = json.loads(raw_json)

        if 'name' not in new_values['data'].keys() or \
                not isinstance(new_values['data']['name'], str) or \
                len(str.strip(new_values['data']['name'])) == 0:
            raise falcon.HTTPError(falcon.HTTP_400, title='API.BAD_REQUEST',
                                   description='API.INVALID_SENSOR_NAME')
        name = str.strip(new_values['data']['name'])

        if 'description' in new_values['data'].keys() and \
                new_values['data']['description'] is not None and \
                len(str(new_values['data']['description'])) > 0:
            description = str.strip(new_values['data']['description'])
        else:
            description = None

        cnx = mysql.connector.connect(**config.myems_system_db)
        cursor = cnx.cursor()

        cursor.execute(" SELECT name "
                       " FROM tbl_sensors "
                       " WHERE name = %s ", (name,))
        if cursor.fetchone() is not None:
            cursor.close()
            cnx.disconnect()
            raise falcon.HTTPError(falcon.HTTP_404, title='API.BAD_REQUEST',
                                   description='API.SENSOR_NAME_IS_ALREADY_IN_USE')

        add_values = (" INSERT INTO tbl_sensors "
                      "    (name, uuid, description) "
                      " VALUES (%s, %s, %s) ")
        cursor.execute(add_values, (name,
                                    str(uuid.uuid4()),
                                    description))
        new_id = cursor.lastrowid
        cnx.commit()
        cursor.close()
        cnx.disconnect()

        resp.status = falcon.HTTP_201
        resp.location = '/sensors/' + str(new_id)


class SensorItem:
    @staticmethod
    def __init__():
        """"Initializes SensorItem"""
        pass

    @staticmethod
    def on_options(req, resp, id_):
        resp.status = falcon.HTTP_200

    @staticmethod
    def on_get(req, resp, id_):
        if not id_.isdigit() or int(id_) <= 0:
            raise falcon.HTTPError(falcon.HTTP_400, title='API.BAD_REQUEST',
                                   description='API.INVALID_SENSOR_ID')

        cnx = mysql.connector.connect(**config.myems_system_db)
        cursor = cnx.cursor(dictionary=True)

        query = (" SELECT id, name, uuid, description "
                 " FROM tbl_sensors "
                 " WHERE id = %s ")
        cursor.execute(query, (id_,))
        row = cursor.fetchone()
        cursor.close()
        cnx.disconnect()

        if row is None:
            raise falcon.HTTPError(falcon.HTTP_404, title='API.NOT_FOUND',
                                   description='API.SENSOR_NOT_FOUND')
        else:
            meta_result = {"id": row['id'],
                           "name": row['name'],
                           "uuid": row['uuid'],
                           "description": row['description']}

        resp.text = json.dumps(meta_result)

    @staticmethod
    @user_logger
    def on_delete(req, resp, id_):
        if not id_.isdigit() or int(id_) <= 0:
            raise falcon.HTTPError(falcon.HTTP_400, title='API.BAD_REQUEST',
                                   description='API.INVALID_SENSOR_ID')

        cnx = mysql.connector.connect(**config.myems_system_db)
        cursor = cnx.cursor()

        cursor.execute(" SELECT name "
                       " FROM tbl_sensors "
                       " WHERE id = %s ", (id_,))
        if cursor.fetchone() is None:
            cursor.close()
            cnx.disconnect()
            raise falcon.HTTPError(falcon.HTTP_404, title='API.NOT_FOUND',
                                   description='API.SENSOR_NOT_FOUND')

        # check relation with spaces
        cursor.execute(" SELECT id "
                       " FROM tbl_spaces_sensors "
                       " WHERE sensor_id = %s ", (id_,))
        rows_spaces = cursor.fetchall()
        if rows_spaces is not None and len(rows_spaces) > 0:
            cursor.close()
            cnx.disconnect()
            raise falcon.HTTPError(falcon.HTTP_400,
                                   title='API.BAD_REQUEST',
                                   description='API.THERE_IS_RELATION_WITH_SPACES')

        # check relation with tenants
        cursor.execute(" SELECT id "
                       " FROM tbl_tenants_sensors "
                       " WHERE sensor_id = %s ", (id_,))
        rows_tenants = cursor.fetchall()
        if rows_tenants is not None and len(rows_tenants) > 0:
            cursor.close()
            cnx.disconnect()
            raise falcon.HTTPError(falcon.HTTP_400,
                                   title='API.BAD_REQUEST',
                                   description='API.THERE_IS_RELATION_WITH_TENANTS')

        # check relation with stores
        cursor.execute(" SELECT store_id "
                       " FROM tbl_stores_sensors "
                       " WHERE sensor_id = %s ", (id_,))
        rows_stores = cursor.fetchall()
        if rows_stores is not None and len(rows_stores) > 0:
            cursor.close()
            cnx.disconnect()
            raise falcon.HTTPError(falcon.HTTP_400,
                                   title='API.BAD_REQUEST',
                                   description='API.THERE_IS_RELATION_WITH_STORES')

        # check relation with points
        cursor.execute(" SELECT id "
                       " FROM tbl_sensors_points "
                       " WHERE sensor_id = %s ", (id_,))
        rows_points = cursor.fetchall()
        if rows_points is not None and len(rows_points) > 0:
            cursor.close()
            cnx.disconnect()
            raise falcon.HTTPError(falcon.HTTP_400,
                                   title='API.BAD_REQUEST',
                                   description='API.THERE_IS_RELATION_WITH_POINTS')

        cursor.execute(" DELETE FROM tbl_sensors WHERE id = %s ", (id_,))
        cnx.commit()

        cursor.close()
        cnx.disconnect()

        resp.status = falcon.HTTP_204

    @staticmethod
    @user_logger
    def on_put(req, resp, id_):
        """Handles PUT requests"""
        try:
            raw_json = req.stream.read().decode('utf-8')
        except Exception as ex:
            raise falcon.HTTPError(falcon.HTTP_400, title='API.EXCEPTION', description=ex)

        if not id_.isdigit() or int(id_) <= 0:
            raise falcon.HTTPError(falcon.HTTP_400, title='API.BAD_REQUEST',
                                   description='API.INVALID_SENSOR_ID')

        new_values = json.loads(raw_json)

        if 'name' not in new_values['data'].keys() or \
                not isinstance(new_values['data']['name'], str) or \
                len(str.strip(new_values['data']['name'])) == 0:
            raise falcon.HTTPError(falcon.HTTP_400, title='API.BAD_REQUEST',
                                   description='API.INVALID_SENSOR_NAME')
        name = str.strip(new_values['data']['name'])

        if 'description' in new_values['data'].keys() and \
                new_values['data']['description'] is not None and \
                len(str(new_values['data']['description'])) > 0:
            description = str.strip(new_values['data']['description'])
        else:
            description = None

        cnx = mysql.connector.connect(**config.myems_system_db)
        cursor = cnx.cursor()

        cursor.execute(" SELECT name "
                       " FROM tbl_sensors "
                       " WHERE id = %s ", (id_,))
        if cursor.fetchone() is None:
            cursor.close()
            cnx.disconnect()
            raise falcon.HTTPError(falcon.HTTP_404, title='API.NOT_FOUND',
                                   description='API.SENSOR_NOT_FOUND')

        cursor.execute(" SELECT name "
                       " FROM tbl_sensors "
                       " WHERE name = %s AND id != %s ", (name, id_))
        if cursor.fetchone() is not None:
            cursor.close()
            cnx.disconnect()
            raise falcon.HTTPError(falcon.HTTP_404, title='API.BAD_REQUEST',
                                   description='API.SENSOR_NAME_IS_ALREADY_IN_USE')

        update_row = (" UPDATE tbl_sensors "
                      " SET name = %s, description = %s "
                      " WHERE id = %s ")
        cursor.execute(update_row, (name,
                                    description,
                                    id_,))
        cnx.commit()

        cursor.close()
        cnx.disconnect()

        resp.status = falcon.HTTP_200


class SensorPointCollection:
    @staticmethod
    def __init__():
        """"Initializes SensorPointCollection"""
        pass

    @staticmethod
    def on_options(req, resp, id_):
        resp.status = falcon.HTTP_200

    @staticmethod
    def on_get(req, resp, id_):
        if not id_.isdigit() or int(id_) <= 0:
            raise falcon.HTTPError(falcon.HTTP_400, title='API.BAD_REQUEST',
                                   description='API.INVALID_SENSOR_ID')

        cnx = mysql.connector.connect(**config.myems_system_db)
        cursor = cnx.cursor()

        cursor.execute(" SELECT name "
                       " FROM tbl_sensors "
                       " WHERE id = %s ", (id_,))
        if cursor.fetchone() is None:
            cursor.close()
            cnx.disconnect()
            raise falcon.HTTPError(falcon.HTTP_404, title='API.NOT_FOUND',
                                   description='API.SENSOR_NOT_FOUND')

        query = (" SELECT p.id, p.name, "
                 "        ds.id, ds.name, ds.uuid, "
                 "        p.address "
                 " FROM tbl_points p, tbl_sensors_points sp, tbl_data_sources ds "
                 " WHERE sp.sensor_id = %s AND p.id = sp.point_id AND p.data_source_id = ds.id "
                 " ORDER BY p.name ")
        cursor.execute(query, (id_,))
        rows = cursor.fetchall()

        result = list()
        if rows is not None and len(rows) > 0:
            for row in rows:
                meta_result = {"id": row[0], "name": row[1],
                               "data_source": {"id": row[2], "name": row[3], "uuid": row[4]},
                               "address": row[5]}
                result.append(meta_result)

        resp.text = json.dumps(result)

    @staticmethod
    @user_logger
    def on_post(req, resp, id_):
        """Handles POST requests"""
        try:
            raw_json = req.stream.read().decode('utf-8')
        except Exception as ex:
            raise falcon.HTTPError(falcon.HTTP_400, title='API.EXCEPTION', description=ex)

        if not id_.isdigit() or int(id_) <= 0:
            raise falcon.HTTPError(falcon.HTTP_400, title='API.BAD_REQUEST',
                                   description='API.INVALID_SENSOR_ID')

        new_values = json.loads(raw_json)

        cnx = mysql.connector.connect(**config.myems_system_db)
        cursor = cnx.cursor()

        cursor.execute(" SELECT name "
                       " from tbl_sensors "
                       " WHERE id = %s ", (id_,))
        if cursor.fetchone() is None:
            cursor.close()
            cnx.disconnect()
            raise falcon.HTTPError(falcon.HTTP_404, title='API.NOT_FOUND',
                                   description='API.SENSOR_NOT_FOUND')

        cursor.execute(" SELECT name "
                       " FROM tbl_points "
                       " WHERE id = %s ", (new_values['data']['point_id'],))
        if cursor.fetchone() is None:
            cursor.close()
            cnx.disconnect()
            raise falcon.HTTPError(falcon.HTTP_404, title='API.NOT_FOUND',
                                   description='API.POINT_NOT_FOUND')

        query = (" SELECT id " 
                 " FROM tbl_sensors_points "
                 " WHERE sensor_id = %s AND point_id = %s")
        cursor.execute(query, (id_, new_values['data']['point_id'],))
        if cursor.fetchone() is not None:
            cursor.close()
            cnx.disconnect()
            raise falcon.HTTPError(falcon.HTTP_400, title='API.ERROR',
                                   description='API.SENSOR_POINT_RELATION_EXISTS')

        add_row = (" INSERT INTO tbl_sensors_points (sensor_id, point_id) "
                   " VALUES (%s, %s) ")
        cursor.execute(add_row, (id_, new_values['data']['point_id'],))
        new_id = cursor.lastrowid
        cnx.commit()
        cursor.close()
        cnx.disconnect()

        resp.status = falcon.HTTP_201
        resp.location = '/sensors/' + str(id_) + '/points/' + str(new_values['data']['point_id'])


class SensorPointItem:
    @staticmethod
    def __init__():
        """"Initializes SensorPointItem"""
        pass

    @staticmethod
    def on_options(req, resp, id_, pid):
        resp.status = falcon.HTTP_200

    @staticmethod
    @user_logger
    def on_delete(req, resp, id_, pid):
        if not id_.isdigit() or int(id_) <= 0:
            raise falcon.HTTPError(falcon.HTTP_400, title='API.BAD_REQUEST',
                                   description='API.INVALID_SENSOR_ID')

        if not pid.isdigit() or int(pid) <= 0:
            raise falcon.HTTPError(falcon.HTTP_400, title='API.BAD_REQUEST',
                                   description='API.INVALID_POINT_ID')

        cnx = mysql.connector.connect(**config.myems_system_db)
        cursor = cnx.cursor()

        cursor.execute(" SELECT name "
                       " FROM tbl_sensors "
                       " WHERE id = %s ", (id_,))
        if cursor.fetchone() is None:
            cursor.close()
            cnx.disconnect()
            raise falcon.HTTPError(falcon.HTTP_404, title='API.NOT_FOUND',
                                   description='API.SENSOR_NOT_FOUND')

        cursor.execute(" SELECT name "
                       " FROM tbl_points "
                       " WHERE id = %s ", (pid,))
        if cursor.fetchone() is None:
            cursor.close()
            cnx.disconnect()
            raise falcon.HTTPError(falcon.HTTP_404, title='API.NOT_FOUND',
                                   description='API.POINT_NOT_FOUND')

        cursor.execute(" SELECT id "
                       " FROM tbl_sensors_points "
                       " WHERE sensor_id = %s AND point_id = %s ", (id_, pid))
        if cursor.fetchone() is None:
            cursor.close()
            cnx.disconnect()
            raise falcon.HTTPError(falcon.HTTP_404, title='API.NOT_FOUND',
                                   description='API.SENSOR_POINT_RELATION_NOT_FOUND')

        cursor.execute(" DELETE FROM tbl_sensors_points WHERE sensor_id = %s AND point_id = %s ", (id_, pid))
        cnx.commit()

        cursor.close()
        cnx.disconnect()

        resp.status = falcon.HTTP_204