import logging
import os
from datetime import datetime

import paho.mqtt.client as mqtt
from dotenv import load_dotenv

from constants import callback_api_version_map, protocol_map

try:
    from meshtastic.mesh_pb2 import MeshPacket
    from meshtastic.mqtt_pb2 import ServiceEnvelope
except ImportError:
    from meshtastic.protobuf.mesh_pb2 import MeshPacket
    from meshtastic.protobuf.mqtt_pb2 import ServiceEnvelope

from prometheus_client import CollectorRegistry, start_http_server
from psycopg_pool import ConnectionPool

connection_pool = None


def get_connection():
    return connection_pool.getconn()


def release_connection(conn):
    connection_pool.putconn(conn)


def handle_connect(client, userdata, flags, reason_code, properties):
    print(f"Connected with result code {reason_code}")
    client.subscribe(os.getenv('MQTT_TOPIC', 'msh/israel/#'))


def update_node_status(node_number, status):
    with connection_pool.connection() as conn:
        with conn.cursor() as cur:
            cur.execute("INSERT INTO client_details (node_id, mqtt_status) VALUES (%s, %s)"
                        "ON CONFLICT(node_id)"
                        "DO UPDATE SET mqtt_status = %s", (node_number, status, status))
            conn.commit()


def handle_message(client, userdata, message):
    current_timestamp = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    print(f"Received message on topic '{message.topic}' at {current_timestamp}")
    if '/json/' in message.topic:
        # Ignore JSON messages as there are also protobuf messages sent on other topic
        # Source: https://github.com/meshtastic/firmware/blob/master/src/mqtt/MQTT.cpp#L448
        return

    if '/stat/' in message.topic or '/tele/' in message.topic:
        try:
            user_id = message.topic.split('/')[-1]  # Hexadecimal user ID
            if user_id[0] == '!':
                node_number = str(int(user_id[1:], 16))
                update_node_status(node_number, message.payload.decode('utf-8'))
            return
        except Exception as e:
            logging.error(f"Failed to handle user MQTT stat: {e}")
            return

    envelope = ServiceEnvelope()
    try:
        envelope.ParseFromString(message.payload)
        packet: MeshPacket = envelope.packet

        with connection_pool.connection() as conn:
            with conn.cursor() as cur:
                cur.execute("SELECT id FROM messages WHERE id = %s", (str(packet.id),))
                if cur.fetchone() is not None:
                    logging.debug(f"Packet {packet.id} already processed")
                    return

                cur.execute("INSERT INTO messages (id, received_at) VALUES (%s, NOW()) ON CONFLICT (id) DO NOTHING",
                            (str(packet.id),))
                conn.commit()

        processor.process(packet)
    except Exception as e:
        logging.error(f"Failed to handle message: {e}")
        return


if __name__ == "__main__":
    load_dotenv()

    # We have to load_dotenv before we can import MessageProcessor to allow filtering of message types
    from exporter.processor_base import MessageProcessor

    # Setup a connection pool
    connection_pool = ConnectionPool(
        os.getenv('DATABASE_URL'),
        min_size=1,
        max_size=10
    )

    # Configure Prometheus exporter
    registry = CollectorRegistry()
    start_http_server(int(os.getenv('PROMETHEUS_COLLECTOR_PORT', 8000)), registry=registry)

    # Create an MQTT client
    mqtt_protocol = os.getenv('MQTT_PROTOCOL', 'MQTTv5')
    mqtt_callback_api_version = os.getenv('MQTT_CALLBACK_API_VERSION', 'VERSION2')
    mqtt_client = mqtt.Client(
        callback_api_version=callback_api_version_map.get(mqtt_callback_api_version, mqtt.CallbackAPIVersion.VERSION2),
        protocol=protocol_map.get(mqtt_protocol, mqtt.MQTTv5)
    )
    mqtt_client.on_connect = handle_connect
    mqtt_client.on_message = handle_message

    if os.getenv('MQTT_IS_TLS', 'false') == 'true':
        tls_context = mqtt.ssl.create_default_context()
        mqtt_client.tls_set_context(tls_context)

    if os.getenv('MQTT_USERNAME', None) and os.getenv('MQTT_PASSWORD', None):
        mqtt_client.username_pw_set(os.getenv('MQTT_USERNAME'), os.getenv('MQTT_PASSWORD'))

    try:
        mqtt_client.connect(
            os.getenv('MQTT_HOST'),
            int(os.getenv('MQTT_PORT')),
            keepalive=int(os.getenv('MQTT_KEEPALIVE', 60)),
        )
    except Exception as e:
        logging.error(f"Failed to connect to MQTT broker: {e}")
        exit(1)

    # Configure the Processor and the Exporter
    processor = MessageProcessor(registry, connection_pool)

    mqtt_client.loop_forever()