import json
import os
from config import Config
from mqtt_client import MqttHandler
from keycloak_handler import KeycloakHandler
from sql_handler import SQLHandler

def has_permission(user_permissions, machine_id):
    parsed_permissions = [permission.split('.') for permission in user_permissions]
    parsed_machine_id = machine_id.split('.')

    for permission in parsed_permissions:
        missmatch = False
        for i, id_sequence in enumerate(parsed_machine_id):
            if permission[i] == '*':
                return True
            if permission[i] != id_sequence:
                missmatch = True
                break
        if not missmatch:
            return True

    return False

def gen_display_name(user):
    # display names must be not longer than 8 chrs
    if 'firstName' in user.keys() and 'lastName' in user.keys():
        full_name = f'{user["firstName"]} {user["lastName"]}'
        if len(full_name) > 8:
            display_name = f'{user["firstName"][0]}.{user["lastName"][:6]}'
    else:
        try:
            display_name = user['username'][:8]
        except KeyError:
            print('user has no username')
            return 'Error'
    return(display_name)

def handle_request(msg, client):
    print('')
    print(f'Received `{msg.payload.decode()}` from `{msg.topic}` topic')
    fabcard_id = json.loads(msg.payload.decode())['UID']
    reader_id = msg.topic.split('/')[-1]
    
    KeycloakHandler.login()
    user = KeycloakHandler.get_user_by_card_id(fabcard_id)
    if not user:
        MqttHandler.print_to_display(reader_id, 16, fabcard_id)
        return

    db_data = SQLHandler.get_machine_data(reader_id)

    machine_id = db_data["machine_id"]
    last_user = db_data["last_user"]
    machine_status = db_data["machine_status"]
    plug_id = db_data["plug_id"]

    try:
        user_permissions = json.loads(user['attributes']['FabPermissions'][0])
    except KeyError:
        print(f'user with id {fabcard_id} is missing FabPermissions attr')
    except IndexError:
        print(f'user with id {fabcard_id} is missing FabPermissions attr')

    if not has_permission(user_permissions, machine_id):
        print(f"user with id {fabcard_id} is missing {machine_id}")
        MqttHandler.print_to_display(reader_id, 7, '')
        return

    username = user['username']
    display_name = gen_display_name(user)

    if not machine_status:
        print(f'Turn Plug {plug_id} on')
        MqttHandler.switch_plug(plug_id, 1)
        MqttHandler.print_to_display(reader_id, 20, f'Login\n{display_name}')
    else:
        if not (username == last_user or KeycloakHandler.user_is_privileged(username)):
            MqttHandler.print_to_display(reader_id, 9, last_user)
            return
        print(f'Turn Plug {plug_id} off')
        MqttHandler.switch_plug(plug_id, 0)
        MqttHandler.print_to_display(reader_id, 20, f'Bitte anmelden')

    SQLHandler.update_machine(reader_id, username, machine_status)
    MqttHandler.publish(f'/FabLogging/{plug_id}/USER', username)


def main():
    MqttHandler.setup(handle_request)
    KeycloakHandler.login()
    SQLHandler.setup()

    MqttHandler.connect_mqtt()
    MqttHandler.subscribe("/rfid_reader/#")
    SQLHandler.init_db()
    MqttHandler.loop()

if __name__ == '__main__':
    main()