import csv
import logging
import os
import re
import sqlite3
from dataclasses import dataclass
from datetime import datetime, timedelta
from time import sleep
from typing import List, Optional

import click
import routeros_api
from jinja2 import Environment, select_autoescape, FileSystemLoader

from config import Config


def _get_db(filepath: str):
    logging.debug(f"Opening database: {filepath}")
    connection = sqlite3.connect(filepath)

    c = connection.cursor()
    c.execute(
        '''CREATE TABLE IF NOT EXISTS spottings (
                id INTEGER PRIMARY KEY,
                ts INTEGER,
                mac TEXT,
                hostname TEXT,
                ip TEXT    
            )'''
    )
    connection.commit()

    return connection


def _fetch_leases(db, from_ts: datetime):
    c = db.cursor()
    query = c.execute(
        'SELECT ts, mac, hostname, ip FROM spottings WHERE ts > ? ORDER BY ts DESC',
        (int(from_ts.timestamp()),)
    )
    for row in query:
        yield Lease(datetime.fromtimestamp(row[0]), row[1], row[2], row[3])


@dataclass
class Lease:
    ts: datetime
    mac: str
    hostname: Optional[str]
    ip: str


@dataclass
class Status:
    status: str
    text: str


@click.command()
@click.option('--address', default=os.getenv("ROUTER_IP", "192.168.42.1"), help='Address of the router.')
@click.option('--period', default=60, help='How often to check for clients (in seconds).')
@click.option('--ssid', default=os.getenv("SSID", "anabasis"), help='Limit clients to SSID containing this string.')
@click.option('-o', '--output', multiple=True, help="Output file.")
def run_forever(address: str, period: int, ssid: str, output: str):
    logging.basicConfig(level=logging.DEBUG, format='%(asctime)s - [%(levelname)s] %(message)s')
    config = Config
    db = _get_db("clients.sqlite3")

    connection = routeros_api.RouterOsApiPool(
        address,
        username='admin',
        password=os.environ["ROUTER_PASSWORD"],
        plaintext_login=True
    )

    jinja_env = Environment(
        loader=FileSystemLoader('templates'),
        autoescape=select_autoescape(['html', 'xml'])
    )

    while True:
        logging.info(f"Querying router at {address}...")
        api = connection.get_api()

        currently_registered = api.get_resource('/caps-man/registration-table').call('print')
        logging.debug(f"Got {len(currently_registered)} registered clients.")
        dhcp_leases = api.get_resource('/ip/dhcp-server/lease').call('print')
        logging.debug(f"Got {len(dhcp_leases)} DHCP leases.")

        now = datetime.now()
        timestamp = int(now.timestamp())

        registered_leases: List[Lease] = []
        for client in filter(lambda c: ssid in c['ssid'], currently_registered):
            try:
                lease = next(
                    lease for lease in dhcp_leases if lease.get('active-mac-address') == client['mac-address']
                )
            except StopIteration:
                continue
            registered_leases.append(
                Lease(ts=now, ip=lease['active-address'], mac=lease['active-mac-address'],
                      hostname=lease.get('host-name'))
            )
        logging.info(f"Found {len(registered_leases)} registered leases.")
        logging.debug(", ".join([str(lease) for lease in registered_leases]))

        if len(registered_leases) > 0:
            if len([lease for lease in registered_leases
                    if not any(re.match(ch, lease.hostname or "") for ch in config.computer_hostnames)]) > 0:
                status = Status(status="populated", text="There seem to be people!")
            else:
                status = Status(status="empty", text="There are only computers.")
        else:
            status = Status(status="empty", text="There are no devices connected?")

        logging.debug("Logging into the database...")
        cur = db.cursor()
        cur.executemany("INSERT INTO spottings (ts, mac, hostname, ip) VALUES (?,?,?,?)", [
            (timestamp, lease.mac, lease.hostname, lease.ip) for lease in registered_leases
        ])
        db.commit()

        for output_file in output:
            if output_file.endswith(".csv"):
                logging.debug(f"Outputting CSV file into {output_file}...")
                with open(output_file, 'w') as file:
                    writer = csv.writer(file)
                    for lease in registered_leases:
                        writer.writerow((lease.ip, lease.mac, lease.hostname or "???"))
            elif output_file.endswith(".lst"):
                logging.debug(f"Outputting LST file into {output_file}...")
                with open(output_file, 'w') as file:
                    file.write(f"{now}\n")
                    writer = csv.writer(file)
                    for lease in registered_leases:
                        writer.writerow((lease.ip, lease.mac, lease.hostname or "???"))
            elif output_file.endswith(".html"):
                last_human = next((lease for lease in _fetch_leases(db, now - timedelta(hours=24))
                                   if not any(re.match(ch, lease.hostname or "") for ch in config.computer_hostnames)),
                                  None)

                logging.debug(f"Outputting HTML file into {output_file}...")
                with open(output_file, 'w') as file:
                    out_str = jinja_env.get_template("index.html").render(
                        now=now,
                        leases=registered_leases,
                        status=status,
                        last_human=last_human
                    )
                    file.write(out_str)

        logging.info(f"Sleeping for {period} seconds.")
        sleep(period)


if __name__ == '__main__':
    run_forever()