from socket import socket, AF_INET, SOCK_STREAM, SHUT_RDWR
from time import strftime, gmtime

from backend import run
from utils import validate_url, parse_cookies, parse_query, parse_headers, add_headers, NOT_FOUND, BAD_REQUEST
from templater import render_template
from config import *
import db


def log_func(func):
    def wrapper(*args, **kwargs):
        address = kwargs['address'] if 'address' in kwargs else args[0]
        method = kwargs['method'] if 'method' in kwargs else args[1]
        url = kwargs['url'] if 'url' in kwargs else args[2]
        http_ver = kwargs['http_ver'] if 'http_ver' in kwargs else args[3]

        response = func(*args, **kwargs)
        status = response.split('\n').pop(0).split()[1]

        log_line = f'{address[0]}: {strftime("[%d %b %Y %H:%M:%S]", gmtime())} "{method} {url} {http_ver}" Status: {status}'
        print(log_line)

        return response

    return wrapper


@log_func
def process_request(address, method, url, http_ver, headers: dict, query):
    if validate_url(url):
        try:
            cookies = parse_cookies(headers['Cookie'])
        except (ValueError, KeyError):
            cookies = {}

        response = run(method, url, cookies, query)
    else:
        response = add_headers(NOT_FOUND, '404 NOT FOUND')

    return response


def get_request(connection):
    buffer = b''
    request = b''
    while not request.endswith(b'\r\n\r\n'):
        data = connection.recv(1024).split(b'\r\n\r\n')
        if len(data) == 1:
            if not data[0]:
                return None
            request += data[0]
        else:
            request += data[0] + b'\r\n\r\n'
            buffer += data[1]

    method, url, http_ver, headers = parse_headers(request.strip().decode())
    if 'Content-Type' in headers and headers['Content-Type'] == 'application/x-www-form-urlencoded':
        length = int(headers['Content-Length']) - len(buffer)
        while length > 0:
            if length < CHUNK:
                data = connection.recv(length)
                length = 0
            else:
                data = connection.recv(CHUNK)
                length -= CHUNK

            buffer += data[0]

    query = parse_query(buffer.strip().decode()) if buffer else {}

    return method, url, http_ver, headers, query


def get_color():
    color = db.get_cookie('bg_color', 'white')
    if color not in ['green', 'white']:
        color = 'white'
    return color


def handle_connection(connection, address):
    try:
        request = get_request(connection)
    except ValueError as e:
        response = add_headers(BAD_REQUEST, render_template(
            TEXT_TEMPLATE_NAME, color=get_color(),
            text=BAD_REQUEST + ('<br>' + str(e) if db.get_config_entry('show_errors') else '')
        ))
        connection.sendall(response.encode())
        return

    if request is None:
        return

    method, url, http_ver, headers, query = request

    response = process_request(address, method, url, http_ver, headers, query)
    connection.sendall(response.encode())


def main(host, port):
    sock = socket(AF_INET, SOCK_STREAM)
    sock.bind((host, port))
    sock.listen(5)
    print(f'* Server started on http://{host}:{port}/')
    print('* Listening to new connections...')

    while True:
        try:
            connection, address = sock.accept()

            handle_connection(connection, address)

            connection.shutdown(SHUT_RDWR)
            connection.close()
            del connection

        except KeyboardInterrupt:
            print('Stopping server...')

            try:
                connection.shutdown(SHUT_RDWR)
                connection.close()
            except UnboundLocalError:
                pass

            sock.shutdown(SHUT_RDWR)
            sock.close()

            print('Server stopped')
            break


if __name__ == '__main__':
    HOST, PORT = ADDR = '0.0.0.0', 4002
    main(HOST, PORT)