import socket
import struct
from db import search_by_date
import re
import json
import time


def pack_data(data):
    encoded = data.encode()
    return struct.pack('I', len(encoded)) + encoded


def handle_request(data):
    match = re.match(r'(\d+):?(\d+)?:?(\d+)?-(.*)', data)
    if match:
        *date, msg = match.groups()

        t = time.time()
        found = search_by_date(*map(lambda i: int(i) if i is not None else i, date), msg)
        print(f'Search took {time.time() - t} seconds')
        return pack_data(json.dumps(found))

    else:
        print('String not matched.')
        return pack_data(json.dumps([]))


def get_data(connection):
    buffer = b''
    while len(buffer) < 4:
        data = connection.recv(4 - len(buffer))
        if not data:
            raise ConnectionError('Connection was closed')

        buffer += data

    size_packed, buffer = buffer[:4], buffer[4:]
    if not size_packed:
        raise ConnectionError('Connection was closed')

    (size,) = struct.unpack('I', size_packed)
    data = connection.recv(size - len(buffer))
    return buffer + data


def handle_connection(connection, address):
    while True:
        try:
            data = get_data(connection)

        except ConnectionResetError:
            print(f'Connection with {address[0]} was unexpectedly closed')
            break

        except ConnectionError:
            print(f'Connection with {address[0]} was ended')
            break

        except KeyboardInterrupt:
            raise KeyboardInterrupt()

        else:
            if not data:
                print(f'Connection with {address[0]} was ended')
                break
            response = handle_request(data.decode())
            connection.sendall(response)


HOST, PORT = ADDR = '0.0.0.0', 6000
sock = socket.socket()
sock.bind(ADDR)
sock.listen(5)

while True:
    print('Listening for new connections...')
    try:
        connection, address = sock.accept()
        print(f'Got a connection from {address[0]}')
        handle_connection(connection, address)

    except KeyboardInterrupt:
        print('Stopping server...')
        sock.close()
        print('Server stopped')
        break