"""
Onionr - Private P2P Communication

Gossip plugin server, multiplexing using selectors
"""
import os
import sys

import selectors
import socket
from time import sleep

from kasten.main import Kasten
from onionrblocks.generators.anonvdf import AnonVDFGenerator
from blockio import store

sys.path.insert(0, os.path.dirname(os.path.realpath(__file__)))
from commands import GossipCommands  # noqa
import commandhandlers

from constants import SERVER_SOCKET
from blockio import subprocgenerate, store_block
"""
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.
"""


def start_server(shared_state):

    bl = subprocgenerate.vdf_block(b"yep", "txt", 120)
    store_block(Kasten(bl.id, bl.get_packed(), generator=AnonVDFGenerator), shared_state.get_by_string('SafeDB'))
    print(bl.id)

    sel = selectors.DefaultSelector()

    def accept(sock, mask):
        conn, addr = sock.accept()  # Should be ready
        conn.setblocking(False)
        sel.register(conn, selectors.EVENT_READ, read)

    def do_close(conn, msg=None):
        if msg:
            conn.sendall(msg)
            sleep(0.1)
        sel.unregister(conn)
        conn.close()

    def read(conn, mask):
        data = conn.recv(1000)  # Should be ready
        cmd = None
        if data:
            try:
                cmd = int(int(data[0]).to_bytes(1, 'little'))
                data = data[1:]
            except IndexError:
                do_close(conn, b'MALFORMED COMMAND')
            if cmd == GossipCommands.PING:
                conn.sendall(b'PONG')
            elif cmd == GossipCommands.EXIT:
                do_close(conn, b'BYE')
            elif cmd == GossipCommands.PUT_BLOCK:
                conn.sendall(
                    commandhandlers.put_block(
                        shared_state.get_by_string('SafeDB'), data
                    )
                )
            elif cmd == GossipCommands.GET_BLOCK:
                conn.sendall(
                    commandhandlers.get_block(
                        shared_state.get_by_string('SafeDB'), data))
            elif cmd == GossipCommands.LIST_BLOCKS_BY_TYPE:
                conn.sendall(
                    commandhandlers.list_blocks_by_type(
                        shared_state.get_by_string('SafeDB'), data))
            elif cmd == GossipCommands.LIST_BLOCKS_BY_TYPE_OFFSET:
                conn.sendall(
                    commandhandlers.list_blocks_by_type_and_offset(
                        shared_state.get_by_string('SafeDB'), data)
                )
            elif cmd == GossipCommands.CHECK_HAS_BLOCK:
                conn.sendall(
                    commandhandlers.handle_check_block(
                        shared_state.get_by_string('SafeDB'), data))
            elif cmd == GossipCommands.PEER_EXCHANGE:
                conn.sendall(
                    commandhandlers.peer_exchange(
                        shared_state.get_by_string('TorGossipPeers'), data))
            elif cmd == GossipCommands.ANNOUNCE_PEER:
                conn.sendall(
                    commandhandlers.announce_peer(
                        shared_state.get_by_string('TorGossipPeers'), data)
                    )
            else:
                conn.sendall(b'Unknown ' + str(cmd).encode('utf-8'))
        else:
            do_close(conn)

    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)

    try:
        os.remove(SERVER_SOCKET)
    except FileNotFoundError:
        pass

    sock.bind(SERVER_SOCKET)
    sock.listen(100)
    sock.setblocking(False)
    sel.register(sock, selectors.EVENT_READ, accept)

    while True:
        events = sel.select()
        for key, mask in events:
            callback = key.data
            callback(key.fileobj, mask)