import ipaddress
import json
import os
import shutil
import typing

from starlette.exceptions import HTTPException

import const
import script.wireguard
from sqlalchemy.orm import Session
from database import models
import schemas
import logging

_LOGGER = logging.getLogger(__name__)
_LOGGER.setLevel(logging.DEBUG)


def start_client(sess: Session, peer: schemas.WGPeer):
    db_peer: models.WGPeer = peer_query_get_by_address(sess, peer.address, peer.server).one()
    client_file = os.path.join(const.CLIENT_DIR(db_peer.server.interface), str(db_peer.id) + ".conf")
    import subprocess
    output = subprocess.check_output(const.CMD_WG_QUICK + ["up", client_file], stderr=subprocess.STDOUT)


def get_server_by_id(sess: Session, server_id):
    return sess.query(models.WGServer).filter_by(id=server_id).one()


def peer_query_get_by_address(sess: Session, address: str, server: str):
    return sess.query(models.WGPeer) \
        .filter(models.WGPeer.address == address) \
        .filter(models.WGPeer.server == server)


def peer_dns_set(sess: Session, peer: schemas.WGPeer) -> schemas.WGPeer:
    db_peer: models.WGPeer = peer_query_get_by_address(sess, peer.address, peer.server).one()
    db_peer.dns = peer.dns

    sess.add(db_peer)
    sess.commit()

    return peer.from_orm(db_peer)


def peer_remove(sess: Session, peer: schemas.WGPeer) -> bool:
    db_peers = sess.query(models.WGPeer).filter_by(id=peer.id).all()

    for db_peer in db_peers:
        sess.delete(db_peer)
        sess.commit()

    server_update_configuration(sess, peer.server_id)

    return True


def peer_edit(sess: Session, peer: schemas.WGPeer):
    # Retrieve server from db
    server: models.WGServer = get_server_by_id(sess, peer.server_id)

    # Generate peer configuration
    peer.configuration = script.wireguard.generate_config(dict(
        peer=peer,
        server=server
    ))

    # Update database record for Peer
    sess.query(models.WGPeer) \
        .filter_by(id=peer.id) \
        .update(peer.dict(exclude={"id"}))
    sess.commit()

    server_update_configuration(sess, server.id)

    return peer


def peer_key_pair_generate(sess: Session, peer: schemas.WGPeer) -> schemas.WGPeer:
    db_peer: models.WGPeer = peer_query_get_by_address(sess, peer.address, peer.server).one()
    private_key, public_key = script.wireguard.generate_keys()
    db_peer.private_key = private_key
    db_peer.public_key = public_key

    sess.add(db_peer)
    sess.commit()

    return peer.from_orm(db_peer)


def peer_ip_address_set(sess: Session, peer: schemas.WGPeer) -> schemas.WGPeer:
    db_peer: models.WGPeer = peer_query_get_by_address(sess, peer.address, peer.server).one()
    db_peer.address = peer.address
    sess.add(db_peer)
    sess.commit()
    return peer.from_orm(db_peer)


def peer_update(sess: Session, peer: schemas.WGPeer) -> schemas.WGPeer:
    db_peer: models.WGPeer = peer_query_get_by_address(sess, peer.address, peer.server).one()
    db_peer.address = peer.address
    db_peer.public_key = peer.public_key
    db_peer.private_key = peer.private_key
    db_peer.name = peer.name
    db_peer.dns = peer.dns
    db_peer.allowed_ips = peer.allowed_ips

    sess.add(db_peer)
    sess.commit()

    return peer.from_orm(db_peer)


def peer_get(sess: Session, server: schemas.WGServer) -> typing.List[schemas.WGPeer]:
    db_server = server_query_get_by_interface(sess, server.interface).one()
    return db_server.peers


def server_query_get_by_interface(sess: Session, interface: str):
    return sess.query(models.WGServer) \
        .filter(models.WGServer.interface == interface)


def server_update_field(sess: Session, interface: str, server: schemas.WGServer, fields: typing.Set):
    if server_query_get_by_interface(sess, interface) \
            .update(
        server.dict(include=fields), synchronize_session=False
    ) == 1:
        sess.commit()
        return True
    return False


def server_get_all(sess: Session) -> typing.List[schemas.WGServer]:
    db_interfaces = sess.query(models.WGServer) \
        .all()
    return [schemas.WGServer.from_orm(db_interface) for db_interface in db_interfaces]


def server_add_on_init(sess: Session):
    """
    Routine for adding server from env variable.
    :param server:
    :param sess:
    :return:
    """
    try:
        init_data = json.loads(const.SERVER_INIT_INTERFACE)

        if init_data["endpoint"] == "||external||":
            import requests
            init_data["endpoint"] = requests.get("https://api.ipify.org").text
        elif init_data["endpoint"] == "||internal||":
            import socket
            init_data["endpoint"] = socket.gethostbyname(socket.gethostname())

        if sess.query(models.WGServer) \
                .filter_by(endpoint=init_data["endpoint"], listen_port=init_data["listen_port"]) \
                .count() == 0:
            # Only add if it does not already exists.
            server_add(schemas.WGServerAdd(**init_data), sess, start=const.SERVER_INIT_INTERFACE_START)
    except Exception as e:
        _LOGGER.warning("Failed to setup initial server interface with exception:")
        _LOGGER.exception(e)


def server_add(server: schemas.WGServerAdd, sess: Session, start=False):
    # Configure POST UP with defaults if not manually set.
    if server.post_up == "":
        server.post_up = const.DEFAULT_POST_UP
        if server.v6_address is not None:
            server.post_up += const.DEFAULT_POST_UP_v6

    # Configure POST DOWN with defaults if not manually set.
    if server.post_down == "":
        server.post_down = const.DEFAULT_POST_DOWN
        if server.v6_address is not None:
            server.post_down += const.DEFAULT_POST_DOWN_v6

    peers = server.peers if server.peers else []

    # Public/Private key
    try:

        if sess.query(models.WGServer) \
                .filter(
            (models.WGServer.interface == server.interface) |
            (models.WGServer.address == server.address) |
            (models.WGServer.v6_address == server.v6_address)).count() != 0:
            raise HTTPException(status_code=400,
                                detail="The server interface or ip %s already exists in the database" % server.interface)

        if not server.private_key:
            keys = script.wireguard.generate_keys()
            server.private_key = keys["private_key"]
            server.public_key = keys["public_key"]

        server.configuration = script.wireguard.generate_config(server)
        server.peers = []
        server.sync(sess)

        if len(peers) > 0:
            server.from_db(sess)

            for schemaPeer in peers:
                schemaPeer.server_id = server.id
                schemaPeer.configuration = script.wireguard.generate_config(dict(
                    peer=schemaPeer,
                    server=server
                ))
                dbPeer = models.WGPeer(**schemaPeer.dict())
                sess.add(dbPeer)
                sess.commit()

        server.from_db(sess)

    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))

    if start and not script.wireguard.is_running(server):
        script.wireguard.start_interface(server)

    return server


def server_remove(sess: Session, server: schemas.WGServer) -> bool:
    db_server = server_query_get_by_interface(sess, server.interface).one()
    if db_server is None:
        raise ValueError("The server with interface %s is already deleted." % server.interface)

    sess.delete(db_server)
    sess.commit()

    shutil.rmtree(const.SERVER_DIR(db_server.interface))

    return True


def server_preshared_key(sess: Session, server: schemas.WGServer) -> bool:
    return server_update_field(sess, server.interface, server, {"shared_key"})


def server_key_pair_set(sess: Session, server: schemas.WGServer) -> bool:
    return server_update_field(sess, server.interface, server, {"private_key", "public_key"})


def server_listen_port_set(sess: Session, server: schemas.WGServer) -> bool:
    if server.listen_port < 1024 or server.listen_port > 65535:
        raise ValueError("The listen_port is not in port range 1024 < x < 65535")

    return server_update_field(sess, server.interface, server, {"listen_port"})


def server_ip_address_set(sess: Session, server: schemas.WGServer) -> bool:
    network = ipaddress.ip_network(server.address, False)
    if not network.is_private:
        raise ValueError("The network is not in private range")

    return server_update_field(sess, server.interface, server, {"address"})


def server_post_up_set(sess: Session, server: schemas.WGServer) -> bool:
    return server_update_field(sess, server.interface, server, {"post_up"})


def server_post_down_set(sess: Session, server: schemas.WGServer) -> bool:
    return server_update_field(sess, server.interface, server, {"post_down"})


def server_endpoint_set(sess: Session, server: schemas.WGServer) -> bool:
    return server_update_field(sess, server.interface, server, {"endpoint"})


def server_update_configuration(sess: Session, server_id: int) -> bool:
    # Generate server configuration
    server: models.WGServer = sess.query(models.WGServer).filter_by(id=server_id).one()
    server.configuration = script.wireguard.generate_config(server)
    sess.add(server)
    sess.commit()