#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import json
from Basis.Exception import buildException
from Basis.Constant import ssMethods, ssAllMethods, mbedtlsMethods


def loadConfig(proxyInfo: dict, socksInfo: dict) -> dict:  # load basic config option
    config = {
        'server': proxyInfo['server'],
        'server_port': proxyInfo['port'],  # type -> int
        'local_address': socksInfo['addr'],
        'local_port': socksInfo['port'],  # type -> int
        'method': proxyInfo['method'],
        'password': proxyInfo['passwd'],
    }
    if proxyInfo['plugin'] is not None:  # with plugin
        config['plugin'] = proxyInfo['plugin']['type']
        config['plugin_opts'] = proxyInfo['plugin']['param']
    return config


def pluginUdp(plugin: str, pluginParam: str) -> bool:  # whether the plugin uses udp
    if plugin in ['obfs-local', 'simple-tls', 'ck-client', 'gq-client', 'mtt-client', 'rabbit-plugin']:
        return False  # UDP is not used
    if plugin in ['v2ray-plugin', 'xray-plugin', 'gost-plugin']:
        if 'mode=quic' not in pluginParam.split(';'):  # non-quic mode does not use udp
            return False
    return True  # udp is assumed by default


def ssRust(proxyInfo: dict, socksInfo: dict, isUdp: bool) -> tuple[dict, list, dict]:
    config = loadConfig(proxyInfo, socksInfo)
    if isUdp:  # proxy udp traffic
        config['mode'] = 'tcp_and_udp'
    return config, ['ss-rust-local', '-v'], {'RUST_BACKTRACE': 'full'}  # enable rust trace


def ssLibev(proxyInfo: dict, socksInfo: dict, isUdp: bool) -> tuple[dict, list, dict]:
    config = loadConfig(proxyInfo, socksInfo)
    if isUdp:  # proxy udp traffic
        config['mode'] = 'tcp_and_udp'
    return config, ['ss-libev-local', '-v'], {}


def ssPython(proxyInfo: dict, socksInfo: dict, isUdp: bool) -> tuple[dict, list, dict]:
    config = loadConfig(proxyInfo, socksInfo)
    if config['method'] in mbedtlsMethods:  # mbedtls methods should use prefix `mbedtls:`
        config['method'] = 'mbedtls:' + config['method']
    if config['method'] in ['idea-cfb', 'seed-cfb']:  # only older versions of openssl are supported
        config['extra_opts'] = '--libopenssl=libcrypto.so.1.0.0'
    if not isUdp:
        config['no_udp'] = True  # udp traffic is not proxied
    config['shadowsocks'] = 'ss-python-local'
    return config, ['ss-bootstrap-local', '--debug', '-vv'], {}


def ssPythonLegacy(proxyInfo: dict, socksInfo: dict, isUdp: bool) -> tuple[dict, list, dict]:
    config = loadConfig(proxyInfo, socksInfo)
    if not isUdp:
        config['no_udp'] = True  # udp traffic is not proxied
    config['shadowsocks'] = 'ss-python-legacy-local'
    return config, ['ss-bootstrap-local', '--debug', '-vv'], {}


def load(proxyInfo: dict, socksInfo: dict, configFile: str) -> tuple[list, str, dict]:
    isUdp = True if proxyInfo['plugin'] is None else (  # udp enabled when server without plugin
        not pluginUdp(proxyInfo['plugin']['type'], proxyInfo['plugin']['param'])  # udp conflict status of plugins
    )
    if proxyInfo['method'] not in ssAllMethods:  # unknown shadowsocks method
        raise buildException('Unknown shadowsocks method')
    for client in ssMethods:  # traverse all shadowsocks client
        if proxyInfo['method'] not in ssMethods[client]:
            continue
        ssConfig, ssClient, ssEnv = {  # found appropriate client
            'ss-rust': ssRust,
            'ss-libev': ssLibev,
            'ss-python': ssPython,
            'ss-python-legacy': ssPythonLegacy
        }[client](proxyInfo, socksInfo, isUdp)  # generate config file
        return ssClient + ['-c', configFile], json.dumps(ssConfig), ssEnv  # command, fileContent, envVar