# -*- coding: utf-8 -*-

from typing import Any

import os, abc, sys, pwd
from enum import Flag, auto

from ..util import pretty_cmd
from ..log import *
from ..base import Result
from ..ExecContext import ExecContext
from urllib.parse import urlparse

class SSHClient(ExecContext):

    class Caps(Flag):
        LogOutput = auto()
        Interactive = auto()
        ModEnv = auto()
        Wd = auto()

    def __init__(self, uri: str, caps: Caps=Caps(0), *args, **kwargs) -> None:
        super().__init__(uri=uri, *args, **kwargs)
        self.__caps = caps
        try:
            parsed = urlparse(uri)
        except Exception as e:
            log(ERR, f'Failed to parse SSH URI "{uri}"')
            raise

        self.__hostname = parsed.hostname
        if self.__hostname is None:
            raise Exception(f'Can\'t parse host name from SSH URI "{uri}"')
        self.__port = parsed.port
        self.__password = parsed.password
        self.__username = parsed.username

    @abc.abstractmethod
    async def _run_ssh(
        cmd: list[str],
        wd: str|None,
        verbose: bool,
        cmd_input: bytes|None,
        mod_env: dict[str, str]|None,
        interactive: bool,
        log_prefix: str
    ) -> Result:
        pass

    async def _run(
        self,
        cmd: list[str],
        wd: str|None,
        verbose: bool,
        cmd_input: bytes|None,
        mod_env: dict[str, str]|None,
        interactive: bool,
        log_prefix: str
    ) -> Result:

        def __log(prio: int, *args):
            log(prio, log_prefix, *args)

        def __log_block(prio: int, title: str, block: str):
            if self.__caps & self.Caps.LogOutput:
                return
            if not block:
                return
            encoding = sys.stdout.encoding or 'utf-8'
            block = block.decode(encoding).strip()
            if not block:
                return
            delim = f'---- {title} ----'
            __log(prio, f',{delim}')
            for line in block.splitlines():
                __log(prio, '|', line)
            __log(prio, f'`{delim}')

        if wd is not None and not self.__caps & self.Caps.Wd:
            cmd = ['cd', wd, '&&', *cmd]

        if interactive and not self.__caps & self.Caps.Interactive:
            raise NotImplementedError('Interactive SSH is not yet implemented')

        if mod_env is not None and not self.__caps & self.Caps.ModEnv:
            raise NotImplementedError('Passing an environment to SSH commands is not yet implemented')

        ret = await self._run_ssh(
            cmd=cmd,
            wd=wd,
            verbose=verbose,
            cmd_input=cmd_input,
            mod_env=mod_env,
            interactive=interactive,
            log_prefix=log_prefix
        )

        if verbose:
            __log_block(NOTICE, 'stdout', ret.stdout)
            __log_block(NOTICE, 'stderr', ret.stderr)
            if ret.status != 0:
                __log(WARNING, f'Exit code {ret.status}')

        return ret

    @property
    def hostname(self) -> str|None:
        return self.__hostname

    @property
    def port(self) -> int|None:
        return self.__port

    def set_password(self, password: str) -> None:
        self.__password = password

    @property
    def password(self) -> str|None:
        return self.__password

    def set_username(self, username: str) -> None:
        self.__username = username

    def _username(self) -> str:
        if self.__username is None:
            return pwd.getpwuid(os.getuid()).pw_name
        return self.__username

def ssh_client(*args, type: str|list[str]|None=None, **kwargs) -> SSHClient: # export
    from importlib import import_module
    errors: list[str] = []
    if type is None:
        val = os.getenv('JW_DEFAULT_SSH_CLIENT')
        if val is not None:
            type = val.split(',')
        else:
            type = ['AsyncSSH', 'Paramiko', 'Exec']
    if isinstance(type, str):
        type = [type]
    for name in type:
        try:
            ret = getattr(import_module(f'jw.pkg.lib.ec.ssh.{name}'), name)(*args, **kwargs)
            log(INFO, f'Using SSH-client "{name}"')
            return ret
        except Exception as e:
            msg = f'Can\'t instantiate SSH client class {name} ({str(e)})'
            errors.append(msg)
            log(DEBUG, f'{msg}, trying next')
    msg = f'No working SSH clients for {" ".join(args)}'
    log(ERR, f'----- {msg}')
    for error in errors:
        log(ERR, error)
    raise Exception(msg)