import logging
import os
from pathlib import Path

from yuxi.channel.extensions.irc.config import IrcAccountConfig, IrcConfig, IrcNickServConfig
from yuxi.channel.extensions.irc.types import ResolvedIrcAccount

logger = logging.getLogger(__name__)


def _read_password_file(file_path: str) -> str:
    p = Path(file_path)
    if not p.is_file():
        logger.warning("Password file not found: %s", file_path)
        return ""
    if p.is_symlink():
        logger.warning("Password file is a symlink, refusing to read: %s", file_path)
        return ""
    try:
        content = p.read_text(encoding="utf-8").strip()
        return content
    except Exception as e:
        logger.warning("Failed to read password file %s: %s", file_path, e)
        return ""


def _resolve_password(password: str, password_file: str | None, account_id: str) -> tuple[str, str]:
    if account_id == "default":
        env_val = os.environ.get("IRC_PASSWORD")
        if env_val:
            return env_val, "env"
    if password_file:
        content = _read_password_file(password_file)
        if content:
            return content, "passwordFile"
    if password:
        return password, "config"
    return "", "none"


def _resolve_nickserv_password(nickserv: IrcNickServConfig, account_id: str) -> tuple[str, str]:
    if nickserv.password:
        return nickserv.password, "config"
    if account_id == "default":
        env_val = os.environ.get("IRC_NICKSERV_PASSWORD")
        if env_val:
            return env_val, "env"
    if nickserv.password_file:
        content = _read_password_file(nickserv.password_file)
        if content:
            return content, "passwordFile"
    return "", "none"


def _merge_channels(global_channels: list[str], account_channels: list[str]) -> list[str]:
    if account_channels:
        return account_channels
    return global_channels


def _merge_groups(
    global_groups: dict[str, object],
    account_groups: dict[str, object],
) -> dict[str, object]:
    merged = dict(global_groups)
    merged.update(account_groups)
    return merged


def resolve_irc_account(cfg: IrcConfig, account_id: str = "default") -> ResolvedIrcAccount:
    account_cfg = cfg.accounts.get(account_id)
    if account_cfg is None:
        if account_id == "default":
            account_cfg = IrcAccountConfig(
                host=cfg.host,
                port=cfg.port,
                tls=cfg.tls,
                nick=cfg.nick,
                username=cfg.username,
                realname=cfg.realname,
                password=cfg.password,
                password_file=cfg.password_file,
                nickserv=cfg.nickserv,
                dm_policy=cfg.dm_policy,
                allow_from=cfg.allow_from,
                group_policy=cfg.group_policy,
                group_allow_from=cfg.group_allow_from,
                groups=cfg.groups,
                channels=cfg.channels,
                dangerously_allow_name_matching=cfg.dangerously_allow_name_matching,
                text_chunk_limit=cfg.text_chunk_limit,
            )
        else:
            raise KeyError(f"Account '{account_id}' not found")

    host = account_cfg.host or cfg.host
    port = account_cfg.port or cfg.port
    tls = account_cfg.tls if account_cfg.host else cfg.tls
    nick = account_cfg.nick or cfg.nick
    username = account_cfg.username or cfg.username
    realname = account_cfg.realname or cfg.realname

    password, password_source = _resolve_password(
        account_cfg.password or cfg.password,
        account_cfg.password_file or cfg.password_file,
        account_id,
    )

    nickserv_cfg = account_cfg.nickserv
    if not nickserv_cfg.password and not nickserv_cfg.password_file:
        nickserv_cfg = cfg.nickserv

    nickserv_password, nickserv_password_source = _resolve_nickserv_password(
        nickserv_cfg, account_id
    )

    channels = _merge_channels(cfg.channels, account_cfg.channels)
    groups = _merge_groups(cfg.groups, account_cfg.groups)
    dm_policy = account_cfg.dm_policy if account_cfg.host else cfg.dm_policy
    allow_from = account_cfg.allow_from or cfg.allow_from
    group_policy = account_cfg.group_policy if account_cfg.host else cfg.group_policy
    group_allow_from = account_cfg.group_allow_from or cfg.group_allow_from
    dangerously_allow_name_matching = (
        account_cfg.dangerously_allow_name_matching or cfg.dangerously_allow_name_matching
    )

    resolved_config = IrcAccountConfig(
        name=account_cfg.name or account_id,
        enabled=account_cfg.enabled,
        dangerously_allow_name_matching=dangerously_allow_name_matching,
        host=host,
        port=port,
        tls=tls,
        nick=nick,
        username=username,
        realname=realname,
        password=password,
        password_file=account_cfg.password_file or cfg.password_file,
        nickserv=nickserv_cfg,
        dm_policy=dm_policy,
        allow_from=allow_from,
        group_policy=group_policy,
        group_allow_from=group_allow_from,
        groups=groups,
        channels=channels,
        text_chunk_limit=account_cfg.text_chunk_limit,
        block_streaming=account_cfg.block_streaming,
    )

    configured = bool(host and nick)
    if not configured and account_id == "default":
        env_host = os.environ.get("IRC_HOST")
        env_nick = os.environ.get("IRC_NICK")
        if env_host and env_nick:
            configured = True

    return ResolvedIrcAccount(
        account_id=account_id,
        enabled=account_cfg.enabled,
        name=resolved_config.name,
        configured=configured,
        host=host,
        port=port,
        tls=tls,
        nick=nick,
        username=username,
        realname=realname,
        password=password,
        password_source=password_source,
        nickserv_password=nickserv_password,
        nickserv_password_source=nickserv_password_source,
        config=resolved_config,
    )


def list_irc_account_ids(cfg: IrcConfig) -> list[str]:
    if cfg.accounts:
        return list(cfg.accounts.keys())
    return ["default"]


def has_configured_state(cfg: IrcConfig) -> bool:
    if cfg.host and cfg.nick:
        return True
    for acc in cfg.accounts.values():
        if acc.host and acc.nick:
            return True
    if os.environ.get("IRC_HOST") and os.environ.get("IRC_NICK"):
        return True
    return False