from __future__ import annotations

from dataclasses import dataclass, field
from typing import Any


@dataclass
class IMessageAccount:
    account_id: str
    name: str = ""
    server_url: str = "http://localhost:1234"
    password: str = ""
    dm_policy: str = "pairing"
    group_policy: str = "allowlist"
    allow_from: list[str] = field(default_factory=list)
    group_allow_from: list[str] = field(default_factory=list)
    require_mention: bool = False
    default_to: str = ""
    enabled: bool = True


def resolve_accounts(config: dict[str, Any]) -> list[IMessageAccount]:
    """解析多账户配置。

    支持两种配置模式：
    1. 顶层单账户：config 直接包含 server_url / password
    2. accounts 块：config["accounts"] 为 {accountId: {...}, ...}

    返回扁平化的 IMessageAccount 列表。
    """
    accounts_raw = config.get("accounts")

    if not accounts_raw:
        account = _account_from_top_level(config)
        return [account] if account.server_url else []

    result: list[IMessageAccount] = []
    default_account_id = config.get("defaultAccount", config.get("default_account", ""))

    for account_id, acct_config in accounts_raw.items():
        if not isinstance(acct_config, dict):
            continue
        merged = _merge_account_config(config, account_id, acct_config)
        result.append(merged)

    if default_account_id:
        result.sort(key=lambda a: 0 if a.account_id == default_account_id else 1)

    return result


def list_enabled_accounts(config: dict[str, Any]) -> list[IMessageAccount]:
    accounts = resolve_accounts(config)
    return [a for a in accounts if a.enabled]


def resolve_default_account(config: dict[str, Any]) -> IMessageAccount | None:
    accounts = list_enabled_accounts(config)
    if not accounts:
        return None
    default_id = config.get("defaultAccount", config.get("default_account", ""))
    for acct in accounts:
        if acct.account_id == default_id:
            return acct
    return accounts[0]


def _account_from_top_level(config: dict[str, Any]) -> IMessageAccount:
    return IMessageAccount(
        account_id="default",
        name=config.get("name", "iMessage"),
        server_url=config.get("server_url", "http://localhost:1234"),
        password=config.get("password", ""),
        dm_policy=config.get("dmPolicy", config.get("dm_policy", "pairing")),
        group_policy=config.get("groupPolicy", config.get("group_policy", "allowlist")),
        allow_from=config.get("allowFrom", config.get("allow_from", [])),
        group_allow_from=config.get("groupAllowFrom", config.get("group_allow_from", [])),
        require_mention=config.get("requireMention", config.get("require_mention", False)),
        default_to=config.get("defaultTo", config.get("default_to", "")),
    )


def _merge_account_config(top: dict[str, Any], account_id: str, acct: dict[str, Any]) -> IMessageAccount:
    return IMessageAccount(
        account_id=account_id,
        name=acct.get("name", account_id),
        server_url=acct.get("server_url", top.get("server_url", "http://localhost:1234")),
        password=acct.get("password", top.get("password", "")),
        dm_policy=acct.get("dmPolicy", acct.get("dm_policy", top.get("dmPolicy", top.get("dm_policy", "pairing")))),
        group_policy=acct.get(
            "groupPolicy", acct.get("group_policy", top.get("groupPolicy", top.get("group_policy", "allowlist")))
        ),
        allow_from=acct.get("allowFrom", acct.get("allow_from", top.get("allowFrom", top.get("allow_from", [])))),
        group_allow_from=acct.get(
            "groupAllowFrom", acct.get("group_allow_from", top.get("groupAllowFrom", top.get("group_allow_from", [])))
        ),
        require_mention=acct.get(
            "requireMention", acct.get("require_mention", top.get("requireMention", top.get("require_mention", False)))
        ),
        default_to=acct.get("defaultTo", acct.get("default_to", top.get("defaultTo", top.get("default_to", "")))),
        enabled=acct.get("enabled", True),
    )