from __future__ import annotations

from dataclasses import dataclass

from django.conf import settings


@dataclass(frozen=True)
class ResolvedFeishuTarget:
    ok: bool
    identifier_type: str
    identifier_value: str
    display_name: str
    masked_identifier: str
    error_code: str = ""
    error_message: str = ""


def mask_identifier(value: str) -> str:
    if not value:
        return ""
    if len(value) <= 8:
        return value[:2] + "***"
    return f"{value[:4]}***{value[-4:]}"


def resolve_configured_personal_recipient() -> ResolvedFeishuTarget:
    open_id = getattr(settings, "FEISHU_DEFAULT_USER_OPEN_ID", "")
    user_id = getattr(settings, "FEISHU_DEFAULT_USER_ID", "")
    display_name = getattr(settings, "FEISHU_DEFAULT_TARGET_NAME", "默认飞书接收人")
    if open_id:
        return ResolvedFeishuTarget(
            ok=True,
            identifier_type="open_id",
            identifier_value=open_id,
            display_name=display_name,
            masked_identifier=mask_identifier(open_id),
        )
    if user_id:
        return ResolvedFeishuTarget(
            ok=True,
            identifier_type="user_id",
            identifier_value=user_id,
            display_name=display_name,
            masked_identifier=mask_identifier(user_id),
        )
    return ResolvedFeishuTarget(
        ok=False,
        identifier_type="missing",
        identifier_value="",
        display_name=display_name,
        masked_identifier="",
        error_code="recipient_missing",
        error_message="未配置 FEISHU_DEFAULT_USER_OPEN_ID 或 FEISHU_DEFAULT_USER_ID",
    )