"""续费检查服务

检查即将到期的资产，生成提醒消息并通过通知渠道发送。
发送前会先尝试从平台侧核对真实状态（见 verification_service），
核对到的到期日/状态会回写本地记录，避免按过期的手工数据误报。
"""

import logging
from datetime import date, timedelta

from sqlmodel import Session, select

from app.core.config import settings
from app.models.asset import Asset, AssetStatus
from app.services import notification_service, verification_service

logger = logging.getLogger("vps-manager.renewal")


def get_expiring_assets(session: Session, threshold_days: int) -> list:
    """返回 threshold_days 天内到期（含已过期未处理）的资产列表 [(asset, days), ...]

    到期日不设下界：过了续费日仍未注销/续费的资产，提醒不能就此消失。
    已注销资产直接排除；已停止资产仅在开启自动续费时提醒
    （停止实例不等于停止扣费，自动续费仍可能产生费用）。
    """
    today = date.today()
    deadline = today + timedelta(days=threshold_days)
    assets = session.exec(
        select(Asset).where(
            Asset.expiry_date.is_not(None),
            Asset.expiry_date <= deadline,
            Asset.status != AssetStatus.CANCELLED,
        )
    ).all()
    assets = [
        asset
        for asset in assets
        if not (asset.status == AssetStatus.STOPPED and not asset.auto_renew)
    ]
    expiring = [(asset, (asset.expiry_date - today).days) for asset in assets]
    expiring.sort(key=lambda x: x[1])
    return expiring


def day_text(days: int) -> str:
    """单项到期文案（提醒消息与 check_renewals 脚本共用）

    days 可以为负（已过期），直接拼成「{days} 天后到期」会得到「-3 天后到期」；
    前端对应的统一文案是 Fmt.countdownText，两边保持一致。
    """
    if days < 0:
        return f"已过期 {-days} 天"
    if days == 0:
        return "今天到期"
    return f"{days} 天后"


def build_renewal_message(expiring: list, threshold_days: int, verification: dict = None) -> str:
    """生成续费提醒消息（纯文本，兼容 Telegram/邮件）"""
    if not expiring:
        return ""
    overdue = sum(1 for _, d in expiring if d < 0)
    if overdue:
        head = f"⏰ 资产续费提醒（已过期 {overdue} 项 + {threshold_days} 天内到期 {len(expiring) - overdue} 项）"
    else:
        head = f"⏰ 资产续费提醒（{threshold_days} 天内到期，共 {len(expiring)} 项）"
    lines = [head, ""]
    for asset, days in expiring:
        lines.append(f"• {asset.name} [{asset.provider}] （{day_text(days)}） 到期 {asset.expiry_date}")
        result = (verification or {}).get(getattr(asset, "id", None))
        if result is not None:
            if result.verified:
                lines.append(f"  ↳ 已核对：{result.detail}")
            else:
                lines.append(f"  ↳ 未核对：{result.detail}，按手工登记日期提醒")

    if verification:
        verified = sum(
            1 for asset, _ in expiring
            if getattr(verification.get(getattr(asset, "id", None)), "verified", False)
        )
        lines.append("")
        lines.append(f"核对：已核对 {verified} 项，未核对 {len(expiring) - verified} 项")
    return "\n".join(lines)


def check_renewals(
    session: Session,
    threshold_days: int = None,
    send: bool = True,
    verify: bool = True,
) -> dict:
    """检查续费并（可选）发送提醒

    threshold_days: 提醒阈值天数，默认取配置 RENEWAL_THRESHOLD_DAYS
    send: 是否实际发送通知（False 时仅返回预览）
    verify: 发送前是否向平台核对真实状态（测试/排查时可关闭）
    """
    if threshold_days is None:
        threshold_days = settings.RENEWAL_THRESHOLD_DAYS

    expiring = get_expiring_assets(session, threshold_days)
    verification = {}
    if verify and expiring:
        try:
            verification = verification_service.verify_assets(
                session, [asset for asset, _ in expiring]
            )
        except Exception:  # noqa: BLE001
            # 核对是增强项：核对服务整体异常时仍按本地数据提醒，不能因此不发消息
            logger.exception("续费核对异常，退回本地登记数据")
        # 核对可能已把到期日/状态改成最新值，重新筛选
        expiring = get_expiring_assets(session, threshold_days)

    message = build_renewal_message(expiring, threshold_days, verification)

    result = {
        "threshold_days": threshold_days,
        "expiring_count": len(expiring),
        "expiring": [
            {
                "name": asset.name,
                "provider": asset.provider,
                "days": days,
                "expiry_date": str(asset.expiry_date),
                "verified": getattr(verification.get(asset.id), "verified", None),
                "verify_source": getattr(verification.get(asset.id), "source", ""),
                "verify_detail": getattr(verification.get(asset.id), "detail", ""),
            }
            for asset, days in expiring
        ],
        "message": message,
    }
    if verification:
        verified_count = sum(
            1 for asset, _ in expiring
            if getattr(verification.get(asset.id), "verified", False)
        )
        result["verification"] = {
            "verified": verified_count,
            "unverified": len(expiring) - verified_count,
        }
    else:
        result["verification"] = None

    if send and message:
        result["notifications"] = notification_service.notify(message)
    else:
        result["notifications"] = []
    return result