"""System configuration API — get/set runtime settings like notification time."""

from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select
from app.database import get_db
from app.middleware.auth import get_current_user, require_director
from app.models.system_config import SystemConfig
from app.services.holidays import refresh_holidays
from app.services.scheduler_manager import reschedule_daily_check

router = APIRouter(prefix="/system-config", tags=["SystemConfig"])

DEFAULT_NOTIFICATION_TIME = "17:30"


def _parse_time(time_str: str) -> tuple[int, int]:
    """Parse 'HH:MM' string to (hour, minute). Raises ValueError on bad input."""
    parts = time_str.strip().split(":")
    if len(parts) != 2:
        raise ValueError("时间格式必须为 HH:MM")
    h, m = int(parts[0]), int(parts[1])
    if not (0 <= h <= 23 and 0 <= m <= 59):
        raise ValueError("小时 0-23，分钟 0-59")
    return h, m


async def _get_config(db: AsyncSession, key: str) -> str | None:
    row = await db.get(SystemConfig, key)
    return row.value if row else None


async def _set_config(db: AsyncSession, key: str, value: str):
    row = await db.get(SystemConfig, key)
    if row:
        row.value = value
    else:
        db.add(SystemConfig(key=key, value=value))
    await db.commit()


async def get_notification_time(db: AsyncSession) -> str:
    """Read notification_time from DB, falling back to default."""
    val = await _get_config(db, "notification_time")
    return val if val else DEFAULT_NOTIFICATION_TIME


@router.get("")
async def list_config(
    current_user: dict = Depends(require_director),
    db: AsyncSession = Depends(get_db),
):
    """Return all system config as {key: value} dict."""
    result = await db.execute(select(SystemConfig))
    rows = result.scalars().all()
    config = {r.key: r.value for r in rows}
    # Ensure notification_time always has a value
    if "notification_time" not in config:
        config["notification_time"] = DEFAULT_NOTIFICATION_TIME
    return config


@router.put("/{key}")
async def update_config(
    key: str,
    body: dict,
    current_user: dict = Depends(require_director),
    db: AsyncSession = Depends(get_db),
):
    """Update a single config key. Only directors can change settings."""
    value = body.get("value", "")
    valid_keys = {"notification_time", "holidays", "ai_summary_prompt"}

    if key not in valid_keys:
        raise HTTPException(status_code=400, detail=f"不支持的配置项: {key}")

    if key == "notification_time":
        try:
            h, m = _parse_time(value)
        except ValueError as e:
            raise HTTPException(status_code=400, detail=str(e))
        await _set_config(db, key, value)
        await reschedule_daily_check(h, m)
        return {"key": key, "value": value, "scheduled": f"{h:02d}:{m:02d}"}

    if key == "holidays":
        # Validate: comma-separated YYYY-MM-DD dates
        if value.strip():
            for s in value.split(","):
                s = s.strip()
                if s:
                    try:
                        from datetime import date
                        date.fromisoformat(s)
                    except ValueError:
                        raise HTTPException(status_code=400, detail=f"日期格式错误: {s}，应为 YYYY-MM-DD")
        await _set_config(db, key, value)
        return {"key": key, "value": value}

    await _set_config(db, key, value)
    return {"key": key, "value": value}


@router.post("/refresh-holidays")
async def refresh_holidays_endpoint(
    current_user: dict = Depends(require_director),
    db: AsyncSession = Depends(get_db),
):
    """Fetch the latest Chinese holiday data from apisbo.com and cache it."""
    try:
        result = await refresh_holidays(db)
        return {"status": "ok", **result}
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"刷新节假日数据失败: {str(e)}")