import logging
import re
from datetime import date, datetime, timedelta

from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel

from .. import db
from .auth import get_current_user


logger = logging.getLogger(__name__)

router = APIRouter(prefix="/api/v1/checkin", tags=["checkin"])

CHECKIN_STATUSES = {"正常", "迟到", "请假", "不参加讨论", "早退"}
DEFAULT_STATUS = "正常"
DEFAULT_COURSE_TYPE = "会员课程"
MAX_NOTE_LEN = 500
DATE_RE = re.compile(r"^\d{4}-\d{2}-\d{2}$")
SELECT_COLS = "id,user_id,class_date,checked_at,status,course_type,note"


def get_class_date():
    today = date.today()
    return today + timedelta(days=(6 - today.weekday()))


def _is_valid_date(value):
    if not isinstance(value, str) or not DATE_RE.match(value):
        return False
    try:
        return datetime.strptime(value, "%Y-%m-%d").date().isoformat() == value
    except ValueError as exc:
        logger.warning("日期校验失败: %s", exc)
        return False


def fmt_dt(value):
    if isinstance(value, datetime):
        return value.strftime("%Y-%m-%d %H:%M:%S")
    return str(value) if value else ""


def fmt_rec(rec, name=""):
    return {
        "id": rec["id"],
        "user_id": rec["user_id"],
        "name": name,
        "class_date": str(rec["class_date"]),
        "checked_at": fmt_dt(rec.get("checked_at")),
        "status": rec.get("status", DEFAULT_STATUS),
        "course_type": rec.get("course_type", DEFAULT_COURSE_TYPE),
        "note": rec.get("note", ""),
    }


class CheckinRequest(BaseModel):
    status: str = DEFAULT_STATUS
    class_date: str = ""
    note: str = ""
    course_type: str = DEFAULT_COURSE_TYPE


@router.get("/week")
def week(user=Depends(get_current_user)):
    class_date = str(get_class_date())
    rec = db.fetch_one(
        "SELECT " + SELECT_COLS + " FROM checkin_records_old WHERE user_id=%s AND class_date=%s",
        (user["id"], class_date),
    )
    return {"class_date": class_date, "checked": rec is not None, "record": fmt_rec(rec) if rec else None}


@router.post("")
def checkin(req: CheckinRequest, user=Depends(get_current_user)):
    status = req.status.strip()
    if status not in CHECKIN_STATUSES:
        raise HTTPException(status_code=400, detail="无效的打卡状态")

    class_date = req.class_date.strip() or str(get_class_date())
    if not _is_valid_date(class_date):
        raise HTTPException(status_code=400, detail="无效的上课日期")

    note = req.note.strip() if status != DEFAULT_STATUS else ""
    if len(note) > MAX_NOTE_LEN:
        raise HTTPException(status_code=400, detail="备注过长")

    now = datetime.now()
    # 根据 user_id 判断当天是否已打卡：已打卡 → 更新；未打卡 → 新增
    existing = db.fetch_one(
        "SELECT id FROM checkin_records_old WHERE user_id=%s AND class_date=%s",
        (user["id"], class_date),
    )
    if existing:
        db.execute(
            "UPDATE checkin_records_old SET checked_at=%s, status=%s, course_type=%s, note=%s WHERE id=%s",
            (now, status, DEFAULT_COURSE_TYPE, note, existing["id"]),
        )
    else:
        # course_type 固定为会员课程（规范），忽略客户端传入值
        db.execute(
            "INSERT INTO checkin_records_old (user_id, class_date, checked_at, status, course_type, note) "
            "VALUES (%s, %s, %s, %s, %s, %s)",
            (user["id"], class_date, now, status, DEFAULT_COURSE_TYPE, note),
        )
    rec = db.fetch_one(
        "SELECT " + SELECT_COLS + " FROM checkin_records_old WHERE user_id=%s AND class_date=%s",
        (user["id"], class_date),
    )
    return {"success": True, "record": fmt_rec(rec, user.get("name", "")) if rec else None}


@router.get("/list")
def list_records(page: int = 1, size: int = 10, user=Depends(get_current_user)):
    page = max(1, page)
    size = max(1, min(50, size))
    offset = (page - 1) * size
    total_row = db.fetch_one(
        "SELECT COUNT(*) AS cnt FROM checkin_records_old WHERE user_id=%s", (user["id"],)
    )
    total = total_row["cnt"] if total_row else 0
    rows = db.fetch_all(
        "SELECT " + SELECT_COLS + " FROM checkin_records_old "
        "WHERE user_id=%s ORDER BY class_date DESC LIMIT %s OFFSET %s",
        (user["id"], size, offset),
    )
    return {"list": [fmt_rec(r, user.get("name", "")) for r in rows], "total": total, "page": page, "size": size}


@router.get("/group")
def group_view(class_date: str = "", user=Depends(get_current_user)):
    class_date = class_date.strip() or str(get_class_date())
    if not _is_valid_date(class_date):
        raise HTTPException(status_code=400, detail="无效的上课日期")

    user_row = db.fetch_one("SELECT `group` FROM auth_users WHERE id=%s", (user["id"],))
    if not user_row or not user_row.get("group"):
        return {"class_date": class_date, "group_name": "", "members": []}

    group_name = user_row["group"]
    # 单查询：成员 + 同组成员该上课日的打卡记录，LEFT JOIN 一次取回
    rows = db.fetch_all(
        "SELECT m.id AS user_id, m.student_id, m.name, "
        "       r.status, r.checked_at, r.note "
        "FROM auth_users m "
        "LEFT JOIN checkin_records_old r "
        "  ON r.user_id = m.id AND r.class_date = %s "
        "WHERE m.`group` = %s "
        "ORDER BY m.student_id",
        (class_date, group_name),
    )

    result_members = []
    for row in rows:
        rec = None
        if row.get("status") is not None:
            rec = {
                "status": row["status"],
                "checked_at": fmt_dt(row.get("checked_at")),
                "note": row.get("note", ""),
            }
        result_members.append({
            "user_id": row["user_id"],
            "student_id": row["student_id"],
            "name": row["name"],
            "role": "",
            "checked": rec is not None,
            "record": rec,
        })
    return {"class_date": class_date, "group_name": group_name, "members": result_members}