"""小程序鉴权：微信登录 / 绑定 openid。"""
from __future__ import annotations

from datetime import datetime

from fastapi import APIRouter, Depends, HTTPException, Request
from sqlalchemy.orm import Session

from app.core.auth import get_current_user_by_token
from app.core.database import get_db
from app.core.response import error_response, success_response
from app.crud.user import user_crud
from app.services import wx_qr_session
from app.services.issue_user_tokens import issue_tokens_for_user
from app.services.wechat_login_service import (
    resolve_wechat_login_by_openid_only,
    resolve_wechat_login_user,
)
from app.services.wechat_mini_auth import (
    WechatMiniAuthError,
    code2session,
    get_phone_number,
)
from app.services.wechat_mp_auth import WechatMpAuthError, oauth_code_to_openid


router = APIRouter(prefix="/mini/auth", tags=["小程序鉴权"])


async def _resolve_user_id(request: Request, db: Session) -> str:
    authorization = request.headers.get("Authorization", "")
    if not authorization.startswith("Bearer "):
        raise HTTPException(status_code=401, detail="未授权")
    token = authorization.replace("Bearer ", "")
    current = await get_current_user_by_token(token=token, db=db)
    user_id = current.get("user_id") or current.get("sub")
    if not user_id:
        raise HTTPException(status_code=401, detail="未授权")
    return user_id


@router.post("/wechat-login", response_model=dict)
async def wechat_login(body: dict, db: Session = Depends(get_db)):
    """微信登录：openid 已绑定时可静默换票；否则须授权手机号且与账号 phone_no 一致。"""
    login_code = (body.get("loginCode") or "").strip()
    phone_code = (body.get("phoneCode") or "").strip() or None

    try:
        sess = code2session(login_code)
    except WechatMiniAuthError as exc:
        return error_response(400, str(exc))

    if not phone_code:
        user, err_msg, err_code = resolve_wechat_login_by_openid_only(
            db, openid=sess["openid"]
        )
        if err_msg:
            return error_response(err_code or 400, err_msg)
    else:
        try:
            phone = get_phone_number(phone_code)
        except WechatMiniAuthError as exc:
            return error_response(400, str(exc))

        user, err_msg, err_code = resolve_wechat_login_user(
            db, openid=sess["openid"], phone=phone
        )
        if err_msg:
            return error_response(err_code or 400, err_msg)

        unionid = (sess.get("unionid") or "").strip()
        if unionid and not (getattr(user, "wx_unionid", None) or "").strip():
            user.wx_unionid = unionid
            user.update_time = datetime.now()
            db.add(user)
            db.commit()
            db.refresh(user)

    try:
        data = await issue_tokens_for_user(db, user)
    except ValueError as exc:
        return error_response(403, str(exc))
    return success_response(data)


@router.post("/wechat-bind", response_model=dict)
async def wechat_bind(
    request: Request,
    body: dict,
    db: Session = Depends(get_db),
):
    """密码登录后绑定当前微信 openid（需 Bearer）。"""
    try:
        user_id = await _resolve_user_id(request, db)
    except HTTPException:
        return error_response(401, "未授权")

    login_code = (body.get("loginCode") or "").strip()
    try:
        sess = code2session(login_code)
    except WechatMiniAuthError as exc:
        return error_response(400, str(exc))

    openid = sess["openid"]
    user = user_crud.get(db, user_id)
    if not user or user.del_flag != 0:
        return error_response(401, "用户不存在")

    other = user_crud.get_by_wx_openid(db, openid)
    if other and other.id != user.id:
        return error_response(409, "该微信已绑定其他账号")

    existing_oid = (getattr(user, "wx_openid", None) or "").strip()
    if existing_oid == openid:
        return success_response({"bound": True, "message": "已绑定"})

    if existing_oid and existing_oid != openid:
        return error_response(409, "该账号已绑定其他微信，请联系管理员")

    user.wx_openid = openid
    user.update_time = datetime.now()
    db.add(user)
    db.commit()
    return success_response({"bound": True, "message": "绑定成功"})


@router.get("/mp-bind-status", response_model=dict)
async def mp_bind_status(request: Request, db: Session = Depends(get_db)):
    """当前用户是否已绑定微信服务号 openid。"""
    try:
        user_id = await _resolve_user_id(request, db)
    except HTTPException:
        return error_response(401, "未授权")

    user = user_crud.get(db, user_id)
    bound = bool(user and (getattr(user, "wx_mp_openid", None) or "").strip())
    return success_response({"bound": bound})


@router.post("/mp-bind", response_model=dict)
async def mp_bind(request: Request, body: dict, db: Session = Depends(get_db)):
    """服务号网页授权 code 绑定当前用户（需 Bearer）。"""
    try:
        user_id = await _resolve_user_id(request, db)
    except HTTPException:
        return error_response(401, "未授权")

    code = (body.get("code") or "").strip()
    try:
        info = oauth_code_to_openid(code)
    except WechatMpAuthError as exc:
        return error_response(400, str(exc))

    mp_openid = info["openid"]
    other = user_crud.get_by_wx_mp_openid(db, mp_openid)
    if other and other.id != user_id:
        return error_response(409, "该微信服务号已绑定其他账号")

    user = user_crud.get(db, user_id)
    if not user or user.del_flag != 0:
        return error_response(401, "用户不存在")

    user.wx_mp_openid = mp_openid
    if info.get("unionid"):
        user.wx_unionid = info["unionid"]
    user.wx_mp_bind_time = datetime.now()
    user.update_time = datetime.now()
    db.add(user)
    db.commit()
    return success_response({"bound": True})


@router.post("/web-qr-scanned", response_model=dict)
async def web_qr_scanned(body: dict):
    raw = (body.get("sessionId") or body.get("scene") or "").strip()
    sid = wx_qr_session.resolve_session_id(raw) or raw
    data = wx_qr_session.get_session(sid)
    if not data or data.get("status") in ("expired", "consumed"):
        return error_response(400, "二维码已过期，请在电脑上刷新后重扫")
    wx_qr_session.mark_scanned(sid)
    return success_response({"ok": True})


@router.post("/web-qr-confirm", response_model=dict)
async def web_qr_confirm(body: dict, db: Session = Depends(get_db)):
    raw = (body.get("sessionId") or body.get("scene") or "").strip()
    sid = wx_qr_session.resolve_session_id(raw) or raw
    data = wx_qr_session.get_session(sid)
    if not data or data.get("status") in ("expired", "consumed", "failed"):
        return error_response(400, "二维码已过期，请在电脑上刷新后重扫")
    if data.get("status") == "success":
        return success_response({"ok": True, "message": "电脑端即将登录"})

    wx_qr_session.mark_scanned(sid)

    login_code = (body.get("loginCode") or "").strip()
    phone_code = (body.get("phoneCode") or "").strip()
    if not login_code or not phone_code:
        wx_qr_session.mark_failed(sid, "需要授权手机号才能完成扫码登录")
        return error_response(400, "需要授权手机号才能完成扫码登录")

    try:
        sess = code2session(login_code)
        phone = get_phone_number(phone_code)
    except WechatMiniAuthError as exc:
        wx_qr_session.mark_failed(sid, str(exc))
        return error_response(400, str(exc))

    user, err_msg, err_code = resolve_wechat_login_user(
        db, openid=sess["openid"], phone=phone
    )
    if err_msg:
        wx_qr_session.mark_failed(sid, err_msg)
        return error_response(err_code or 400, err_msg)

    unionid = (sess.get("unionid") or "").strip()
    if unionid and not (getattr(user, "wx_unionid", None) or "").strip():
        user.wx_unionid = unionid
        user.update_time = datetime.now()
        db.add(user)
        db.commit()
        db.refresh(user)

    try:
        tokens = await issue_tokens_for_user(db, user)
    except ValueError as exc:
        wx_qr_session.mark_failed(sid, str(exc))
        return error_response(403, str(exc))

    if not wx_qr_session.mark_success(sid, tokens):
        return error_response(400, "二维码已过期，请在电脑上刷新后重扫")
    return success_response({"ok": True, "message": "电脑端即将登录，可关闭本页"})