import time
from pathlib import Path

from fastapi import APIRouter, Depends, File, UploadFile, status
from fastapi.responses import FileResponse

from app.core.config import settings
from app.core.cos_url_keys import (
    avatar_url_for_api_response,
    best_effort_delete_cos_object_for_url,
)
from app.core.deps_types import CurrentUserDep
from app.core.errors import BadRequestError, NotFoundError
from app.core.logging import get_logger
from app.core.openapi import error_responses
from app.features.auth.deps import get_auth_service
from app.features.auth.preset_avatars import (
    avatar_url_for_preset_filename,
    list_preset_items,
    preset_file_path,
    preset_filename_for_id,
    safe_avatar_upload_path,
)
from app.features.auth.schemas import (
    AvatarPresetItem,
    ChangePasswordRequest,
    ChangePhoneRequest,
    LoginRequest,
    MockSmsLoginRequest,
    RefreshTokenRequest,
    RegisterRequest,
    ResetPasswordRequest,
    SendSmsRequest,
    SetAvatarPresetRequest,
    SmsLoginRequest,
    SmsRegisterRequest,
    TokenResponse,
    UpdateNicknameRequest,
    UserResponse,
)
from app.features.auth.service import AuthService
from app.features.user.models import User

logger = get_logger(__name__)

router = APIRouter(
    prefix="/api/auth",
    tags=["auth"],
    responses=error_responses(401),
)

AVATAR_DIR = Path("uploads/avatars")

# ── helpers ──────────────────────────────────────────────────

def _user_response(user: User) -> UserResponse:
    raw_lang = getattr(user, "language_preference", "zh")
    lang = str(raw_lang).strip().lower() if isinstance(raw_lang, str) else "zh"
    if lang not in ("zh", "en"):
        lang = "zh"
    return UserResponse(
        id=user.id,
        phone=user.phone,
        email=user.email,
        nickname=user.nickname,
        avatar_url=avatar_url_for_api_response(user.avatar_url),
        subscription_type=user.subscription_type,
        created_at=user.created_at.isoformat(),
        language_preference=lang,
    )


def _check_terms(agreed: bool) -> None:
    if not agreed:
        raise BadRequestError("请先阅读并同意用户协议和隐私政策")


def _mock_sms_login_route_enabled() -> bool:
    env = (settings.app_environment or "").lower().strip()
    if env == "production":
        return False
    return bool(settings.mock_sms_login_enabled)


# ── registration & login ─────────────────────────────────────


@router.post(
    "/register",
    response_model=TokenResponse,
    status_code=status.HTTP_201_CREATED,
    summary="手机号密码注册",
    responses=error_responses(400, descriptions={400: "手机号/邮箱已注册或参数错误"}),
)
async def register(
    request: RegisterRequest,
    service: AuthService = Depends(get_auth_service),
):
    _check_terms(request.agreed_to_terms)
    result = await service.register(
        phone=request.phone,
        password=request.password,
        nickname=request.nickname,
        email=request.email,
        language=request.language,
    )
    return TokenResponse(
        access_token=result["access_token"],
        refresh_token=result["refresh_token"],
    )


@router.post(
    "/login",
    response_model=TokenResponse,
    summary="手机号密码登录",
    responses=error_responses(401, descriptions={401: "手机号或密码错误"}),
)
async def login(
    request: LoginRequest,
    service: AuthService = Depends(get_auth_service),
):
    _check_terms(request.agreed_to_terms)
    result = await service.login(
        phone=request.phone,
        password=request.password,
    )
    return TokenResponse(
        access_token=result["access_token"],
        refresh_token=result["refresh_token"],
    )


@router.post(
    "/refresh",
    response_model=TokenResponse,
    summary="刷新访问令牌",
    responses=error_responses(
        401,
        descriptions={
            401: "刷新令牌无效/已过期；已轮换 token 被重复使用时会吊销全部会话（REFRESH_TOKEN_REUSE）"
        },
    ),
)
async def refresh_token(
    request: RefreshTokenRequest,
    service: AuthService = Depends(get_auth_service),
):
    result = await service.refresh_tokens(
        refresh_token=request.refresh_token,
    )
    return TokenResponse(
        access_token=result["access_token"],
        refresh_token=result["refresh_token"],
    )


# ── logout ────────────────────────────────────────────────────


@router.post(
    "/logout",
    status_code=status.HTTP_200_OK,
    summary="登出当前设备",
)
async def logout(
    request: RefreshTokenRequest,
    current_user: CurrentUserDep,
    service: AuthService = Depends(get_auth_service),
):
    await service.logout(request.refresh_token, current_user.id)
    return {"message": "登出成功"}


@router.post(
    "/logout/all",
    summary="登出所有设备",
)
async def logout_all_devices(
    current_user: CurrentUserDep,
    service: AuthService = Depends(get_auth_service),
):
    count = await service.logout_all(current_user.id)
    return {"message": f"已登出所有设备，共撤销 {count} 个令牌"}


# ── user profile ──────────────────────────────────────────────


@router.get(
    "/me",
    response_model=UserResponse,
    summary="获取当前用户信息",
)
async def get_me(
    current_user: CurrentUserDep,
):
    return _user_response(current_user)


@router.put(
    "/me/nickname",
    response_model=UserResponse,
    summary="修改昵称",
)
async def update_nickname(
    request: UpdateNicknameRequest,
    current_user: CurrentUserDep,
    service: AuthService = Depends(get_auth_service),
):
    user = await service.update_nickname(current_user.id, request.nickname)
    return _user_response(user)


# ── avatar ────────────────────────────────────────────────────


@router.post(
    "/me/avatar",
    response_model=UserResponse,
    summary="上传头像",
    responses=error_responses(400, descriptions={400: "文件类型或大小不符合要求"}),
)
async def upload_avatar(
    current_user: CurrentUserDep,
    service: AuthService = Depends(get_auth_service),
    file: UploadFile = File(...),
):
    file_content = await file.read()
    logger.debug(
        "上传头像: user_id={} filename={} content_type={} size={}",
        current_user.id,
        file.filename,
        file.content_type,
        len(file_content),
    )
    user = await service.upload_avatar(
        current_user.id,
        file_content,
        file.content_type or "",
        old_avatar_url=current_user.avatar_url,
    )
    return _user_response(user)


@router.get(
    "/avatar-presets",
    response_model=list[AvatarPresetItem],
    summary="预设头像列表",
)
async def list_avatar_presets():
    return [
        AvatarPresetItem(id=item_id, url=item_url)
        for item_id, item_url in list_preset_items()
    ]


@router.put(
    "/me/avatar/preset",
    response_model=UserResponse,
    summary="使用预设头像",
    responses=error_responses(400, descriptions={400: "无效的预设编号"}),
)
async def set_avatar_preset(
    request: SetAvatarPresetRequest,
    current_user: CurrentUserDep,
    service: AuthService = Depends(get_auth_service),
):
    filename = preset_filename_for_id(request.preset_id)
    if filename is None:
        raise BadRequestError("无效的预设头像编号")
    path = preset_file_path(filename)
    if path is None or not path.exists():
        raise BadRequestError("预设头像不可用")
    best_effort_delete_cos_object_for_url(current_user.avatar_url)

    avatar_url = f"{avatar_url_for_preset_filename(filename)}?v={time.time_ns()}"
    user = await service.update_avatar_url(current_user.id, avatar_url)
    return _user_response(user)


@router.get(
    "/avatar-presets/{filename}",
    summary="获取预设头像图片",
    responses=error_responses(404, descriptions={404: "预设不存在"}),
)
async def get_avatar_preset(filename: str):
    path = preset_file_path(filename)
    if path is None or not path.exists():
        raise NotFoundError("预设头像不存在")
    return FileResponse(path, media_type="image/png")


@router.get(
    "/avatars/{filename}",
    summary="获取头像图片",
    responses=error_responses(404, descriptions={404: "头像不存在"}),
)
async def get_avatar(filename: str):
    AVATAR_DIR.mkdir(parents=True, exist_ok=True)
    file_path = safe_avatar_upload_path(filename, AVATAR_DIR)
    if file_path is None or not file_path.exists():
        raise NotFoundError("头像不存在")
    return FileResponse(file_path, media_type="image/jpeg")


# ── SMS verification ──────────────────────────────────────────


@router.post(
    "/sms/send",
    summary="发送短信验证码",
    responses=error_responses(
        400,
        429,
        502,
        503,
        descriptions={
            400: "手机号格式或用途不合法",
            429: "发送过于频繁（RATE_LIMITED）",
            502: "短信服务商调用失败（PROVIDER_ERROR，可重试）",
            503: "短信服务未配置或不可用（SERVICE_UNAVAILABLE）",
        },
    ),
)
async def send_sms_code(
    request: SendSmsRequest,
    service: AuthService = Depends(get_auth_service),
):
    if not request.phone.isdigit():
        raise BadRequestError("手机号格式不正确")

    valid_purposes = ["register", "login", "reset_password", "change_phone"]
    if request.purpose not in valid_purposes:
        raise BadRequestError(f"无效的用途，必须是: {', '.join(valid_purposes)}")

    _success, message, expires_in = await service.send_sms_code(
        phone=request.phone,
        purpose=request.purpose,
        ip_address=None,
    )

    return {"message": message, "expires_in": expires_in}


@router.post(
    "/login/sms",
    response_model=TokenResponse,
    summary="短信验证码登录（新用户自动注册）",
    responses=error_responses(400, descriptions={400: "验证码错误"}),
)
async def login_with_sms(
    request: SmsLoginRequest,
    service: AuthService = Depends(get_auth_service),
):
    _check_terms(request.agreed_to_terms)
    result = await service.login_with_sms(
        phone=request.phone,
        code=request.code,
        nickname=request.nickname,
        language=request.language,
    )
    return TokenResponse(
        access_token=result["access_token"],
        refresh_token=result["refresh_token"],
    )


@router.post(
    "/mock/sms-login",
    response_model=TokenResponse,
    summary="[评测] Mock 短信登录（跳过验证码）",
    description=(
        "需 config deploy.mock_sms_login_enabled=true 且 APP_ENV 非 production。"
        "供 Eval Web 等内网工具联调，勿在生产环境开启。"
    ),
    responses=error_responses(404, descriptions={404: "未启用或生产环境已禁用"}),
)
async def mock_sms_login_route(
    request: MockSmsLoginRequest,
    service: AuthService = Depends(get_auth_service),
):
    if not _mock_sms_login_route_enabled():
        raise NotFoundError("Not Found")
    _check_terms(request.agreed_to_terms)
    result = await service.mock_sms_login(
        phone=request.phone,
        nickname=request.nickname,
        language=request.language,
    )
    return TokenResponse(
        access_token=result["access_token"],
        refresh_token=result["refresh_token"],
    )


@router.post(
    "/register/sms",
    response_model=TokenResponse,
    status_code=status.HTTP_201_CREATED,
    summary="短信验证码注册",
    responses=error_responses(400, descriptions={400: "验证码错误或手机号/邮箱已注册"}),
)
async def register_with_sms(
    request: SmsRegisterRequest,
    service: AuthService = Depends(get_auth_service),
):
    _check_terms(request.agreed_to_terms)
    result = await service.register_with_sms(
        phone=request.phone,
        code=request.code,
        password=request.password,
        nickname=request.nickname,
        email=request.email,
        language=request.language,
    )
    return TokenResponse(
        access_token=result["access_token"],
        refresh_token=result["refresh_token"],
    )


# ── password & phone management ───────────────────────────────


@router.post(
    "/password/reset",
    summary="通过短信验证码重置密码",
    responses=error_responses(
        400,
        404,
        descriptions={
            400: "验证码错误",
            404: "用户不存在",
        },
    ),
)
async def reset_password(
    request: ResetPasswordRequest,
    service: AuthService = Depends(get_auth_service),
):
    await service.reset_password(
        phone=request.phone,
        code=request.code,
        new_password=request.new_password,
    )
    return {"message": "密码重置成功"}


@router.post(
    "/password/change",
    summary="修改密码（需旧密码）",
    responses=error_responses(400, descriptions={400: "旧密码错误"}),
)
async def change_password(
    request: ChangePasswordRequest,
    current_user: CurrentUserDep,
    service: AuthService = Depends(get_auth_service),
):
    await service.change_password(
        user_id=current_user.id,
        old_password=request.old_password,
        new_password=request.new_password,
    )
    return {"message": "密码修改成功"}


@router.post(
    "/phone/change",
    response_model=UserResponse,
    summary="更换手机号",
    responses=error_responses(400, descriptions={400: "验证码错误或手机号已被占用"}),
)
async def change_phone(
    request: ChangePhoneRequest,
    current_user: CurrentUserDep,
    service: AuthService = Depends(get_auth_service),
):
    user = await service.change_phone(
        user_id=current_user.id,
        new_phone=request.new_phone,
        code=request.code,
    )
    return _user_response(user)