from fastapi import APIRouter, Depends, HTTPException, status, Header, Request
from fastapi.security import OAuth2PasswordRequestForm
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select
from typing import Optional
import uuid
from app.database import get_db
from app.models.user import User
from app.core.security import hash_password, verify_password, create_access_token, create_refresh_token, decode_token
from pydantic import BaseModel, EmailStr
from datetime import datetime, timedelta
from app.services.admin import AdminService

router = APIRouter()


class RegisterRequest(BaseModel):
    phone: str
    password: str
    username: str = ""


class LoginResponse(BaseModel):
    access_token: str
    refresh_token: str
    token_type: str = "bearer"
    user: dict


class LoginRequest(BaseModel):
    username: str = ""
    phone: str = ""
    password: str


class RefreshRequest(BaseModel):
    refresh_token: str


@router.post("/register")
async def register(data: RegisterRequest, request: Request, db: AsyncSession = Depends(get_db)):
    existing = await db.execute(select(User).where(User.phone == data.phone))
    if existing.scalar_one_or_none():
        raise HTTPException(status_code=400, detail="Phone already registered")

    user = User(
        phone=data.phone,
        username=data.username or data.phone,
        password_hash=hash_password(data.password),
        tier="free",
    )
    db.add(user)
    await db.flush()

    client_ip = request.client.host if request.client else None
    await AdminService(db).log_usage(str(user.id), "user.register", {"phone": data.phone}, ip=client_ip)

    return {
        "id": str(user.id),
        "phone": user.phone,
        "username": user.username,
        "tier": user.tier,
        "role": user.role,
    }


@router.post("/login", response_model=LoginResponse)
async def login(
    data: LoginRequest,
    request: Request,
    db: AsyncSession = Depends(get_db),
):
    login_id = data.username or data.phone
    if not login_id:
        raise HTTPException(status_code=422, detail="phone required")
    result = await db.execute(
        select(User).where(
            (User.phone == login_id) | (User.username == login_id)
        )
    )
    user = result.scalar_one_or_none()

    if not user or not verify_password(data.password, user.password_hash):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid credentials",
        )

    client_ip = request.client.host if request.client else None
    await AdminService(db).log_usage(str(user.id), "user.login", {"login_id": login_id}, ip=client_ip)

    return LoginResponse(
        access_token=create_access_token({"sub": str(user.id), "tier": user.tier, "role": user.role}),
        refresh_token=create_refresh_token({"sub": str(user.id)}),
        user={
            "id": str(user.id),
            "phone": user.phone,
            "username": user.username,
            "tier": user.tier,
        },
    )


@router.post("/login/guest")
async def guest_login(request: Request, db: AsyncSession = Depends(get_db)):
    guest_id = str(uuid.uuid4())
    access_token = create_access_token(
        {"sub": guest_id, "tier": "guest", "role": "guest", "is_guest": True},
        expires_delta=timedelta(hours=24)
    )
    refresh_token = create_refresh_token({"sub": guest_id, "is_guest": True})
    
    client_ip = request.client.host if request.client else None
    await AdminService(db).log_usage(guest_id, "user.login_guest", {}, ip=client_ip)

    return LoginResponse(
        access_token=access_token,
        refresh_token=refresh_token,
        token_type="bearer",
        user={
            "id": guest_id,
            "phone": None,
            "username": "游客用户",
            "tier": "guest",
            "is_guest": True,
        },
    )


@router.post("/refresh")
async def refresh(data: RefreshRequest):
    payload = decode_token(data.refresh_token)
    if not payload or payload.get("type") != "refresh":
        raise HTTPException(status_code=401, detail="Invalid refresh token")

    # 保留游客/角色等信息
    extra = {}
    if payload.get("is_guest"):
        extra = {"is_guest": True, "tier": "guest", "role": "guest"}
    else:
        extra = {
            "tier": payload.get("tier", "free"),
            "role": payload.get("role", "user"),
        }

    return {
        "access_token": create_access_token({"sub": payload["sub"], **extra}),
        "token_type": "bearer",
    }


@router.get("/me")
async def get_me(
    authorization: Optional[str] = Header(None, alias="Authorization"),
    db: AsyncSession = Depends(get_db),
):
    if not authorization or not authorization.startswith("Bearer "):
        raise HTTPException(status_code=401, detail="Missing token")

    payload = decode_token(authorization[7:])
    if not payload:
        raise HTTPException(status_code=401, detail="Invalid token")

    if payload.get("is_guest"):
        return {
            "id": payload["sub"],
            "phone": None,
            "username": "游客用户",
            "tier": "guest",
            "role": "guest",
            "is_guest": True,
            "settings": {},
            "created_at": None,
        }

    result = await db.execute(select(User).where(User.id == payload["sub"]))
    user = result.scalar_one_or_none()
    if not user:
        raise HTTPException(status_code=404, detail="User not found")

    return {
        "id": str(user.id),
        "phone": user.phone,
        "username": user.username,
        "tier": user.tier,
        "role": user.role,
        "settings": user.settings,
        "created_at": user.created_at.isoformat() if user.created_at else None,
    }


class SettingsUpdate(BaseModel):
    preferred_translate_provider: str = None
    reply_tone: str = None
    timezone: str = None
    languages: list = None


class WeChatLoginRequest(BaseModel):
    code: str
    encrypted_data: str = ""
    iv: str = ""


@router.get("/wechat/config")
async def wechat_config():
    from app.config import settings
    return {
        "available": bool(settings.WECHAT_APP_ID and settings.WECHAT_APP_SECRET),
        "app_id": settings.WECHAT_APP_ID or "",
    }


@router.post("/wechat-login")
async def wechat_login(data: WeChatLoginRequest, request: Request, db: AsyncSession = Depends(get_db)):
    from app.services.wechat import wechat_service

    session = await wechat_service.code2session(data.code)
    if not session:
        raise HTTPException(status_code=400, detail="WeChat login failed")

    openid = session.get("openid")
    result = await db.execute(select(User).where(User.wechat_openid == openid))
    user = result.scalar_one_or_none()
    is_new = False

    if not user:
        user = User(
            wechat_openid=openid,
            username=f"wx_{openid[-8:]}",
            tier="free",
        )
        db.add(user)
        await db.flush()
        is_new = True

    client_ip = request.client.host if request.client else None
    await AdminService(db).log_usage(str(user.id), "user.wechat_login", {"is_new": is_new}, ip=client_ip)

    return LoginResponse(
        access_token=create_access_token({"sub": str(user.id), "tier": user.tier, "role": user.role}),
        refresh_token=create_refresh_token({"sub": str(user.id)}),
        user={
            "id": str(user.id),
            "phone": user.phone,
            "username": user.username,
            "tier": user.tier,
            "role": user.role,
        },
    )


@router.patch("/settings")
async def update_settings(
    data: SettingsUpdate,
    authorization: Optional[str] = Header(None, alias="Authorization"),
    db: AsyncSession = Depends(get_db),
):
    if not authorization or not authorization.startswith("Bearer "):
        raise HTTPException(status_code=401, detail="Missing token")

    payload = decode_token(authorization[7:])
    if not payload:
        raise HTTPException(status_code=401, detail="Invalid token")

    result = await db.execute(select(User).where(User.id == payload["sub"]))
    user = result.scalar_one_or_none()
    if not user:
        raise HTTPException(status_code=404, detail="User not found")

    settings = user.settings or {}
    for key, value in data.dict(exclude_unset=True).items():
        if value is not None:
            settings[key] = value

    user.settings = settings
    await db.flush()

    return {"settings": user.settings}