from datetime import datetime
from fastapi import APIRouter, Depends, HTTPException, Response, Request, status
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select

from app.auth.jwt import (
    create_access_token,
    create_refresh_token,
    decode_token,
    hash_password,
    verify_password,
)
from app.dependencies import get_db, get_current_user
from app.models.user import User
from app.models.subject import Subject
from app.schemas.auth import LoginRequest, RegisterRequest, TokenResponse
from app.schemas.user import UserOut

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

REFRESH_COOKIE = "refresh_token"
COOKIE_OPTS = {
    "httponly": True,
    "samesite": "lax",
    "secure": False,  # set True in production with HTTPS
}


@router.post("/register", response_model=TokenResponse, status_code=status.HTTP_201_CREATED)
async def register(body: RegisterRequest, response: Response, db: AsyncSession = Depends(get_db)):
    existing = await db.execute(select(User).where(User.email == body.email))
    if existing.scalar_one_or_none():
        raise HTTPException(status_code=400, detail="Email already registered")

    user = User(
        email=body.email,
        hashed_password=hash_password(body.password),
        full_name=body.full_name,
    )
    db.add(user)
    await db.commit()
    await db.refresh(user)

    meeting = Subject(
        user_id=user.id,
        name="Meeting",
        icon="📅",
        color="#6366f1",
        is_system=True,
    )
    db.add(meeting)
    await db.commit()

    access = create_access_token({"sub": str(user.id)})
    refresh = create_refresh_token({"sub": str(user.id)})
    response.set_cookie(REFRESH_COOKIE, refresh, **COOKIE_OPTS)
    return TokenResponse(access_token=access)


@router.post("/login", response_model=TokenResponse)
async def login(body: LoginRequest, response: Response, db: AsyncSession = Depends(get_db)):
    result = await db.execute(select(User).where(User.email == body.email))
    user = result.scalar_one_or_none()
    if not user or not verify_password(body.password, user.hashed_password):
        raise HTTPException(status_code=401, detail="Invalid credentials")
    if not user.is_active:
        raise HTTPException(status_code=403, detail="This account has been disabled. Please contact your administrator.")

    user.last_active_at = datetime.utcnow()
    await db.commit()

    access = create_access_token({"sub": str(user.id)})
    refresh = create_refresh_token({"sub": str(user.id)})
    response.set_cookie(REFRESH_COOKIE, refresh, **COOKIE_OPTS)
    return TokenResponse(access_token=access)


@router.post("/refresh", response_model=TokenResponse)
async def refresh_token(request: Request, response: Response, db: AsyncSession = Depends(get_db)):
    token = request.cookies.get(REFRESH_COOKIE)
    if not token:
        raise HTTPException(status_code=401, detail="No refresh token")

    try:
        payload = decode_token(token)
    except ValueError:
        raise HTTPException(status_code=401, detail="Invalid refresh token")

    if payload.get("type") != "refresh":
        raise HTTPException(status_code=401, detail="Wrong token type")

    user_id = payload.get("sub")
    result = await db.execute(select(User).where(User.id == int(user_id), User.is_active == True))
    user = result.scalar_one_or_none()
    if not user:
        raise HTTPException(status_code=401, detail="User not found")

    user.last_active_at = datetime.utcnow()
    await db.commit()

    access = create_access_token({"sub": str(user.id)})
    new_refresh = create_refresh_token({"sub": str(user.id)})
    response.set_cookie(REFRESH_COOKIE, new_refresh, **COOKIE_OPTS)
    return TokenResponse(access_token=access)


@router.post("/logout")
async def logout(response: Response):
    response.delete_cookie(REFRESH_COOKIE)
    return {"detail": "Logged out"}


@router.post("/change-password")
async def change_password(
    body: dict,
    current_user: User = Depends(get_current_user),
    db: AsyncSession = Depends(get_db),
):
    current = body.get("current_password", "")
    new = body.get("new_password", "").strip()
    if not current or not new:
        raise HTTPException(status_code=400, detail="current_password and new_password are required")
    if not verify_password(current, current_user.hashed_password):
        raise HTTPException(status_code=400, detail="Current password is incorrect")
    current_user.hashed_password = hash_password(new)
    await db.commit()
    return {"ok": True}