from uuid import UUID

from fastapi import APIRouter, Depends
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.auth import AuthUser, require_auth
from app.core.database import get_session
from app.models.user import User
from app.schemas.base import CamelModel

router = APIRouter()


class UserResponse(CamelModel):
    id: UUID
    email: str
    display_name: str | None = None
    is_admin: bool = False


@router.post("/me", response_model=UserResponse)
async def sync_current_user(
    session: AsyncSession = Depends(get_session),
    auth_user: AuthUser = Depends(require_auth),
):
    """
    Sync the current authenticated user from Supabase to local DB.
    Creates user on first login, updates email if changed.
    """
    user_id = UUID(auth_user.id)

    result = await session.execute(select(User).where(User.id == user_id))
    user = result.scalar_one_or_none()

    if user is None:
        # First login - create user record
        user = User(
            id=user_id,
            email=auth_user.email or "",
            display_name=None,
        )
        session.add(user)
    elif auth_user.email and user.email != auth_user.email:
        # Email changed in Supabase - update local record
        user.email = auth_user.email

    await session.commit()
    await session.refresh(user)
    return user


@router.get("/me", response_model=UserResponse)
async def get_current_user(
    session: AsyncSession = Depends(get_session),
    auth_user: AuthUser = Depends(require_auth),
):
    """Get the current authenticated user's profile."""
    user_id = UUID(auth_user.id)

    result = await session.execute(select(User).where(User.id == user_id))
    user = result.scalar_one_or_none()

    if user is None:
        # Auto-create if not exists (shouldn't happen if /me POST is called on login)
        user = User(
            id=user_id,
            email=auth_user.email or "",
            display_name=None,
        )
        session.add(user)
        await session.commit()
        await session.refresh(user)

    return user


class UserUpdateRequest(CamelModel):
    display_name: str | None = None


@router.patch("/me", response_model=UserResponse)
async def update_current_user(
    data: UserUpdateRequest,
    session: AsyncSession = Depends(get_session),
    auth_user: AuthUser = Depends(require_auth),
):
    """Update the current user's profile (display name)."""
    user_id = UUID(auth_user.id)

    result = await session.execute(select(User).where(User.id == user_id))
    user = result.scalar_one_or_none()

    if user is None:
        user = User(
            id=user_id,
            email=auth_user.email or "",
            display_name=data.display_name,
        )
        session.add(user)
    else:
        if data.display_name is not None:
            user.display_name = data.display_name

    await session.commit()
    await session.refresh(user)
    return user