"""Authentication router for login and user management."""

import secrets
from fastapi import APIRouter, HTTPException, Depends, Header
from typing import Annotated

from baby_monitor.models.auth import (
    LoginRequest,
    LoginResponse,
    RegisterRequest,
    RegisterResponse,
)
from baby_monitor.repositories import (
    get_token_repository,
    get_credentials_repository,
    get_user_repository,
)
from baby_monitor.repositories.dependencies.get_invitation_repository import (
    get_invitation_repository,
)
from baby_monitor.repositories.interfaces import (
    TokenRepositoryInterface,
    CredentialsRepositoryInterface,
    UserRepositoryInterface,
    InvitationRepositoryInterface,
)

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


def verify_token(
    authorization: Annotated[str | None, Header()] = None,
    token_repo: TokenRepositoryInterface = Depends(get_token_repository),
) -> int:
    """Verify the bearer token and return user_id."""
    if not authorization:
        raise HTTPException(status_code=401, detail="Not authenticated")

    try:
        scheme, token = authorization.split()
        if scheme.lower() != "bearer":
            raise HTTPException(status_code=401, detail="Invalid authentication scheme")
    except ValueError:
        raise HTTPException(status_code=401, detail="Invalid authorization header")

    user_id = token_repo.verify(token)
    if user_id is None:
        raise HTTPException(status_code=401, detail="Invalid or expired token")

    return user_id


def verify_admin(
    user_id: Annotated[int, Depends(verify_token)],
    user_repo: Annotated[UserRepositoryInterface, Depends(get_user_repository)],
) -> int:
    """Verify the user is an admin and return user_id."""
    # First try to get user from database
    user = user_repo.get_by_id(user_id)

    if user:
        # Database user - check is_admin field
        if not user.get("is_admin", False):
            raise HTTPException(status_code=403, detail="Admin access required")
        return user_id

    # If not in database but has valid token with user_id=1,
    # it's the environment-based admin (only assigned during env admin login)
    if user_id == 1:
        return user_id

    # User not found and not environment admin
    raise HTTPException(status_code=401, detail="User not found")


@router.post("/login", response_model=LoginResponse)
def login(
    credentials: LoginRequest,
    token_repo: Annotated[TokenRepositoryInterface, Depends(get_token_repository)],
    user_repo: Annotated[UserRepositoryInterface, Depends(get_user_repository)],
    creds_repo: Annotated[
        CredentialsRepositoryInterface, Depends(get_credentials_repository)
    ],
) -> LoginResponse:
    """
    API endpoint for user authentication.

    Returns user info and access token on successful login.
    Raises 401 on invalid credentials.
    """
    # First check if it's a database user
    user = user_repo.get_by_username(credentials.username)
    if user:
        # TODO: Use proper password hashing (bcrypt/argon2)
        # For now, compare plain text (matches registration)
        if user["hashed_password"] == credentials.password:
            # Generate a secure random token
            access_token = secrets.token_urlsafe(32)
            token_repo.store(access_token, user_id=user["id"], ttl=3600)

            return LoginResponse(
                message="Login successful",
                username=credentials.username,
                access_token=access_token,
                is_admin=user.get("is_admin", False),
            )

    # Fallback to admin credentials from environment
    if creds_repo.verify_admin_credentials(credentials.username, credentials.password):
        # Generate a secure random token
        access_token = secrets.token_urlsafe(32)
        # Store token with user_id (hardcoded 1 for admin)
        token_repo.store(access_token, user_id=1, ttl=3600)

        return LoginResponse(
            message="Login successful",
            username=credentials.username,
            access_token=access_token,
            is_admin=True,
        )

    raise HTTPException(status_code=401, detail="Invalid username or password")


@router.post("/logout")
def logout(
    user_id: Annotated[int, Depends(verify_token)],
    token_repo: TokenRepositoryInterface = Depends(get_token_repository),
) -> dict[str, str]:
    """Logout and invalidate the current token."""
    # Note: We'd need to pass the token itself, not user_id
    # This is simplified - in production, extract token from verify_token
    return {"message": "Logged out successfully"}


@router.get("/verify-invitation")
def verify_invitation(
    token: str,
    invitation_repo: Annotated[
        InvitationRepositoryInterface, Depends(get_invitation_repository)
    ],
) -> dict[str, bool]:
    """Verify if an invitation token is valid."""
    is_valid = invitation_repo.verify_invitation(token)
    if not is_valid:
        raise HTTPException(status_code=400, detail="Invalid or expired invitation")
    return {"valid": True}


@router.post("/register", response_model=RegisterResponse)
def register(
    request: RegisterRequest,
    user_repo: Annotated[UserRepositoryInterface, Depends(get_user_repository)],
    invitation_repo: Annotated[
        InvitationRepositoryInterface, Depends(get_invitation_repository)
    ],
    token_repo: Annotated[TokenRepositoryInterface, Depends(get_token_repository)],
) -> RegisterResponse:
    """
    Register a new user with an invitation token.

    Verifies the invitation, creates the user, consumes the invitation,
    and returns an authentication token.
    """
    # Verify invitation token
    if not invitation_repo.verify_invitation(request.invitation_token):
        raise HTTPException(
            status_code=400,
            detail="Invalid or expired invitation token",
        )

    # Check if username already exists
    existing_user = user_repo.get_by_username(request.username)
    if existing_user:
        raise HTTPException(
            status_code=400,
            detail="Username already exists",
        )

    # Create the new user
    # TODO: Hash password before storing (currently plain text)
    user = user_repo.create(
        username=request.username,
        hashed_password=request.password,
    )

    # Consume the invitation token
    invitation_repo.consume_invitation(request.invitation_token)

    # Generate authentication token
    access_token = secrets.token_urlsafe(32)
    token_repo.store(access_token, user_id=user["id"], ttl=3600)

    return RegisterResponse(
        message="Registration successful",
        username=user["username"],
        access_token=access_token,
        is_admin=user.get("is_admin", False),
    )


@router.get("/me")
def get_current_user(
    user_id: Annotated[int, Depends(verify_token)],
    user_repo: Annotated[UserRepositoryInterface, Depends(get_user_repository)],
    creds_repo: Annotated[
        CredentialsRepositoryInterface, Depends(get_credentials_repository)
    ],
) -> dict:
    """Get current user info including admin status."""
    user = user_repo.get_by_id(user_id)

    # If user not found in DB, might be env-based admin
    if not user:
        # Return admin info from environment
        return {
            "id": user_id,
            "username": creds_repo.get_admin_username(),
            "is_admin": True,  # Env-based admin is always admin
        }

    return {
        "id": user["id"],
        "username": user["username"],
        "is_admin": user.get("is_admin", False),
    }