from typing import Annotated

from fastapi import APIRouter, Depends, HTTPException, status
from fastapi.security import OAuth2PasswordRequestForm
from sqlalchemy.orm import Session

from app.auth import (
    authenticate_user,
    create_access_token,
    get_current_user,
    get_password_hash,
    get_user_by_email,
    get_user_by_username,
)
from app.database import get_db
from app.models.user import User, UserRole
from app.models.verification_token import TokenType
from app.schemas import (
    ActivateAccountRequest,
    ForgotPasswordRequest,
    MessageResponse,
    RegisterResponse,
    ResetPasswordRequest,
    Token,
    UserCreate,
    UserResponse,
)
from app.services.email_service import send_activation_email, send_password_reset_email
from app.services.verification import create_verification_token, verify_code

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


@router.post("/register", response_model=RegisterResponse, status_code=status.HTTP_201_CREATED)
def register(user_data: UserCreate, db: Annotated[Session, Depends(get_db)]):
    if user_data.password != user_data.confirm_password:
        raise HTTPException(status_code=400, detail="Passwords do not match")

    if get_user_by_email(db, user_data.email):
        raise HTTPException(status_code=400, detail="Email already registered")
    if get_user_by_username(db, user_data.username):
        raise HTTPException(status_code=400, detail="Username already taken")

    user = User(
        email=user_data.email,
        username=user_data.username,
        hashed_password=get_password_hash(user_data.password),
        role=UserRole.user,
        is_active=False,
    )
    db.add(user)
    db.flush()

    token = create_verification_token(db, user, TokenType.activation)
    db.commit()

    send_activation_email(user.email, user.username, token.code)

    return RegisterResponse(
        message="Registration successful. Check your email for the activation code.",
        email=user.email,
    )


@router.post("/activate", response_model=MessageResponse)
def activate_account(
    data: ActivateAccountRequest,
    db: Annotated[Session, Depends(get_db)],
):
    user = verify_code(db, data.email, data.code, TokenType.activation)
    if not user:
        raise HTTPException(status_code=400, detail="Invalid or expired activation code")

    user.is_active = True
    db.commit()

    return MessageResponse(message="Account activated. You can now log in.")


@router.post("/resend-activation", response_model=MessageResponse)
def resend_activation(
    data: ForgotPasswordRequest,
    db: Annotated[Session, Depends(get_db)],
):
    user = get_user_by_email(db, data.email)
    if not user:
        return MessageResponse(
            message="If the email exists, a new activation code has been sent."
        )

    if user.is_active:
        raise HTTPException(status_code=400, detail="Account is already activated")

    token = create_verification_token(db, user, TokenType.activation)
    db.commit()
    send_activation_email(user.email, user.username, token.code)

    return MessageResponse(
        message="If the email exists, a new activation code has been sent."
    )


@router.post("/forgot-password", response_model=MessageResponse)
def forgot_password(
    data: ForgotPasswordRequest,
    db: Annotated[Session, Depends(get_db)],
):
    user = get_user_by_email(db, data.email)
    if user and user.is_active:
        token = create_verification_token(db, user, TokenType.password_reset)
        db.commit()
        send_password_reset_email(user.email, user.username, token.code)

    return MessageResponse(
        message="If the email exists, a password reset code has been sent."
    )


@router.post("/reset-password", response_model=MessageResponse)
def reset_password(
    data: ResetPasswordRequest,
    db: Annotated[Session, Depends(get_db)],
):
    if data.password != data.confirm_password:
        raise HTTPException(status_code=400, detail="Passwords do not match")

    user = verify_code(db, data.email, data.code, TokenType.password_reset)
    if not user:
        raise HTTPException(status_code=400, detail="Invalid or expired reset code")

    user.hashed_password = get_password_hash(data.password)
    db.commit()

    return MessageResponse(message="Password updated. You can now log in.")


@router.post("/login", response_model=Token)
def login(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
    db: Annotated[Session, Depends(get_db)],
):
    user = authenticate_user(db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect username or password",
            headers={"WWW-Authenticate": "Bearer"},
        )
    if not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Account not activated. Check your email for the activation code.",
        )
    token = create_access_token(data={"sub": user.username})
    return Token(access_token=token)


@router.get("/me", response_model=UserResponse)
def get_me(current_user: Annotated[User, Depends(get_current_user)]):
    return current_user