from fastapi import APIRouter, Depends, HTTPException, status
from fastapi.security import OAuth2PasswordRequestForm
from sqlalchemy.orm import Session
from datetime import datetime, timedelta
from typing import List
import uuid

from ...core.database import get_db
from ...core.security import verify_password, get_password_hash, create_access_token
from ...models.models import User, UserRole, PasswordResetToken
from ...schemas import (
    UserCreate, UserResponse, Token, LoginRequest, MessageResponse,
    ForgotPasswordRequest, ResetPasswordRequest, ChangePasswordRequest
)
from ...services.email_service import email_service
from ...api.dependencies import get_current_active_user

router = APIRouter()


@router.post("/register", response_model=UserResponse, status_code=status.HTTP_201_CREATED)
async def register(
    user_data: UserCreate,
    db: Session = Depends(get_db)
):
    """Register a new user"""
    # Check if user already exists
    existing_user = db.query(User).filter(User.email == user_data.email).first()
    if existing_user:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Email already registered"
        )
    
    # Create new user
    hashed_password = get_password_hash(user_data.password)
    db_user = User(
        email=user_data.email,
        hashed_password=hashed_password,
        first_name=user_data.first_name,
        last_name=user_data.last_name,
        phone=user_data.phone,
        address=user_data.address,
        role=UserRole.MEMBER
    )
    
    db.add(db_user)
    db.commit()
    db.refresh(db_user)
    
    # Send welcome email (non-blocking, ignore errors)
    try:
        await email_service.send_welcome_email(
            to_email=db_user.email,
            first_name=db_user.first_name
        )
    except Exception as e:
        # Log error but don't fail registration
        print(f"Failed to send welcome email: {e}")
    
    return db_user


@router.post("/login", response_model=Token)
async def login(
    form_data: OAuth2PasswordRequestForm = Depends(),
    db: Session = Depends(get_db)
):
    """Login with email and password"""
    # Find user
    user = db.query(User).filter(User.email == form_data.username).first()
    
    if not user or not verify_password(form_data.password, user.hashed_password):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect email or password",
            headers={"WWW-Authenticate": "Bearer"},
        )
    
    if not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Inactive user account"
        )
    
    # Update last login
    user.last_login = datetime.utcnow()
    db.commit()
    
    # Create access token
    access_token = create_access_token(subject=user.id)
    
    return {
        "access_token": access_token,
        "token_type": "bearer"
    }


@router.post("/login-json", response_model=Token)
async def login_json(
    login_data: LoginRequest,
    db: Session = Depends(get_db)
):
    """Login with JSON body (email and password)"""
    # Find user
    user = db.query(User).filter(User.email == login_data.email).first()
    
    if not user or not verify_password(login_data.password, user.hashed_password):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect email or password",
            headers={"WWW-Authenticate": "Bearer"},
        )
    
    if not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Inactive user account"
        )
    
    # Update last login
    user.last_login = datetime.utcnow()
    db.commit()
    
    # Create access token
    access_token = create_access_token(subject=user.id)
    
    return {
        "access_token": access_token,
        "token_type": "bearer"
    }


@router.post("/forgot-password", response_model=MessageResponse)
async def forgot_password(
    request: ForgotPasswordRequest,
    db: Session = Depends(get_db)
):
    """Request password reset for a user"""
    # Find user by email
    user = db.query(User).filter(User.email == request.email).first()
    
    if not user or not user.is_active:
        # Don't reveal if email exists or not for security
        return {"message": "If an account with this email exists, a password reset link has been sent."}
    
    # Invalidate any existing reset tokens for this user
    db.query(PasswordResetToken).filter(
        PasswordResetToken.user_id == user.id,
        PasswordResetToken.used == False,
        PasswordResetToken.expires_at > datetime.utcnow()
    ).update({"used": True})
    
    # Generate new reset token
    reset_token = str(uuid.uuid4())
    expires_at = datetime.utcnow() + timedelta(hours=1)  # Token expires in 1 hour
    
    # Create password reset token
    db_token = PasswordResetToken(
        user_id=user.id,
        token=reset_token,
        expires_at=expires_at,
        used=False
    )
    
    db.add(db_token)
    db.commit()
    
    # Send password reset email (non-blocking, ignore errors)
    try:
        await email_service.send_password_reset_email(
            to_email=user.email,
            first_name=user.first_name,
            reset_token=reset_token
        )
    except Exception as e:
        # Log error but don't fail the request
        print(f"Failed to send password reset email: {e}")
    
    return {"message": "If an account with this email exists, a password reset link has been sent."}


@router.post("/reset-password", response_model=MessageResponse)
async def reset_password(
    request: ResetPasswordRequest,
    db: Session = Depends(get_db)
):
    """Reset password using reset token"""
    # Find valid reset token
    reset_token = db.query(PasswordResetToken).filter(
        PasswordResetToken.token == request.token,
        PasswordResetToken.used == False,
        PasswordResetToken.expires_at > datetime.utcnow()
    ).first()
    
    if not reset_token:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid or expired reset token"
        )
    
    # Get the user
    user = db.query(User).filter(User.id == reset_token.user_id).first()
    if not user or not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid reset token"
        )
    
    # Update password
    hashed_password = get_password_hash(request.new_password)
    user.hashed_password = hashed_password
    user.updated_at = datetime.utcnow()
    
    # Mark token as used
    reset_token.used = True
    
    db.commit()
    
    return {"message": "Password has been reset successfully. You can now log in with your new password."}


@router.post("/change-password", response_model=MessageResponse)
async def change_password(
    request: ChangePasswordRequest,
    current_user: User = Depends(get_current_active_user),
    db: Session = Depends(get_db)
):
    """Change password for authenticated user"""
    # Verify current password
    if not verify_password(request.current_password, current_user.hashed_password):
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Current password is incorrect"
        )
    
    # Update password
    hashed_password = get_password_hash(request.new_password)
    current_user.hashed_password = hashed_password
    current_user.updated_at = datetime.utcnow()
    
    db.commit()
    
    return {"message": "Password has been changed successfully."}