# backend/routes/auth.py
from flask import Blueprint, request, jsonify
from datetime import datetime, timedelta
import bcrypt
import jwt

from ..db import get_db_connection, release_db_connection
from ..middleware import SECRET_KEY, token_required

auth_blueprint = Blueprint('auth', __name__)

@auth_blueprint.route('/auth/register', methods=['POST'])
def register():
    data = request.json
    username = data.get('username')
    password = data.get('password')
    
    if not username or not password:
        return jsonify({"error": "Username and password are required"}), 400
        
    conn = get_db_connection()
    cur = conn.cursor()
    
    # Check if exists
    cur.execute("SELECT id FROM users WHERE username = %s", (username,))
    if cur.fetchone():
        release_db_connection(conn)
        return jsonify({"error": "Username already exists"}), 400
        
    hashed_password = bcrypt.hashpw(password.encode('utf-8'), bcrypt.gensalt()).decode('utf-8')
    
    cur.execute(
        "INSERT INTO users (username, password_hash) VALUES (%s, %s) RETURNING id",
        (username, hashed_password)
    )
    user_id = cur.fetchone()[0]
    conn.commit()
    release_db_connection(conn)
    
    return jsonify({"message": "User registered successfully", "user_id": user_id}), 201

@auth_blueprint.route('/auth/login', methods=['POST'])
def login():
    data = request.json
    username = data.get('username')
    password = data.get('password')
    
    conn = get_db_connection()
    cur = conn.cursor()
    cur.execute("SELECT id, password_hash FROM users WHERE username = %s", (username,))
    user = cur.fetchone()
    release_db_connection(conn)
    
    if not user or not bcrypt.checkpw(password.encode('utf-8'), user[1].encode('utf-8')):
        return jsonify({"error": "Invalid credentials"}), 401
        
    token = jwt.encode({
        'user_id': user[0],
        'exp': datetime.utcnow() + timedelta(days=7)
    }, SECRET_KEY, algorithm="HS256")
    
    return jsonify({"token": token})

@auth_blueprint.route('/auth/me', methods=['GET'])
@token_required
def get_me(current_user_id):
    conn = get_db_connection()
    cur = conn.cursor()
    cur.execute("SELECT id, username, plan FROM users WHERE id = %s", (current_user_id,))
    user = cur.fetchone()
    release_db_connection(conn)
    
    if not user:
        return jsonify({"error": "User not found"}), 404
        
    return jsonify({"id": user[0], "username": user[1], "plan": user[2]})

@auth_blueprint.route('/auth/upgrade', methods=['POST'])
@token_required
def upgrade_plan(current_user_id):
    """Simulates payment success and upgrades to PRO."""
    conn = get_db_connection()
    cur = conn.cursor()
    cur.execute("UPDATE users SET plan = 'pro' WHERE id = %s", (current_user_id,))
    conn.commit()
    release_db_connection(conn)
    
    return jsonify({"message": "Successfully upgraded to PRO"}), 200