from flask import Flask, request, jsonify
from pymongo import MongoClient
from flask_cors import CORS
from bson import ObjectId
import json
import os

app = Flask(__name__)
CORS(app)
print("applied CORS")

# MongoDB Connection
MONGO_URI = "mongodb+srv://nanduvinay719:76qqKRX4zC97yQun@travis.744fuyn.mongodb.net/?retryWrites=true&w=majority&appName=travis"
client = MongoClient(MONGO_URI)
print("connected to mongodb")
db = client["travisDB"]

# Define collections
user_collection = db["users"]
agent_collection = db["agents"]

# Helper function to convert ObjectId to string for JSON serialization
class JSONEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, ObjectId):
            return str(obj)
        return json.JSONEncoder.default(self, obj)

@app.route("/", methods=["GET"])
def home():
    return jsonify({"message": "Travis Backend API is running"})

@app.route("/login", methods=["POST"])
def login():
    data = request.json
    email = data.get("email")
    password = data.get("password")
    role = data.get("role")
    
    try:
        # First, try to find the user based on email and role
        user = None
        
        # Try to find in the appropriate collection based on provided role
        if role == "admin":
            user = user_collection.find_one({"email": email, "password": password})
        else:
            user = agent_collection.find_one({"email": email, "password": password})
        
        # If user is found, verify their role
        if user:
            # Return user information including their actual role from DB
            return jsonify({
                "success": True,
                "role": user.get("role"),
                "userId": str(user.get("_id"))
            })
        else:
            # Try the other collection as fallback (in case the user selected the wrong role)
            other_collection = agent_collection if role == "admin" else user_collection
            other_user = other_collection.find_one({"email": email, "password": password})
            
            if other_user:
                # User exists but in the other collection
                return jsonify({
                    "success": True,
                    "role": other_user.get("role"),
                    "userId": str(other_user.get("_id"))
                })
            else:
                # No user found in either collection
                return jsonify({"success": False, "message": "Invalid credentials"})
    except Exception as e:
        print(f"Login error: {e}")
        return jsonify({"success": False, "message": "Server error"}), 500

@app.route("/register", methods=["POST"])
def register():
    print(f"Registration request received: {request.json}")
    data = request.json
    email = data.get("email")
    password = data.get("password")
    
    if not email or not password:
        print("Missing required fields")
        return jsonify({
            "success": False,
            "message": "Email and password are required"
        }), 400
    
    try:
        # Check if an agent with this email already exists
        existing_agent = agent_collection.find_one({"email": email})
        if existing_agent:
            return jsonify({
                "success": False,
                "message": "An agent with this email already exists"
            }), 400
        
        # Check if a user with this email exists in the User collection
        existing_user = user_collection.find_one({"email": email})
        if existing_user:
            return jsonify({
                "success": False,
                "message": "A user with this email already exists"
            }), 400
        
        # Create new agent with role explicitly set to "agent"
        new_agent = {
            "email": email,
            "password": password,
            "role": "agent"  # Always set to "agent" as required
        }
        
        # Save the new agent to the database
        result = agent_collection.insert_one(new_agent)
        
        return jsonify({
            "success": True,
            "message": "Agent registered successfully",
            "role": "agent"
        }), 201
    
    except Exception as e:
        print(f"Registration error: {e}")
        return jsonify({
            "success": False,
            "message": "Server error during registration"
        }), 500

if __name__ == "__main__":
    app.run(host="0.0.0.0", port=int(os.environ.get("PORT", 7860)))