//[SECTION] Dependencies and Modules
	const User = require("../models/User");
	const Course = require("../models/Course");
	const bcrypt = require('bcrypt');
	const auth = require("../auth");


//[SECTION] Check if the email already exists

	module.exports.checkEmailExists = (reqBody) => {

		// The result is sent back to the frontend via the "then" method found in the route file
		return User.find({email : reqBody.email}).then(result => {

			// The "find" method returns a record if a match is found
			if (result.length > 0) {
				return true;

			// No duplicate email found
			// The user is not yet registered in the database
			} else {
				return false;
			}
		})
		.catch(err => res.send(err))
	};


//[SECTION] User registration
	module.exports.registerUser = (reqBody) => {

		// Creates a variable "newUser" and instantiates a new "User" object using the mongoose model
		// Uses the information from the request body to provide all the necessary information
		let newUser = new User({
			firstName : reqBody.firstName,
			lastName : reqBody.lastName,
			email : reqBody.email,
			mobileNo : reqBody.mobileNo,
			password : bcrypt.hashSync(reqBody.password, 10)
		})

		// Saves the created object to our database
		return newUser.save().then((user, error) => {

			// User registration failed
			if (error) {
				return false;

			// User registration successful
			} else {
				return true;
			}
		})
		.catch(err => err)
	};


//[SECTION] User authentication

	module.exports.loginUser = (req, res) => {
		User.findOne({ email : req.body.email} ).then(result => {

			console.log(result);

			// User does not exist
			if(result == null){

				return res.send(false);

			// User exists
			} else {
				
				const isPasswordCorrect = bcrypt.compareSync(req.body.password, result.password);
				// If the passwords match/result of the above code is true
				if (isPasswordCorrect) {
	
					return res.send({ access : auth.createAccessToken(result) })

				// Passwords do not match
				} else {

					return res.send(false);
				}
			}
		})
		.catch(err => res.send(err))
	};




//[SECTION] Retrieve user details

	module.exports.getProfile = (req, res) => {

		return User.findById(req.user.id)
		.then(result => {
			result.password = "";
			return res.send(result);
		})
		.catch(err => res.send(err))
	};



//[SECTION] Enroll a registered User

	module.exports.enroll = async (req, res) => {

	  	console.log(req.user.id) //the user's id from the decoded token after verify()
	  	console.log(req.body.courseId) //the course from our request body

	  	//process stops here and sends response IF user is an admin
	  	if(req.user.isAdmin){
	    	return res.send("Action Forbidden")
	  	}


	  	let isUserUpdated = await User.findById(req.user.id).then(user => {
	    let newEnrollment = {
	        courseId: req.body.courseId,
	        courseName: req.body.courseName,
	        courseDescription: req.body.courseDescription,
	        coursePrice: req.body.coursePrice
	    }
		    user.enrollments.push(newEnrollment);
		    
		    return user.save().then(user => true).catch(err => err.message)
	  	})
	  

	  	if(isUserUpdated !== true) {
	      	return res.send({message: isUserUpdated})
	  	}

		let isCourseUpdated = await Course.findById(req.body.courseId).then(course => {

		    let enrollee = {
		        userId: req.user.id
		    }

		    course.enrollees.push(enrollee);

	    	return course.save().then(course => true).catch(err => err.message)
	 	})


	 	if(isCourseUpdated !== true) {
	      	return res.send({ message: isCourseUpdated})
	  	}


	  	if(isUserUpdated && isCourseUpdated) {
	      	return res.send({ message: "Enrolled Successfully."})
	  	}
	}

	//[ACTIVITY] Getting user's enrolled courses
	module.exports.getEnrollments = (req, res) => {
	    User.findById(req.user.id)
	    .then(result => res.send(result.enrollments))
	    .catch(err => res.send(err))
	}


	//ChatGPT Generated

	//[SECTION] Reset Password

	module.exports.resetPassword = async (req, res) => {
		try {

		//console.log(req.user)
		//console.log(req.body)

		  const { newPassword } = req.body;
		  const { id } = req.user; // Extracting user ID from the authorization header
	  
		  // Hashing the new password
		  const hashedPassword = await bcrypt.hash(newPassword, 10);
	  
		  // Updating the user's password in the database
		  await User.findByIdAndUpdate(id, { password: hashedPassword });
	  
		  // Sending a success response
		  res.status(200).send({ message: 'Password reset successfully' });
		} catch (error) {
		  console.error(error);
		  res.status(500).send({ message: 'Internal server error' });
		}
	};

	//[SECTION] Reset Profile
	module.exports.updateProfile = async (req, res) => {
		try {

			console.log(req.user);
			console.log(req.body);
			
		// Get the user ID from the authenticated token
		  const userId = req.user.id;
	  
		  // Retrieve the updated profile information from the request body
		  const { firstName, lastName, mobileNo } = req.body;
	  
		  // Update the user's profile in the database
		  const updatedUser = await User.findByIdAndUpdate(
			userId,
			{ firstName, lastName, mobileNo },
			{ new: true }
		  );
	  
		  res.send(updatedUser);
		} catch (error) {
		  console.error(error);
		  res.status(500).send({ message: 'Failed to update profile' });
		}
	  }

	//[ACTIVITY] Update Enrollment Status
	module.exports.updateEnrollmentStatus = async (req, res) => {
		try {
		  const { userId, courseId, status } = req.body;
	  
		  // Find the user and update the enrollment status
		  const user = await User.findById(userId);
	  
		  // Find the enrollment for the course in the user's enrollments array
		  const enrollment = user.enrollments.find((enrollment) => enrollment.courseId === courseId);
	  
		  if (!enrollment) {
			return res.status(404).json({ error: 'Enrollment not found' });
		  }
	  
		  enrollment.status = status;
	  
		  // Save the updated user document
		  await user.save();
	  
		  res.status(200).json({ message: 'Enrollment status updated successfully' });
		} catch (error) {
		  res.status(500).json({ error: 'An error occurred while updating the enrollment status' });
		}
	  };	


//[ACTIVITY] Update user as admin controller
exports.updateUserAsAdmin = async (req, res) => {
	try {
	  const { userId } = req.body;
  
	  // Find the user and update isAdmin flag
	  const user = await User.findById(userId);
  
	  if (!user) {
		return res.status(404).json({ error: 'User not found' });
	  }
  
	  user.isAdmin = true;
  
	  // Save the updated user document
	  await user.save();
  
	  res.status(200).json({ message: 'User updated as admin successfully' });
	} catch (error) {
	  res.status(500).json({ error: 'An error occurred while updating the user as admin' });
	}
  };