<?

if(!isset($_SESSION))
{
    session_start();
}

function connectToDB($usr, $pw, $server_name, $db_name)
{
	// Create connection
	$conn = mysqli_connect($server_name, $usr, $pw);

	// Check connection
	if (!$conn) {
  	  return(mysqli_connect_error());
	}

	mysqli_select_db($conn, $db_name);
	return $conn;

}






//
//
/*  GENERAL GET AND SET FUNCTIONS  */
//
//


//fetch all the user IDs
function fetchAllAccounts(){
    $db_token = connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm');
    $query = "SELECT account_id FROM users";
    $user_id = $db_token->query($query);

    $user_array = array();

    while($row = $user_id->fetch_row())
        array_push($user_array, $row);

    return $user_array;

}

//Fetch a username from an email
function fetchUsername($email)
{
    $db_token = connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm');
    $query = "SELECT username FROM users WHERE email = '$email'";
    $username = $db_token->query($query);
    $results = mysqli_fetch_array($username, MYSQLI_NUM);

    return $results[0];

}

//Check if the user id is for an administrator
function isAdmin($id)
{
    $db_token = connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm');
    $query = "SELECT COUNT(*) FROM users WHERE id = '$id' AND is_admin = '1'";
    $results = mysqli_fetch_array($db_token->query($query), MYSQLI_NUM)[0];

    return $results;
}

//fetch an email address from an account ID
function getEmailFromAccountID($account_id){
    $db_token = connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm');
    $query = "SELECT user_id FROM accounts WHERE acct_id='$account_id'";
    $user_id = mysqli_fetch_array($db_token->query($query), MYSQLI_NUM)[0];

    $query = "SELECT email FROM users WHERE id='$user_id'";
    $email = mysqli_fetch_array($db_token->query($query), MYSQLI_NUM)[0];

    return $email;
}

//Fetch an account ID from a user ID
function fetchAccountID($user_id){
    $db_token = connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm');
    $query = "SELECT acct_id FROM accounts WHERE user_id='$user_id'";
    $account_id = mysqli_fetch_array($db_token->query($query), MYSQLI_NUM)[0];

    return $account_id;
}


//Gets balance from accounts based on the username
function getBalance($email)
{
    $username = fetchUsername($email);
    $id = fetchID($username);
    $token = connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm');
    $query = "SELECT balance FROM accounts WHERE user_id = '$id'";
    $result = mysqli_query($token, $query);

    if($result != FALSE)
    {
        $row = $result->fetch_assoc();
        $balance = $row['balance'];
        return $balance;
    }
    else
        return "Error: ".mysqli_error($token);


}

//Fetch user ID from username function
function fetchID($username)
{

    $token = connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm');

    $query = "SELECT id FROM users WHERE username='$username'";

    $result = $token->query($query);
    //$result = $result->fetch_assoc();


    if(!$result)
    {
        echo mysqli_error($result->fetch_assoc());
    }

    else
    {
        $result = $result->fetch_assoc();
        $id = $result['id'];
        return $id;
    }


}





//
//
/*  LOGIN AND REGISTER AND FORGOT PASSWORD FUNCTIONS  */
//
//


// Takes in a username and registers the user, also creates a bank account
function registerAccount($username, $password, $email)
{
	$db_token = connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm');

	$query = "SELECT COUNT(*) FROM users WHERE email='$email'";
    $results = $db_token->query($query);

    $results = mysqli_fetch_array($results,MYSQLI_NUM);

    $password = md5($password);


    if($results[0] == 0)
    {
    	$query = "INSERT INTO users (password, username, is_admin, email, account_id) VALUES ('$password', '$username', '0', '$email', null)";
    	$db_token->query($query);

        $query = "SELECT id FROM users WHERE email = '$email'";
        $user_id = $db_token->query($query);
        $user_id = mysqli_fetch_array($user_id,MYSQLI_NUM)[0];

        $query = "INSERT INTO accounts (user_id, balance) VALUES ('$user_id', 0)";
        $db_token->query($query);

        $query = "SELECT acct_id FROM accounts WHERE user_id = '$user_id'";
        $acct_id = $db_token->query($query);
        $acct_id = mysqli_fetch_array($acct_id,MYSQLI_NUM)[0];

        $query = "UPDATE users SET account_id = '$acct_id' WHERE id='$user_id'";
        $db_token->query($query);

    	return mysqli_error($db_token);
    }
    else
    {
    	return 1;
    }

}


//login function
function login($email, $password)
{
	$db_token = connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm');

	$query = "SELECT * FROM users WHERE email='$email'";
    $results = $db_token->query($query);

    $results = mysqli_fetch_array($results,MYSQLI_NUM);


    if($results == NULL)
    {
    	return 2;
    }
    else if($results[1] == md5($password) && $results[4] == $email)
    {
    	return 1; //good
    }
    else
    {
        echo $password;
        echo md5(trim($password))." ".$email;
    	return 0;  //not good
    }
}


//send the user their new password if it got reset
function sendPassword($email)
{
	$db_token = connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm');

	$query = "SELECT * FROM users WHERE email='$email'";
    $results = $db_token->query($query);

    $results = mysqli_fetch_array($results,MYSQLI_NUM);

	if($results != null)
    	return mail ( $email , "Password Reminder" , "Your password is ".$results[1] );
    else
    	return 0;
}




//
//
/*  ACCOUNT FUNCTIONS  */
//
//

//Modify balance function
function modifyBalance($userID,$newBalance)
{
    $token = connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm');
    $query = "UPDATE accounts SET balance=$newBalance WHERE user_id=$userID";
    $balanceResult = mysqli_query($token, $query);


    if(!$balanceResult)
    {
        echo "Error @ modifyBalance: ".mysqli_error($token);
    }

    return $balanceResult;

}

//Delete user function
function deleteUser($userID)
{
    $token = connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm');
    $queryTwo = "DELETE FROM accounts WHERE user_id=$userID";
    $queryThree = "DELETE FROM users WHERE id=$userID";

    //May also need to add a query to delete the transfer history?
    $resultTwo = mysqli_query($token,$queryTwo);

    if(!$resultTwo)
    {
        echo "Error @ deleteUser: ".mysqli_error($token);
    }

    $resultThree = mysqli_query($token,$queryThree);

    if(!$resultThree)
    {
        echo "Error @ deleteUser: ".mysqli_error($token);
    }

    else
    {
        return "Success";
    }


}


//Add user function
function addUser($email,$password,$balance,$admin, $username)
{

    $token = connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm');

    //Inserting new user into the users table
    $queryOne = "INSERT INTO users(password,email,is_admin, username) VALUES('$password','$email',$admin, '$username')";
    $resultOne = mysqli_query($token,$queryOne);

    if(!$resultOne)
    {
        echo "Error @ deleteUser: ".mysqli_error($token);
    }

    //Inserting id and balance into te account table
    $id = fetchID($username);

    $queryTwo = "INSERT INTO accounts (user_id, balance) VALUES ($id, $balance)";
    $resultTwo = mysqli_query($token,$queryTwo);

    if(!$resultTwo)
    {
        echo "Error @ deleteUser: ".mysqli_error($token);
    }

    $acct_id = fetchAccountID($id);

    $queryThree = "UPDATE users SET account_id = '$acct_id' WHERE id='$id'";
    $resultThree = mysqli_query($token,$queryThree);

    if(!$resultThree)
    {
        echo "Error @ deleteUser: ".mysqli_error($token);
    }



    else
    {
        //Do not return the id
        return "$username has successfully been added!";
    }
}







//
//
/*  ADMIN PAGE FUNCTIONS  */
//
//


//Fetches all of the user's information and displays it
function fetchUsers()
{

    //Fetches the user id, username and balance to be displayed
    $query = "SELECT user_id,username,balance FROM users JOIN accounts WHERE users.id = accounts.user_id;";

    //If there is an error, it is probably here
    $result = mysqli_query(connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm'), $query);


    while($row = $result->fetch_assoc())
    {
        $userID = $row['user_id'];
        $username = $row['username'];
        $balance = $row['balance'];



        //Printing out data in html form
        if(1==1)
        {
            ?>

            <form action="<?php echo $_SERVER['PHP_SELF']; ?>" method='POST' class="accountHolder">


                <fieldset class="form-group">
                    <label>Name of Account Holder: </label>
                    <p><?php echo $username; ?></p>

                    <label>Balance: </label>
                    <input type='text' id='balance' name='balance' placeholder="<?php echo $balance; ?>"/>

                    <!-- Every user has a different submit button name -->
                    <button class="btn btn-primary" type='submit' name='balanceChange<?php echo $userID?>'>Modify</button>


                </fieldset>


                <fieldset class="form-group">
                    <!-- Delete User button -->
                    <button class="btn btn-primary" type='submit' name='deleteUser<?php echo $userID?>'>Delete User</button>
                </fieldset>
            </form>

            <?php
        }

        //If the balance change button is pressed
        if(isset($_POST["balanceChange$userID"]))
        {
            $newBalance = $_POST["balance"];
            $bbb = modifyBalance($userID,$newBalance);
            if($bbb)
                echo "Successfully changed the salary to $newBalance!<br>";
        }

        if(isset($_POST["deleteUser$userID"]))
        {

            $ccc = deleteUser($userID);
            if($ccc)
                echo "Successfully deleted user $username!<br>";
                header("Location: admin.php");
        }

    }


}







//
//
/*  TRANSFER FUNCTIONS  */
//
//


//Update the balance of a user for transaction
function updateBalance($user,$newBal)
{
  $token = connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm');
  $query = "UPDATE accounts SET balance='$newBal' WHERE user_id='$user'";
  $balResult = mysqli_query($token, $query);

    //incase the balance cannot be updated
  if(!$balResult)
  {
    echo "Error @ updateBalance: ".mysqli_error($token);
  }
    //return the results
  return $balResult;

}


function logTransfer($to, $from, $amount)
{
    $db_token = connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm');
    $query = "INSERT INTO transfers (user_id, to_acct, amount) VALUES ('$from', '$to', '$amount')";
    $db_token->query($query);

    return mysqli_error($db_token);
}






//
//
/*  EDIT PASSWORD FUNCTION  */
//
//

function changePassword($oldpw, $newpw){
    $db_token = connectToDB('colinm', 'B00599161', 'db.cs.dal.ca', 'colinm');
    $email = $_SESSION['email'];

    $query = "SELECT COUNT(*) FROM users WHERE email = '$email' AND password = '$oldpw'";
    $results = mysqli_fetch_array($db_token->query($query), MYSQLI_NUM)[0];

    if($results != 0)
    {
        $query = "UPDATE users SET password = '$newpw' WHERE email='$email'";
        $db_token->query($query);

        return mysqli_error($db_token);
    }
    else
    {
        return -1;
    }

}




?>