process_payment.php

<?php
require_once 'includes/session_config.php';
include 'conn.php';

// Check if user is logged in
if (!isset($_SESSION['user_id'])) {
    echo json_encode(['success' => false, 'message' => 'Not logged in']);
    exit();
}

// Check if user is a client
if ($_SESSION['user_type'] !== 'client') {
    echo json_encode(['success' => false, 'message' => 'Only clients can release payments']);
    exit();
}

// Get data from POST request
$project_id = isset($_POST['project_id']) ? intval($_POST['project_id']) : 0;
$amount = isset($_POST['amount']) ? floatval($_POST['amount']) : 0;

if ($project_id <= 0 || $amount <= 0) {
    echo json_encode(['success' => false, 'message' => 'Invalid project ID or amount']);
    exit();
}

// Verify that the client owns this project
$verify_sql = "SELECT * FROM projects WHERE id = ? AND user_id = ?";
$verify_stmt = $conn->prepare($verify_sql);
$verify_stmt->bind_param("ii", $project_id, $_SESSION['user_id']);
$verify_stmt->execute();
$verify_result = $verify_stmt->get_result();

if ($verify_result->num_rows === 0) {
    echo json_encode(['success' => false, 'message' => 'You do not have permission to release payment for this project']);
    exit();
}

// Get the freelancer ID for this project
$freelancer_sql = "SELECT freelancer_id FROM project_assignments WHERE project_id = ? AND is_accepted = 1";
$freelancer_stmt = $conn->prepare($freelancer_sql);
$freelancer_stmt->bind_param("i", $project_id);
$freelancer_stmt->execute();
$freelancer_result = $freelancer_stmt->get_result();

if ($freelancer_result->num_rows === 0) {
    echo json_encode(['success' => false, 'message' => 'No freelancer assigned to this project']);
    exit();
}

$freelancer_data = $freelancer_result->fetch_assoc();
$freelancer_id = $freelancer_data['freelancer_id'];

// Begin transaction
$conn->begin_transaction();

try {
    // Record the payment in the project_payments table
    $payment_sql = "INSERT INTO project_payments (project_id, client_id, freelancer_id, amount, payment_date) 
                   VALUES (?, ?, ?, ?, NOW())";
    $payment_stmt = $conn->prepare($payment_sql);
    $payment_stmt->bind_param("iiid", $project_id, $_SESSION['user_id'], $freelancer_id, $amount);
    $payment_stmt->execute();
    
    // Update the payment_released column in the projects table to 'yes'
    $update_sql = "UPDATE projects SET payment_released = 'yes' WHERE id = ?";
    $update_stmt = $conn->prepare($update_sql);
    $update_stmt->bind_param("i", $project_id);
    $update_stmt->execute();
    
    // Commit the transaction
    $conn->commit();
    
    echo json_encode(['success' => true]);
} catch (Exception $e) {
    // Rollback the transaction in case of error
    $conn->rollback();
    echo json_encode(['success' => false, 'message' => 'Error processing payment: ' . $e->getMessage()]);
}

$conn->close();
?>