<?php
// Start session
session_start();

// Check if user has admin privileges
if (!isset($_SESSION['role']) || ($_SESSION['role'] !== 'admin' && $_SESSION['role'] !== 'director')) {
    echo json_encode(['success' => false, 'message' => 'Unauthorized access']);
    exit;
}

// Include database configuration
require_once '../../admin/database/db_config.php';

// Check if enrollment ID is provided
if (!isset($_GET['enrollment_id']) || empty($_GET['enrollment_id'])) {
    echo json_encode(['success' => false, 'message' => 'Invalid enrollment ID']);
    exit;
}

$enrollment_id = intval($_GET['enrollment_id']);

try {
    // First get the user_id and course_id from the enrollment
    $query = "SELECT user_id, course_id FROM enrollments WHERE id = ?";
    $stmt = $conn->prepare($query);
    $stmt->bind_param("i", $enrollment_id);
    $stmt->execute();
    $result = $stmt->get_result();
    
    if ($result->num_rows === 0) {
        throw new Exception('Enrollment not found');
    }
    
    $enrollment = $result->fetch_assoc();
    $user_id = $enrollment['user_id'];
    $course_id = $enrollment['course_id'];
    
    // Get all payments for this user and course
    $payments_query = "SELECT p.*, 
                      c.title as course_title,
                      u.first_name, u.last_name, u.email
                      FROM payments p
                      LEFT JOIN courses c ON p.course_id = c.id
                      LEFT JOIN users u ON p.user_id = u.id
                      WHERE p.user_id = ? AND p.course_id = ?
                      ORDER BY p.payment_date DESC";
    $stmt = $conn->prepare($payments_query);
    $stmt->bind_param("ii", $user_id, $course_id);
    $stmt->execute();
    $payments_result = $stmt->get_result();
    
    $payments = [];
    $total_paid = 0;
    
    while ($payment = $payments_result->fetch_assoc()) {
        // Format the payment data
        $payment['payment_date_formatted'] = date('M d, Y g:i A', strtotime($payment['payment_date']));
        $payment['amount_formatted'] = number_format($payment['amount'], 2);
        
        // Parse payment details if exists
        if (!empty($payment['payment_details'])) {
            $payment['details'] = json_decode($payment['payment_details'], true);
        } else {
            $payment['details'] = null;
        }
        
        // Define status badges
        $payment_statuses = [
            'completed' => 'success',
            'pending' => 'warning',
            'failed' => 'danger',
            'refunded' => 'info'
        ];
        
        $payment['status_badge'] = isset($payment_statuses[$payment['status']]) ? 
                                  $payment_statuses[$payment['status']] : 
                                  'secondary';
        
        $payments[] = $payment;
        
        // Add to total if payment is completed
        if ($payment['status'] === 'completed') {
            $total_paid += $payment['amount'];
        }
    }
    
    // Get course price for comparison
    $course_query = "SELECT price, discount_price FROM courses WHERE id = ?";
    $stmt = $conn->prepare($course_query);
    $stmt->bind_param("i", $course_id);
    $stmt->execute();
    $course = $stmt->get_result()->fetch_assoc();
    
    $course_price = !empty($course['discount_price']) ? $course['discount_price'] : $course['price'];
    $payment_progress = $course_price > 0 ? min(100, round(($total_paid / $course_price) * 100)) : 0;
    
    // Get payment summary
    $stats = [
        'total_payments' => count($payments),
        'total_paid' => $total_paid,
        'total_paid_formatted' => number_format($total_paid, 2),
        'course_price' => $course_price,
        'course_price_formatted' => number_format($course_price, 2),
        'payment_progress' => $payment_progress,
        'payment_status' => $total_paid >= $course_price ? 'fully_paid' : ($total_paid > 0 ? 'partially_paid' : 'unpaid')
    ];
    
    echo json_encode([
        'success' => true,
        'payments' => $payments,
        'stats' => $stats
    ]);
    
} catch (Exception $e) {
    echo json_encode([
        'success' => false,
        'message' => $e->getMessage()
    ]);
}
?>