<?php
// Include database connection
require_once __DIR__ . '/../../config.php';

// Check if courses table exists
$result = $conn->query("SHOW TABLES LIKE 'courses'");
if ($result->num_rows == 0) {
    echo "Courses table does not exist. Please create it first.<br>";
    exit;
}

// Check if what_youll_learn column exists
$result = $conn->query("SHOW COLUMNS FROM courses LIKE 'what_youll_learn'");
if ($result->num_rows == 0) {
    // Add what_youll_learn column if it doesn't exist
    $conn->query("ALTER TABLE courses ADD COLUMN what_youll_learn TEXT NULL AFTER description");
    echo "Added what_youll_learn column to courses table.<br>";
}

// Check if requirements column exists
$result = $conn->query("SHOW COLUMNS FROM courses LIKE 'requirements'");
if ($result->num_rows == 0) {
    // Add requirements column if it doesn't exist
    $conn->query("ALTER TABLE courses ADD COLUMN requirements TEXT NULL AFTER what_youll_learn");
    echo "Added requirements column to courses table.<br>";
}

// Check if language column exists
$result = $conn->query("SHOW COLUMNS FROM courses LIKE 'language'");
if ($result->num_rows == 0) {
    // Add language column if it doesn't exist
    $conn->query("ALTER TABLE courses ADD COLUMN language VARCHAR(50) DEFAULT 'English' AFTER level");
    echo "Added language column to courses table.<br>";
}

// Check if certificate column exists
$result = $conn->query("SHOW COLUMNS FROM courses LIKE 'certificate'");
if ($result->num_rows == 0) {
    // Add certificate column if it doesn't exist
    $conn->query("ALTER TABLE courses ADD COLUMN certificate TINYINT(1) DEFAULT 0 AFTER lessons_count");
    echo "Added certificate column to courses table.<br>";
}

// Check if lessons_count column exists
$result = $conn->query("SHOW COLUMNS FROM courses LIKE 'lessons_count'");
if ($result->num_rows == 0) {
    // Add lessons_count column if it doesn't exist
    $conn->query("ALTER TABLE courses ADD COLUMN lessons_count INT DEFAULT 0 AFTER language");
    echo "Added lessons_count column to courses table.<br>";
}

// Check if instructor_id column exists
$result = $conn->query("SHOW COLUMNS FROM courses LIKE 'instructor_id'");
if ($result->num_rows == 0) {
    // Add instructor_id column if it doesn't exist
    $conn->query("ALTER TABLE courses ADD COLUMN instructor_id INT NULL AFTER id");
    $conn->query("ALTER TABLE courses ADD FOREIGN KEY (instructor_id) REFERENCES users(id) ON DELETE SET NULL");
    echo "Added instructor_id column to courses table.<br>";
}

// Check if short_description column exists
$result = $conn->query("SHOW COLUMNS FROM courses LIKE 'short_description'");
if ($result->num_rows == 0) {
    // Add short_description column if it doesn't exist
    $conn->query("ALTER TABLE courses ADD COLUMN short_description TEXT NULL AFTER title");
    echo "Added short_description column to courses table.<br>";
}

// Check if discount_price column exists
$result = $conn->query("SHOW COLUMNS FROM courses LIKE 'discount_price'");
if ($result->num_rows == 0) {
    // Add discount_price column if it doesn't exist
    $conn->query("ALTER TABLE courses ADD COLUMN discount_price DECIMAL(10,2) NULL AFTER price");
    echo "Added discount_price column to courses table.<br>";
}

// Check if tags column exists
$result = $conn->query("SHOW COLUMNS FROM courses LIKE 'tags'");
if ($result->num_rows == 0) {
    // Add tags column if it doesn't exist
    $conn->query("ALTER TABLE courses ADD COLUMN tags VARCHAR(255) NULL AFTER status");
    echo "Added tags column to courses table.<br>";
}

echo "Database update completed successfully.<br>";
?>