<?php
/**
 * Installation File for Admin Panel
 * This file handles requirement checks, database configuration, migrations, and super admin setup.
 */

session_start();

$step = isset($_GET['step']) ? (int)$_GET['step'] : 1;
$error = '';
$success = '';

// Path to config file
$config_file = __DIR__ . '/db/config.php';

// Helper to update config file
function update_config($host, $name, $user, $pass) {
    $content = "<?php\n";
    $content .= "// Database configuration generated by installer\n";
    $content .= "define('DB_HOST', " . var_export($host, true) . ");\n";
    $content .= "define('DB_NAME', " . var_export($name, true) . ");\n";
    $content .= "define('DB_USER', " . var_export($user, true) . ");\n";
    $content .= "define('DB_PASS', " . var_export($pass, true) . ");\n\n";
    $content .= "function db() {\n";
    $content .= "  static $pdo;
";
    $content .= "  if (!$pdo) {\n";
    $content .= "    try {\n";
    $content .= "      $pdo = new PDO('mysql:host='.DB_HOST.';dbname='.DB_NAME.';charset=utf8mb4', DB_USER, DB_PASS, [
";
    $content .= "        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
";
    $content .= "        PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
";
    $content .= "      ]);\n";
    $content .= "    } catch (PDOException $e) {\n";
    $content .= "      die('Database connection failed: ' . $e->getMessage());\n";
    $content .= "    }\n";
    $content .= "  }\n";
    $content .= "  return $pdo;
";
    $content .= "}\n\n";
    
    // Include existing helpers if needed, or keep it clean
    $content .= "/**
 * Generates the next reference number
 */\n";
    $content .= "function generateRefNo($type) {\n";
    $content .= "    $prefix = 'IN';
";
    $content .= "    if ($type === 'outbound') $prefix = 'OUT';
";
    $content .= "    if ($type === 'internal') $prefix = 'INT';
    
";
    $content .= "    $year = date('Y');
";
    $content .= "    $pattern = $prefix . '-' . $year . '-%';
    
";
    $content .= "    $stmt = db()->prepare(\"SELECT ref_no FROM mailbox WHERE type = ? AND ref_no LIKE ? ORDER BY id DESC LIMIT 1\");
";
    $content .= "    $stmt->execute([$type, $pattern]);
";
    $content .= "    $last_ref = $stmt->fetchColumn();
    
";
    $content .= "    $serial = 1;
";
    $content .= "    if ($last_ref) {\n";
    $content .= "        $parts = explode('-', $last_ref);
";
    $content .= "        if (count($parts) === 3) {\n";
    $content .= "            $serial = (int)$parts[2] + 1;
";
    $content .= "        }
";
    $content .= "    }
    
";
    $content .= "    return $prefix . '-' . $year . '-' . str_pad($serial, 3, '0', STR_PAD_LEFT);
";
    $content .= "}
";

    return file_put_contents(__DIR__ . '/db/config.php', $content);
}

// Step 2: Database Connection Test & Save
if ($step == 2 && $_SERVER['REQUEST_METHOD'] == 'POST') {
    $host = $_POST['db_host'] ?? '';
    $name = $_POST['db_name'] ?? '';
    $user = $_POST['db_user'] ?? '';
    $pass = $_POST['db_pass'] ?? '';

    try {
        $pdo = new PDO("mysql:host=$host;dbname=$name;charset=utf8mb4", $user, $pass);
        $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        
        if (update_config($host, $name, $user, $pass)) {
            header('Location: install.php?step=3');
            exit;
        } else {
            $error = "Failed to write to db/config.php. Check permissions.";
        }
    } catch (PDOException $e) {
        $error = "Connection failed: " . $e->getMessage();
    }
}

// Step 3: Run Migrations
if ($step == 3 && isset($_POST['run_migrations'])) {
    try {
        require_once $config_file;
        $pdo = db();
        $migrations_dir = __DIR__ . '/db/migrations';
        $files = glob($migrations_dir . '/*.sql');
        sort($files);

        foreach ($files as $file) {
            $sql = file_get_contents($file);
            // Split by semicolon to execute multiple statements if needed, 
            // but PDO::exec usually handles multiple statements in one call for SQL scripts.
            $pdo->exec($sql);
        }
        $success = "Migrations completed successfully!";
        header('Location: install.php?step=4');
        exit;
    } catch (Exception $e) {
        $error = "Migration error: " . $e->getMessage();
    }
}

// Step 4: Super Admin Setup
if ($step == 4 && $_SERVER['REQUEST_METHOD'] == 'POST') {
    $admin_user = $_POST['admin_user'] ?? '';
    $admin_pass = $_POST['admin_pass'] ?? '';
    $admin_email = $_POST['admin_email'] ?? '';

    if (empty($admin_user) || empty($admin_pass)) {
        $error = "Username and password are required.";
    } else {
        try {
            require_once $config_file;
            $pdo = db();
            $hash = password_hash($admin_pass, PASSWORD_DEFAULT);
            
            // Check if user exists
            $stmt = $pdo->prepare("SELECT id FROM users WHERE username = ?");
            $stmt->execute([$admin_user]);
            $existing = $stmt->fetch();

            if ($existing) {
                $stmt = $pdo->prepare("UPDATE users SET password = ?, email = ?, is_super_admin = 1 WHERE id = ?");
                $stmt->execute([$hash, $admin_email, $existing['id']]);
            } else {
                $stmt = $pdo->prepare("INSERT INTO users (username, password, email, is_super_admin) VALUES (?, ?, ?, 1)");
                $stmt->execute([$admin_user, $hash, $admin_email]);
            }
            
            // Set some default settings if table exists
            $pdo->exec("INSERT IGNORE INTO charity_settings (id, site_name) VALUES (1, 'Admin Panel')");

            $_SESSION['installed'] = true;
            header('Location: install.php?step=5');
            exit;
        } catch (Exception $e) {
            $error = "Admin setup error: " . $e->getMessage();
        }
    }
}

?>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Installer - Admin Panel</title>
    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/css/bootstrap.min.css" rel="stylesheet">
    <style>
        body { background-color: #f8f9fa; }
        .install-card { max-width: 600px; margin: 50px auto; border-radius: 15px; box-shadow: 0 10px 30px rgba(0,0,0,0.1); }
        .step-indicator { display: flex; justify-content: space-between; margin-bottom: 30px; }
        .step-dot { width: 30px; height: 30px; border-radius: 50%; background: #dee2e6; display: flex; align-items: center; justify-content: center; font-weight: bold; color: white; }
        .step-dot.active { background: #0d6efd; }
        .step-dot.completed { background: #198754; }
    </style>
</head>
<body>

<div class="container">
    <div class="card install-card">
        <div class="card-body p-5">
            <h2 class="text-center mb-4">Installation</h2>
            
            <div class="step-indicator">
                <div class="step-dot <?php echo $step >= 1 ? ($step > 1 ? 'completed' : 'active') : ''; ?>">1</div>
                <div class="step-dot <?php echo $step >= 2 ? ($step > 2 ? 'completed' : 'active') : ''; ?>">2</div>
                <div class="step-dot <?php echo $step >= 3 ? ($step > 3 ? 'completed' : 'active') : ''; ?>">3</div>
                <div class="step-dot <?php echo $step >= 4 ? ($step > 4 ? 'completed' : 'active') : ''; ?>">4</div>
                <div class="step-dot <?php echo $step >= 5 ? 'active' : ''; ?>">5</div>
            </div>

            <?php if ($error): ?>
                <div class="alert alert-danger"><?php echo $error; ?></div>
            <?php endif; ?>

            <?php if ($step == 1): ?>
                <h4>Step 1: System Requirements</h4>
                <ul class="list-group mb-4">
                    <?php
                    $reqs = [
                        'PHP Version >= 7.4' => version_compare(PHP_VERSION, '7.4.0', '>='),
                        'PDO MySQL Extension' => extension_loaded('pdo_mysql'),
                        'Config File Writable' => is_writable(__DIR__ . '/db') || is_writable($config_file),
                        'Uploads Directory Writable' => is_writable(__DIR__ . '/uploads')
                    ];
                    $all_ok = true;
                    foreach ($reqs as $label => $ok):
                        if (!$ok) $all_ok = false;
                    ?>
                        <li class="list-group-item d-flex justify-content-between align-items-center">
                            <?php echo $label; ?>
                            <span class="badge <?php echo $ok ? 'bg-success' : 'bg-danger'; ?> rounded-pill">
                                <?php echo $ok ? 'OK' : 'Fail'; ?>
                            </span>
                        </li>
                    <?php endforeach; ?>
                </ul>
                <?php if ($all_ok): ?>
                    <a href="install.php?step=2" class="btn btn-primary w-100">Continue to Database Setup</a>
                <?php else:
                    // This is a deliberate newline for readability in the code, not an escaping issue.
                    ?>
                    <div class="alert alert-warning">Please fix the issues above to continue.</div>
                    <button onclick="window.location.reload()" class="btn btn-secondary w-100">Check Again</button>
                <?php endif; ?>

            <?php elseif ($step == 2):
                // Deliberate newline for readability.
                ?>
                <h4>Step 2: Database Configuration</h4>
                <form method="POST">
                    <div class="mb-3">
                        <label class="form-label">DB Host</label>
                        <input type="text" name="db_host" class="form-control" value="127.0.0.1" required>
                    </div>
                    <div class="mb-3">
                        <label class="form-label">DB Name</label>
                        <input type="text" name="db_name" class="form-control" value="app_database" required>
                    </div>
                    <div class="mb-3">
                        <label class="form-label">DB User</label>
                        <input type="text" name="db_user" class="form-control" value="root" required>
                    </div>
                    <div class="mb-3">
                        <label class="form-label">DB Password</label>
                        <input type="password" name="db_pass" class="form-control">
                    </div>
                    <button type="submit" class="btn btn-primary w-100">Test & Save Config</button>
                </form>

            <?php elseif ($step == 3):
                // Deliberate newline for readability.
                ?>
                <h4>Step 3: Database Migrations</h4>
                <p>Ready to set up the database tables and initial data.</p>
                <form method="POST">
                    <button type="submit" name="run_migrations" class="btn btn-primary w-100">Run Migrations Now</button>
                </form>

            <?php elseif ($step == 4):
                // Deliberate newline for readability.
                ?>
                <h4>Step 4: Super Admin Setup</h4>
                <form method="POST">
                    <div class="mb-3">
                        <label class="form-label">Admin Username</label>
                        <input type="text" name="admin_user" class="form-control" value="admin" required>
                    </div>
                    <div class="mb-3">
                        <label class="form-label">Admin Email</label>
                        <input type="email" name="admin_email" class="form-control" placeholder="admin@example.com">
                    </div>
                    <div class="mb-3">
                        <label class="form-label">Admin Password</label>
                        <input type="password" name="admin_pass" class="form-control" required>
                    </div>
                    <button type="submit" class="btn btn-primary w-100">Complete Installation</button>
                </form>

            <?php elseif ($step == 5):
                // Deliberate newline for readability.
                ?>
                <div class="text-center">
                    <div class="mb-4">
                        <svg xmlns="http://www.w3.org/2000/svg" width="64" height="64" fill="currentColor" class="bi bi-check-circle-fill text-success" viewBox="0 0 16 16">
                          <path d="M16 8A8 8 0 1 1 0 8a8 8 0 0 1 16 0zm-3.97-3.03a.75.75 0 0 0-1.08.022L7.477 9.417 5.384 7.323a.75.75 0 0 0-1.06 1.06L6.97 11.03a.75.75 0 0 0 1.079-.02l3.992-4.99a.75.75 0 0 0-.01-1.05z"/>
                        </svg>
                    </div>
                    <h4>Success!</h4>
                    <p>The application has been installed successfully.</p>
                    <div class="alert alert-warning small">
                        <strong>Security Warning:</strong> Please delete the <code>install.php</code> file from your server.
                    </div>
                    <a href="login.php" class="btn btn-primary w-100">Go to Login</a>
                </div>
            <?php endif; ?>

        </div>
    </div>
</div>

</body>
</html>