<?php
// teacher_page.php

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

include('include/headscript.php');

// QR Code library
require_once __DIR__ . '/../../vendor/autoload.php';

use Endroid\QrCode\QrCode;
use Endroid\QrCode\Writer\PngWriter;

$dbHandler = DBHandlerSelect::getInstance();
$pdo = $dbHandler->getConnection();

if (!isset($iduserlogin)) {
    die("Errore: ID utente non definito.");
}

/**
 * QR helper compatible with older/newer Endroid versions (best-effort)
 */
function writeQrPng($text, $filename, $size = 150, $margin = 10)
{
    // Your installed version seems to require text in constructor
    $qrCode = new \Endroid\QrCode\QrCode($text);

    if (method_exists($qrCode, 'setSize')) {
        $qrCode->setSize($size);
    } elseif (method_exists($qrCode, 'setModuleSize')) {
        $module = max(3, (int)round($size / 25));
        $qrCode->setModuleSize($module);
    }

    if (method_exists($qrCode, 'setMargin')) {
        $qrCode->setMargin($margin);
    } elseif (method_exists($qrCode, 'setPadding')) {
        $qrCode->setPadding($margin);
    }

    $writer = new \Endroid\QrCode\Writer\PngWriter();

    if (method_exists($writer, 'writeFile')) {
        $writer->writeFile($qrCode, $filename);
    } else {
        $result = $writer->write($qrCode);
        if (is_object($result) && method_exists($result, 'saveToFile')) {
            $result->saveToFile($filename);
        } else {
            file_put_contents($filename, (string)$result);
        }
    }
}

function generateUniqueCode($pdo, $length = 16)
{
    do {
        $code = bin2hex(random_bytes($length / 2));
        $stmt = $pdo->prepare("SELECT COUNT(*) FROM teachers WHERE unique_code = ?");
        $stmt->execute([$code]);
    } while ($stmt->fetchColumn() > 0);
    return $code;
}

/**
 * Detect view mode
 * - Owner view: teacher_page.php?id=TEACHER_ID (teachers.id)
 * - Teacher self view: teacher_page.php
 */
$teacher_id = (int)($_GET['id'] ?? 0);
$is_owner_view = ($teacher_id > 0);

$success_message = $error = null;

/**
 * 1) LOAD teacher row
 */
if ($is_owner_view) {
    // OWNER VIEW: load teacher by teachers.id only if owner has rights
    $stmt = $pdo->prepare("
        SELECT 
            t.*, 
            u.first_name, u.last_name, u.email
        FROM teachers t
        JOIN auth_users u ON t.user_id = u.id
        JOIN teacher_schools ts ON ts.teacher_id = t.id
        JOIN schools s ON s.id = ts.school_id
        WHERE t.id = ?
          AND s.owner_id = ?
        LIMIT 1
    ");
    $stmt->execute([$teacher_id, $iduserlogin]);
    $teacher = $stmt->fetch(PDO::FETCH_ASSOC);

    if (!$teacher) {
        die("Errore: insegnante non trovata o non hai permessi.");
    }
} else {
    // TEACHER SELF VIEW: load by logged user
    $stmt = $pdo->prepare("
        SELECT 
            t.*, 
            u.first_name, u.last_name, u.email
        FROM auth_users u
        LEFT JOIN teachers t ON t.user_id = u.id
        WHERE u.id = ?
        LIMIT 1
    ");
    $stmt->execute([$iduserlogin]);
    $teacher = $stmt->fetch(PDO::FETCH_ASSOC);

    // If not exists in teachers, CREATE IT before showing the form (auto-create)
    if (empty($teacher['id'])) {
        // ✅ SOLO QUI: quando auto-crei il profilo teacher (SELF VIEW), aggiungi created_by = iduserlogin

        $unique_code = generateUniqueCode($pdo);

        $stmtIns = $pdo->prepare("
    INSERT INTO teachers (user_id, unique_code, phone, description, specializations, profile_picture, status, created_by)
    VALUES (?, ?, NULL, '', '', '', 'active', ?)
");
        $ok = $stmtIns->execute([$iduserlogin, $unique_code, $iduserlogin]);


        if (!$ok) {
            die("Errore: impossibile creare il profilo insegnante.");
        }

        // Reload teacher after insert
        $stmt = $pdo->prepare("
            SELECT 
                t.*, 
                u.first_name, u.last_name, u.email
            FROM teachers t
            JOIN auth_users u ON t.user_id = u.id
            WHERE t.user_id = ?
            LIMIT 1
        ");
        $stmt->execute([$iduserlogin]);
        $teacher = $stmt->fetch(PDO::FETCH_ASSOC);
    }
}

/**
 * Now teacher MUST exist (in owner view and in self view due to auto-create)
 */
$is_new = empty($teacher['id']); // should be false at this point

/**
 * 2) HANDLE POST (save)
 */
if ($_SERVER['REQUEST_METHOD'] === 'POST') {

    // target user is the teacher being edited
    $target_user_id = $is_owner_view ? (int)$teacher['user_id'] : (int)$iduserlogin;

    $first_name      = trim($_POST['first_name'] ?? '');
    $last_name       = trim($_POST['last_name'] ?? '');
    $phone           = trim($_POST['phone'] ?? '');
    $description     = trim($_POST['description'] ?? '');
    $specializations = trim($_POST['specializations'] ?? '');
    $status          = (($_POST['status'] ?? 'active') === 'active') ? 'active' : 'inactive';

    // Update auth_users names for the target teacher
    $stmt = $pdo->prepare("UPDATE auth_users SET first_name = ?, last_name = ? WHERE id = ?");
    $stmt->execute([$first_name, $last_name, $target_user_id]);

    // Photo upload (use target user id in filename)
    $profile_picture = $teacher['profile_picture'] ?? '';
    if (!empty($_FILES['profile_picture']['name']) && $_FILES['profile_picture']['error'] === UPLOAD_ERR_OK) {

        $ext = strtolower(pathinfo($_FILES['profile_picture']['name'], PATHINFO_EXTENSION));

        if (in_array($ext, ['jpg', 'jpeg', 'png', 'gif'])) {
            $new_name = "phototeachers/{$target_user_id}-" . time() . "-profile.$ext";

            if (move_uploaded_file($_FILES['profile_picture']['tmp_name'], $new_name)) {
                if ($profile_picture && file_exists($profile_picture)) {
                    @unlink($profile_picture);
                }
                $profile_picture = $new_name;
            } else {
                $error = "Errore caricamento foto.";
            }
        } else {
            $error = "Solo JPG, PNG, GIF ammessi.";
        }
    }

    if (!$error) {
        // Update teachers row (always exists at this point)
        $stmt = $pdo->prepare("
            UPDATE teachers 
            SET phone = ?, description = ?, specializations = ?, profile_picture = ?, status = ?
            WHERE user_id = ?
        ");
        $success = $stmt->execute([
            $phone ?: null,
            $description,
            $specializations,
            $profile_picture,
            $status,
            $target_user_id
        ]);

        if ($success) {
            $success_message = "Dati aggiornati!";

            // Reload teacher (with correct target user)
            $stmt = $pdo->prepare("
                SELECT t.*, u.first_name, u.last_name, u.email
                FROM teachers t
                JOIN auth_users u ON t.user_id = u.id
                WHERE t.user_id = ?
                LIMIT 1
            ");
            $stmt->execute([$target_user_id]);
            $teacher = $stmt->fetch(PDO::FETCH_ASSOC);
        } else {
            $error = "Errore aggiornamento.";
        }
    }
}

/**
 * 3) QR generation (after teacher is loaded)
 */
$qr_code_path = null;
if (!empty($teacher['unique_code'])) {
    try {
        $unique_code = $teacher['unique_code'];

        // IMPORTANT: file name uses target user_id (teacher user), not owner id
        $qr_user_id = (int)$teacher['user_id'];

        $base_dir = __DIR__ . '/../../public/phototeachers/qrcodes/';
        $qr_filename = "{$base_dir}{$qr_user_id}-{$unique_code}.png";
        $qr_code_path = "phototeachers/qrcodes/{$qr_user_id}-{$unique_code}.png";

        if (!file_exists($qr_filename)) {
            if (!is_dir($base_dir)) mkdir($base_dir, 0755, true);
            writeQrPng($unique_code, $qr_filename, 150, 10);
        }
    } catch (Exception $e) {
        error_log("Errore QR: " . $e->getMessage());
    }
}
?>

<!doctype html>
<html lang="it">

<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Profilo Insegnante</title>
    <?php include('cssinclude.php'); ?>
    <?php include('siteinfo.php'); ?>

    <link href="https://cdn.jsdelivr.net/npm/quill@2.0.2/dist/quill.snow.css" rel="stylesheet" />

    <style>
        .teacher-photo {
            max-width: 100%;
            height: auto;
            max-height: 260px;
            object-fit: contain;
            border: 1px solid #dee2e6;
            border-radius: 8px;
            box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
            background: #fff;
            padding: 10px;
            margin-bottom: 1.5rem;
        }

        .quill-wrapper {
            min-height: 300px;
            display: flex;
            flex-direction: column;
        }

        .ql-container {
            flex: 1;
            font-size: 15px;
            border: 1px solid #ced4da;
            border-radius: 0 0 0.375rem 0.375rem;
        }

        .ql-editor {
            min-height: 220px;
        }

        .ql-toolbar {
            border-radius: 0.375rem 0.375rem 0 0;
            border-color: #ced4da;
        }

        .form-section {
            margin-bottom: 2rem;
        }

        .form-label {
            font-weight: 500;
            margin-bottom: 0.5rem;
        }
    </style>
</head>

<body>
    <div class="wrapper">
        <?php include('include/navbar.php'); ?>
        <?php include('include/topbar.php'); ?>

        <div class="page-wrapper">
            <div class="page-content">
                <div class="card radius-10">
                    <div class="card-header">
                        <h6 class="mb-0">Profilo Insegnante</h6>
                    </div>

                    <div class="card-body">
                        <?php if (!empty($success_message)): ?>
                            <div class="alert alert-success alert-dismissible fade show">
                                <?php echo htmlspecialchars($success_message); ?>
                                <button type="button" class="btn-close" data-bs-dismiss="alert"></button>
                            </div>
                        <?php endif; ?>

                        <?php if (!empty($error)): ?>
                            <div class="alert alert-danger alert-dismissible fade show">
                                <?php echo htmlspecialchars($error); ?>
                                <button type="button" class="btn-close" data-bs-dismiss="alert"></button>
                            </div>
                        <?php endif; ?>

                        <form method="POST" enctype="multipart/form-data" id="teacherForm">
                            <div class="row g-4">
                                <div class="col-lg-4 text-center">
                                    <img src="<?php echo $teacher['profile_picture'] ? htmlspecialchars($teacher['profile_picture']) : 'phototeachers/ndphoto.png'; ?>"
                                        alt="Foto Profilo" class="teacher-photo">

                                    <div class="mb-4">
                                        <label for="profile_picture" class="form-label">Carica nuova foto</label>
                                        <input type="file" class="form-control" id="profile_picture" name="profile_picture" accept="image/jpeg,image/png,image/gif">
                                        <small class="text-muted d-block mt-1">Max 2MB – JPG, PNG, GIF</small>
                                    </div>

                                    <?php if (!empty($teacher['unique_code']) && $qr_code_path): ?>
                                        <div class="mb-3">
                                            <label class="form-label">Codice Univoco</label>
                                            <input type="text" class="form-control" value="<?php echo htmlspecialchars($teacher['unique_code']); ?>" readonly>
                                        </div>

                                        <div class="mb-3">
                                            <label class="form-label">QR Code</label><br>
                                            <img src="<?php echo htmlspecialchars($qr_code_path); ?>" alt="QR Code" class="img-fluid shadow-sm" style="max-width: 180px;">
                                        </div>
                                    <?php endif; ?>
                                </div>

                                <div class="col-lg-8">
                                    <div class="row g-3">
                                        <div class="col-md-6">
                                            <label for="first_name" class="form-label">Nome</label>
                                            <input type="text" class="form-control" id="first_name" name="first_name"
                                                value="<?php echo htmlspecialchars($teacher['first_name'] ?? ''); ?>" required>
                                        </div>

                                        <div class="col-md-6">
                                            <label for="last_name" class="form-label">Cognome</label>
                                            <input type="text" class="form-control" id="last_name" name="last_name"
                                                value="<?php echo htmlspecialchars($teacher['last_name'] ?? ''); ?>" required>
                                        </div>

                                        <div class="col-12">
                                            <label for="email" class="form-label">Email</label>
                                            <input type="email" class="form-control" id="email" name="email"
                                                value="<?php echo htmlspecialchars($teacher['email'] ?? ''); ?>" readonly>
                                        </div>

                                        <div class="col-md-6">
                                            <label for="phone" class="form-label">Telefono</label>
                                            <input type="tel" class="form-control" id="phone" name="phone"
                                                value="<?php echo htmlspecialchars($teacher['phone'] ?? ''); ?>">
                                        </div>

                                        <div class="col-12 form-section">
                                            <label class="form-label">Descrizione insegnante</label>
                                            <div class="quill-wrapper">
                                                <div id="quill-editor"></div>
                                            </div>
                                            <input type="hidden" name="description" id="description-hidden">
                                        </div>

                                        <div class="col-12 form-section">
                                            <label for="specializations" class="form-label">Specializzazioni</label>
                                            <textarea class="form-control" id="specializations" name="specializations" rows="3"><?php echo htmlspecialchars($teacher['specializations'] ?? ''); ?></textarea>
                                            <small class="text-muted">Es: Hatha Yoga, Vinyasa, Yin, Restorative...</small>
                                        </div>

                                        <div class="col-md-6">
                                            <label class="form-label">Stato</label>
                                            <div class="form-check form-switch mt-2">
                                                <input class="form-check-input" type="checkbox" id="status" name="status" value="active"
                                                    <?php echo ($teacher['status'] ?? 'active') === 'active' ? 'checked' : ''; ?>>
                                                <label class="form-check-label" for="status">
                                                    <?php echo ($teacher['status'] ?? 'active') === 'active' ? 'Attivo' : 'Inattivo'; ?>
                                                </label>
                                            </div>
                                        </div>

                                        <div class="col-md-6">
                                            <label class="form-label">Creato</label>
                                            <input type="text" class="form-control" value="<?php echo htmlspecialchars($teacher['created_at'] ?? ''); ?>" readonly>
                                        </div>

                                        <div class="col-md-6">
                                            <label class="form-label">Aggiornato</label>
                                            <input type="text" class="form-control" value="<?php echo htmlspecialchars($teacher['updated_at'] ?? ''); ?>" readonly>
                                        </div>

                                        <div class="col-12 mt-5">
                                            <button type="submit" class="btn btn-primary btn-lg px-5">
                                                Salva Modifiche
                                            </button>
                                        </div>

                                    </div>
                                </div>

                            </div>
                        </form>

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

        <div class="overlay toggle-icon"></div>
        <a href="javaScript:;" class="back-to-top"><i class='bx bxs-up-arrow-alt'></i></a>
        <?php include('include/footer.php'); ?>
    </div>

    <?php include('jsinclude.php'); ?>

    <script src="https://cdn.jsdelivr.net/npm/quill@2.0.2/dist/quill.js"></script>
    <script>
        const quill = new Quill('#quill-editor', {
            theme: 'snow',
            modules: {
                toolbar: [
                    ['bold', 'italic', 'underline', 'strike'],
                    ['blockquote', 'code-block'],
                    [{
                        'header': [1, 2, 3, false]
                    }],
                    [{
                        'color': ['#000000', '#ff0000', '#00ff00', '#0000ff', '#ffff00', '#ff00ff', '#00ffff', '#808080', '#c0c0c0']
                    }, {
                        'background': []
                    }],
                    [{
                        'list': 'ordered'
                    }, {
                        'list': 'bullet'
                    }],
                    [{
                        'align': []
                    }],
                    ['link', 'clean']
                ]
            }
        });

        quill.root.innerHTML = `<?php echo addslashes($teacher['description'] ?? ''); ?>`;

        document.getElementById('teacherForm').addEventListener('submit', function() {
            document.getElementById('description-hidden').value = quill.root.innerHTML;
        });
    </script>
</body>

</html>