<?php
$user_id = require_auth();

// GET /api/tutorials
if (get_method() === 'GET' && empty($segments[1])) {
    $stmt = $pdo->prepare("
        SELECT t.id, t.slug, t.title, t.description, t.duration_min, t.sort_order,
            COALESCE(tp.completed, false) AS completed, tp.completed_at
        FROM tutorials t
        LEFT JOIN tutorial_progress tp ON tp.tutorial_id = t.id AND tp.user_id = :uid
        ORDER BY t.sort_order
    ");
    $stmt->execute([':uid' => $user_id]);
    json_ok(['tutorials' => $stmt->fetchAll()]);
}

// GET /api/tutorials/{slug}
if (get_method() === 'GET' && !empty($segments[1]) && ($segments[2] ?? '') !== 'complete') {
    $stmt = $pdo->prepare("
        SELECT t.*, COALESCE(tp.completed, false) AS completed
        FROM tutorials t
        LEFT JOIN tutorial_progress tp ON tp.tutorial_id = t.id AND tp.user_id = :uid
        WHERE t.slug = :slug
    ");
    $stmt->execute([':slug' => $segments[1], ':uid' => $user_id]);
    $tutorial = $stmt->fetch();
    if (!$tutorial) json_error('Tutorial nicht gefunden', 404);
    json_ok(['tutorial' => $tutorial]);
}

// POST /api/tutorials/{slug}/complete
if (get_method() === 'POST' && !empty($segments[1]) && ($segments[2] ?? '') === 'complete') {
    $stmt = $pdo->prepare("SELECT id FROM tutorials WHERE slug = :slug");
    $stmt->execute([':slug' => $segments[1]]);
    $tutorial = $stmt->fetch();
    if (!$tutorial) json_error('Tutorial nicht gefunden', 404);

    $stmt = $pdo->prepare("
        INSERT INTO tutorial_progress (user_id, tutorial_id, completed, completed_at)
        VALUES (:uid, :tid, true, NOW())
        ON CONFLICT (user_id, tutorial_id) DO UPDATE SET completed = true, completed_at = NOW()
    ");
    $stmt->execute([':uid' => $user_id, ':tid' => $tutorial['id']]);
    json_ok(['ok' => true]);
}

json_error('Unbekannter Tutorials-Endpunkt', 404);