<?php
/**
 * Content Import - reads Markdown files from content/ and upserts into DB.
 */

function import_all_content($pdo) {
    $stats = ['decks' => 0, 'cards' => 0, 'tutorials' => 0, 'cheatsheets' => 0];

    $flashcard_dir = CONTENT_DIR . '/flashcards';
    if (is_dir($flashcard_dir)) {
        $sort = 0;
        foreach (glob($flashcard_dir . '/deck-*.md') as $file) {
            $count = import_flashcard_deck($pdo, $file, $sort++);
            $stats['decks']++;
            $stats['cards'] += $count;
        }
    }

    $tutorial_dir = CONTENT_DIR . '/tutorials';
    if (is_dir($tutorial_dir)) {
        $sort = 0;
        foreach (glob($tutorial_dir . '/*.md') as $file) {
            $basename = basename($file);
            if ($basename === 'onboarding-path.md' || $basename === 'progress.md') continue;
            import_tutorial($pdo, $file, $sort++);
            $stats['tutorials']++;
        }
    }

    $cheatsheet_dir = CONTENT_DIR . '/cheatsheets';
    if (is_dir($cheatsheet_dir)) {
        foreach (glob($cheatsheet_dir . '/*-cheatsheet.md') as $file) {
            import_cheatsheet($pdo, $file);
            $stats['cheatsheets']++;
        }
    }

    return $stats;
}

function import_flashcard_deck($pdo, $filepath, $deck_sort) {
    $content = file_get_contents($filepath);
    $basename = basename($filepath);

    preg_match('/^# Flashcard Deck: (.+)$/m', $content, $m);
    $deck_name = $m[1] ?? str_replace(['deck-', '.md'], '', $basename);
    $slug = slugify($deck_name);

    $stmt = $pdo->prepare("
        INSERT INTO decks (slug, name, sort_order, source_file, updated_at)
        VALUES (:slug, :name, :sort, :src, NOW())
        ON CONFLICT (slug) DO UPDATE SET name = :name, sort_order = :sort, source_file = :src, updated_at = NOW()
        RETURNING id
    ");
    $stmt->execute([':slug' => $slug, ':name' => $deck_name, ':sort' => $deck_sort, ':src' => $basename]);
    $deck_id = $stmt->fetchColumn();

    // Parse cards
    preg_match_all(
        '/## Karte (\d+) \| (\w+)\s*\n\*\*Q:\*\*\s*(.+?)(?:\n)\*\*A:\*\*\s*(.+?)(?=\n---|\n## Karte|\n## Spaced|\Z)/s',
        $content, $matches, PREG_SET_ORDER
    );

    // Delete old cards for this deck, then re-insert
    $pdo->prepare("DELETE FROM cards WHERE deck_id = :did")->execute([':did' => $deck_id]);

    $card_count = 0;
    foreach ($matches as $i => $match) {
        $level = strtolower(trim($match[2]));
        $question = trim($match[3]);
        $answer = trim($match[4]);

        $stmt = $pdo->prepare("
            INSERT INTO cards (deck_id, question, answer, level, sort_order, source_file)
            VALUES (:did, :q, :a, :lvl, :sort, :src)
        ");
        $stmt->execute([
            ':did' => $deck_id, ':q' => $question, ':a' => $answer,
            ':lvl' => $level, ':sort' => $i, ':src' => $basename
        ]);
        $card_count++;
    }

    $pdo->prepare("UPDATE decks SET card_count = :c WHERE id = :id")
        ->execute([':c' => $card_count, ':id' => $deck_id]);

    return $card_count;
}

function import_tutorial($pdo, $filepath, $sort_order) {
    $content = file_get_contents($filepath);
    $basename = basename($filepath);

    preg_match('/^# (.+)$/m', $content, $m);
    $title = $m[1] ?? str_replace('.md', '', $basename);
    $slug = slugify($basename);

    preg_match('/\*\*Dauer\*\*:\s*ca\.\s*(\d+)/i', $content, $dm);
    $duration = $dm[1] ?? null;

    preg_match('/\*\*Ziel\*\*:\s*(.+)$/m', $content, $desc);
    $description = $desc[1] ?? '';

    $stmt = $pdo->prepare("
        INSERT INTO tutorials (slug, title, description, content_md, duration_min, sort_order, source_file, updated_at)
        VALUES (:slug, :title, :desc, :content, :dur, :sort, :src, NOW())
        ON CONFLICT (slug) DO UPDATE SET
            title = :title, description = :desc, content_md = :content,
            duration_min = :dur, sort_order = :sort, source_file = :src, updated_at = NOW()
    ");
    $stmt->execute([
        ':slug' => $slug, ':title' => $title, ':desc' => $description,
        ':content' => $content, ':dur' => $duration,
        ':sort' => $sort_order, ':src' => $basename
    ]);
}

function import_cheatsheet($pdo, $filepath) {
    $content = file_get_contents($filepath);
    $basename = basename($filepath);

    preg_match('/^# (.+)$/m', $content, $m);
    $title = $m[1] ?? str_replace(['-cheatsheet', '.md'], ['', ''], $basename);
    $slug = slugify($basename);
    $category = ucfirst(str_replace(['-cheatsheet.md', '-'], ['', ' '], $basename));

    $stmt = $pdo->prepare("
        INSERT INTO cheatsheets (slug, title, category, content_md, source_file, updated_at)
        VALUES (:slug, :title, :cat, :content, :src, NOW())
        ON CONFLICT (slug) DO UPDATE SET
            title = :title, category = :cat, content_md = :content, source_file = :src, updated_at = NOW()
    ");
    $stmt->execute([
        ':slug' => $slug, ':title' => $title, ':cat' => $category,
        ':content' => $content, ':src' => $basename
    ]);
}

function slugify($text) {
    $text = str_replace(['.md', 'deck-'], '', $text);
    $text = strtolower($text);
    $text = preg_replace('/[^a-z0-9\-]/', '-', $text);
    $text = preg_replace('/-+/', '-', $text);
    return trim($text, '-');
}