<?php

use PHPUnit\Framework\TestCase;
use League\CommonMark\CommonMarkConverter;
use League\CommonMark\Extension\HeadingPermalink\HeadingPermalinkExtension;

/**
 * MarkdownHelperTest — TOC extraction from markdown headings.
 *
 * Regression: TOC labels used to show raw markdown (`*Licence*`, `**Gras**`,
 * `` `code` ``), because the raw heading text was passed straight to the
 * template. Labels must be plain text and hrefs must match the heading ids
 * CommonMark generates on the rendered page.
 */
class MarkdownHelperTest extends TestCase
{
    /**
     * Render markdown exactly like the content controllers do, and return the
     * heading ids in document order.
     */
    private function renderedHeadingIds(string $markdown): array
    {
        $converter = new CommonMarkConverter([
            'html_input' => 'strip',
            'heading_permalink' => [
                'apply_id_to_heading' => true,
                'id_prefix' => '',
                'insert' => 'before',
                'aria_hidden' => true,
            ],
        ]);
        $converter->getEnvironment()->addExtension(new HeadingPermalinkExtension());
        $html = $converter->convert($markdown)->getContent();

        preg_match_all('/<h[1-3] id="([^"]+)"/', $html, $matches);
        return $matches[1];
    }

    // ── Labels are plain text ─────────────────────────────────────────────────

    public function testItalicMarkupIsStrippedFromLabel(): void
    {
        $toc = MarkdownHelper::extractToc('## *Licence* CC');

        $this->assertSame('Licence CC', $toc[0]['label']);
    }

    public function testBoldMarkupIsStrippedFromLabel(): void
    {
        $toc = MarkdownHelper::extractToc('## **Gros** gras');

        $this->assertSame('Gros gras', $toc[0]['label']);
    }

    public function testInlineCodeMarkupIsStrippedFromLabel(): void
    {
        $toc = MarkdownHelper::extractToc('## `code` inline');

        $this->assertSame('code inline', $toc[0]['label']);
    }

    public function testLinkKeepsLabelTextNotUrl(): void
    {
        $toc = MarkdownHelper::extractToc('## [lien](http://x) ici');

        $this->assertSame('lien ici', $toc[0]['label']);
    }

    public function testNestedMarkupIsFullyStripped(): void
    {
        $toc = MarkdownHelper::extractToc('## *[lien](http://x)* et `code`');

        $this->assertSame('lien et code', $toc[0]['label']);
    }

    public function testNoMarkdownSyntaxLeaksIntoAnyLabel(): void
    {
        $markdown = "## *Italique*\n\n## **Gras**\n\n## `Code`\n\n## [Lien](http://x)\n";
        $labels = array_column(MarkdownHelper::extractToc($markdown), 'label');

        foreach ($labels as $label) {
            $this->assertDoesNotMatchRegularExpression('/[*`]|\[|\]\(/', $label);
        }
    }

    // ── Hrefs match rendered heading ids ──────────────────────────────────────

    public function testHrefsMatchRenderedHeadingIdsForInlineMarkup(): void
    {
        $markdown = "## *Licence* CC\n\n## **Gros** gras\n\n## `code` inline\n\n## [lien](http://x) ici\n";

        $toc = MarkdownHelper::extractToc($markdown);
        $headingIds = $this->renderedHeadingIds($markdown);

        foreach ($toc as $index => $item) {
            $this->assertSame('#' . $headingIds[$index], $item['href'], "TOC href mismatch at index {$index}");
        }
    }

    public function testHrefsMatchRenderedHeadingIdsForAccents(): void
    {
        $markdown = "## Été accents\n\n## Emoji 🎉 fin\n";

        $toc = MarkdownHelper::extractToc($markdown);
        $headingIds = $this->renderedHeadingIds($markdown);

        foreach ($toc as $index => $item) {
            $this->assertSame('#' . $headingIds[$index], $item['href'], "TOC href mismatch at index {$index}");
        }
    }

    // ── Levels and structure ──────────────────────────────────────────────────

    public function testLevelsAreCapturedFromHashes(): void
    {
        $markdown = "# Un\n\n## Deux\n\n### Trois\n";
        $toc = MarkdownHelper::extractToc($markdown);

        $this->assertSame([1, 2, 3], array_column($toc, 'level'));
    }

    public function testHeadingsDeeperThanThreeAreIgnored(): void
    {
        $toc = MarkdownHelper::extractToc("# Un\n\n#### Quatre\n");

        $this->assertCount(1, $toc);
    }

    public function testContentWithoutHeadingsYieldsEmptyToc(): void
    {
        $this->assertSame([], MarkdownHelper::extractToc("Juste du texte.\n\nEt un paragraphe."));
    }

    public function testEmptyContentYieldsEmptyToc(): void
    {
        $this->assertSame([], MarkdownHelper::extractToc(''));
    }
}