<?php

declare(strict_types=1);

namespace LIT\MCP\Tests\Unit\Integrations\Divi\Release;

use FilesystemIterator;
use LIT\MCP\Integrations\Divi\Release\DiviAdapter;
use LIT\MCP\Integrations\Divi\Release\DiviAdapters;
use LIT\MCP\Integrations\Divi\Release\DiviTouches;
use PHPUnit\Framework\TestCase;
use RecursiveDirectoryIterator;
use RecursiveIteratorIterator;
use ReflectionClass;

/**
 * Spec §3: only the adapters in DiviAdapters::CLASSES touch Divi, and every Divi name an adapter uses stands in its
 * manifest (and nothing more).
 */
final class DiviBoundaryTest extends TestCase
{
    public function testOnlyAdaptersTouchDivi(): void
    {
        $offenders = [];
        foreach (self::sourceFiles() as $relative => $path) {
            $touches = DiviTouches::inFile($path);
            if ($touches === []) {
                continue;
            }
            if (! in_array(self::classOf($relative), DiviAdapters::CLASSES, true)) {
                $offenders[] = $relative . ': ' . implode(', ', array_unique(array_column($touches, 'name')));
            }
        }

        self::assertSame([], $offenders, "Divi darf nur ein Adapter aus DiviAdapters::CLASSES berühren:\n"
            . implode("\n", $offenders));
    }

    public function testAdaptersDeclareExactlyTheDiviNamesTheyUse(): void
    {
        foreach (DiviAdapters::CLASSES as $class) {
            self::assertTrue(is_subclass_of($class, DiviAdapter::class), $class . ' implementiert DiviAdapter nicht');
            $declared = $class::manifest()->names();
            $used = array_values(array_unique(array_column(
                DiviTouches::inFile((string) (new ReflectionClass($class))->getFileName()),
                'name'
            )));

            self::assertSame([], array_values(array_diff($used, $declared)), $class . ': nicht im Manifest');
            self::assertSame(
                [],
                array_values(array_diff(array_filter($declared, [DiviTouches::class, 'detects']), $used)),
                $class . ': im Manifest, aber nicht benutzt'
            );
        }
    }

    public function testMirrorIdsAreUniqueAndFilesRelative(): void
    {
        $ids = [];
        foreach (DiviAdapters::mirrors() as $mirror) {
            self::assertNotContains($mirror->id, $ids, 'doppelte Mirror-ID ' . $mirror->id);
            self::assertStringStartsNotWith('/', $mirror->file);
            $ids[] = $mirror->id;
        }
    }

    /** @return array<string, string> Path below src/ => absolute path. */
    private static function sourceFiles(): array
    {
        $root = dirname(__DIR__, 5) . '/src/';
        $files = [];
        $iterator = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($root, FilesystemIterator::SKIP_DOTS));
        foreach ($iterator as $file) {
            if ($file->getExtension() === 'php') {
                $files[substr((string) $file->getPathname(), strlen($root))] = (string) $file->getPathname();
            }
        }
        ksort($files);

        return $files;
    }

    private static function classOf(string $relative): string
    {
        return 'LIT\\MCP\\' . str_replace(['/', '.php'], ['\\', ''], $relative);
    }
}