<?php

declare(strict_types=1);

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

use LIT\MCP\Integrations\Divi\Release\SourceFingerprint;
use PHPUnit\Framework\TestCase;
use RuntimeException;

final class SourceFingerprintTest extends TestCase
{
    /** Shaped like Divi's files: a guarded function, two classes with a method of the same name. */
    private const SOURCE = <<<'PHP'
<?php
use function et_demo_save;
if ( ! function_exists( 'et_demo_save' ) ) {
	/**
	 * Saves.
	 */
	function et_demo_save( $id, $data = array() ) {
		$value = "{$data['x']}";
		if ( $id ) {
			update_post_meta( $id, '_et_demo', $value );
		}
		return Foo::class;
	}
}

class Controller {
	public static function update( $request ) {
		return array( 'a' => 1 );
	}
}

class Other {
	public static function update( $request ) {
		return array( 'b' => 2 );
	}
}
PHP;

    public function testFindsAFunctionInsideAFunctionExistsGuard(): void
    {
        $print = SourceFingerprint::fromSource(self::SOURCE, 'et_demo_save');

        self::assertNotNull($print);
        self::assertSame(7, $print->startLine);
        self::assertSame(13, $print->endLine);
        self::assertStringStartsWith('function et_demo_save(', $print->source);
        self::assertStringEndsWith('}', $print->source);
        self::assertMatchesRegularExpression('/^[0-9a-f]{64}$/', $print->hash);
    }

    public function testClassConstantsAndInterpolationDoNotConfuseTheBraceCount(): void
    {
        $print = SourceFingerprint::fromSource(self::SOURCE, 'et_demo_save');

        self::assertNotNull($print);
        self::assertStringContainsString('return Foo::class;', $print->source);
        self::assertStringNotContainsString('class Controller', $print->source);
    }

    public function testMethodIsFoundInItsOwnClassOnly(): void
    {
        $controller = SourceFingerprint::fromSource(self::SOURCE, 'update', 'ET\Builder\VisualBuilder\Controller');
        $other = SourceFingerprint::fromSource(self::SOURCE, 'update', 'Other');

        self::assertNotNull($controller);
        self::assertNotNull($other);
        self::assertStringContainsString("'a' => 1", $controller->source);
        self::assertStringContainsString("'b' => 2", $other->source);
        self::assertNotSame($controller->hash, $other->hash);
        self::assertNull(SourceFingerprint::fromSource(self::SOURCE, 'update'), 'a method is no top-level function');
        self::assertNull(SourceFingerprint::fromSource(self::SOURCE, 'et_demo_save', 'Controller'));
        self::assertNull(SourceFingerprint::fromSource(self::SOURCE, 'missing'));
    }

    public function testCommentsAndWhitespaceDoNotChangeTheHash(): void
    {
        $reformatted = str_replace(
            ["\t\t\$value = ", "if ( \$id ) {"],
            ["\t\t// Why: demo.\n\t\t\$value   =   ", "if (\$id)\n\t\t{"],
            self::SOURCE
        );

        self::assertSame(
            SourceFingerprint::fromSource(self::SOURCE, 'et_demo_save')?->hash,
            SourceFingerprint::fromSource($reformatted, 'et_demo_save')?->hash
        );
    }

    public function testACodeChangeChangesTheHash(): void
    {
        $changed = str_replace("'_et_demo'", "'_et_demo_v2'", self::SOURCE);

        self::assertNotSame(
            SourceFingerprint::fromSource(self::SOURCE, 'et_demo_save')?->hash,
            SourceFingerprint::fromSource($changed, 'et_demo_save')?->hash
        );
    }

    public function testOfReadsTheFileAndThrowsForMissingFunctions(): void
    {
        $file = (string) tempnam(sys_get_temp_dir(), 'lit');
        file_put_contents($file, self::SOURCE);

        try {
            self::assertSame(
                SourceFingerprint::fromSource(self::SOURCE, 'et_demo_save')?->hash,
                SourceFingerprint::of($file, 'et_demo_save')->hash
            );
            try {
                SourceFingerprint::of($file, 'update', 'Missing');
                self::fail('a missing method must throw');
            } catch (RuntimeException $e) {
                self::assertStringContainsString('Missing::update() not found', $e->getMessage());
            }
        } finally {
            unlink($file);
        }
    }

    public function testOfThrowsForAnUnreadableFile(): void
    {
        $this->expectException(RuntimeException::class);
        $this->expectExceptionMessage('is not readable');

        SourceFingerprint::of('/nonexistent/lit-divi.php', 'et_demo_save');
    }
}