<?php

declare(strict_types=1);

use Symfony\Component\Process\Process;

function branchTopologyGit(string $repository, string ...$arguments): string
{
    $process = new Process(['git', ...$arguments], $repository);
    $process->setTimeout(15);
    $process->run();

    expect($process->isSuccessful())
        ->toBeTrue(trim($process->getErrorOutput()) ?: trim($process->getOutput()));

    return trim($process->getOutput());
}

function branchTopologyCommit(string $repository, string $path, string $contents, string $message): string
{
    $absolutePath = $repository.DIRECTORY_SEPARATOR.$path;
    $directory = dirname($absolutePath);

    if (! is_dir($directory)) {
        mkdir($directory, 0777, true);
    }

    file_put_contents($absolutePath, $contents);
    branchTopologyGit($repository, 'add', $path);
    branchTopologyGit($repository, 'commit', '-m', $message);

    return branchTopologyGit($repository, 'rev-parse', 'HEAD');
}

function branchTopologyRepository(): string
{
    $repository = sys_get_temp_dir().DIRECTORY_SEPARATOR.'tenantpilot-branch-topology-'.bin2hex(random_bytes(8));
    mkdir($repository, 0777, true);

    branchTopologyGit($repository, 'init', '-b', 'main');
    branchTopologyGit($repository, 'config', 'user.email', 'branch-topology@example.test');
    branchTopologyGit($repository, 'config', 'user.name', 'Branch Topology Fixture');
    branchTopologyCommit($repository, 'baseline.txt', "baseline\n", 'baseline');

    return $repository;
}

function branchTopologyRemoveDirectory(string $directory): void
{
    if (! is_dir($directory)) {
        return;
    }

    $iterator = new RecursiveIteratorIterator(
        new RecursiveDirectoryIterator($directory, FilesystemIterator::SKIP_DOTS),
        RecursiveIteratorIterator::CHILD_FIRST,
    );

    foreach ($iterator as $item) {
        $item->isDir() ? rmdir($item->getPathname()) : unlink($item->getPathname());
    }

    rmdir($directory);
}

/**
 * @return array{expectedBranch: string, targetCommit: string, featureCommit: string}
 */
function branchTopologyPrepareStream(
    string $repository,
    string $family,
    bool $remoteRef,
    bool $localRef = true,
    bool $diverged = false,
): array {
    $expectedBranch = $family === 'platform' ? 'platform-dev' : 'website-dev';
    $baseline = branchTopologyGit($repository, 'rev-parse', 'main');

    branchTopologyGit($repository, 'branch', $expectedBranch, $baseline);

    if ($diverged) {
        branchTopologyGit($repository, 'checkout', $expectedBranch);
        $targetCommit = branchTopologyCommit(
            $repository,
            $family.'-integration.txt',
            $family." integration\n",
            $family.' integration',
        );
    } else {
        $targetCommit = $baseline;
    }

    branchTopologyGit($repository, 'checkout', '-b', 'feat/'.$family.'-fixture', $baseline);
    $featureCommit = branchTopologyCommit(
        $repository,
        $family.'-feature.txt',
        $family." feature\n",
        $family.' feature',
    );

    if ($remoteRef) {
        branchTopologyGit($repository, 'update-ref', 'refs/remotes/origin/'.$expectedBranch, $targetCommit);
    }

    if (! $localRef) {
        branchTopologyGit($repository, 'branch', '-D', $expectedBranch);
    }

    return compact('expectedBranch', 'targetCommit', 'featureCommit');
}

/**
 * @param  list<string>  $arguments
 * @param  array<string, string|false>  $environment
 */
function branchTopologyResolve(
    string $repository,
    array $arguments,
    array $environment = [],
    bool $machineReadable = true,
): Process {
    $isolatedEnvironment = [
        'TENANTATLAS_BRANCH_FAMILY' => false,
        'TENANTATLAS_WORK_CLASSIFICATION' => false,
        'TENANTATLAS_PR_TARGET' => false,
        'TENANTATLAS_ACTIVE_SPEC' => false,
        'TENANTATLAS_BASE_REF' => false,
        'TENANTATLAS_REPO_SCOPE' => false,
        'GITHUB_BASE_REF' => false,
        'GITEA_BASE_REF' => false,
    ];

    $command = [repo_path('scripts/resolve-feature-base')];

    if ($machineReadable) {
        $command[] = '--format=kv';
    }

    $process = new Process(
        [...$command, ...$arguments],
        $repository,
        array_replace($isolatedEnvironment, $environment),
    );
    $process->setTimeout(15);
    $process->run();

    return $process;
}

/**
 * @return array<string, string>
 */
function branchTopologyKeyValues(string $output): array
{
    $values = [];

    foreach (preg_split('/\R/', trim($output)) ?: [] as $line) {
        if (! str_contains($line, '=')) {
            continue;
        }

        [$key, $value] = explode('=', $line, 2);
        $values[$key] = $value;
    }

    return $values;
}

function branchTopologyFixture(Closure $assertions): void
{
    $repository = branchTopologyRepository();

    try {
        $assertions($repository);
    } finally {
        branchTopologyRemoveDirectory($repository);
    }
}

it('[BS-001] selects the platform remote ref with its merge-base result', function (): void {
    branchTopologyFixture(function (string $repository): void {
        $stream = branchTopologyPrepareStream($repository, 'platform', remoteRef: true);
        $process = branchTopologyResolve($repository, ['--branch-family=platform']);
        $values = branchTopologyKeyValues($process->getOutput());
        expect($process->getExitCode())->toBe(0)
            ->and($values['branch_family'] ?? null)->toBe('platform')
            ->and($values['expected_branch'] ?? null)->toBe('platform-dev')
            ->and($values['selected_ref'] ?? null)->toBe('origin/platform-dev')
            ->and($values['target_commit'] ?? null)->toBe($stream['targetCommit'])
            ->and($values['merge_base'] ?? null)->toBe($stream['targetCommit'])
            ->and($values['base_range'] ?? null)->toBe($stream['targetCommit'].'...HEAD');
    });
});

it('[BS-002] falls back only to the local platform ref with its merge-base result', function (): void {
    branchTopologyFixture(function (string $repository): void {
        $stream = branchTopologyPrepareStream($repository, 'platform', remoteRef: false);
        $process = branchTopologyResolve($repository, ['--branch-family=platform']);
        $values = branchTopologyKeyValues($process->getOutput());
        expect($process->getExitCode())->toBe(0)
            ->and($values['branch_family'] ?? null)->toBe('platform')
            ->and($values['expected_branch'] ?? null)->toBe('platform-dev')
            ->and($values['selected_ref'] ?? null)->toBe('platform-dev')
            ->and($values['target_commit'] ?? null)->toBe($stream['targetCommit'])
            ->and($values['merge_base'] ?? null)->toBe($stream['targetCommit'])
            ->and($values['base_range'] ?? null)->toBe($stream['targetCommit'].'...HEAD');
    });
});

it('[BS-003] selects the website remote ref with its merge-base result', function (): void {
    branchTopologyFixture(function (string $repository): void {
        $stream = branchTopologyPrepareStream($repository, 'website', remoteRef: true);
        $process = branchTopologyResolve($repository, ['--branch-family=website']);
        $values = branchTopologyKeyValues($process->getOutput());
        expect($process->getExitCode())->toBe(0)
            ->and($values['branch_family'] ?? null)->toBe('website')
            ->and($values['expected_branch'] ?? null)->toBe('website-dev')
            ->and($values['selected_ref'] ?? null)->toBe('origin/website-dev')
            ->and($values['target_commit'] ?? null)->toBe($stream['targetCommit'])
            ->and($values['merge_base'] ?? null)->toBe($stream['targetCommit'])
            ->and($values['base_range'] ?? null)->toBe($stream['targetCommit'].'...HEAD');
    });
});

it('[BS-004] falls back only to the local website ref with its merge-base result', function (): void {
    branchTopologyFixture(function (string $repository): void {
        $stream = branchTopologyPrepareStream($repository, 'website', remoteRef: false);
        $process = branchTopologyResolve($repository, ['--branch-family=website']);
        $values = branchTopologyKeyValues($process->getOutput());
        expect($process->getExitCode())->toBe(0)
            ->and($values['branch_family'] ?? null)->toBe('website')
            ->and($values['expected_branch'] ?? null)->toBe('website-dev')
            ->and($values['selected_ref'] ?? null)->toBe('website-dev')
            ->and($values['target_commit'] ?? null)->toBe($stream['targetCommit'])
            ->and($values['merge_base'] ?? null)->toBe($stream['targetCommit'])
            ->and($values['base_range'] ?? null)->toBe($stream['targetCommit'].'...HEAD');
    });
});

it('[BS-005] accepts dev only for an explicitly classified promotion', function (): void {
    branchTopologyFixture(function (string $repository): void {
        $baseline = branchTopologyGit($repository, 'rev-parse', 'main');
        branchTopologyGit($repository, 'branch', 'dev', $baseline);
        branchTopologyGit($repository, 'update-ref', 'refs/remotes/origin/dev', $baseline);
        branchTopologyGit($repository, 'checkout', '-b', 'feat/promotion-fixture', $baseline);
        branchTopologyCommit($repository, 'promotion.txt', "promotion\n", 'promotion feature');
        $process = branchTopologyResolve($repository, [
            '--branch-family=repository-wide',
            '--work-classification=promotion',
            '--pull-request-target=dev',
        ]);
        $values = branchTopologyKeyValues($process->getOutput());
        expect($process->getExitCode())->toBe(0)
            ->and($values['branch_family'] ?? null)->toBe('repository-wide')
            ->and($values['work_classification'] ?? null)->toBe('promotion')
            ->and($values['expected_branch'] ?? null)->toBe('dev')
            ->and($values['selected_ref'] ?? null)->toBe('origin/dev')
            ->and($values['target_commit'] ?? null)->toBe($baseline)
            ->and($values['merge_base'] ?? null)->toBe($baseline)
            ->and($values['base_range'] ?? null)->toBe($baseline.'...HEAD');
    });
});

it('[BS-006] fails closed when platform family refs are missing', function (): void {
    branchTopologyFixture(function (string $repository): void {
        $baseline = branchTopologyGit($repository, 'rev-parse', 'main');
        branchTopologyGit($repository, 'branch', 'dev', $baseline);
        branchTopologyGit($repository, 'update-ref', 'refs/remotes/origin/dev', $baseline);
        $process = branchTopologyResolve($repository, ['--branch-family=platform']);
        $error = $process->getErrorOutput();
        expect($process->getExitCode())->toBe(2)
            ->and($error)->toContain('status=failed', 'reason=missing-family-ref')
            ->and($error)->toContain(
                'branch_family=platform',
                'expected_branch=platform-dev',
                'attempted_refs=origin/platform-dev,platform-dev',
                'guidance=Declare a consistent branch family',
                'diff_ran=false',
            )
            ->and($error)->not->toContain(
                'selected_ref=origin/dev',
                'selected_ref=dev',
                'HEAD~1',
                'merge_base=',
                'base_range=',
            );
    });
});

it('[BS-007] fails closed when website family refs are missing', function (): void {
    branchTopologyFixture(function (string $repository): void {
        $baseline = branchTopologyGit($repository, 'rev-parse', 'main');
        branchTopologyGit($repository, 'branch', 'platform-dev', $baseline);
        branchTopologyGit($repository, 'branch', 'dev', $baseline);
        branchTopologyGit($repository, 'update-ref', 'refs/remotes/origin/dev', $baseline);
        $process = branchTopologyResolve($repository, ['--branch-family=website']);
        $error = $process->getErrorOutput();
        expect($process->getExitCode())->toBe(2)
            ->and($error)->toContain(
                'reason=missing-family-ref',
                'branch_family=website',
                'expected_branch=website-dev',
                'attempted_refs=origin/website-dev,website-dev',
                'guidance=Declare a consistent branch family',
                'diff_ran=false',
            )
            ->and($error)->not->toContain(
                'selected_ref=origin/dev',
                'selected_ref=dev',
                'HEAD~1',
                'merge_base=',
                'base_range=',
            );
    });
});

it('[BS-008] returns only the platform feature path for diverged history', function (): void {
    branchTopologyFixture(function (string $repository): void {
        branchTopologyPrepareStream($repository, 'platform', remoteRef: true, diverged: true);
        $process = branchTopologyResolve($repository, ['--branch-family=platform']);
        $values = branchTopologyKeyValues($process->getOutput());
        $changed = branchTopologyGit($repository, 'diff', '--name-only', $values['base_range']);
        expect($process->getExitCode())->toBe(0)
            ->and($changed)->toBe('platform-feature.txt')
            ->and($values['merge_base'] ?? null)->not->toBe($values['target_commit'] ?? null);
    });
});

it('[BS-009] returns only the website feature path for diverged history', function (): void {
    branchTopologyFixture(function (string $repository): void {
        branchTopologyPrepareStream($repository, 'website', remoteRef: true, diverged: true);
        $process = branchTopologyResolve($repository, ['--branch-family=website']);
        $values = branchTopologyKeyValues($process->getOutput());
        $changed = branchTopologyGit($repository, 'diff', '--name-only', $values['base_range']);
        expect($process->getExitCode())->toBe(0)
            ->and($changed)->toBe('website-feature.txt')
            ->and($values['merge_base'] ?? null)->not->toBe($values['target_commit'] ?? null);
    });
});

it('[BS-010] rejects an explicit platform family plus website PR target', function (): void {
    branchTopologyFixture(function (string $repository): void {
        branchTopologyPrepareStream($repository, 'platform', remoteRef: true);
        $process = branchTopologyResolve($repository, [
            '--branch-family=platform',
            '--pull-request-target=website-dev',
        ]);
        expect($process->getExitCode())->toBe(2)
            ->and($process->getErrorOutput())->toContain(
                'reason=branch-family-conflict',
                'explicit=platform',
                'pull_request_target=website',
                'guidance=Declare a consistent branch family',
                'diff_ran=false',
            );
    });
});

it('[BS-011] rejects conflicting branch-name and repository-scope signals', function (): void {
    branchTopologyFixture(function (string $repository): void {
        $specPath = $repository.'/spec.md';
        file_put_contents($specPath, "# Ambiguous fixture\n\nNo branch metadata.\n");
        $process = branchTopologyResolve($repository, [
            '--branch-name=feat/platform-fixture',
            '--repo-scope=website',
            '--spec='.$specPath,
        ]);
        expect($process->getExitCode())->toBe(2)
            ->and($process->getErrorOutput())->toContain(
                'reason=ambiguous-branch-family',
                'branch_name=feat/platform-fixture',
                'repo_scope=website',
                'spec_path='.$specPath,
                'guidance=Declare a consistent branch family',
                'diff_ran=false',
            );
    });
});

it('[BS-012] rejects an explicit ref from the wrong family before merge-base work', function (): void {
    branchTopologyFixture(function (string $repository): void {
        $baseline = branchTopologyGit($repository, 'rev-parse', 'main');
        branchTopologyGit($repository, 'branch', 'platform-dev', $baseline);
        branchTopologyGit($repository, 'branch', 'website-dev', $baseline);
        branchTopologyGit($repository, 'update-ref', 'refs/remotes/origin/website-dev', $baseline);
        $process = branchTopologyResolve($repository, [
            '--branch-family=platform',
            '--ref=origin/website-dev',
        ]);
        expect($process->getExitCode())->toBe(2)
            ->and($process->getErrorOutput())->toContain(
                'reason=wrong-family-ref',
                'expected_branch=platform-dev',
                'explicit_ref=origin/website-dev',
                'guidance=Declare a consistent branch family',
                'diff_ran=false',
            )
            ->and($process->getErrorOutput())->not->toContain(
                'target_commit=',
                'merge_base=',
                'base_range=',
            );
    });
});

it('proves Stage 1 priority, diagnostics, ancestry failure, and executable portability', function (): void {
    branchTopologyFixture(function (string $repository): void {
        branchTopologyPrepareStream($repository, 'website', remoteRef: true);
        $process = branchTopologyResolve($repository, ['--pull-request-target=website-dev']);
        $values = branchTopologyKeyValues($process->getOutput());
        expect($process->getExitCode())->toBe(0)
            ->and($values['branch_family'] ?? null)->toBe('website')
            ->and($values['family_source'] ?? null)->toBe('pull-request-target');
    });

    branchTopologyFixture(function (string $repository): void {
        branchTopologyPrepareStream($repository, 'platform', remoteRef: true);
        $specPath = $repository.'/spec.md';
        file_put_contents($specPath, "**Feature Base**: platform-dev\n**Normal Merge Target**: platform-dev\n");
        $process = branchTopologyResolve($repository, ['--spec='.$specPath]);
        $values = branchTopologyKeyValues($process->getOutput());
        expect($process->getExitCode())->toBe(0)
            ->and($values['branch_family'] ?? null)->toBe('platform')
            ->and($values['family_source'] ?? null)->toBe('spec-metadata');
    });

    branchTopologyFixture(function (string $repository): void {
        branchTopologyPrepareStream($repository, 'platform', remoteRef: true);
        $process = branchTopologyResolve($repository, [
            '--branch-name=feat/platform-policy-fixture',
            '--repo-scope=platform',
        ]);
        $values = branchTopologyKeyValues($process->getOutput());
        expect($process->getExitCode())->toBe(0)
            ->and($values['branch_family'] ?? null)->toBe('platform')
            ->and($values['family_source'] ?? null)->toBe('branch-and-scope');
    });

    branchTopologyFixture(function (string $repository): void {
        branchTopologyPrepareStream($repository, 'platform', remoteRef: true);
        $process = branchTopologyResolve($repository, ['--branch-family=platform']);
        $values = branchTopologyKeyValues($process->getOutput());
        expect($process->getExitCode())->toBe(0)
            ->and($values)->toHaveKeys([
                'status',
                'branch_family',
                'work_classification',
                'family_source',
                'expected_branch',
                'selected_ref',
                'target_commit',
                'merge_base',
                'base_range',
            ])
            ->and($values['status'])->toBe('resolved')
            ->and($values['target_commit'])->toMatch('/^[0-9a-f]{40}$/')
            ->and($values['merge_base'])->toMatch('/^[0-9a-f]{40}$/')
            ->and($values['base_range'])->toBe($values['merge_base'].'...HEAD');
    });

    branchTopologyFixture(function (string $repository): void {
        $baseline = branchTopologyGit($repository, 'rev-parse', 'main');
        branchTopologyGit($repository, 'branch', 'dev', $baseline);
        $process = branchTopologyResolve($repository, ['--pull-request-target=dev']);
        expect($process->getExitCode())->toBe(2)
            ->and($process->getErrorOutput())->toContain(
                'reason=explicit-promotion-classification-required',
                'diff_ran=false',
            );
    });

    branchTopologyFixture(function (string $repository): void {
        $process = branchTopologyResolve($repository, ['--branch-family=unknown']);
        expect($process->getExitCode())->toBe(2)
            ->and($process->getErrorOutput())->toContain(
                'reason=invalid-branch-family',
                'explicit=unknown',
                'diff_ran=false',
            );
    });

    branchTopologyFixture(function (string $repository): void {
        $specPath = $repository.'/spec.md';
        file_put_contents($specPath, "**Feature Base**: platform-dev\n**Normal Merge Target**: platform-dev\n");
        $process = branchTopologyResolve($repository, [
            '--pull-request-target=website-dev',
            '--spec='.$specPath,
        ]);
        expect($process->getExitCode())->toBe(2)
            ->and($process->getErrorOutput())->toContain(
                'reason=branch-family-conflict',
                'selected=website',
                'spec_metadata=platform',
                'diff_ran=false',
            );
    });

    branchTopologyFixture(function (string $repository): void {
        branchTopologyPrepareStream($repository, 'platform', remoteRef: true);
        $process = branchTopologyResolve($repository, ['--branch-name=feat/platform-name-only']);
        expect($process->getExitCode())->toBe(2)
            ->and($process->getErrorOutput())->toContain(
                'reason=ambiguous-branch-family',
                'diff_ran=false',
            );
    });

    branchTopologyFixture(function (string $repository): void {
        branchTopologyPrepareStream($repository, 'platform', remoteRef: true);
        $process = branchTopologyResolve(
            $repository,
            [],
            ['TENANTATLAS_BRANCH_FAMILY' => 'platform'],
        );
        $values = branchTopologyKeyValues($process->getOutput());
        expect($process->getExitCode())->toBe(0)
            ->and($values['branch_family'] ?? null)->toBe('platform')
            ->and($values['family_source'] ?? null)->toBe('explicit');
    });

    branchTopologyFixture(function (string $repository): void {
        branchTopologyPrepareStream($repository, 'website', remoteRef: true);
        $process = branchTopologyResolve(
            $repository,
            [],
            ['GITHUB_BASE_REF' => 'website-dev'],
        );
        $values = branchTopologyKeyValues($process->getOutput());
        expect($process->getExitCode())->toBe(0)
            ->and($values['branch_family'] ?? null)->toBe('website')
            ->and($values['family_source'] ?? null)->toBe('pull-request-target');
    });

    branchTopologyFixture(function (string $repository): void {
        branchTopologyPrepareStream($repository, 'platform', remoteRef: true);
        $process = branchTopologyResolve($repository, [
            '--branch-family=platform',
            '--ref=platform-dev',
        ]);
        expect($process->getExitCode())->toBe(0)
            ->and(branchTopologyKeyValues($process->getOutput())['selected_ref'] ?? null)->toBe('platform-dev');
    });

    branchTopologyFixture(function (string $repository): void {
        branchTopologyPrepareStream($repository, 'platform', remoteRef: true);
        $process = branchTopologyResolve(
            $repository,
            ['--pull-request-target=platform-dev'],
            ['GITHUB_BASE_REF' => 'refs/heads/platform-dev'],
        );
        expect($process->getExitCode())->toBe(0)
            ->and(branchTopologyKeyValues($process->getOutput())['branch_family'] ?? null)->toBe('platform');
    });

    branchTopologyFixture(function (string $repository): void {
        branchTopologyPrepareStream($repository, 'platform', remoteRef: true);
        $process = branchTopologyResolve($repository, [
            '--branch-family=platform',
            '--branch-name=feat/website-stale-hint',
            '--repo-scope=website',
        ]);
        $values = branchTopologyKeyValues($process->getOutput());
        expect($process->getExitCode())->toBe(0)
            ->and($values['branch_family'] ?? null)->toBe('platform')
            ->and($values['family_source'] ?? null)->toBe('explicit');
    });

    branchTopologyFixture(function (string $repository): void {
        $baseline = branchTopologyGit($repository, 'rev-parse', 'main');
        branchTopologyGit($repository, 'branch', 'dev', $baseline);
        branchTopologyGit($repository, 'update-ref', 'refs/remotes/origin/dev', $baseline);
        $process = branchTopologyResolve($repository, [
            '--branch-family=repository-wide',
            '--work-classification=promotion',
        ]);
        expect($process->getExitCode())->toBe(2)
            ->and($process->getErrorOutput())->toContain(
                'reason=explicit-target-required',
                'work_classification=promotion',
                'diff_ran=false',
            );
    });

    branchTopologyFixture(function (string $repository): void {
        branchTopologyPrepareStream($repository, 'platform', remoteRef: true);
        $process = branchTopologyResolve(
            $repository,
            ['--branch-family=platform'],
            [],
            machineReadable: false,
        );
        expect($process->getExitCode())->toBe(0)
            ->and($process->getOutput())->toContain(
                'Feature base resolved.',
                'Branch family: platform',
                'Expected integration branch: platform-dev',
                'Selected ref: origin/platform-dev',
                'Target commit:',
                'Merge base:',
                'Base range:',
            );
    });

    branchTopologyFixture(function (string $repository): void {
        branchTopologyGit($repository, 'checkout', '--orphan', 'platform-dev');
        branchTopologyGit($repository, 'rm', '-rf', '.');
        branchTopologyCommit($repository, 'unrelated.txt', "unrelated\n", 'unrelated root');
        branchTopologyGit($repository, 'checkout', 'main');
        $process = branchTopologyResolve($repository, ['--branch-family=platform']);
        expect($process->getExitCode())->toBe(2)
            ->and($process->getErrorOutput())->toContain(
                'reason=no-common-merge-base',
                'selected_ref=platform-dev',
                'diff_ran=false',
            );
    });

    $resolver = repo_path('scripts/resolve-feature-base');
    $syntax = new Process(['bash', '-n', $resolver], repo_root());
    $syntax->run();
    expect(is_executable($resolver))->toBeTrue()
        ->and($syntax->getExitCode())->toBe(0, $syntax->getErrorOutput());
});