<?php

use App\Models\GithubApp;
use App\Models\InstanceSettings;
use App\Models\PrivateKey;
use App\Models\Team;
use App\Models\User;
use Illuminate\Foundation\Testing\RefreshDatabase;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Http;

uses(RefreshDatabase::class);

beforeEach(function () {
    InstanceSettings::unguarded(fn () => InstanceSettings::query()->create(['id' => 0]));

    $this->team = Team::factory()->create();
    $this->user = User::factory()->create();
    $this->team->members()->attach($this->user->id, ['role' => 'owner']);

    $this->githubApp = GithubApp::create([
        'name' => 'Test GitHub App',
        'api_url' => 'https://api.github.com',
        'html_url' => 'https://github.com',
        'custom_user' => 'git',
        'custom_port' => 22,
        'team_id' => $this->team->id,
        'is_system_wide' => false,
    ]);
});

function cacheGithubAppSetupState(string $state, string $action, GithubApp $githubApp): void
{
    Cache::put('github-app-setup-state:'.hash('sha256', $state), [
        'action' => $action,
        'github_app_id' => $githubApp->id,
        'team_id' => $githubApp->team_id,
    ], now()->addMinutes(15));
}

function authenticateGithubSetupCallbackTest(object $test): void
{
    $test->actingAs($test->user);
    session(['currentTeam' => $test->team]);
}

function fakeGithubManifestConversion(): void
{
    $key = openssl_pkey_new([
        'private_key_bits' => 2048,
        'private_key_type' => OPENSSL_KEYTYPE_RSA,
    ]);
    openssl_pkey_export($key, $privateKey);

    Http::preventStrayRequests();
    Http::fake([
        'https://api.github.com/app-manifests/*/conversions' => Http::response([
            'id' => 987654,
            'slug' => 'attacker-controlled-app',
            'client_id' => 'new-client-id',
            'client_secret' => 'new-client-secret',
            'pem' => $privateKey,
            'webhook_secret' => 'new-webhook-secret',
        ]),
    ]);
}

function configureGithubAppCredentials(GithubApp $githubApp): void
{
    $key = openssl_pkey_new([
        'private_key_bits' => 2048,
        'private_key_type' => OPENSSL_KEYTYPE_RSA,
    ]);
    openssl_pkey_export($key, $privateKey);

    $privateKeyModel = PrivateKey::create([
        'name' => 'github-app-test-key',
        'private_key' => $privateKey,
        'team_id' => $githubApp->team_id,
        'is_git_related' => true,
    ]);

    $githubApp->forceFill([
        'app_id' => 123456,
        'private_key_id' => $privateKeyModel->id,
    ])->save();
}

function fakeGithubInstallationVerification(int $appId): void
{
    Http::preventStrayRequests();
    Http::fake([
        'https://api.github.com/zen' => Http::response('Keep it logically awesome.', 200, [
            'Date' => now()->toRfc7231String(),
        ]),
        'https://api.github.com/app/installations/*' => Http::response([
            'id' => 555,
            'app_id' => $appId,
        ], 200),
    ]);
}

function fakeGithubInstallationVerificationFailure(): void
{
    Http::preventStrayRequests();
    Http::fake([
        'https://api.github.com/zen' => Http::response('Keep it logically awesome.', 200, [
            'Date' => now()->toRfc7231String(),
        ]),
        'https://api.github.com/app/installations/*' => Http::response(['message' => 'Not Found'], 404),
    ]);
}

it('requires authentication before processing github app manifest callbacks', function () {
    fakeGithubManifestConversion();
    cacheGithubAppSetupState('valid-state', 'manifest', $this->githubApp);

    $this->get('/webhooks/source/github/redirect?state=valid-state&code=attacker-code')
        ->assertRedirect();

    Http::assertNothingSent();

    $this->githubApp->refresh();
    expect($this->githubApp->app_id)->toBeNull()
        ->and($this->githubApp->client_id)->toBeNull()
        ->and($this->githubApp->webhook_secret)->toBeNull();
});

it('rejects github app manifest callbacks with invalid state without calling github', function () {
    authenticateGithubSetupCallbackTest($this);
    fakeGithubManifestConversion();

    $this->withHeader('Accept', 'application/json')->get('/webhooks/source/github/redirect?state='.$this->githubApp->uuid.'&code=attacker-code')
        ->assertNotFound();

    Http::assertNothingSent();

    $this->githubApp->refresh();
    expect($this->githubApp->app_id)->toBeNull()
        ->and($this->githubApp->client_id)->toBeNull()
        ->and($this->githubApp->webhook_secret)->toBeNull();
});

it('blocks rebinding an already configured github app through manifest callback', function () {
    authenticateGithubSetupCallbackTest($this);
    fakeGithubManifestConversion();

    $this->githubApp->forceFill([
        'app_id' => 123456,
        'client_id' => 'existing-client-id',
        'client_secret' => 'existing-client-secret',
        'webhook_secret' => 'existing-webhook-secret',
    ])->save();

    cacheGithubAppSetupState('valid-state', 'manifest', $this->githubApp);

    $this->withHeader('Accept', 'application/json')->get('/webhooks/source/github/redirect?state=valid-state&code=attacker-code')
        ->assertForbidden();

    Http::assertNothingSent();

    $this->githubApp->refresh();
    expect($this->githubApp->app_id)->toBe(123456)
        ->and($this->githubApp->client_id)->toBe('existing-client-id')
        ->and($this->githubApp->webhook_secret)->toBe('existing-webhook-secret');
});

it('configures an unbound github app with a valid one-time manifest state', function () {
    authenticateGithubSetupCallbackTest($this);
    fakeGithubManifestConversion();
    cacheGithubAppSetupState('valid-state', 'manifest', $this->githubApp);

    $this->get('/webhooks/source/github/redirect?state=valid-state&code=real-code')
        ->assertRedirect(route('source.github.show', ['github_app_uuid' => $this->githubApp->uuid]));

    Http::assertSentCount(1);

    $this->githubApp->refresh();
    expect($this->githubApp->name)->toBe('attacker-controlled-app')
        ->and($this->githubApp->app_id)->toBe(987654)
        ->and($this->githubApp->client_id)->toBe('new-client-id')
        ->and($this->githubApp->webhook_secret)->toBe('new-webhook-secret')
        ->and($this->githubApp->private_key_id)->not->toBeNull();
});

it('rejects replayed github app manifest states', function () {
    authenticateGithubSetupCallbackTest($this);
    fakeGithubManifestConversion();
    cacheGithubAppSetupState('valid-state', 'manifest', $this->githubApp);

    $this->get('/webhooks/source/github/redirect?state=valid-state&code=real-code')
        ->assertRedirect();

    $this->withHeader('Accept', 'application/json')->get('/webhooks/source/github/redirect?state=valid-state&code=real-code')
        ->assertNotFound();

    Http::assertSentCount(1);
});

it('requires authentication before processing github app install callbacks', function () {
    Http::preventStrayRequests();

    $this->get('/webhooks/source/github/install?source='.$this->githubApp->uuid.'&setup_action=install&installation_id=123456')
        ->assertRedirect();

    Http::assertNothingSent();

    $this->githubApp->refresh();
    expect($this->githubApp->installation_id)->toBeNull();
});

it('rejects github app install callbacks for an unknown github app', function () {
    authenticateGithubSetupCallbackTest($this);
    Http::preventStrayRequests();

    $this->withHeader('Accept', 'application/json')->get('/webhooks/source/github/install?source=does-not-exist&setup_action=install&installation_id=123456')
        ->assertNotFound();

    Http::assertNothingSent();
});

it('rejects an installation id that github does not confirm belongs to the app', function () {
    authenticateGithubSetupCallbackTest($this);
    configureGithubAppCredentials($this->githubApp);
    fakeGithubInstallationVerificationFailure();

    $this->withHeader('Accept', 'application/json')->get('/webhooks/source/github/install?source='.$this->githubApp->uuid.'&setup_action=install&installation_id=999999')
        ->assertForbidden();

    $this->githubApp->refresh();
    expect($this->githubApp->installation_id)->toBeNull();
});

it('sets installation id when github confirms it belongs to the app', function () {
    authenticateGithubSetupCallbackTest($this);
    configureGithubAppCredentials($this->githubApp);
    fakeGithubInstallationVerification($this->githubApp->app_id);

    $this->get('/webhooks/source/github/install?source='.$this->githubApp->uuid.'&setup_action=install&installation_id=123456')
        ->assertRedirect(route('source.github.show', ['github_app_uuid' => $this->githubApp->uuid]));

    $this->githubApp->refresh();
    expect($this->githubApp->installation_id)->toBe(123456);
});

it('allows reinstalling an already configured github app installation id', function () {
    authenticateGithubSetupCallbackTest($this);
    configureGithubAppCredentials($this->githubApp);
    $this->githubApp->forceFill(['installation_id' => 111111])->save();
    fakeGithubInstallationVerification($this->githubApp->app_id);

    $this->get('/webhooks/source/github/install?source='.$this->githubApp->uuid.'&setup_action=install&installation_id=222222')
        ->assertRedirect(route('source.github.show', ['github_app_uuid' => $this->githubApp->uuid]));

    $this->githubApp->refresh();
    expect($this->githubApp->installation_id)->toBe(222222);
});