<?php

namespace Tests\Feature\OAuth;

use App\Models\OAuthClient;
use App\Models\Tenant;
use App\Models\User;
use Illuminate\Foundation\Testing\RefreshDatabase;
use Illuminate\Support\Str;
use Tests\TestCase;

class AuthorizeTest extends TestCase
{
    use RefreshDatabase;

    public function test_authorize_redirects_guests_to_login(): void
    {
        $tenant = Tenant::factory()->create();
        $client = $this->createClientForTenant($tenant);
        $query = $this->buildAuthorizeQuery($client);
        $fullUrl = url('/api/v1/oauth/authorize?'.http_build_query($query));

        $response = $this->get('/api/v1/oauth/authorize?'.http_build_query($query));

        $response->assertRedirect();
        $location = $response->headers->get('Location');
        $this->assertNotNull($location);

        $this->assertStringStartsWith(route('tenant.admin.login'), $location);

        $parsed = parse_url($location);
        $actualQuery = [];
        parse_str($parsed['query'] ?? '', $actualQuery);

        $this->assertSame('login_required', $actualQuery['error'] ?? null);
        $this->assertSame('Please sign in to continue.', $actualQuery['error_description'] ?? null);
        $this->assertReturnToMatches($query, $actualQuery['return_to'] ?? null);

        $this->assertIntendedUrlMatches($query);
    }

    public function test_authorize_returns_json_payload_for_ajax_guests(): void
    {
        $tenant = Tenant::factory()->create();
        $client = $this->createClientForTenant($tenant);
        $query = $this->buildAuthorizeQuery($client);

        $response = $this->withHeaders(['Accept' => 'application/json'])
            ->get('/api/v1/oauth/authorize?'.http_build_query($query));

        $response->assertStatus(401)
            ->assertJson([
                'error' => 'login_required',
                'error_description' => 'Please sign in to continue.',
            ]);

        $this->assertIntendedUrlMatches($query);
    }

    public function test_authorize_rejects_when_user_cannot_access_client_tenant(): void
    {
        $homeTenant = Tenant::factory()->create();
        $otherTenant = Tenant::factory()->create();
        $user = User::factory()->create([
            'tenant_id' => $homeTenant->id,
            'role' => 'tenant_admin',
        ]);

        $client = $this->createClientForTenant($otherTenant);

        $this->actingAs($user);

        $query = $this->buildAuthorizeQuery($client);
        $response = $this->get('/api/v1/oauth/authorize?'.http_build_query($query));

        $response->assertRedirect();
        $location = $response->headers->get('Location');
        $this->assertNotNull($location);

        $parsed = parse_url($location);
        $actualQuery = [];
        parse_str($parsed['query'] ?? '', $actualQuery);

        $this->assertSame('tenant_mismatch', $actualQuery['error'] ?? null);
        $this->assertReturnToMatches($query, $actualQuery['return_to'] ?? null);
    }

    public function test_authorize_redirects_with_error_when_client_unknown(): void
    {
        $tenant = Tenant::factory()->create();
        $this->actingAs(User::factory()->create([
            'tenant_id' => $tenant->id,
            'role' => 'tenant_admin',
        ]));

        $query = $this->buildAuthorizeQuery(new OAuthClient([
            'client_id' => 'missing-client',
            'redirect_uris' => ['http://localhost/callback'],
            'scopes' => ['tenant:read', 'tenant:write'],
        ]));

        $response = $this->get('/api/v1/oauth/authorize?'.http_build_query($query));

        $response->assertRedirect();
        $location = $response->headers->get('Location');
        $this->assertNotNull($location);

        $parsed = parse_url($location);
        $actualQuery = [];
        parse_str($parsed['query'] ?? '', $actualQuery);

        $this->assertSame('invalid_client', $actualQuery['error'] ?? null);
        $this->assertReturnToMatches($query, $actualQuery['return_to'] ?? null);
    }

    public function test_authorize_returns_json_error_for_tenant_mismatch_when_requested(): void
    {
        $homeTenant = Tenant::factory()->create();
        $otherTenant = Tenant::factory()->create();
        $user = User::factory()->create([
            'tenant_id' => $homeTenant->id,
            'role' => 'tenant_admin',
        ]);

        $client = $this->createClientForTenant($otherTenant);

        $this->actingAs($user);

        $query = $this->buildAuthorizeQuery($client);
        $response = $this->withHeaders(['Accept' => 'application/json'])
            ->get('/api/v1/oauth/authorize?'.http_build_query($query));

        $response->assertStatus(403)
            ->assertJson([
                'error' => 'tenant_mismatch',
            ]);
    }

    private function createClientForTenant(Tenant $tenant): OAuthClient
    {
        return OAuthClient::create([
            'id' => (string) Str::uuid(),
            'client_id' => 'tenant-admin-app-'.$tenant->id,
            'tenant_id' => $tenant->id,
            'client_secret' => null,
            'redirect_uris' => ['http://localhost/callback'],
            'scopes' => ['tenant:read', 'tenant:write'],
            'is_active' => true,
        ]);
    }

    private function buildAuthorizeQuery(OAuthClient $client): array
    {
        return [
            'client_id' => $client->client_id,
            'redirect_uri' => 'http://localhost/callback',
            'response_type' => 'code',
            'scope' => 'tenant:read tenant:write',
            'state' => Str::random(10),
            'code_challenge' => rtrim(strtr(base64_encode(hash('sha256', Str::random(32), true)), '+/', '-_'), '='),
            'code_challenge_method' => 'S256',
        ];
    }

    private function assertIntendedUrlMatches(array $expectedQuery): void
    {
        $intended = session('url.intended');
        $this->assertNotNull($intended, 'Expected intended URL to be recorded in session.');

        $parts = parse_url($intended);
        $this->assertSame('/api/v1/oauth/authorize', $parts['path'] ?? null);

        $actualQuery = [];
        parse_str($parts['query'] ?? '', $actualQuery);

        $this->assertEqualsCanonicalizing($expectedQuery, $actualQuery);
    }

    private function decodeReturnTo(?string $value): ?string
    {
        if ($value === null) {
            return null;
        }

        $padded = str_pad($value, strlen($value) + ((4 - (strlen($value) % 4)) % 4), '=');
        $normalized = strtr($padded, '-_', '+/');

        return base64_decode($normalized) ?: null;
    }

    private function assertReturnToMatches(array $expectedQuery, ?string $encoded): void
    {
        $decoded = $this->decodeReturnTo($encoded);
        $this->assertNotNull($decoded, 'Failed to decode return_to parameter.');

        $parts = parse_url($decoded);
        $this->assertSame('/api/v1/oauth/authorize', $parts['path'] ?? null);

        $actualQuery = [];
        parse_str($parts['query'] ?? '', $actualQuery);

        $this->assertEqualsCanonicalizing($expectedQuery, $actualQuery);
    }
}