<?php

declare(strict_types=1);

namespace Modules\Helpdesk\Http\Controllers;

use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Carbon;
use Illuminate\Support\Facades\Log;
use JsonException;
use Modules\Helpdesk\Models\GitCommit;
use Modules\Helpdesk\Models\GitRepository;
use Modules\Helpdesk\Services\GitWebhookIngestionService;

final class GitWebhookController
{
    /**
     * Handle an incoming Gitea webhook delivery.
     */
    public function __invoke(Request $request): JsonResponse
    {
        Log::info('Gitea webhook endpoint hit.', [
            'event' => $request->header('X-Gitea-Event'),
            'github_event' => $request->header('X-GitHub-Event'),
            'delivery' => $request->header('X-Gitea-Delivery'),
            'authorization_present' => $request->headers->has('Authorization'),
            'signature_present' => $request->headers->has('X-Gitea-Signature'),
        ]);

        $authResponse = $this->validateAuthorization($request);

        if ($authResponse instanceof JsonResponse) {
            return $authResponse;
        }

        $signatureResponse = $this->validateSignature($request);

        if ($signatureResponse instanceof JsonResponse) {
            return $signatureResponse;
        }

        $event = (string) ($request->header('X-Gitea-Event') ?: $request->header('X-GitHub-Event'));
        $payload = $request->json()->all();

        if ($event !== 'push') {
            Log::info('Gitea webhook ignored.', [
                'event' => $event,
                'delivery' => $request->header('X-Gitea-Delivery'),
            ]);

            return response()->json([
                'message' => 'Gitea webhook ignored.',
                'event' => $event,
            ]);
        }

        $commits = data_get($payload, 'commits', []);

        Log::info('Gitea push webhook received.', [
            'repository' => data_get($payload, 'repository.full_name'),
            'ref' => data_get($payload, 'ref'),
            'branch' => str_replace('refs/heads/', '', (string) data_get($payload, 'ref')),
            'before' => data_get($payload, 'before'),
            'after' => data_get($payload, 'after'),
            'commit_count' => is_countable($commits) ? count($commits) : 0,
        ]);

        foreach ($commits as $commit) {
            GitCommit::updateOrCreate(
                [
                    'sha' => data_get($commit, 'id'),
                ],
                [
                    'repository_full_name' => data_get($payload, 'repository.full_name'),
                    'repository_name' => data_get($payload, 'repository.name'),
                    'branch' => str_replace(
                        'refs/heads/',
                        '',
                        (string) data_get($payload, 'ref'),
                    ),
                    'author_name' => data_get($commit, 'author.name'),
                    'author_email' => data_get($commit, 'author.email'),
                    'message' => data_get($commit, 'message'),
                    'commit_url' => data_get($commit, 'url'),
                    'committed_at' => data_get($commit, 'timestamp')
                        ? Carbon::parse(data_get($commit, 'timestamp'))
                        : now(),
                    'payload' => $commit,
                ],
            );

            Log::info('Git commit stored.', [
                'sha' => data_get($commit, 'id'),
                'message' => data_get($commit, 'message'),
            ]);
        }

        return response()->json([
            'message' => 'Gitea push processed.',
            'repository' => data_get($payload, 'repository.full_name'),
            'branch' => str_replace('refs/heads/', '', (string) data_get($payload, 'ref')),
            'commit_count' => is_countable($commits) ? count($commits) : 0,
        ]);
    }

    /**
     * Validate the optional Gitea Authorization header.
     */
    private function validateAuthorization(Request $request): ?JsonResponse
    {
        $expected = (string) config('services.gitea.webhook_authorization');

        if ($expected === '') {
            return null;
        }

        $actual = (string) $request->header('Authorization');

        if (hash_equals($expected, $actual)) {
            return null;
        }

        Log::warning('Rejected Gitea webhook because Authorization header was invalid.', [
            'delivery' => $request->header('X-Gitea-Delivery'),
            'authorization_present' => $request->headers->has('Authorization'),
        ]);

        return response()->json([
            'message' => 'Invalid authorization header.',
        ], 403);
    }

    /**
     * Validate the optional Gitea HMAC SHA-256 signature.
     */
    private function validateSignature(Request $request): ?JsonResponse
    {
        $secret = (string) config('services.gitea.webhook_secret');

        if ($secret === '') {
            return null;
        }

        $payload = $request->getContent();
        $signature = (string) $request->header('X-Gitea-Signature');

        $expected = hash_hmac('sha256', $payload, $secret);

        if ($signature !== '' && hash_equals($expected, $signature)) {
            return null;
        }

        Log::warning('Rejected Gitea webhook because signature was invalid.', [
            'delivery' => $request->header('X-Gitea-Delivery'),
            'signature_present' => $request->headers->has('X-Gitea-Signature'),
            'expected' => $expected,
            'actual' => $signature,
        ]);

        return response()->json([
            'message' => 'Invalid Gitea signature.',
        ], 403);
    }
}