<?php

namespace App\Services\Editorial;

use Illuminate\Contracts\Http\Kernel;
use Illuminate\Http\Request;
use Illuminate\Http\UploadedFile;

/** Calls the existing HTTP routes on the application server, without opening its public API. */
final class ProcessApi
{
    private array $credential;

    public function __construct()
    {
        abort_unless(PHP_SAPI === 'cli', 403);
        $this->credential = ['schema' => 'gemdocs.credential.v1', 'project' => 'fna-v3',
            'environment' => app()->environment(), 'base_url' => config('editorial.base_url'),
            'expires_at' => time() + 600, 'fields' => ['api_key' => 'fna_ed_'.bin2hex(random_bytes(32))]];
    }

    public function call(string $method, string $path, array $data = [], ?UploadedFile $image = null): array
    {
        abort_unless(in_array($method, ['GET', 'POST']) && preg_match('~\A[a-zA-Z0-9_/-]+\z~', $path), 422);
        $response = $this->dispatch($method, '/api/editorial/v1/'.$path, $data, $image);
        $body = json_decode($response->getContent(), true);
        abort_unless($response->isSuccessful(), $response->getStatusCode(), 'Editorial API rejected operation; inspect state before retry');
        abort_unless(is_array($body), 502, 'Unexpected API response');

        return $body;
    }

    public function preview(string $url): string
    {
        $base = rtrim(config('editorial.base_url'), '/');
        abort_unless(str_starts_with($url, $base.'/api/editorial/v1/preview/'), 422, 'Preview origin mismatch');
        $response = $this->dispatch('GET', substr($url, strlen($base)));
        abort_unless($response->isSuccessful() && str_contains($response->headers->get('Content-Type', ''), 'text/html')
            && str_contains($response->headers->get('X-Robots-Tag', ''), 'noindex'), 502, 'Preview render failed');

        return $response->getContent();
    }

    private function dispatch(string $method, string $path, array $data = [], ?UploadedFile $image = null)
    {
        abort_unless(time() < $this->credential['expires_at'], 401, 'Process session expired');
        $before = ['editorial.enabled' => config('editorial.enabled'),
            'editorial.process_credential' => config('editorial.process_credential')];
        $originalRequest = app('request');
        config(['editorial.enabled' => true, 'editorial.process_credential' => $this->credential]);
        try {
            $server = ['HTTP_ACCEPT' => 'application/json', 'HTTP_AUTHORIZATION' => 'Bearer '.$this->credential['fields']['api_key'],
                'CONTENT_TYPE' => 'application/json', 'REMOTE_ADDR' => '127.0.0.1'];
            $request = Request::create(rtrim(config('editorial.base_url'), '/').$path, $method, [], [],
                $image ? ['image' => $image] : [], $server, $image ? null : json_encode($data));
            $kernel = app(Kernel::class);
            $response = $kernel->handle($request);
            $kernel->terminate($request, $response);

            return $response;
        } finally {
            config($before);
            app()->instance('request', $originalRequest);
        }
    }
}