<?php

namespace Modules\ChatGPT\Services;

use Illuminate\Http\Client\PendingRequest;
use Illuminate\Support\Facades\Http;
use Modules\ChatGPT\Exceptions\OpenAiFileException;

class OpenAiFileService
{
    private const BASE_URL = 'https://api.openai.com/v1';

    public function __construct(private readonly string $apiKey) {}

    /**
     * List all OpenAI API files visible to the configured API key.
     *
     * @return array<int, array<string, mixed>>
     */
    public function listFiles(): array
    {
        $files = [];
        $after = null;

        do {
            $query = ['limit' => 100];

            if (is_string($after) && $after !== '') {
                $query['after'] = $after;
            }

            $response = $this->client()
                ->get(self::BASE_URL . '/files', $query);

            if ($response->failed()) {
                throw new OpenAiFileException('OpenAI file list request failed: ' . $response->body());
            }

            $payload = $response->json();
            $batch = $payload['data'] ?? [];

            foreach ($batch as $file) {
                if (is_array($file)) {
                    $files[] = $file;
                }
            }

            $hasMore = (bool) ($payload['has_more'] ?? false);
            $after = $payload['last_id'] ?? null;
        } while ($hasMore && is_string($after) && $after !== '');

        return $files;
    }

    /**
     * Delete one OpenAI API file by ID.
     *
     * @return array<string, mixed>
     */
    public function deleteFile(string $fileId): array
    {
        $response = $this->client()
            ->delete(self::BASE_URL . '/files/' . rawurlencode($fileId));

        if ($response->failed()) {
            throw new OpenAiFileException("OpenAI file delete request failed for {$fileId}: " . $response->body());
        }

        return $response->json() ?? [];
    }

    /**
     * Delete every OpenAI API file visible to the configured API key.
     *
     * @return array{listed:int, deleted:int, failed:int, failures:array<int, array{file_id:string, error:string}>}
     */
    public function deleteAllFiles(): array
    {
        $files = $this->listFiles();
        $deleted = 0;
        $failures = [];

        foreach ($files as $file) {
            $fileId = (string) ($file['id'] ?? '');

            if ($fileId === '') {
                continue;
            }

            try {
                $this->deleteFile($fileId);
                $deleted++;
            } catch (OpenAiFileException $exception) {
                $failures[] = [
                    'file_id' => $fileId,
                    'error' => $exception->getMessage(),
                ];
            }
        }

        return [
            'listed' => count($files),
            'deleted' => $deleted,
            'failed' => count($failures),
            'failures' => $failures,
        ];
    }

    /**
     * Build the authenticated OpenAI HTTP client.
     */
    private function client(): PendingRequest
    {
        return Http::withToken($this->apiKey)
            ->acceptJson()
            ->timeout(60)
            ->retry(2, 500);
    }
}