import { minioClient, MINIO_BUCKET } from "@/lib/minio";

const UPLOAD_PATH_PREFIX = "/api/uploads/";

function uploadKeyFromUrl(url: string): string | null {
  if (!url.startsWith(UPLOAD_PATH_PREFIX)) return null;
  const key = url.slice(UPLOAD_PATH_PREFIX.length);
  if (!key || key.includes("..")) return null;
  return key;
}

export async function resolveAssistantImageDataUrl(url: string): Promise<string> {
  const key = uploadKeyFromUrl(url);
  if (!key) {
    throw new Error("Unsupported image URL");
  }

  const stream = await minioClient.getObject(MINIO_BUCKET, key);
  const chunks: Buffer[] = [];
  for await (const chunk of stream) {
    chunks.push(Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk as Uint8Array));
  }
  const buffer = Buffer.concat(chunks);

  const stat = await minioClient.statObject(MINIO_BUCKET, key);
  const metaData = stat.metaData as Record<string, string> | undefined;
  const contentType =
    metaData?.["content-type"] ?? metaData?.["Content-Type"] ?? "application/octet-stream";

  return `data:${contentType};base64,${buffer.toString("base64")}`;
}

export async function resolveAssistantImageDataUrls(urls: string[]): Promise<string[]> {
  return Promise.all(urls.map((url) => resolveAssistantImageDataUrl(url)));
}