// Producer-side helper for the toolctrl.file-preview BullMQ queue. Web routes
// call enqueueFilePreview(...) after a successful upload (and on the "regenerate
// preview" action) to trigger asynchronous preview generation in the worker.
// Mirrors fileScanQueue.server.ts so the queue lifecycle is the same shared
// pattern. Unlike the scan queue there is no enable-flag: preview generation is
// always desired; if Redis is unreachable the enqueue is a no-op and the file
// simply keeps previewStatus=pending until re-triggered.

import {
  buildFilePreviewJob,
  enqueueJob,
  queueNames,
  resolveRedisConnectionOptions,
  resolveRedisConnectionOptionsFromProcessEnv,
  type RedisConnectionEnv,
  type TypedQueue,
} from "@toolctrl/queue";

export type EnqueueFilePreviewInput = {
  fileId: string;
  tenantId: string;
  bucket: string;
  storageKey: string;
  mimeType: string;
  metadata?: Record<string, unknown>;
};

export type EnqueueFilePreviewResult = { enqueued: true; jobId?: string } | { enqueued: false; reason: "queue-unavailable" };

type Dependencies = {
  env?: RedisConnectionEnv;
  queue?: TypedQueue<typeof queueNames.filePreview>;
};

export async function enqueueFilePreview(input: EnqueueFilePreviewInput, dependencies: Dependencies = {}): Promise<EnqueueFilePreviewResult> {
  let queue = dependencies.queue;
  let shouldCloseQueue = false;
  const connection = queue
    ? undefined
    : dependencies.env
      ? resolveRedisConnectionOptions({ env: dependencies.env })
      : resolveRedisConnectionOptionsFromProcessEnv();

  if (!queue && !connection) {
    return { enqueued: false, reason: "queue-unavailable" };
  }

  if (!queue && connection) {
    const queueRuntimeModule = "@toolctrl/queue/runtime";
    const { createQueue } = (await import(/* @vite-ignore */ queueRuntimeModule)) as typeof import("@toolctrl/queue/runtime");
    queue = createQueue(queueNames.filePreview, { connection });
    shouldCloseQueue = true;
  }
  if (!queue) {
    return { enqueued: false, reason: "queue-unavailable" };
  }

  try {
    const descriptor = buildFilePreviewJob({
      fileId: input.fileId,
      tenantId: input.tenantId,
      bucket: input.bucket,
      storageKey: input.storageKey,
      mimeType: input.mimeType,
      metadata: input.metadata,
    });
    const job = await enqueueJob(queue, descriptor, { tenantId: input.tenantId });
    return { enqueued: true, jobId: typeof job.id === "string" ? job.id : undefined };
  } finally {
    if (shouldCloseQueue && queue) {
      await queue.close().catch(() => {});
    }
  }
}