import type { TranscriptionTask } from "@prisma/client";
import { prepareAudio } from "./audio";
import {
  AsrError,
  downloadTranscript,
  getAsrConfig,
  queryTranscription,
  submitTranscription,
} from "./dashscope";
import { claimTask, completeTask, updateOwnedTask } from "./tasks";

export const defaultServices = {
  prepareAudio,
  submitTranscription,
  queryTranscription,
  downloadTranscript,
};
export async function processTask(
  task: TranscriptionTask,
  services = defaultServices,
) {
  let submitting = false;
  const heartbeat = setInterval(() => {
    void updateOwnedTask(task, {
      leaseUntil: new Date(Date.now() + 180_000),
    }).catch(() => {});
  }, 30_000);
  try {
    getAsrConfig();
    if (!task.providerTaskId) {
      if (task.submittingAt)
        throw new AsrError(
          "上次提交结果不确定，请核对百炼任务后手动重试，避免重复计费",
        );
      const url = await services.prepareAudio(task.videoId);
      if (url === null) {
        await completeTask(task, []);
        return;
      }
      await updateOwnedTask(task, { submittingAt: new Date() });
      submitting = true;
      const providerTaskId = await services.submitTranscription(url);
      await updateOwnedTask(task, {
        providerTaskId,
        submittedAt: new Date(),
        nextPollAt: new Date(Date.now() + 10_000),
        leaseToken: null,
        leaseUntil: null,
        lastError: null,
      });
      return;
    }
    // Provider result URLs expire after 24 hours; do not poll forever.
    if (
      task.submittedAt &&
      Date.now() - task.submittedAt.getTime() > 24 * 60 * 60 * 1000
    ) {
      throw new AsrError("ASR 任务超过 24 小时，请手动重试");
    }
    const result = await services.queryTranscription(task.providerTaskId);
    if (result.status === "SUCCEEDED") {
      const transcript = await services.downloadTranscript(result.resultURL);
      await completeTask(task, transcript);
    } else {
      await updateOwnedTask(task, {
        nextPollAt: new Date(Date.now() + 10_000),
        leaseToken: null,
        leaseUntil: null,
        lastError: null,
        attempts: 0,
      });
    }
  } catch (error) {
    // Unknown exceptions (e.g. database outage) leave the lease and submitting marker
    // intact. Recovery can query a saved ID, but must never blindly submit again.
    if (!(error instanceof AsrError)) throw error;
    const retry = !submitting && !!task.providerTaskId && error.retryable;
    await updateOwnedTask(task, {
      status: retry ? "PROCESSING" : "FAILED",
      lastError:
        submitting && !error.definitiveRejection
          ? `${error.message}；提交结果不确定，请核对百炼任务后手动重试`
          : error.message,
      attempts: { increment: 1 },
      leaseToken: null,
      leaseUntil: null,
      nextPollAt: new Date(
        Date.now() +
          Math.min(300_000, 10_000 * 2 ** Math.min(task.attempts, 5)),
      ),
    });
    console.warn(`[ASR] ${task.videoId}: ${retry ? "等待重试" : "失败"}`);
  } finally {
    clearInterval(heartbeat);
  }
}
export async function workerTick(services = defaultServices) {
  const tasks: TranscriptionTask[] = [];
  for (let i = 0; i < 2; i++) {
    const task = await claimTask();
    if (task) tasks.push(task);
  }
  await Promise.all(
    tasks.map(async (task) => {
      try {
        await processTask(task, services);
      } catch {
        console.error(`[ASR] ${task.videoId}: 执行中断，租约到期后恢复`);
      }
    }),
  );
}