import fs from "node:fs";
import path from "node:path";
import { spawn } from "node:child_process";
import { sendStream, setHeader } from "h3";
import { getExportTaskForUser, markExportTaskExpired } from "#server/service/export/jobs";

export default defineWrappedResponseHandler(async (event) => {
  const user = await event.context.auth.requireUser();
  const idRaw = getRouterParam(event, "id");
  const taskId = Number(idRaw);
  if (!Number.isInteger(taskId) || taskId < 1) {
    throw createError({ statusCode: 400, statusMessage: "无效的任务 id" });
  }

  const task = await getExportTaskForUser(taskId, user.id);
  if (!task) {
    throw createError({ statusCode: 404, statusMessage: "导出任务不存在" });
  }
  if (task.status !== "succeeded") {
    throw createError({ statusCode: 409, statusMessage: "导出任务尚未完成" });
  }
  if (!task.expiresAt || task.expiresAt.getTime() <= Date.now()) {
    await markExportTaskExpired(task.id, "导出结果已过期，请重新导出");
    throw createError({ statusCode: 410, statusMessage: "导出结果已过期" });
  }
  if (!task.outputDir || !task.outputName) {
    await markExportTaskExpired(task.id, "导出结果缺失，请重新导出");
    throw createError({ statusCode: 410, statusMessage: "导出文件已丢失，请重新导出" });
  }

  const manifestPath = path.resolve(task.outputDir, "manifest.json");
  if (!fs.existsSync(manifestPath)) {
    await markExportTaskExpired(task.id, "导出文件已丢失，请重新导出");
    throw createError({ statusCode: 410, statusMessage: "导出文件已丢失，请重新导出" });
  }

  const archiveName = `${task.outputName}.tar.gz`;
  const tarProc = spawn("tar", ["-czf", "-", "-C", task.outputDir, "."], {
    stdio: ["ignore", "pipe", "pipe"],
  });
  tarProc.on("exit", async (code) => {
    if (code === 0) {
      return;
    }
    await markExportTaskExpired(task.id, "导出文件打包失败，请重新导出");
  });

  setHeader(event, "Content-Type", "application/gzip");
  setHeader(event, "Content-Disposition", `attachment; filename="${archiveName}"`);
  return sendStream(event, tarProc.stdout);
});