Function start

api/src/services/generateReport.ts:548–684

(controller)

  // Set up Server-Sent Events response
  const stream = new ReadableStream({
    start(controller) {
      // Helper function to send SSE events
      const sendEvent = (eventType: string, data: any) => {
        controller.enqueue(
          `event: ${eventType}\ndata: ${JSON.stringify(data)}\n\n`
        );
      };

      // Self-invoking async function to handle the report generation process
      (async () => {
        try {
          sendEvent("status", { message: "Checking for cached report..." });

          // If force_regen is true, delete any existing report
          if (forceRegen) {
            try {
              await redisClient.del(`report:${reportKey}`);
              sendEvent("status", {
                message: "Forced regeneration, cleared cache.",
              });
            } catch (err) {
              console.error("Error deleting cached report:", err);
              sendEvent("generate_error", {
                message: "服务器出现错误，请稍后再试。",
              });
            }
          }

          // Check if we already have a report for this data
          const existingReport = await getReport(reportKey);
          if (existingReport && !forceRegen) {
            console.log("Returning cached report");
            sendEvent("complete", { message: existingReport });
            controller.close();
            return;
          }

          // Check if a report is already being generated for this data
          if (await isReportGenerationPending(reportKey)) {
            sendEvent("generate_error", {
              message: "报告正在生成中，请等待上次生成结束后再试。",
            });
            controller.close();
            return;
          }

          // Mark this report as pending
          await setReportGenerationPending(reportKey);

          // Get the prompt from presets
          const initialPrompt = presets[presetKey].prompt;
          if (!initialPrompt) {
            await clearReportGenerationPending(reportKey);
            sendEvent("generate_error", {
              message: `Preset '${presetKey}' not found.`,
            });
            controller.close();
            return;