fal-js/apps/demo-nextjs-app-router/services/tuziApiQueueService.ts

import PQueue from "p-queue";
import { v4 as uuidv4 } from "uuid"; // Make sure to install this package

// Configure the queue with a concurrency limit
const scriptQueue = new PQueue({ concurrency: 2 });

// Cleanup interval (1 hours in ms)
const CLEANUP_INTERVAL = 1 * 60 * 60 * 1000;
const RESULT_EXPIRY = 3 * 60 * 60 * 1000;
// API authentication settings
const API_AUTH_SETTINGS: [RegExp, string][] = [
  [/(\.|^)tu-zi\.com$/, `Bearer ${process.env.TUZI_API_KEY}`],
];

export type ApiParams = {
  apiTarget: string;
  postBody: string;
  headers?: Map<string, string>;
};

export type ApiResult = {
  taskId: string;
  success: boolean;
  response: string;
  error?: string;
};

export type ApiQueueState = {
  status: "pending" | "running" | "completed" | "failed";
  result?: ApiResult;
  timestamp: number;
};

// Store execution results by token
const apiExecResults = new Map<string, ApiQueueState>();
/**
 * Clean up expired execution results
 */
function cleanupExpiredResults() {
  const now = Date.now();
  for (const [token, data] of apiExecResults.entries()) {
    if (now - data.timestamp > RESULT_EXPIRY) {
      apiExecResults.delete(token);
    }
  }
}

// Set up periodic cleanup
setInterval(cleanupExpiredResults, CLEANUP_INTERVAL);

export function queueApiRequest(params: ApiParams): string {
  const token = uuidv4();

  // Initialize result as pending with current timestamp
  apiExecResults.set(token, {
    status: "pending",
    timestamp: Date.now(),
  });

  // Add the API request to the queue
  scriptQueue.add(async () => {
    try {
      // Update status to running
      apiExecResults.set(token, {
        status: "running",
        timestamp: Date.now(),
      });

      // Prepare headers with authentication
      const headers = new Headers();

      // Add authentication based on URL pattern
      var allowdHost = false;
      const targetURL = new URL(params.apiTarget);
      // Iterate over the API_AUTH_SETTINGS array
      for (const [pattern, authValue] of API_AUTH_SETTINGS) {
        if (pattern.test(targetURL.hostname)) {
          headers.set("Authorization", authValue);
          allowdHost = true;
          break; // Stop checking once a match is found
        }
      }

      // If no matching pattern found, throw an error
      if (!allowdHost) {
        throw new Error(
          `No matching authentication pattern for ${targetURL.hostname}`,
        );
      }

      if (params.headers) {
        for (const [key, value] of params.headers.entries()) {
          headers.set(key, value);
        }
      }

      // Set content type if not already set
      if (!headers.has("Content-Type")) {
        headers.set("Content-Type", "application/json");
      }

      // Execute the fetch request
      const response = await fetch(params.apiTarget, {
        method: "POST",
        headers: headers,
        body: params.postBody,
      });

      // Check if response is OK
      if (!response.ok) {
        throw new Error(`API request failed with status ${response.status}`);
      }

      // Get the response text
      const responseText = await response.text();

      // Store successful result
      apiExecResults.set(token, {
        status: "completed",
        result: {
          taskId: token,
          success: true,
          response: responseText,
        },
        timestamp: Date.now(),
      });
    } catch (error: any) {
      // Handle API execution errors
      apiExecResults.set(token, {
        status: "failed",
        result: {
          taskId: token,
          success: false,
          response: "",
          error: error.message || "Failed to execute API request",
        },
        timestamp: Date.now(),
      });
    }
  });

  return token;
}

/**
 * Query the status and result of a script execution
 * @param token The token returned by executeScript
 * @returns An object containing execution status and result (if available)
 */
export function getApiCallState(token: string): ApiQueueState {
  const execution = apiExecResults.get(token);

  if (!execution) {
    return {
      status: "failed",
      result: {
        taskId: token,
        success: false,
        response: "",
        error: "Invalid execution token or result expired",
      },
      timestamp: Date.now(),
    };
  }

  return {
    status: execution.status,
    result: execution.result,
    timestamp: Date.now(),
  };
}

// Get current queue size and pending tasks
export function getQueueStats() {
  return {
    size: scriptQueue.size,
    pending: scriptQueue.pending,
    isPaused: scriptQueue.isPaused,
    activeExecutions: apiExecResults.size,
  };
}

// Pause the queue (no further tasks will be executed until resumed)
export function pauseQueue() {
  scriptQueue.pause();
}

// Resume the queue
export function resumeQueue() {
  scriptQueue.start();
}