import * as plugins from './taskbuffer.plugins.js';
import { Task } from './taskbuffer.classes.task.js';
import { AbstractDistributedCoordinator } from './taskbuffer.classes.distributedcoordinator.js';

export interface ICronJob {
  cronString: string;
  taskNameArg: string;
  job: any;
}

export interface ITaskManagerConstructorOptions {
  distributedCoordinator?: AbstractDistributedCoordinator;
}

export class TaskManager {
  public randomId = plugins.isounique.uni();
  public taskMap = new plugins.lik.ObjectMap<Task>();
  private cronJobManager = new plugins.smarttime.CronManager();

  public options: ITaskManagerConstructorOptions = {
    distributedCoordinator: null,
  };

  constructor(optionsArg: ITaskManagerConstructorOptions = {}) {
    this.options = Object.assign(this.options, optionsArg);
  }

  /**
   * checks if a task is already present
   * @param taskNameArg
   */
  public getTaskByName(taskNameArg: string): Task {
    return this.taskMap.findSync((itemArg) => {
      return itemArg.name === taskNameArg;
    });
  }

  /**
   * adds a Task to the TaskManager
   * @param taskArg
   */
  public addTask(taskArg: Task): void {
    if (!taskArg.name) {
      throw new Error('taskArg needs a name to be added to taskManager');
    }
    this.taskMap.add(taskArg);
  }

  /**
   * adds and schedules a task at once
   * @param taskArg
   * @param cronStringArg
   */
  public addAndScheduleTask(taskArg: Task, cronStringArg: string) {
    this.addTask(taskArg);
    this.scheduleTaskByName(taskArg.name, cronStringArg);
  }

  /**
   * triggers a task in the TaskManagerByName
   * @param taskNameArg
   */
  public triggerTaskByName(taskNameArg: string): Promise<any> {
    const taskToTrigger = this.getTaskByName(taskNameArg);
    if (!taskToTrigger) {
      throw new Error(`There is no task with the name of ${taskNameArg}`);
    }
    return taskToTrigger.trigger();
  }

  public async triggerTask(task: Task) {
    return task.trigger();
  }

  /**
   * schedules the task by name
   * @param taskNameArg
   */
  public scheduleTaskByName(taskNameArg: string, cronStringArg: string) {
    const taskToSchedule = this.getTaskByName(taskNameArg);
    const cronJob = this.cronJobManager.addCronjob(
      cronStringArg,
      async (triggerTimeArg: number) => {
        console.log(`taskbuffer schedule triggered task >>${taskToSchedule.name}<<`);
        console.log(
          `task >>${taskToSchedule.name}<< is ${
            taskToSchedule.buffered
              ? `buffered with max ${taskToSchedule.bufferMax} buffered calls`
              : `unbuffered`
          }`
        );
        if (this.options.distributedCoordinator) {
          console.log(`Found a distrubuted coordinator, performing distributed consultation.`);
          const announcementResult =
            await this.options.distributedCoordinator.fireDistributedTaskRequest({
              submitterRandomId: this.randomId,
              status: 'requesting',
              taskExecutionParallel: 1,
              taskExecutionTime: triggerTimeArg,
              taskExecutionTimeout: taskToSchedule.timeout,
              taskName: taskToSchedule.name,
              taskVersion: taskToSchedule.version,
            });

          if (!announcementResult.shouldTrigger) {
            console.log('distributed coordinator result: NOT EXECUTING');
            return;
          } else {
            console.log('distributed coordinator result: CHOSEN AND EXECUTING');
          }
        }
        await taskToSchedule.trigger();
      }
    );
    taskToSchedule.cronJob = cronJob;
  }

  /**
   * deschedules a task by name
   * @param taskNameArg
   */
  public descheduleTaskByName(taskNameArg: string) {
    const taskToDeSchedule = this.getTaskByName(taskNameArg);
    if (taskToDeSchedule.cronJob) {
      this.cronJobManager.removeCronjob(taskToDeSchedule.cronJob);
      taskToDeSchedule.cronJob = null;
    }
    if (this.cronJobManager.cronjobs.isEmpty) {
      this.cronJobManager.stop();
    }
  }

  /**
   * deschedules a task
   * @param task
   */
  public async descheduleTask(task: Task) {
    await this.descheduleTaskByName(task.name);
  }

  /**
 * returns the schedule of a specific task
 * @param taskNameArg
 */
public getScheduleForTaskName(taskNameArg: string): string | null {
  const task = this.getTaskByName(taskNameArg);
  if (!task || !task.cronJob) {
    return null;
  }
  return task.cronJob.cronExpression;
}


  /**
   * starts the taskmanager
   */
  public start() {
    this.cronJobManager.start();
  }

  /**
   * stops the taskmanager
   */
  public stop() {
    this.cronJobManager.stop();
  }
}