import * as plugins from './taskbuffer.plugins.js';
import { BufferRunner } from './taskbuffer.classes.bufferrunner.js';
import { CycleCounter } from './taskbuffer.classes.cyclecounter.js';

import { logger } from './taskbuffer.logging.js';

export interface ITaskFunction<T = undefined> {
  (x?: any, setupValue?: T): PromiseLike<any>;
}

export interface ITaskSetupFunction<T = undefined> {
  (): Promise<T>;
}

export type TPreOrAfterTaskFunction = () => Task<any>;

export class Task<T = undefined> {
  public static extractTask<T = undefined>(
    preOrAfterTaskArg: Task<T> | TPreOrAfterTaskFunction
  ): Task<T> {
    switch (true) {
      case !preOrAfterTaskArg:
        return null;
      case preOrAfterTaskArg instanceof Task:
        return preOrAfterTaskArg as Task<T>;
      case typeof preOrAfterTaskArg === 'function':
        const taskFunction = preOrAfterTaskArg as TPreOrAfterTaskFunction;
        return taskFunction();
      default:
        return null;
    }
  }

  public static emptyTaskFunction: ITaskFunction = function (x) {
    const done = plugins.smartpromise.defer();
    done.resolve();
    return done.promise;
  };

  public static isTask = (taskArg: Task<any>): boolean => {
    if (taskArg instanceof Task && typeof taskArg.taskFunction === 'function') {
      return true;
    } else {
      return false;
    }
  };

  public static isTaskTouched<T = undefined>(
    taskArg: Task<T> | TPreOrAfterTaskFunction,
    touchedTasksArray: Task<T>[]
  ): boolean {
    const taskToCheck = Task.extractTask(taskArg);
    let result = false;
    for (const keyArg in touchedTasksArray) {
      if (taskToCheck === touchedTasksArray[keyArg]) {
        result = true;
      }
    }
    return result;
  }

  public static runTask = async <T>(
    taskArg: Task<T> | TPreOrAfterTaskFunction,
    optionsArg: { x?: any; touchedTasksArray?: Task<T>[] }
  ) => {
    const taskToRun = Task.extractTask(taskArg);
    const done = plugins.smartpromise.defer();

    // Wait for all blocking tasks to finish
    for (const task of taskToRun.blockingTasks) {
      await task.finished;
    }

    if (!taskToRun.setupValue && taskToRun.taskSetup) {
      taskToRun.setupValue = await taskToRun.taskSetup();
    }

    if (taskToRun.execDelay) {
      await plugins.smartdelay.delayFor(taskToRun.execDelay);
    }

    taskToRun.running = true;

    done.promise.then(async () => {
      taskToRun.running = false;

      // When the task has finished running, resolve the finished promise
      taskToRun.resolveFinished();

      // Create a new finished promise for the next run
      taskToRun.finished = new Promise((resolve) => {
        taskToRun.resolveFinished = resolve;
      });
    });

    const options = {
      ...{ x: undefined, touchedTasksArray: [] },
      ...optionsArg,
    };
    const x = options.x;
    const touchedTasksArray: Task<T>[] = options.touchedTasksArray;

    touchedTasksArray.push(taskToRun);

    const localDeferred = plugins.smartpromise.defer();
    localDeferred.promise
      .then(() => {
        if (taskToRun.preTask && !Task.isTaskTouched(taskToRun.preTask, touchedTasksArray)) {
          return Task.runTask(taskToRun.preTask, { x, touchedTasksArray });
        } else {
          const done2 = plugins.smartpromise.defer();
          done2.resolve(x);
          return done2.promise;
        }
      })
      .then(async (x) => {
        try {
          return await taskToRun.taskFunction(x, taskToRun.setupValue);
        } catch (e) {
          console.log(e);
        }
      })
      .then((x) => {
        if (taskToRun.afterTask && !Task.isTaskTouched(taskToRun.afterTask, touchedTasksArray)) {
          return Task.runTask(taskToRun.afterTask, { x: x, touchedTasksArray: touchedTasksArray });
        } else {
          const done2 = plugins.smartpromise.defer();
          done2.resolve(x);
          return done2.promise;
        }
      })
      .then((x) => {
        done.resolve(x);
      })
      .catch((err) => {
        console.log(err);
      });
    localDeferred.resolve();
    return await done.promise;
  };

  public name: string;
  public version: string;
  public taskFunction: ITaskFunction<T>;
  public buffered: boolean;
  public cronJob: plugins.smarttime.CronJob;

  public bufferMax: number;
  public execDelay: number;
  public timeout: number;

  public preTask: Task<T> | TPreOrAfterTaskFunction;
  public afterTask: Task<T> | TPreOrAfterTaskFunction;

  // Add a list to store the blocking tasks
  public blockingTasks: Task[] = [];

  // Add a promise that will resolve when the task has finished
  private finished: Promise<void>;
  private resolveFinished: () => void;

  public running: boolean = false;
  public bufferRunner = new BufferRunner(this);
  public cycleCounter = new CycleCounter(this);

  public get idle() {
    return !this.running;
  }

  public taskSetup: ITaskSetupFunction<T>;
  public setupValue: T;

  constructor(optionsArg: {
    taskFunction: ITaskFunction<T>;
    preTask?: Task<T> | TPreOrAfterTaskFunction;
    afterTask?: Task<T> | TPreOrAfterTaskFunction;
    buffered?: boolean;
    bufferMax?: number;
    execDelay?: number;
    name?: string;
    taskSetup?: ITaskSetupFunction<T>;
  }) {
    this.taskFunction = optionsArg.taskFunction;
    this.preTask = optionsArg.preTask;
    this.afterTask = optionsArg.afterTask;
    this.buffered = optionsArg.buffered;
    this.bufferMax = optionsArg.bufferMax;
    this.execDelay = optionsArg.execDelay;
    this.name = optionsArg.name;
    this.taskSetup = optionsArg.taskSetup;

    // Create the finished promise
    this.finished = new Promise((resolve) => {
      this.resolveFinished = resolve;
    });
  }

  public trigger(x?: any): Promise<any> {
    if (this.buffered) {
      return this.triggerBuffered(x);
    } else {
      return this.triggerUnBuffered(x);
    }
  }

  public triggerUnBuffered(x?: any): Promise<any> {
    return Task.runTask<T>(this, { x: x });
  }

  public triggerBuffered(x?: any): Promise<any> {
    return this.bufferRunner.trigger(x);
  }
}