import * as plugins from './taskbuffer.plugins.js';
import { BufferRunner } from './taskbuffer.classes.bufferrunner.js';
import { CycleCounter } from './taskbuffer.classes.cyclecounter.js';
import { TaskStep, type ITaskStep } from './taskbuffer.classes.taskstep.js';
import type { ITaskMetadata } from './taskbuffer.interfaces.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>;

// Type helper to extract step names from array
export type StepNames<T> = T extends ReadonlyArray<{ name: infer N }> ? N : never;

export class Task<T = undefined, TSteps extends ReadonlyArray<{ name: string; description: string; percentage: number }> = []> {
  public static extractTask<T = undefined, TSteps extends ReadonlyArray<{ name: string; description: string; percentage: number }> = []>(
    preOrAfterTaskArg: Task<T, TSteps> | TPreOrAfterTaskFunction,
  ): Task<T, TSteps> {
    switch (true) {
      case !preOrAfterTaskArg:
        return null;
      case preOrAfterTaskArg instanceof Task:
        return preOrAfterTaskArg as Task<T, TSteps>;
      case typeof preOrAfterTaskArg === 'function':
        const taskFunction = preOrAfterTaskArg as TPreOrAfterTaskFunction;
        return taskFunction() as unknown as Task<T, TSteps>;
      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, TSteps extends ReadonlyArray<{ name: string; description: string; percentage: number }> = []>(
    taskArg: Task<T, TSteps> | TPreOrAfterTaskFunction,
    touchedTasksArray: Task<T, TSteps>[],
  ): 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, TSteps extends ReadonlyArray<{ name: string; description: string; percentage: number }> = []>(
    taskArg: Task<T, TSteps> | TPreOrAfterTaskFunction,
    optionsArg: { x?: any; touchedTasksArray?: Task<T, TSteps>[] },
  ) => {
    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;
    taskToRun.runCount++;
    taskToRun.lastRun = new Date();
    
    // Reset steps at the beginning of task execution
    taskToRun.resetSteps();

    done.promise.then(async () => {
      taskToRun.running = false;
      
      // Complete all steps when task finishes
      taskToRun.completeAllSteps();

      // 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, TSteps>[] = 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, any> | TPreOrAfterTaskFunction;
  public afterTask: Task<T, any> | 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 lastRun?: Date;
  public runCount: number = 0;

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

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

  // Step tracking properties
  private steps = new Map<string, TaskStep>();
  private stepProgress = new Map<string, number>();
  public currentStepName?: string;
  private providedSteps?: TSteps;

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

    // Initialize steps if provided
    if (optionsArg.steps) {
      this.providedSteps = optionsArg.steps;
      for (const stepConfig of optionsArg.steps) {
        const step = new TaskStep({
          name: stepConfig.name,
          description: stepConfig.description,
          percentage: stepConfig.percentage,
        });
        this.steps.set(stepConfig.name, step);
      }
    }

    // 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, TSteps>(this, { x: x });
  }

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

  // Step notification method with typed step names
  public notifyStep(stepName: StepNames<TSteps>): void {
    // Complete previous step if exists
    if (this.currentStepName) {
      const prevStep = this.steps.get(this.currentStepName);
      if (prevStep && prevStep.status === 'active') {
        prevStep.complete();
        this.stepProgress.set(this.currentStepName, prevStep.percentage);
      }
    }

    // Start new step
    const step = this.steps.get(stepName as string);
    if (step) {
      step.start();
      this.currentStepName = stepName as string;
      
      // Emit event for frontend updates (could be enhanced with event emitter)
      if (this.name) {
        logger.log('info', `Task ${this.name}: Starting step "${stepName}" - ${step.description}`);
      }
    }
  }

  // Get current progress based on completed steps
  public getProgress(): number {
    let totalProgress = 0;
    for (const [stepName, percentage] of this.stepProgress) {
      totalProgress += percentage;
    }
    
    // Add partial progress of current step if exists
    if (this.currentStepName) {
      const currentStep = this.steps.get(this.currentStepName);
      if (currentStep && currentStep.status === 'active') {
        // Could add partial progress calculation here if needed
        // For now, we'll consider active steps as 50% complete
        totalProgress += currentStep.percentage * 0.5;
      }
    }
    
    return Math.min(100, Math.round(totalProgress));
  }

  // Get all steps metadata
  public getStepsMetadata(): ITaskStep[] {
    return Array.from(this.steps.values()).map(step => step.toJSON());
  }

  // Get task metadata
  public getMetadata(): ITaskMetadata {
    return {
      name: this.name || 'unnamed',
      version: this.version,
      status: this.running ? 'running' : 'idle',
      steps: this.getStepsMetadata(),
      currentStep: this.currentStepName,
      currentProgress: this.getProgress(),
      runCount: this.runCount,
      buffered: this.buffered,
      bufferMax: this.bufferMax,
      timeout: this.timeout,
      cronSchedule: this.cronJob?.cronExpression,
    };
  }

  // Reset all steps to pending state
  public resetSteps(): void {
    this.steps.forEach(step => step.reset());
    this.stepProgress.clear();
    this.currentStepName = undefined;
  }

  // Complete all remaining steps (useful for cleanup)
  private completeAllSteps(): void {
    if (this.currentStepName) {
      const currentStep = this.steps.get(this.currentStepName);
      if (currentStep && currentStep.status === 'active') {
        currentStep.complete();
        this.stepProgress.set(this.currentStepName, currentStep.percentage);
      }
    }
    
    // Mark any pending steps as completed (in case of early task completion)
    this.steps.forEach((step, name) => {
      if (step.status === 'pending') {
        // Don't add their percentage to progress since they weren't actually executed
        step.status = 'completed';
      }
    });
  }
}