// task.js
// Copyright (C) 2024 DTP Technologies, LLC
// All Rights Reserved

'use strict';

import mongoose from 'mongoose';
const Task = mongoose.model('Task');
const TaskSession = mongoose.model('TaskSession');

import dayjs from 'dayjs';

import { SiteService, SiteError } from '../../lib/site-lib.js';

export default class TaskService extends SiteService {

  static get name ( ) { return 'TaskService'; }
  static get slug () { return 'task'; }

  constructor (dtp) {
    super(dtp, TaskService);
  }

  async start ( ) {
    const { client: clientService, user: userService } = this.dtp.services;

    // const { jobQueue: jobQueueService } = this.dtp.services;
    // this.linksQueue = jobQueueService.getJobQueue('links', this.dtp.config.jobQueues.links);

    this.populateTask = [
      {
        path: 'user',
        select: userService.USER_SELECT,
      },
      {
        path: 'client',
        populate: clientService.populateClient,
      },
      {
        path: 'project',
        populate: clientService.populateClientProject,
      },
    ];

    this.populateTaskSession = [
      {
        path: 'user',
        select: userService.USER_SELECT,
      },
      {
        path: 'client',
        populate: clientService.populateClient,
      },
      {
        path: 'project',
        populate: clientService.populateClientProject,
      },
      {
        path: 'task',
        populate: this.populateTask,
      },
      {
        path: 'screenshots.image',
      }
    ];
  }

  async createTask (user, taskDefinition) {
    const { text: textService } = this.dtp.services;
    const NOW = new Date();

    const task = new Task();
    task.created = NOW;
    task.user = user._id;
    task.client = mongoose.Types.ObjectId.createFromHexString(taskDefinition.clientId);
    task.project = mongoose.Types.ObjectId.createFromHexString(taskDefinition.projectId);
    task.status = 'pending';
    task.note = textService.filter(taskDefinition.note);

    await task.save();

    return task.toObject();
  }

  async startTask (task) {
    if (task.status !== 'pending') {
      throw new SiteError(400, 'The task is not in the pending state');
    }
    await Task.updateOne(
      { _id: task._id },
      { $set: { status: 'active' } },
    );
  }

  async closeTask (task) {
    await TaskSession
      .find({ task: task._id, status: 'active' })
      .cursor()
      .eachAsync(async (session) => {
        await this.closeTaskSession(session);
      });
    
    await Task.updateOne(
      { _id: task._id },
      { $set: { status: 'finished' } },
    );
  }

  async getTasksForUser (user, options, pagination) {
    const search = { user: user._id };

    options = options || { };
    if (options.pending) {
      search.status = 'pending';
    } else if (options.active) {
      search.status = 'active';
    } else if (options.finished) {
      search.status = 'finished';
    }

    const tasks = await Task
      .find(search)
      .sort({ created: -1 })
      .skip(pagination.skip)
      .limit(pagination.cpp)
      .populate(this.populateTask)
      .lean();

    return tasks.reverse();
  }

  async getTasksForProject (project, options, pagination) {
    const search = { project: project._id };

    options = options || { };
    if (options.pending) {
      search.status = 'pending';
    } else if (options.active) {
      search.status = 'active';
    } else if (options.finished) {
      search.status = 'finished';
    }

    const tasks = await Task
      .find(search)
      .sort({ created: -1 })
      .skip(pagination.skip)
      .limit(pagination.cpp)
      .populate(this.populateTask)
      .lean();

    return tasks.reverse();
  }

  async getTaskGridForUser (user) {
    const pagination = { skip: 0, cpp: 10 };
    const pendingTasks = await this.getTasksForUser(user, { pending: true }, pagination);
    const activeTasks = await this.getTasksForUser(user, { active: true }, pagination);
    const finishedTasks = await this.getTasksForUser(user, { finished: true }, pagination);
    return { pendingTasks, activeTasks, finishedTasks };
  }

  async getTaskGridForProject (project) {
    const pagination = { skip: 0, cpp: 10 };
    const pendingTasks = await this.getTasksForProject(project, { pending: true }, pagination);
    const activeTasks = await this.getTasksForProject(project, { active: true }, pagination);
    const finishedTasks = await this.getTasksForProject(project, { finished: true }, pagination);
    return { pendingTasks, activeTasks, finishedTasks };
  }

  async getTaskById (taskId) {
    const task = await Task
      .findOne({ _id: taskId })
      .populate(this.populateTask)
      .lean();
    return task;
  }

  async createTaskSession (task) {
    const NOW = new Date();

    if (await TaskSession.findOne({ user: task.user._id, status: 'active' })) {
      throw new SiteError(401, "Can't start new session with a currently active session.");
    }

    const session = new TaskSession();
    session.created = NOW;
    session.lastUpdated = NOW;
    session.hourlyRate = task.project.hourlyRate;
    session.user = task.user._id;
    session.client = task.client._id;
    session.project = task.project._id;
    session.task = task._id;
    session.status = 'active';

    await session.save();

    this.log.info('task session created', {
      user: {
        _id: task.user._id,
        username: task.user.username,
      },
    });

    return session.toObject();
  }

  async addTaskSessionScreenshot (session, file) {
    const NOW = new Date();
    const { image: imageService } = this.dtp.services;
    const image = await imageService.create(session.user._id, { }, file);
    await TaskSession.updateOne(
      { _id: session._id },
      {
        $push: {
          screenshots: {
            created: NOW,
            image: image._id,
          },
        },
      },
    );
  }

  async closeTaskSession (session) {
    const NOW = new Date();

    if (session.status !== 'active') {
      throw new SiteError(400, 'The session is not currently active');
    }

    const duration = dayjs(NOW).diff(session.created, 'second');
    await TaskSession.updateOne(
      { _id: session._id },
      {
        $set: {
          finished: NOW,
          status: 'finished',
          duration,
        },
      },
    );

    await Task.updateOne(
      { _id: session.task._id },
      {
        $inc: { duration },
      },
    );

    this.log.info('task session closed', {
      user: {
        _id: session.user._id,
        username: session.user.username,
      },
      duration,
    });
  }

  async getSessionsForTask (task, pagination) {
    const sessions = TaskSession
      .find({ task: task._id })
      .sort({ created: 1 })
      .skip(pagination.skip)
      .limit(pagination.cpp)
      .populate(this.populateTaskSession)
      .lean();
    return sessions;
  }

  async getTaskSessionById (sessionId) {
    const session = await TaskSession
      .findOne({ _id: sessionId })
      .populate(this.populateTaskSession)
      .lean();
    return session;
  }

  async closeTaskSessionForUser (user) {
    await TaskSession
      .find({ user: user._id, status: 'active' })
      .populate(this.populateTaskSession)
      .cursor()
      .eachAsync(async (session) => {
        await this.closeTaskSession(session);
      });
  }
}