import ProjectTaskModel from './project-task-model.js';
import ProjectNodeModel from './project-node-model.js';

import '../references/extensions.dist.js';


class Project {
  constructor(options) {
    const a = this;
    const _options = Object.assign(a.DefaultOptions, options);

    a.Debug = false;
    a.Project = _options;
    a.Tasks = [];
  }


  get StartDate() {
    const a = this;

    return new Date(a.Project.StartDate);
  }

  get FinishDate() {
    const a = this;

    let result = new Date(a.Project.StartDate);

    a.ExportTasks().forEach(e => {
      if (e.FinishDate == null) {
        return;
      }

      result = Date.max(result, e.FinishDate);
    });

    return result;
  }

  get Duration() {
    const a = this;

    return Date.diffDays(a.StartDate, a.FinishDate);
  }

  get DefaultOptions() {
    return {
      Name: "",
      Description: "",
      StartDate: Date.today(),
      Tag: null,
      StartOfWeek: 1,   // Monday
      WorkHours: [0, 7.5, 7.5, 7.5, 7.5, 7.5, 0]    // 0 = Sunday
    };
  }


  AddTask(task) {
    const a = this;
    const newTask = new ProjectTaskModel(task);
    const newTaskNode = new ProjectNodeModel(newTask);

    if ((newTaskNode.PredecessorTaskID == null) && (newTaskNode.CollatedTaskID == null)) {
      a.Tasks.push(newTaskNode);
    } else if (newTaskNode.PredecessorTaskID != null) {
      let node = a.FindTask(newTaskNode.PredecessorTaskID);

      if (node != null) {
        node.Tasks.push(newTaskNode);
      } else {
        a.#log("Task not found (" + newTaskNode.PredecessorTaskID + ")");
      }
    } else if (newTaskNode.CollatedTaskID != null) {
      let node = a.FindTask(newTaskNode.CollatedTaskID);

      if (node != null) {
        node.Tasks.push(newTaskNode);
      } else {
        a.#log("Task not found (" + newTaskNode.CollatedTaskID + ")");
      }
    } else {
      a.#log("Task not found (" + newTaskNode.ID + ")");
    }
  }

  Clear() {
    const a = this;

    a.Tasks = [];
  }

  ExportTasks() {
    const a = this;

    let result = a.Tasks.copy().flatten("Tasks");
    for (var i=0; i<result.length; i++) {
      result[i].Order = (i + 1);

      delete result[i].Tasks;
    }

    return result;
  }

  FindTask(id) {
    const a = this;

    let result = null;

    a.Tasks.forEachTree("Tasks", function(e) {
      if (e.ID == id) {
        result = e;

        return false;
      }

      return true;
    });

    return result;
  }

  /**
   * Get node type.
   * @returns {int} enum
   *
   * 0 = orphan
   * 1 = task no-parent/root
   * 2 = task no-parent/root, collated/group
   * 3 = task with parent
   * 4 = task with parent, collated/group
   * 5 = sub-task
   * 6 = sub-task, collated/group
   *
   */
  GetNodeType(node) {
    if (node == null) {
      // 0 = orphan
      return 0;
    }

    if ((node.PredecessorTaskID == null) && (node.CollatedTaskID == null) && (node.IsCollated == false)) {
      // 1 = task no-parent/root
      return 1;
    }

    if ((node.PredecessorTaskID == null) && (node.CollatedTaskID == null) && (node.IsCollated == true)) {
      // 2 = task no-parent/root, collated/group
      return 2;
    }

    if ((node.PredecessorTaskID != null) && (node.CollatedTaskID == null) && (node.IsCollated == false)) {
      // 3 = task with parent
      return 3;
    }

    if ((node.PredecessorTaskID != null) && (node.CollatedTaskID == null) && (node.IsCollated == true)) {
      // 4 = task with parent, collated/group
      return 4;
    }

    if ((node.CollatedTaskID != null) && (node.IsCollated == false)) {
      // 5 = sub-task
      return 5;
    }

    if ((node.CollatedTaskID != null) && (node.IsCollated == true)) {
      // 6 = sub-task, collated/group
      return 6;
    }

    return 0;
  }

  Invalidate() {
    const a = this;
    let isSuccess = false;

    if (!a.Recalculate()) {
      isSuccess = false;
    }

    return isSuccess;
  }

  Recalculate() {
    const a = this;
    let isSuccess = false;

    a.Sort();

    // Get flat references
    let allTasks = a.Tasks.flatten("Tasks");

    // Reset calculated values
    for (var i=0; i<allTasks.length; i++) {
      allTasks[i].Order = (i + 1);
      allTasks[i].StartDate = null;
      allTasks[i].FinishDate = null;
      allTasks[i].CalcWorkHours = null;
    }

    for (var x=0; x<16; x++) {
      let pendingCount = allTasks.countMany(
        { propName: "StartDate", value: null },
        { propName: "FinishDate", value: null }
      );

      // Done
      if (pendingCount <= 0) {
        isSuccess = true;
        break;
      }

      a.#log("Round " + (x + 1));

      a.#recalculateTask(allTasks, a.Tasks);
    }

    // Calculate work-hours
    a.#recalculateWorkHours(allTasks);

    return isSuccess;
  }

  Sort() {
    const a = this;

    a.#sortNode(a);
  }

  #log(message) {
    const a = this;

    if (a.Debug) {
      console.log(message);
    }
  }

  #recalculateWorkHours(array) {
    const a = this;

    for (var i=0; i<array.length; i++) {
      if (array[i].StartDate == null) {
        continue;
      }

      if (array[i].FinishDate == null) {
        continue;
      }

      if (array[i].Duration <= 0) {
        continue;
      }

      let workHours = 0;
      let date = new Date(array[i].StartDate);
      for (let x=0; x<array[i].Duration; x++) {
        const d = date.getDay();

        workHours += a.Project.WorkHours[d];
      }

      array[i].CalcWorkHours = workHours;
    }
  }

  #recalculateTask(allTasks, tasks) {
    const a = this;

    for (let i=0; i<tasks.length; i++) {
      const task = tasks[i];

      a.#log(task.Name);

      if (task.PredecessorTaskID != null) {
        const parentTask = allTasks.first("ID", task.PredecessorTaskID);
        if (parentTask != null) {
          if (parentTask.FinishDate != null) {
            task.StartDate = Date.addDays(parentTask.FinishDate, task.StartDelay);

            a.#log("> Set StartDate from Predecessor");
          }
        }
      } else if (task.CollatedTaskID != null) {
          const groupTask = allTasks.first("ID", task.CollatedTaskID);
          if (groupTask != null) {
            if (groupTask.StartDate != null) {
              task.StartDate = Date.addDays(groupTask.StartDate, task.StartDelay);

              a.#log("> Set StartDate from Group");
            }
          }
      } else {
        task.StartDate = Date.addDays(a.Project.StartDate, task.StartDelay);

        a.#log("> Set StartDate from Project");
      }

      // if (task.IsCollated) {
      if (task.Tasks.length > 0) {
        a.#recalculateTask(allTasks, task.Tasks);

        a.#log("> Calc inner");
      }
      // }

      if (task.StartDate != null) {
        if (task.IsCollated) {

          const childTasks = task.Tasks.select("CollatedTaskID", task.ID);
          if (childTasks.length <= 0) {
            task.FinishDate = task.StartDate;
            task.Duration = 0;

            a.#log("> Set FinishDate from Group (0)");
          } else {

            if (!childTasks.any("FinishDate", null)) {
              task.FinishDate = childTasks.orderByDesc("FinishDate")[0].FinishDate;
              task.Duration = Date.diffDays(task.StartDate, task.FinishDate);

              a.#log("> Set FinishDate from Group");
            }
          }

        } else {
          task.FinishDate = Date.addDays(task.StartDate, task.Duration);

          a.#log("> Set FinishDate");
        }
      }

    }
  }

  #sortNode(node) {
    const a = this;

    if (Array.isEmpty(node.Tasks)) {
      return;
    }

    node.Tasks.orderBy("StartDelay");

    const childDependentTasks = node.Tasks.notSelect("PredecessorTaskID", null);
    if (childDependentTasks.length > 0) {
      node.Tasks.removeRange(childDependentTasks);
      node.Tasks.addRange(childDependentTasks);
    }

    node.Tasks.forEach(e => {
      a.#sortNode(e);
    });
  }

}


export default Project;