import date_utils from "./date_utils";
import { $, createSVG } from "./svg_utils";
import Bar from "./bar";
import Arrow from "./arrow";
import Popup from "./popup";

import "./gantt.scss";

const VIEW_MODE = {
  HOUR: "Hour",
  QUARTER_DAY: "Quarter Day",
  HALF_DAY: "Half Day",
  DAY: "Day",
  WEEK: "Week",
  MONTH: "Month",
  YEAR: "Year",
};

const VIEW_MODE_PADDING = {
  HOUR: ["7d", "7d"],
  QUARTER_DAY: ["7d", "7d"],
  HALF_DAY: ["7d", "7d"],
  DAY: ["1m", "1m"],
  WEEK: ["1m", "1m"],
  MONTH: ["1m", "1m"],
  YEAR: ["2y", "2y"],
};

export default class Gantt {
  constructor(wrapper, tasks, options) {
    this.setup_wrapper(wrapper);
    this.setup_options(options);
    this.setup_tasks(tasks);
    // initialize with default view mode
    this.change_view_mode();
    this.bind_events();
  }

  setup_wrapper(element) {
    let svg_element, wrapper_element;

    // CSS Selector is passed
    if (typeof element === "string") {
      element = document.querySelector(element);
    }

    // get the SVGElement
    if (element instanceof HTMLElement) {
      wrapper_element = element;
      svg_element = element.querySelector("svg");
    } else if (element instanceof SVGElement) {
      svg_element = element;
    } else {
      throw new TypeError(
        "Frappé Gantt only supports usage of a string CSS selector," +
        " HTML DOM element or SVG DOM element for the 'element' parameter",
      );
    }

    // svg element
    if (!svg_element) {
      // create it
      this.$svg = createSVG("svg", {
        append_to: wrapper_element,
        class: "gantt",
      });
    } else {
      this.$svg = svg_element;
      this.$svg.classList.add("gantt");
    }

    // wrapper element
    this.$container = document.createElement("div");
    this.$container.classList.add("gantt-container");

    const parent_element = this.$svg.parentElement;
    parent_element.appendChild(this.$container);
    this.$container.appendChild(this.$svg);

    // popup wrapper
    this.popup_wrapper = document.createElement("div");
    this.popup_wrapper.classList.add("popup-wrapper");
    this.$container.appendChild(this.popup_wrapper);
  }

  setup_options(options) {
    const default_options = {
      header_height: 50,
      column_width: 30,
      step: 24,
      view_modes: [...Object.values(VIEW_MODE)],
      bar_height: 30,
      bar_corner_radius: 3,
      arrow_curve: 5,
      padding: 18,
      view_mode: "Day",
      date_format: "YYYY-MM-DD",
      popup_trigger: "click",
      custom_popup_html: null,
      language: "en",
      readonly: false,
      highlight_weekend: true,
      scroll_today: true
    };
    this.options = Object.assign({}, default_options, options);
    if (!options.view_mode_padding) options.view_mode_padding = {}
    for (let [key, value] of Object.entries(options.view_mode_padding)) {
      if (typeof value === "string") {
        // Configure for single value given
        options.view_mode_padding[key] = [value, value];
      }
    }

    this.options.view_mode_padding = {
      ...VIEW_MODE_PADDING,
      ...options.view_mode_padding,
    };
  }

  setup_tasks(tasks) {
    // prepare tasks
    this.tasks = tasks.map((task, i) => {
      // convert to Date objects
      task._start = date_utils.parse(task.start);
      if (task.end === undefined && task.duration !== undefined) {
        task.end = task._start;
        let durations = task.duration.split(" ");

        durations.forEach((tmpDuration) => {
          let { duration, scale } = date_utils.parse_duration(tmpDuration);
          task.end = date_utils.add(task.end, duration, scale);
        });
      }
      task._end = date_utils.parse(task.end);

      // make task invalid if duration too large
      if (date_utils.diff(task._end, task._start, "year") > 10) {
        task.end = null;
      }

      // cache index
      task._index = i;

      // invalid dates
      if (!task.start && !task.end) {
        const today = date_utils.today();
        task._start = today;
        task._end = date_utils.add(today, 2, "day");
      }

      if (!task.start && task.end) {
        task._start = date_utils.add(task._end, -2, "day");
      }

      if (task.start && !task.end) {
        task._end = date_utils.add(task._start, 2, "day");
      }

      // if hours is not set, assume the last day is full day
      // e.g: 2018-09-09 becomes 2018-09-09 23:59:59
      const task_end_values = date_utils.get_date_values(task._end);
      if (task_end_values.slice(3).every((d) => d === 0)) {
        task._end = date_utils.add(task._end, 24, "hour");
      }

      // invalid flag
      if (!task.start || !task.end) {
        task.invalid = true;
      }

      // dependencies
      if (typeof task.dependencies === "string" || !task.dependencies) {
        let deps = [];
        if (task.dependencies) {
          deps = task.dependencies
            .split(",")
            .map((d) => d.trim().replaceAll(' ', '_'))
            .filter((d) => d);
        }
        task.dependencies = deps;
      }

      // uids
      if (!task.id) {
        task.id = generate_id(task);
      } else if (typeof task.id === 'string') {
        task.id = task.id.replaceAll(' ', '_')
      } else {
        task.id = `${task.id}`
      }

      return task;
    });

    this.setup_dependencies();
  }

  setup_dependencies() {
    this.dependency_map = {};
    for (let t of this.tasks) {
      for (let d of t.dependencies) {
        this.dependency_map[d] = this.dependency_map[d] || [];
        this.dependency_map[d].push(t.id);
      }
    }
  }

  refresh(tasks) {
    this.setup_tasks(tasks);
    this.change_view_mode();
  }

  change_view_mode(mode = this.options.view_mode) {
    this.update_view_scale(mode);
    this.setup_dates();
    this.render();
    // fire viewmode_change event
    this.trigger_event("view_change", [mode]);
  }

  update_view_scale(view_mode) {
    this.options.view_mode = view_mode;
    if (view_mode === VIEW_MODE.HOUR) {
      this.options.step = 24 / 24;
      this.options.column_width = 38;
    } else if (view_mode === VIEW_MODE.DAY) {
      this.options.step = 24;
      this.options.column_width = 38;
    } else if (view_mode === VIEW_MODE.HALF_DAY) {
      this.options.step = 24 / 2;
      this.options.column_width = 38;
    } else if (view_mode === VIEW_MODE.QUARTER_DAY) {
      this.options.step = 24 / 4;
      this.options.column_width = 38;
    } else if (view_mode === VIEW_MODE.WEEK) {
      this.options.step = 24 * 7;
      this.options.column_width = 140;
    } else if (view_mode === VIEW_MODE.MONTH) {
      this.options.step = 24 * 30;
      this.options.column_width = 120;
    } else if (view_mode === VIEW_MODE.YEAR) {
      this.options.step = 24 * 365;
      this.options.column_width = 120;
    }
  }

  setup_dates() {
    this.setup_gantt_dates();
    this.setup_date_values();
  }

  setup_gantt_dates() {
    this.gantt_start = this.gantt_end = null;

    for (let task of this.tasks) {
      // set global start and end date
      if (!this.gantt_start || task._start < this.gantt_start) {
        this.gantt_start = task._start;
      }
      if (!this.gantt_end || task._end > this.gantt_end) {
        this.gantt_end = task._end;
      }
    }
    let gantt_start, gantt_end;
    if (!this.gantt_start) gantt_start = new Date();
    else gantt_start = date_utils.start_of(this.gantt_start, "day");
    if (!this.gantt_end) gantt_end = new Date();
    else gantt_end = date_utils.start_of(this.gantt_end, "day");

    // add date padding on both sides
    let viewKey;
    for (let [key, value] of Object.entries(VIEW_MODE)) {
      if (value === this.options.view_mode) {
        viewKey = key;
      }
    }
    const [padding_start, padding_end] = this.options.view_mode_padding[
      viewKey
    ].map(date_utils.parse_duration);
    gantt_start = date_utils.add(
      gantt_start,
      -padding_start.duration,
      padding_start.scale,
    );

    let format_string;
    if (this.view_is(VIEW_MODE.YEAR)) {
      format_string = "YYYY"
    } else if (this.view_is(VIEW_MODE.MONTH)) {
      format_string = "YYYY-MM"
    } else if (this.view_is(VIEW_MODE.DAY)) {
      format_string = "YYYY-MM-DD"
    } else {
      format_string = "YYYY-MM-DD HH"
    }
    this.gantt_start = date_utils.parse(date_utils.format(gantt_start, format_string));
    this.gantt_start.setHours(0, 0, 0, 0)
    this.gantt_end = date_utils.add(
      gantt_end,
      padding_end.duration,
      padding_end.scale,
    );
  }

  setup_date_values() {
    this.dates = [];
    let cur_date = null;

    while (cur_date === null || cur_date < this.gantt_end) {
      if (!cur_date) {
        cur_date = date_utils.clone(this.gantt_start);
      } else {
        if (this.view_is(VIEW_MODE.YEAR)) {
          cur_date = date_utils.add(cur_date, 1, "year");
        } else if (this.view_is(VIEW_MODE.MONTH)) {
          cur_date = date_utils.add(cur_date, 1, "month");
        } else {
          cur_date = date_utils.add(cur_date, this.options.step, "hour");
        }
      }
      this.dates.push(cur_date);
    }
  }

  bind_events() {
    if (this.options.readonly) return
    this.bind_grid_click();
    this.bind_bar_events();
  }

  render() {
    this.clear();
    this.setup_layers();
    this.make_grid();
    this.make_dates();
    this.make_bars();
    this.make_arrows();
    this.map_arrows_on_bars();
    this.set_width();
    this.set_scroll_position();
    if (this.options.scroll_today) this.scroll_today()
  }

  setup_layers() {
    this.layers = {};
    const layers = ["grid", "arrow", "progress", "bar", "details", "date"];
    // make group layers
    for (let layer of layers) {
      this.layers[layer] = createSVG("g", {
        class: layer,
        append_to: this.$svg,
      });
    }
  }

  make_grid() {
    this.make_grid_background();
    this.make_grid_rows();
    this.make_grid_header();
    this.make_grid_ticks();
    this.make_grid_highlights();
  }

  make_grid_background() {
    const grid_width = this.dates.length * this.options.column_width;
    const grid_height =
      this.options.header_height +
      this.options.padding +
      (this.options.bar_height + this.options.padding) * this.tasks.length;

    createSVG("rect", {
      x: 0,
      y: 0,
      width: grid_width,
      height: grid_height,
      class: "grid-background",
      append_to: this.layers.date,
    });

    $.attr(this.$svg, {
      height: grid_height + this.options.padding + 100,
      width: "100%",
    });
  }

  make_grid_rows() {
    const rows_layer = createSVG("g", { append_to: this.layers.grid });
    const lines_layer = createSVG("g", { append_to: this.layers.grid });

    const row_width = this.dates.length * this.options.column_width;
    const row_height = this.options.bar_height + this.options.padding;

    let row_y = this.options.header_height + this.options.padding / 2;

    for (let task of this.tasks) {
      createSVG("rect", {
        x: 0,
        y: row_y,
        width: row_width,
        height: row_height,
        class: "grid-row",
        append_to: rows_layer,
      });

      createSVG("line", {
        x1: 0,
        y1: row_y + row_height,
        x2: row_width,
        y2: row_y + row_height,
        class: "row-line",
        append_to: lines_layer,
      });

      row_y += this.options.bar_height + this.options.padding;
    }
  }

  make_grid_header() {
    const header_width = this.dates.length * this.options.column_width;
    const header_height = this.options.header_height + 10;
    createSVG("rect", {
      x: 0,
      y: 0,
      width: header_width,
      height: header_height,
      class: "grid-header",
      append_to: this.layers.grid,
    });
  }

  make_grid_ticks() {
    let tick_x = 0;
    let tick_y = this.options.header_height + this.options.padding / 2;
    let tick_height =
      (this.options.bar_height + this.options.padding) * this.tasks.length;

    for (let date of this.dates) {
      let tick_class = "tick";
      // thick tick for monday
      if (this.view_is(VIEW_MODE.DAY) && date.getDate() === 1) {
        tick_class += " thick";
      }
      // thick tick for first week
      if (
        this.view_is(VIEW_MODE.WEEK) &&
        date.getDate() >= 1 &&
        date.getDate() < 8
      ) {
        tick_class += " thick";
      }
      // thick ticks for quarters
      if (this.view_is(VIEW_MODE.MONTH) && date.getMonth() % 3 === 0) {
        tick_class += " thick";
      }

      createSVG("path", {
        d: `M ${tick_x} ${tick_y} v ${tick_height}`,
        class: tick_class,
        append_to: this.layers.grid,
      });

      if (this.view_is(VIEW_MODE.MONTH)) {
        tick_x +=
          (date_utils.get_days_in_month(date) * this.options.column_width) / 30;
      } else {
        tick_x += this.options.column_width;
      }
    }
  }

  highlightWeekends() {
    if (!this.view_is('Day') && !this.view_is('Half Day')) return
    for (let d = new Date(this.gantt_start); d <= this.gantt_end; d.setDate(d.getDate() + 1)) {
      if (d.getDay() === 0 || d.getDay() === 6) {
        const x = (date_utils.diff(d, this.gantt_start, 'hour') /
          this.options.step) *
          this.options.column_width;
        const height = (this.options.bar_height + this.options.padding) * this.tasks.length;
        createSVG('rect', {
          x,
          y: this.options.header_height + this.options.padding / 2,
          width: (this.view_is('Day') ? 1 : 2) * this.options.column_width,
          height,
          class: 'holiday-highlight',
          append_to: this.layers.grid,
        });
      }
    }
  }

  //compute the horizontal x distance
  computeGridHighlightDimensions(view_mode) {
    let xDist = 0;

    if (this.view_is(VIEW_MODE.DAY)) {
      return (
        (date_utils.diff(date_utils.today(), this.gantt_start, "hour") /
          this.options.step) *
        this.options.column_width
      );
    }

    for (let date of this.dates) {
      const todayDate = new Date();
      const startDate = new Date(date);
      const endDate = new Date(date);
      switch (view_mode) {
        case VIEW_MODE.WEEK:
          endDate.setDate(date.getDate() + 7);
          break;
        case VIEW_MODE.MONTH:
          endDate.setMonth(date.getMonth() + 1);
          break;
        case VIEW_MODE.YEAR:
          endDate.setFullYear(date.getFullYear() + 1);
          break;
      }
      if (todayDate >= startDate && todayDate <= endDate) {
        break;
      } else {
        xDist += this.options.column_width;
      }
    }
    return xDist;
  }

  make_grid_highlights() {
    if (this.options.highlight_weekend) this.highlightWeekends()
    // highlight today's | week's | month's | year's
    if (
      this.view_is(VIEW_MODE.DAY) ||
      this.view_is(VIEW_MODE.WEEK) ||
      this.view_is(VIEW_MODE.MONTH) ||
      this.view_is(VIEW_MODE.YEAR)
    ) {
      const x = this.computeGridHighlightDimensions(this.options.view_mode);
      const y = 0;
      const width = this.options.column_width;
      const height =
        (this.options.bar_height + this.options.padding) * this.tasks.length +
        this.options.header_height +
        this.options.padding / 2;

      let className = "";
      switch (this.options.view_mode) {
        case VIEW_MODE.DAY:
          className = "today-highlight";
          break;
        case VIEW_MODE.WEEK:
          className = "week-highlight";
          break;
        case VIEW_MODE.MONTH:
          className = "month-highlight";
          break;
        case VIEW_MODE.YEAR:
          className = "year-highlight";
          break;
      }
      createSVG("rect", {
        x,
        y,
        width,
        height,
        class: className,
        append_to: this.layers.grid,
      });
    }
  }

  make_dates() {
    for (let date of this.get_dates_to_draw()) {
      createSVG("text", {
        x: date.lower_x,
        y: date.lower_y,
        innerHTML: date.lower_text,
        class: "lower-text",
        append_to: this.layers.date,
      });

      if (date.upper_text) {
        const $upper_text = createSVG("text", {
          x: date.upper_x,
          y: date.upper_y,
          innerHTML: date.upper_text,
          class: "upper-text",
          append_to: this.layers.date,
        });

        // remove out-of-bound dates
        if ($upper_text.getBBox().x2 > this.layers.grid.getBBox().width) {
          $upper_text.remove();
        }
      }
    }
  }

  get_dates_to_draw() {
    let last_date = null;
    const dates = this.dates.map((date, i) => {
      const d = this.get_date_info(date, last_date, i);
      last_date = d;
      return d;
    });
    return dates;
  }

  get_date_info(date, last_date_info, i) {
    let last_date = last_date_info ? last_date_info.date : date_utils.add(date, 1, "day")

    const date_text = {
      Hour_lower: date_utils.format(date, "HH", this.options.language),
      "Quarter Day_lower": date_utils.format(date, "HH", this.options.language),
      "Half Day_lower": date_utils.format(date, "HH", this.options.language),
      Day_lower:
        date.getDate() !== last_date.getDate()
          ? date_utils.format(date, "D", this.options.language)
          : "",
      Week_lower:
        date.getMonth() !== last_date.getMonth()
          ? date_utils.format(date, "D MMM", this.options.language)
          : date_utils.format(date, "D", this.options.language),
      Month_lower: date_utils.format(date, "MMMM", this.options.language),
      Year_lower: date_utils.format(date, "YYYY", this.options.language),
      Hour_upper:
        date.getDate() !== last_date.getDate()
          ? date_utils.format(date, "D MMMM", this.options.language)
          : "",
      "Quarter Day_upper":
        date.getDate() !== last_date.getDate()
          ? date_utils.format(date, "D MMM", this.options.language)
          : "",
      "Half Day_upper":
        date.getDate() !== last_date.getDate()
          ? date.getMonth() !== last_date.getMonth()
            ? date_utils.format(date, "D MMM", this.options.language)
            : date_utils.format(date, "D", this.options.language)
          : "",
      Day_upper:
        date.getMonth() !== last_date.getMonth()
          ? date_utils.format(date, "MMMM", this.options.language)
          : "",
      Week_upper:
        date.getMonth() !== last_date.getMonth()
          ? date_utils.format(date, "MMMM", this.options.language)
          : "",
      Month_upper:
        date.getFullYear() !== last_date.getFullYear()
          ? date_utils.format(date, "YYYY", this.options.language)
          : "",
      Year_upper:
        date.getFullYear() !== last_date.getFullYear()
          ? date_utils.format(date, "YYYY", this.options.language)
          : "",
    };
    let column_width = this.view_is(VIEW_MODE.MONTH) ? (date_utils.get_days_in_month(date) * this.options.column_width) / 30 : this.options.column_width;
    const base_pos = {
      x: last_date_info
        ? last_date_info.base_pos_x + last_date_info.column_width
        : 0,
      lower_y: this.options.header_height,
      upper_y: this.options.header_height - 25,
    };

    const x_pos = {
      Hour_lower: this.options.column_width / 2,
      Hour_upper: this.options.column_width * 12,
      "Quarter Day_lower": this.options.column_width / 2,
      "Quarter Day_upper": this.options.column_width * 2,
      "Half Day_lower": this.options.column_width / 2,
      "Half Day_upper": this.options.column_width,
      Day_lower: this.options.column_width / 2,
      Day_upper: (this.options.column_width * 30) / 2,
      Week_lower: 0,
      Week_upper: (this.options.column_width * 4) / 2,
      Month_lower: column_width / 2,
      Month_upper: (column_width * 12) / 2,
      Year_lower: this.options.column_width / 2,
      Year_upper: (this.options.column_width * 30) / 2,
    };

    return {
      date,
      column_width,
      base_pos_x: base_pos.x,
      upper_text: date_text[`${this.options.view_mode}_upper`],
      lower_text: date_text[`${this.options.view_mode}_lower`],
      upper_x: base_pos.x + x_pos[`${this.options.view_mode}_upper`],
      upper_y: base_pos.upper_y,
      lower_x: base_pos.x + x_pos[`${this.options.view_mode}_lower`],
      lower_y: base_pos.lower_y,
    };
  }

  make_bars() {
    this.bars = this.tasks.map((task) => {
      const bar = new Bar(this, task);
      this.layers.bar.appendChild(bar.group);
      return bar;
    });
  }

  make_arrows() {
    this.arrows = [];
    for (let task of this.tasks) {
      let arrows = [];
      arrows = task.dependencies
        .map((task_id) => {
          const dependency = this.get_task(task_id);
          if (!dependency) return;
          const arrow = new Arrow(
            this,
            this.bars[dependency._index], // from_task
            this.bars[task._index], // to_task
          );
          this.layers.arrow.appendChild(arrow.element);
          return arrow;
        })
        .filter(Boolean); // filter falsy values
      this.arrows = this.arrows.concat(arrows);
    }
  }

  map_arrows_on_bars() {
    for (let bar of this.bars) {
      bar.arrows = this.arrows.filter((arrow) => {
        return (
          arrow.from_task.task.id === bar.task.id ||
          arrow.to_task.task.id === bar.task.id
        );
      });
    }
  }

  set_width() {
    const cur_width = this.$svg.getBoundingClientRect().width;
    const actual_width = this.$svg.querySelector('.grid .grid-row') ? this.$svg
      .querySelector('.grid .grid-row')
      .getAttribute('width') : 0;
    if (cur_width < actual_width) {
      this.$svg.setAttribute("width", actual_width);
    }
  }

  set_scroll_position(date) {
    if (!date) {
      date = this.gantt_start
    }

    const parent_element = this.$svg.parentElement;
    if (!parent_element) return;

    const hours_before_first_task = date_utils.diff(
      this.get_oldest_starting_date(),
      date,
      "hour",
    );

    const scroll_pos =
      (hours_before_first_task / this.options.step) *
      this.options.column_width -
      this.options.column_width;

    parent_element.scrollLeft = scroll_pos;
  }

  scroll_today() {
    const oldest = this.get_oldest_starting_date().getTime()
    const t = new Date() - oldest
    this.set_scroll_position(new Date(this.gantt_start.getTime() - t))
  }

  bind_grid_click() {
    $.on(
      this.$svg,
      this.options.popup_trigger,
      ".grid-row, .grid-header",
      () => {
        this.unselect_all();
        this.hide_popup();
      },
    );
  }

  bind_bar_events() {
    let is_dragging = false;
    let x_on_start = 0;
    let x_on_scroll_start = 0;
    let y_on_start = 0;
    let is_resizing_left = false;
    let is_resizing_right = false;
    let parent_bar_id = null;
    let bars = []; // instanceof Bar
    this.bar_being_dragged = null;

    function action_in_progress() {
      return is_dragging || is_resizing_left || is_resizing_right;
    }

    $.on(this.$svg, "mousedown", ".bar-wrapper, .handle", (e, element) => {
      const bar_wrapper = $.closest(".bar-wrapper", element);

      if (element.classList.contains("left")) {
        is_resizing_left = true;
      } else if (element.classList.contains("right")) {
        is_resizing_right = true;
      } else if (element.classList.contains("bar-wrapper")) {
        is_dragging = true;
      }

      bar_wrapper.classList.add("active");

      x_on_start = e.offsetX;
      y_on_start = e.offsetY;

      parent_bar_id = bar_wrapper.getAttribute("data-id");
      const ids = [
        parent_bar_id,
        ...this.get_all_dependent_tasks(parent_bar_id),
      ];
      bars = ids.map((id) => this.get_bar(id));

      this.bar_being_dragged = parent_bar_id;

      bars.forEach((bar) => {
        const $bar = bar.$bar;
        $bar.ox = $bar.getX();
        $bar.oy = $bar.getY();
        $bar.owidth = $bar.getWidth();
        $bar.finaldx = 0;
      });
    });
    $.on(this.$container, 'scroll', e => {
      let elements = document.querySelectorAll('.bar-wrapper');
      let localBars = [];
      const ids = [];
      let dx;

      this.layers.date.setAttribute('transform', 'translate(0,' + e.currentTarget.scrollTop + ')');
      if (x_on_scroll_start) {
        dx = e.currentTarget.scrollLeft - x_on_scroll_start;
      }

      Array.prototype.forEach.call(elements, function (el, i) {
        ids.push(el.getAttribute('data-id'));
      });

      if (dx) {
        localBars = ids.map(id => this.get_bar(id));

        localBars.forEach(bar => {
          bar.update_label_position_on_horizontal_scroll({ x: dx, sx: e.currentTarget.scrollLeft });
        });
      }

      x_on_scroll_start = e.currentTarget.scrollLeft;
    });

    $.on(this.$svg, "mousemove", (e) => {
      if (!action_in_progress()) return;
      const dx = e.offsetX - x_on_start;
      const dy = e.offsetY - y_on_start;

      bars.forEach((bar) => {
        const $bar = bar.$bar;
        $bar.finaldx = this.get_snap_position(dx);
        this.hide_popup();
        if (is_resizing_left) {
          if (parent_bar_id === bar.task.id) {
            bar.update_bar_position({
              x: $bar.ox + $bar.finaldx,
              width: $bar.owidth - $bar.finaldx,
            });
          } else {
            bar.update_bar_position({
              x: $bar.ox + $bar.finaldx,
            });
          }
        } else if (is_resizing_right) {
          if (parent_bar_id === bar.task.id) {
            bar.update_bar_position({
              width: $bar.owidth + $bar.finaldx,
            });
          }
        } else if (is_dragging && !this.options.readonly) {
          bar.update_bar_position({ x: $bar.ox + $bar.finaldx });
        }
      });
    });

    document.addEventListener("mouseup", (e) => {
      if (is_dragging || is_resizing_left || is_resizing_right) {
        bars.forEach((bar) => bar.group.classList.remove("active"));
      }

      is_dragging = false;
      is_resizing_left = false;
      is_resizing_right = false;
    });

    $.on(this.$svg, "mouseup", (e) => {
      this.bar_being_dragged = null;
      bars.forEach((bar) => {
        const $bar = bar.$bar;
        if (!$bar.finaldx) return;
        bar.date_changed();
        bar.set_action_completed();
      });
    });

    this.bind_bar_progress();
  }

  bind_bar_progress() {
    let x_on_start = 0;
    let y_on_start = 0;
    let is_resizing = null;
    let bar = null;
    let $bar_progress = null;
    let $bar = null;

    $.on(this.$svg, "mousedown", ".handle.progress", (e, handle) => {
      is_resizing = true;
      x_on_start = e.offsetX;
      y_on_start = e.offsetY;

      const $bar_wrapper = $.closest(".bar-wrapper", handle);
      const id = $bar_wrapper.getAttribute("data-id");
      bar = this.get_bar(id);

      $bar_progress = bar.$bar_progress;
      $bar = bar.$bar;

      $bar_progress.finaldx = 0;
      $bar_progress.owidth = $bar_progress.getWidth();
      $bar_progress.min_dx = -$bar_progress.getWidth();
      $bar_progress.max_dx = $bar.getWidth() - $bar_progress.getWidth();
    });

    $.on(this.$svg, "mousemove", (e) => {
      if (!is_resizing) return;
      let dx = e.offsetX - x_on_start;
      let dy = e.offsetY - y_on_start;

      if (dx > $bar_progress.max_dx) {
        dx = $bar_progress.max_dx;
      }
      if (dx < $bar_progress.min_dx) {
        dx = $bar_progress.min_dx;
      }

      const $handle = bar.$handle_progress;
      $.attr($bar_progress, "width", $bar_progress.owidth + dx);
      $.attr($handle, "points", bar.get_progress_polygon_points());
      $bar_progress.finaldx = dx;
    });

    $.on(this.$svg, "mouseup", () => {
      is_resizing = false;
      if (!($bar_progress && $bar_progress.finaldx)) return;

      $bar_progress.finaldx = 0;
      bar.progress_changed();
      bar.set_action_completed();
      bar = null;
      $bar_progress = null;
      $bar = null;
    });
  }

  get_all_dependent_tasks(task_id) {
    let out = [];
    let to_process = [task_id];
    while (to_process.length) {
      const deps = to_process.reduce((acc, curr) => {
        acc = acc.concat(this.dependency_map[curr]);
        return acc;
      }, []);

      out = out.concat(deps);
      to_process = deps.filter((d) => !to_process.includes(d));
    }

    return out.filter(Boolean);
  }

  get_snap_position(dx) {
    let odx = dx,
      rem,
      position;

    if (this.view_is(VIEW_MODE.WEEK)) {
      rem = dx % (this.options.column_width / 7);
      position =
        odx -
        rem +
        (rem < this.options.column_width / 14
          ? 0
          : this.options.column_width / 7);
    } else if (this.view_is(VIEW_MODE.MONTH)) {
      rem = dx % (this.options.column_width / 30);
      position =
        odx -
        rem +
        (rem < this.options.column_width / 60
          ? 0
          : this.options.column_width / 30);
    } else {
      rem = dx % this.options.column_width;
      position =
        odx -
        rem +
        (rem < this.options.column_width / 2 ? 0 : this.options.column_width);
    }
    return position;
  }

  unselect_all() {
    [...this.$svg.querySelectorAll(".bar-wrapper")].forEach((el) => {
      el.classList.remove("active");
    });
  }

  view_is(modes) {
    if (typeof modes === "string") {
      return this.options.view_mode === modes;
    }

    if (Array.isArray(modes)) {
      return modes.some((mode) => this.options.view_mode === mode);
    }

    return false;
  }

  get_task(id) {
    return this.tasks.find((task) => {
      return task.id === id;
    });
  }

  get_bar(id) {
    return this.bars.find((bar) => {
      return bar.task.id === id;
    });
  }

  show_popup(options) {
    if (!this.popup) {
      this.popup = new Popup(
        this.popup_wrapper,
        this.options.custom_popup_html,
      );
    }
    this.popup.show(options);
  }

  hide_popup() {
    this.popup && this.popup.hide();
  }

  trigger_event(event, args) {
    if (this.options["on_" + event]) {
      this.options["on_" + event].apply(null, args);
    }
  }

  /**
   * Gets the oldest starting date from the list of tasks
   *
   * @returns Date
   * @memberof Gantt
   */
  get_oldest_starting_date() {
    if (!this.tasks.length) return new Date()
    return this.tasks
      .map((task) => task._start)
      .reduce((prev_date, cur_date) =>
        cur_date <= prev_date ? cur_date : prev_date,
      );
  }

  /**
   * Clear all elements from the parent svg element
   *
   * @memberof Gantt
   */
  clear() {
    this.$svg.innerHTML = "";
  }
}

Gantt.VIEW_MODE = VIEW_MODE;

function generate_id(task) {
  return task.name + "_" + Math.random().toString(36).slice(2, 12);
}