// Copyright (c) 2026 Dominic Masters
//
// This software is released under the MIT License.
// https://opensource.org/licenses/MIT

// Label + a "< option >"-style value label, cycling a caller-provided
// options array. Same directionInput()-consumes-LEFT/RIGHT shape as
// Slider, stepping the selected index (with wraparound) instead of a
// numeric value.
class Dropdown extends UIElement {
  init() {
    this.label = new Label();
    this.add(this.label);

    this.valueLabel = new Label();
    this.valueLabel.x = 100;
    this.add(this.valueLabel);

    this.options = [];
    this._index = 0;
    this.highlighted = false;
    this.onChange = null;

    this._refresh();
  }

  get text() { return this.label.text; }
  set text(value) { this.label.text = value; }

  get selectedIndex() { return this._index; }
  set selectedIndex(index) {
    if(this.options.length === 0) {
      this._index = 0;
      this._refresh();
      return;
    }

    const count = this.options.length;
    this._index = ((index % count) + count) % count;
    this._refresh();
    if(this.onChange) this.onChange(this._index, this.options[this._index]);
  }

  get selected() { return this.options[this._index]; }

  setHighlighted(highlighted) {
    this.highlighted = highlighted;
    this.label.color = highlighted
      ? Dropdown.COLOR_HIGHLIGHTED
      : Dropdown.COLOR_NORMAL;
  }

  directionInput(dx, dy) {
    if(dx === 0) return false;
    this.selectedIndex = this._index + dx;
    return true;
  }

  _refresh() {
    const value = this.options[this._index];
    this.valueLabel.text = value !== undefined ? ('< ' + value + ' >') : '< >';
  }
}

Dropdown.COLOR_NORMAL = { r: 255, g: 255, b: 255, a: 255 };
Dropdown.COLOR_HIGHLIGHTED = { r: 255, g: 0, b: 0, a: 255 };

module.exports = Dropdown;