/* ************************************************************************

   qooxdoo - the new era of web development

   http://qooxdoo.org

   Copyright:
     2004-2008 1&1 Internet AG, Germany, http://www.1und1.de

   License:
     MIT: https://opensource.org/licenses/MIT
     See the LICENSE file in the project's top-level directory for details.

   Authors:
     * Sebastian Werner (wpbasti)
     * Andreas Ecker (ecker)
     * Christian Hagendorn (chris_schmidt)
     * Martin Wittemann (martinwittemann)

************************************************************************ */

/**
 * The radio group handles a collection of items from which only one item
 * can be selected. Selection another item will deselect the previously selected
 * item.
 *
 * This class is e.g. used to create radio groups or {@link qx.ui.form.RadioButton}
 * or {@link qx.ui.toolbar.RadioButton} instances.
 *
 * We also offer a widget for the same purpose which uses this class. So if
 * you like to act with a widget instead of a pure logic coupling of the
 * widgets, take a look at the {@link qx.ui.form.RadioButtonGroup} widget.
 */
qx.Class.define("qx.ui.form.RadioGroup", {
  extend: qx.core.Object,
  implement: [
    qx.ui.core.ISingleSelection,
    qx.ui.form.IField,
    qx.ui.form.IForm,
    qx.ui.form.IModelSelection
  ],

  include: [qx.ui.core.MSingleSelectionHandling, qx.ui.form.MModelSelection],

  /*
  *****************************************************************************
     CONSTRUCTOR
  *****************************************************************************
  */

  /**
   * @param varargs {qx.core.Object} A variable number of items, which are
   *     initially added to the radio group, the first item will be selected.
   */
  construct(varargs) {
    super();

    // create item array
    this.__items = [];

    // add listener before call add!!!
    this.addListener("changeSelection", this.__onChangeSelection, this);

    if (varargs != null) {
      this.add.apply(this, arguments);
    }
  },

  /*
  *****************************************************************************
     PROPERTIES
  *****************************************************************************
  */

  properties: {
    /**
     * The property name in each of the added widgets that is grouped
     */
    groupedProperty: {
      check: "String",
      apply: "_applyGroupedProperty",
      event: "changeGroupedProperty",
      init: "value"
    },

    /**
     * The property name in each of the added widgets that is informed of the
     * RadioGroup object it is a member of
     */
    groupProperty: {
      check: "String",
      event: "changeGroupProperty",
      init: "group"
    },

    /**
     * Whether the radio group is enabled
     */
    enabled: {
      check: "Boolean",
      apply: "_applyEnabled",
      event: "changeEnabled",
      init: true
    },

    /**
     * Whether the selection should wrap around. This means that the successor of
     * the last item is the first item.
     */
    wrap: {
      check: "Boolean",
      init: true
    },

    /**
     * If is set to <code>true</code> the selection could be empty,
     * otherwise is always one <code>RadioButton</code> selected.
     */
    allowEmptySelection: {
      check: "Boolean",
      init: false,
      apply: "_applyAllowEmptySelection"
    },

    /**
     * Flag signaling if the group at all is valid. All children will have the
     * same state.
     */
    valid: {
      check: "Boolean",
      init: true,
      apply: "_applyValid",
      event: "changeValid"
    },

    /**
     * Flag signaling if the group is required.
     */
    required: {
      check: "Boolean",
      init: false,
      event: "changeRequired"
    },

    /**
     * Message which is shown in an invalid tooltip.
     */
    invalidMessage: {
      check: "String",
      init: "",
      event: "changeInvalidMessage",
      apply: "_applyInvalidMessage"
    },

    /**
     * Message which is shown in an invalid tooltip if the {@link #required} is
     * set to true.
     */
    requiredInvalidMessage: {
      check: "String",
      nullable: true,
      event: "changeInvalidMessage"
    }
  },

  /*
  *****************************************************************************
     MEMBERS
  *****************************************************************************
  */

  members: {
    /** @type {qx.ui.form.IRadioItem[]} The items of the radio group */
    __items: null,

    /*
    ---------------------------------------------------------------------------
      UTILITIES
    ---------------------------------------------------------------------------
    */

    /**
     * Get all managed items
     *
     * @return {qx.ui.form.IRadioItem[]} All managed items.
     */
    getItems() {
      return this.__items;
    },

    /*
    ---------------------------------------------------------------------------
      REGISTRY
    ---------------------------------------------------------------------------
    */

    /**
     * Add the passed items to the radio group.
     *
     * @param varargs {qx.ui.form.IRadioItem} A variable number of items to add.
     */
    add(varargs) {
      var items = this.__items;
      var item;
      var groupedProperty = this.getGroupedProperty();
      var groupedPropertyUp = qx.lang.String.firstUp(groupedProperty);

      for (var i = 0, l = arguments.length; i < l; i++) {
        item = arguments[i];

        if (items.includes(item)) {
          continue;
        }

        // Register listeners
        item.addListener(
          "change" + groupedPropertyUp,
          this._onItemChangeChecked,
          this
        );

        // Push RadioButton to array
        items.push(item);

        // Inform radio button about new group
        item.set(this.getGroupProperty(), this);

        // Need to update internal value?
        if (item.get(groupedProperty)) {
          this.setSelection([item]);
        }
      }

      // Select first item when only one is registered
      if (
        !this.isAllowEmptySelection() &&
        items.length > 0 &&
        !this.getSelection()[0]
      ) {
        this.setSelection([items[0]]);
      }
    },

    /**
     * Remove an item from the radio group.
     *
     * @param item {qx.ui.form.IRadioItem} The item to remove.
     */
    remove(item) {
      var items = this.__items;
      var groupedProperty = this.getGroupedProperty();
      var groupedPropertyUp = qx.lang.String.firstUp(groupedProperty);

      if (items.includes(item)) {
        // Remove RadioButton from array
        qx.lang.Array.remove(items, item);

        // Inform radio button about new group
        if (item.get(this.getGroupProperty()) === this) {
          item.reset(this.getGroupProperty());
        }

        // Deregister listeners
        item.removeListener(
          "change" + groupedPropertyUp,
          this._onItemChangeChecked,
          this
        );

        // if the radio was checked, set internal selection to null
        if (item.get(groupedProperty)) {
          this.resetSelection();
        }
      }
    },

    /**
     * Returns an array containing the group's items.
     *
     * @return {qx.ui.form.IRadioItem[]} The item array
     */
    getChildren() {
      return this.__items;
    },

    /*
    ---------------------------------------------------------------------------
      LISTENER FOR ITEM CHANGES
    ---------------------------------------------------------------------------
    */

    /**
     * Event listener for <code>changeValue</code> event of every managed item.
     *
     * @param e {qx.event.type.Data} Data event
     */
    _onItemChangeChecked(e) {
      var item = e.getTarget();
      var groupedProperty = this.getGroupedProperty();

      if (item.get(groupedProperty)) {
        this.setSelection([item]);
      } else if (this.getSelection()[0] == item) {
        this.resetSelection();
      }
    },

    /*
    ---------------------------------------------------------------------------
      APPLY ROUTINES
    ---------------------------------------------------------------------------
    */

    // property apply
    _applyGroupedProperty(value, old) {
      var item;
      var oldFirstUp = qx.lang.String.firstUp(old);
      var newFirstUp = qx.lang.String.firstUp(value);

      for (var i = 0; i < this.__items.length; i++) {
        item = this.__items[i];

        // remove the listener for the old change event
        item.removeListener(
          "change" + oldFirstUp,
          this._onItemChangeChecked,
          this
        );

        // add the listener for the new change event
        item.removeListener(
          "change" + newFirstUp,
          this._onItemChangeChecked,
          this
        );
      }
    },

    // property apply
    _applyInvalidMessage(value, old) {
      for (var i = 0; i < this.__items.length; i++) {
        this.__items[i].setInvalidMessage(value);
      }
    },

    // property apply
    _applyValid(value, old) {
      for (var i = 0; i < this.__items.length; i++) {
        this.__items[i].setValid(value);
      }
    },

    // property apply
    _applyEnabled(value, old) {
      var items = this.__items;
      if (value == null) {
        for (var i = 0, l = items.length; i < l; i++) {
          items[i].resetEnabled();
        }
      } else {
        for (var i = 0, l = items.length; i < l; i++) {
          items[i].setEnabled(value);
        }
      }
    },

    // property apply
    _applyAllowEmptySelection(value, old) {
      if (!value && this.isSelectionEmpty()) {
        this.resetSelection();
      }
    },

    /*
    ---------------------------------------------------------------------------
      SELECTION
    ---------------------------------------------------------------------------
    */

    /**
     * Select the item following the given item.
     */
    selectNext() {
      var item = this.getSelection()[0];
      var items = this.__items;
      var index = items.indexOf(item);
      if (index == -1) {
        return;
      }

      var i = 0;
      var length = items.length;

      // Find next enabled item
      if (this.getWrap()) {
        index = (index + 1) % length;
      } else {
        index = Math.min(index + 1, length - 1);
      }

      while (i < length && !items[index].getEnabled()) {
        index = (index + 1) % length;
        i++;
      }

      this.setSelection([items[index]]);
    },

    /**
     * Select the item previous the given item.
     */
    selectPrevious() {
      var item = this.getSelection()[0];
      var items = this.__items;
      var index = items.indexOf(item);
      if (index == -1) {
        return;
      }

      var i = 0;
      var length = items.length;

      // Find previous enabled item
      if (this.getWrap()) {
        index = (index - 1 + length) % length;
      } else {
        index = Math.max(index - 1, 0);
      }

      while (i < length && !items[index].getEnabled()) {
        index = (index - 1 + length) % length;
        i++;
      }

      this.setSelection([items[index]]);
    },

    /*
    ---------------------------------------------------------------------------
      HELPER METHODS FOR SELECTION API
    ---------------------------------------------------------------------------
    */

    /**
     * Returns the items for the selection.
     *
     * @return {qx.ui.form.IRadioItem[]} Items to select.
     */
    _getItems() {
      return this.getItems();
    },

    /**
     * Returns if the selection could be empty or not.
     *
     * @return {Boolean} <code>true</code> If selection could be empty,
     *    <code>false</code> otherwise.
     */
    _isAllowEmptySelection() {
      return this.isAllowEmptySelection();
    },

    /**
     * Returns whether the item is selectable. In opposite to the default
     * implementation (which checks for visible items) every radio button
     * which is part of the group is selected even if it is currently not visible.
     *
     * @param item {qx.ui.form.IRadioItem} The item to check if its selectable.
     * @return {Boolean} <code>true</code> if the item is part of the radio group
     *    <code>false</code> otherwise.
     */
    _isItemSelectable(item) {
      return this.__items.indexOf(item) != -1;
    },

    /**
     * Event handler for <code>changeSelection</code>.
     *
     * @param e {qx.event.type.Data} Data event.
     */
    __onChangeSelection(e) {
      var value = e.getData()[0];
      var old = e.getOldData()[0];
      var groupedProperty = this.getGroupedProperty();

      if (old) {
        old.set(groupedProperty, false);
      }

      if (value) {
        value.set(groupedProperty, true);

        // If Group is focused, the selection was changed by keyboard. Switch focus to new value
        if (this.__isGroupFocused() && value.isFocusable()) {
          value.focus();
        }
      }
    },

    /**
     * Checks if this group is focused by checking focused state of each item
     * @returns {Boolean} result
     */
    __isGroupFocused() {
      const focusHandler = qx.ui.core.FocusHandler.getInstance();
      for (const item of this._getItems()) {
        if (focusHandler.isFocused(item)) {
          return true;
        }
      }
      return false;
    }
  },

  /*
  *****************************************************************************
     DESTRUCTOR
  *****************************************************************************
  */

  destruct() {
    this._disposeArray("__items");
  }
});