import { extend } from '../../vue';
import { NAME_BUTTON_TOOLBAR } from '../../constants/components';
import { PROP_TYPE_BOOLEAN } from '../../constants/props';
import { CODE_UP, CODE_LEFT, CODE_DOWN, CODE_RIGHT } from '../../constants/key-codes';
import { selectAll, isVisible, attemptFocus, contains } from '../../utils/dom';
import { stopEvent } from '../../utils/events';
import { makePropsConfigurable, makeProp } from '../../utils/props';
import { normalizeSlotMixin } from '../../mixins/normalize-slot';

// --- Constants ---

const ITEM_SELECTOR = ['.btn:not(.disabled):not([disabled]):not(.dropdown-item)', '.form-control:not(.disabled):not([disabled])', 'select:not(.disabled):not([disabled])', 'input[type="checkbox"]:not(.disabled)', 'input[type="radio"]:not(.disabled)'].join(',');

// --- Props ---

const props = makePropsConfigurable({
  justify: makeProp(PROP_TYPE_BOOLEAN, false),
  keyNav: makeProp(PROP_TYPE_BOOLEAN, false)
}, NAME_BUTTON_TOOLBAR);

// --- Main component ---

// @vue/component
const BButtonToolbar = /*#__PURE__*/extend({
  name: NAME_BUTTON_TOOLBAR,
  mixins: [normalizeSlotMixin],
  props,
  mounted() {
    // Pre-set the tabindexes if the markup does not include
    // `tabindex="-1"` on the toolbar items
    if (this.keyNav) {
      this.getItems();
    }
  },
  methods: {
    getItems() {
      const items = selectAll(ITEM_SELECTOR, this.$el);
      // Ensure `tabindex="-1"` is set on every item
      items.forEach(item => {
        item.tabIndex = -1;
      });
      return items.filter(el => isVisible(el));
    },
    focusFirst() {
      const items = this.getItems();
      attemptFocus(items[0]);
    },
    focusPrev(event) {
      let items = this.getItems();
      const index = items.indexOf(event.target);
      if (index > -1) {
        items = items.slice(0, index).reverse();
        attemptFocus(items[0]);
      }
    },
    focusNext(event) {
      let items = this.getItems();
      const index = items.indexOf(event.target);
      if (index > -1) {
        items = items.slice(index + 1);
        attemptFocus(items[0]);
      }
    },
    focusLast() {
      const items = this.getItems().reverse();
      attemptFocus(items[0]);
    },
    onFocusin(event) {
      const {
        $el
      } = this;
      if (event.target === $el && !contains($el, event.relatedTarget)) {
        stopEvent(event);
        this.focusFirst(event);
      }
    },
    onKeydown(event) {
      const {
        keyCode,
        shiftKey
      } = event;
      if (keyCode === CODE_UP || keyCode === CODE_LEFT) {
        stopEvent(event);
        shiftKey ? this.focusFirst(event) : this.focusPrev(event);
      } else if (keyCode === CODE_DOWN || keyCode === CODE_RIGHT) {
        stopEvent(event);
        shiftKey ? this.focusLast(event) : this.focusNext(event);
      }
    }
  },
  render(h) {
    const {
      keyNav
    } = this;
    return h('div', {
      staticClass: 'btn-toolbar',
      class: {
        'justify-content-between': this.justify
      },
      attrs: {
        role: 'toolbar',
        tabindex: keyNav ? '0' : null
      },
      on: keyNav ? {
        focusin: this.onFocusin,
        keydown: this.onKeydown
      } : {}
    }, [this.normalizeSlot()]);
  }
});

export { BButtonToolbar, props };
