import { extend } from '../../vue';
import { NAME_CAROUSEL } from '../../constants/components';
import { IS_BROWSER, HAS_POINTER_EVENT_SUPPORT, HAS_TOUCH_SUPPORT } from '../../constants/env';
import { EVENT_NAME_PAUSED, EVENT_NAME_UNPAUSED, EVENT_NAME_SLIDING_END, EVENT_NAME_SLIDING_START, EVENT_OPTIONS_NO_CAPTURE } from '../../constants/events';
import { CODE_SPACE, CODE_ENTER, CODE_LEFT, CODE_RIGHT } from '../../constants/key-codes';
import { PROP_TYPE_NUMBER, PROP_TYPE_STRING, PROP_TYPE_BOOLEAN, PROP_TYPE_NUMBER_STRING } from '../../constants/props';
import { requestAF, getActiveElement, addClass, removeClass, reflow, selectAll, setAttr } from '../../utils/dom';
import { eventOn, stopEvent, eventOff } from '../../utils/events';
import { isUndefined } from '../../utils/inspect';
import { mathFloor, mathMax, mathMin, mathAbs } from '../../utils/math';
import { makeModelMixin } from '../../utils/model';
import { toInteger } from '../../utils/number';
import { noop } from '../../utils/noop';
import { sortKeys } from '../../utils/object';
import { observeDom } from '../../utils/observe-dom';
import { makePropsConfigurable, makeProp } from '../../utils/props';
import { props as props$1, idMixin } from '../../mixins/id';
import { normalizeSlotMixin } from '../../mixins/normalize-slot';

// --- Constants ---

const {
  mixin: modelMixin,
  props: modelProps,
  prop: MODEL_PROP_NAME,
  event: MODEL_EVENT_NAME
} = makeModelMixin('value', {
  type: PROP_TYPE_NUMBER,
  defaultValue: 0
});

// Slide directional classes
const DIRECTION = {
  next: {
    dirClass: 'carousel-item-left',
    overlayClass: 'carousel-item-next'
  },
  prev: {
    dirClass: 'carousel-item-right',
    overlayClass: 'carousel-item-prev'
  }
};

// Fallback Transition duration (with a little buffer) in ms
const TRANS_DURATION = 600 + 50;

// Time for mouse compat events to fire after touch
const TOUCH_EVENT_COMPAT_WAIT = 500;

// Number of pixels to consider touch move a swipe
const SWIPE_THRESHOLD = 40;

// PointerEvent pointer types
const PointerType = {
  TOUCH: 'touch',
  PEN: 'pen'
};

// Transition Event names
const TransitionEndEvents = {
  WebkitTransition: 'webkitTransitionEnd',
  MozTransition: 'transitionend',
  OTransition: 'otransitionend oTransitionEnd',
  transition: 'transitionend'
};

// --- Helper methods ---

// Return the browser specific transitionEnd event name
const getTransitionEndEvent = el => {
  for (const name in TransitionEndEvents) {
    if (!isUndefined(el.style[name])) {
      return TransitionEndEvents[name];
    }
  }
  // Fallback
  /* istanbul ignore next */
  return null;
};

// --- Props ---

const props = makePropsConfigurable(sortKeys({
  ...props$1,
  ...modelProps,
  background: makeProp(PROP_TYPE_STRING),
  controls: makeProp(PROP_TYPE_BOOLEAN, false),
  // Enable cross-fade animation instead of slide animation
  fade: makeProp(PROP_TYPE_BOOLEAN, false),
  // Sniffed by carousel-slide
  imgHeight: makeProp(PROP_TYPE_NUMBER_STRING),
  // Sniffed by carousel-slide
  imgWidth: makeProp(PROP_TYPE_NUMBER_STRING),
  indicators: makeProp(PROP_TYPE_BOOLEAN, false),
  interval: makeProp(PROP_TYPE_NUMBER, 5000),
  labelGotoSlide: makeProp(PROP_TYPE_STRING, 'Goto slide'),
  labelIndicators: makeProp(PROP_TYPE_STRING, 'Select a slide to display'),
  labelNext: makeProp(PROP_TYPE_STRING, 'Next slide'),
  labelPrev: makeProp(PROP_TYPE_STRING, 'Previous slide'),
  // Disable slide/fade animation
  noAnimation: makeProp(PROP_TYPE_BOOLEAN, false),
  // Disable pause on hover
  noHoverPause: makeProp(PROP_TYPE_BOOLEAN, false),
  // Sniffed by carousel-slide
  noTouch: makeProp(PROP_TYPE_BOOLEAN, false),
  // Disable wrapping/looping when start/end is reached
  noWrap: makeProp(PROP_TYPE_BOOLEAN, false)
}), NAME_CAROUSEL);

// --- Main component ---

// @vue/component
const BCarousel = /*#__PURE__*/extend({
  name: NAME_CAROUSEL,
  mixins: [idMixin, modelMixin, normalizeSlotMixin],
  provide() {
    return {
      getBvCarousel: () => this
    };
  },
  props,
  data() {
    return {
      index: this[MODEL_PROP_NAME] || 0,
      isSliding: false,
      transitionEndEvent: null,
      slides: [],
      direction: null,
      isPaused: !(toInteger(this.interval, 0) > 0),
      // Touch event handling values
      touchStartX: 0,
      touchDeltaX: 0
    };
  },
  computed: {
    numSlides() {
      return this.slides.length;
    }
  },
  watch: {
    [MODEL_PROP_NAME](newValue, oldValue) {
      if (newValue !== oldValue) {
        this.setSlide(toInteger(newValue, 0));
      }
    },
    interval(newValue, oldValue) {
      /* istanbul ignore next */
      if (newValue === oldValue) {
        return;
      }
      if (!newValue) {
        // Pausing slide show
        this.pause(false);
      } else {
        // Restarting or Changing interval
        this.pause(true);
        this.start(false);
      }
    },
    isPaused(newValue, oldValue) {
      if (newValue !== oldValue) {
        this.$emit(newValue ? EVENT_NAME_PAUSED : EVENT_NAME_UNPAUSED);
      }
    },
    index(to, from) {
      /* istanbul ignore next */
      if (to === from || this.isSliding) {
        return;
      }
      this.doSlide(to, from);
    }
  },
  created() {
    // Create private non-reactive props
    this.$_interval = null;
    this.$_animationTimeout = null;
    this.$_touchTimeout = null;
    this.$_observer = null;
    // Set initial paused state
    this.isPaused = !(toInteger(this.interval, 0) > 0);
  },
  mounted() {
    // Cache current browser transitionend event name
    this.transitionEndEvent = getTransitionEndEvent(this.$el) || null;
    // Get all slides
    this.updateSlides();
    // Observe child changes so we can update slide list
    this.setObserver(true);
  },
  beforeDestroy() {
    this.clearInterval();
    this.clearAnimationTimeout();
    this.clearTouchTimeout();
    this.setObserver(false);
  },
  methods: {
    clearInterval() {
      clearInterval(this.$_interval);
      this.$_interval = null;
    },
    clearAnimationTimeout() {
      clearTimeout(this.$_animationTimeout);
      this.$_animationTimeout = null;
    },
    clearTouchTimeout() {
      clearTimeout(this.$_touchTimeout);
      this.$_touchTimeout = null;
    },
    setObserver() {
      let on = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : false;
      this.$_observer && this.$_observer.disconnect();
      this.$_observer = null;
      if (on) {
        this.$_observer = observeDom(this.$refs.inner, this.updateSlides.bind(this), {
          subtree: false,
          childList: true,
          attributes: true,
          attributeFilter: ['id']
        });
      }
    },
    // Set slide
    setSlide(slide) {
      let direction = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : null;
      // Don't animate when page is not visible
      /* istanbul ignore if: difficult to test */
      if (IS_BROWSER && document.visibilityState && document.hidden) {
        return;
      }
      const noWrap = this.noWrap;
      const numSlides = this.numSlides;
      // Make sure we have an integer (you never know!)
      slide = mathFloor(slide);
      // Don't do anything if nothing to slide to
      if (numSlides === 0) {
        return;
      }
      // Don't change slide while transitioning, wait until transition is done
      if (this.isSliding) {
        // Schedule slide after sliding complete
        this.$once(EVENT_NAME_SLIDING_END, () => {
          // Wrap in `requestAF()` to allow the slide to properly finish to avoid glitching
          requestAF(() => this.setSlide(slide, direction));
        });
        return;
      }
      this.direction = direction;
      // Set new slide index
      // Wrap around if necessary (if no-wrap not enabled)
      this.index = slide >= numSlides ? noWrap ? numSlides - 1 : 0 : slide < 0 ? noWrap ? 0 : numSlides - 1 : slide;
      // Ensure the v-model is synched up if no-wrap is enabled
      // and user tried to slide pass either ends
      if (noWrap && this.index !== slide && this.index !== this[MODEL_PROP_NAME]) {
        this.$emit(MODEL_EVENT_NAME, this.index);
      }
    },
    // Previous slide
    prev() {
      this.setSlide(this.index - 1, 'prev');
    },
    // Next slide
    next() {
      this.setSlide(this.index + 1, 'next');
    },
    // Pause auto rotation
    pause(event) {
      if (!event) {
        this.isPaused = true;
      }
      this.clearInterval();
    },
    // Start auto rotate slides
    start(event) {
      if (!event) {
        this.isPaused = false;
      }
      /* istanbul ignore next: most likely will never happen, but just in case */
      this.clearInterval();
      // Don't start if no interval, or less than 2 slides
      if (this.interval && this.numSlides > 1) {
        this.$_interval = setInterval(this.next, mathMax(1000, this.interval));
      }
    },
    // Restart auto rotate slides when focus/hover leaves the carousel
    /* istanbul ignore next */
    restart() {
      if (!this.$el.contains(getActiveElement())) {
        this.start();
      }
    },
    doSlide(to, from) {
      const isCycling = Boolean(this.interval);
      // Determine sliding direction
      const direction = this.calcDirection(this.direction, from, to);
      const overlayClass = direction.overlayClass;
      const dirClass = direction.dirClass;
      // Determine current and next slides
      const currentSlide = this.slides[from];
      const nextSlide = this.slides[to];
      // Don't do anything if there aren't any slides to slide to
      if (!currentSlide || !nextSlide) {
        /* istanbul ignore next */
        return;
      }
      // Start animating
      this.isSliding = true;
      if (isCycling) {
        this.pause(false);
      }
      this.$emit(EVENT_NAME_SLIDING_START, to);
      // Update v-model
      this.$emit(MODEL_EVENT_NAME, this.index);
      if (this.noAnimation) {
        addClass(nextSlide, 'active');
        removeClass(currentSlide, 'active');
        this.isSliding = false;
        // Notify ourselves that we're done sliding (slid)
        this.$nextTick(() => this.$emit(EVENT_NAME_SLIDING_END, to));
      } else {
        addClass(nextSlide, overlayClass);
        // Trigger a reflow of next slide
        reflow(nextSlide);
        addClass(currentSlide, dirClass);
        addClass(nextSlide, dirClass);
        // Transition End handler
        let called = false;
        /* istanbul ignore next: difficult to test */
        const onceTransEnd = () => {
          if (called) {
            return;
          }
          called = true;
          /* istanbul ignore if: transition events cant be tested in JSDOM */
          if (this.transitionEndEvent) {
            const events = this.transitionEndEvent.split(/\s+/);
            events.forEach(event => eventOff(nextSlide, event, onceTransEnd, EVENT_OPTIONS_NO_CAPTURE));
          }
          this.clearAnimationTimeout();
          removeClass(nextSlide, dirClass);
          removeClass(nextSlide, overlayClass);
          addClass(nextSlide, 'active');
          removeClass(currentSlide, 'active');
          removeClass(currentSlide, dirClass);
          removeClass(currentSlide, overlayClass);
          setAttr(currentSlide, 'aria-current', 'false');
          setAttr(nextSlide, 'aria-current', 'true');
          setAttr(currentSlide, 'aria-hidden', 'true');
          setAttr(nextSlide, 'aria-hidden', 'false');
          this.isSliding = false;
          this.direction = null;
          // Notify ourselves that we're done sliding (slid)
          this.$nextTick(() => this.$emit(EVENT_NAME_SLIDING_END, to));
        };
        // Set up transitionend handler
        /* istanbul ignore if: transition events cant be tested in JSDOM */
        if (this.transitionEndEvent) {
          const events = this.transitionEndEvent.split(/\s+/);
          events.forEach(event => eventOn(nextSlide, event, onceTransEnd, EVENT_OPTIONS_NO_CAPTURE));
        }
        // Fallback to setTimeout()
        this.$_animationTimeout = setTimeout(onceTransEnd, TRANS_DURATION);
      }
      if (isCycling) {
        this.start(false);
      }
    },
    // Update slide list
    updateSlides() {
      this.pause(true);
      // Get all slides as DOM elements
      this.slides = selectAll('.carousel-item', this.$refs.inner);
      const numSlides = this.slides.length;
      // Keep slide number in range
      const index = mathMax(0, mathMin(mathFloor(this.index), numSlides - 1));
      this.slides.forEach((slide, idx) => {
        const n = idx + 1;
        if (idx === index) {
          addClass(slide, 'active');
          setAttr(slide, 'aria-current', 'true');
        } else {
          removeClass(slide, 'active');
          setAttr(slide, 'aria-current', 'false');
        }
        setAttr(slide, 'aria-posinset', String(n));
        setAttr(slide, 'aria-setsize', String(numSlides));
      });
      // Set slide as active
      this.setSlide(index);
      this.start(this.isPaused);
    },
    calcDirection() {
      let direction = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : null;
      let curIndex = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 0;
      let nextIndex = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : 0;
      if (!direction) {
        return nextIndex > curIndex ? DIRECTION.next : DIRECTION.prev;
      }
      return DIRECTION[direction];
    },
    handleClick(event, fn) {
      const keyCode = event.keyCode;
      if (event.type === 'click' || keyCode === CODE_SPACE || keyCode === CODE_ENTER) {
        stopEvent(event);
        fn();
      }
    },
    /* istanbul ignore next: JSDOM doesn't support touch events */
    handleSwipe() {
      const absDeltaX = mathAbs(this.touchDeltaX);
      if (absDeltaX <= SWIPE_THRESHOLD) {
        return;
      }
      const direction = absDeltaX / this.touchDeltaX;
      // Reset touch delta X
      // https://github.com/twbs/bootstrap/pull/28558
      this.touchDeltaX = 0;
      if (direction > 0) {
        // Swipe left
        this.prev();
      } else if (direction < 0) {
        // Swipe right
        this.next();
      }
    },
    /* istanbul ignore next: JSDOM doesn't support touch events */
    touchStart(event) {
      if (HAS_POINTER_EVENT_SUPPORT && PointerType[event.pointerType.toUpperCase()]) {
        this.touchStartX = event.clientX;
      } else if (!HAS_POINTER_EVENT_SUPPORT) {
        this.touchStartX = event.touches[0].clientX;
      }
    },
    /* istanbul ignore next: JSDOM doesn't support touch events */
    touchMove(event) {
      // Ensure swiping with one touch and not pinching
      if (event.touches && event.touches.length > 1) {
        this.touchDeltaX = 0;
      } else {
        this.touchDeltaX = event.touches[0].clientX - this.touchStartX;
      }
    },
    /* istanbul ignore next: JSDOM doesn't support touch events */
    touchEnd(event) {
      if (HAS_POINTER_EVENT_SUPPORT && PointerType[event.pointerType.toUpperCase()]) {
        this.touchDeltaX = event.clientX - this.touchStartX;
      }
      this.handleSwipe();
      // If it's a touch-enabled device, mouseenter/leave are fired as
      // part of the mouse compatibility events on first tap - the carousel
      // would stop cycling until user tapped out of it;
      // here, we listen for touchend, explicitly pause the carousel
      // (as if it's the second time we tap on it, mouseenter compat event
      // is NOT fired) and after a timeout (to allow for mouse compatibility
      // events to fire) we explicitly restart cycling
      this.pause(false);
      this.clearTouchTimeout();
      this.$_touchTimeout = setTimeout(this.start, TOUCH_EVENT_COMPAT_WAIT + mathMax(1000, this.interval));
    }
  },
  render(h) {
    const {
      indicators,
      background,
      noAnimation,
      noHoverPause,
      noTouch,
      index,
      isSliding,
      pause,
      restart,
      touchStart,
      touchEnd
    } = this;
    const idInner = this.safeId('__BV_inner_');

    // Wrapper for slides
    const $inner = h('div', {
      staticClass: 'carousel-inner',
      attrs: {
        id: idInner,
        role: 'list'
      },
      ref: 'inner'
    }, [this.normalizeSlot()]);

    // Prev and next controls
    let $controls = h();
    if (this.controls) {
      const makeControl = (direction, label, handler) => {
        const handlerWrapper = event => {
          /* istanbul ignore next */
          if (!isSliding) {
            this.handleClick(event, handler);
          } else {
            stopEvent(event, {
              propagation: false
            });
          }
        };
        return h('a', {
          staticClass: `carousel-control-${direction}`,
          attrs: {
            href: '#',
            role: 'button',
            'aria-controls': idInner,
            'aria-disabled': isSliding ? 'true' : null
          },
          on: {
            click: handlerWrapper,
            keydown: handlerWrapper
          }
        }, [h('span', {
          staticClass: `carousel-control-${direction}-icon`,
          attrs: {
            'aria-hidden': 'true'
          }
        }), h('span', {
          class: 'sr-only'
        }, [label])]);
      };
      $controls = [makeControl('prev', this.labelPrev, this.prev), makeControl('next', this.labelNext, this.next)];
    }

    // Indicators
    const $indicators = h('ol', {
      staticClass: 'carousel-indicators',
      directives: [{
        name: 'show',
        value: indicators
      }],
      attrs: {
        id: this.safeId('__BV_indicators_'),
        'aria-hidden': indicators ? 'false' : 'true',
        'aria-label': this.labelIndicators,
        'aria-owns': idInner
      }
    }, this.slides.map((slide, i) => {
      const handler = event => {
        this.handleClick(event, () => {
          this.setSlide(i);
        });
      };
      return h('li', {
        class: {
          active: i === index
        },
        attrs: {
          role: 'button',
          id: this.safeId(`__BV_indicator_${i + 1}_`),
          tabindex: indicators ? '0' : '-1',
          'aria-current': i === index ? 'true' : 'false',
          'aria-label': `${this.labelGotoSlide} ${i + 1}`,
          'aria-describedby': slide.id || null,
          'aria-controls': idInner
        },
        on: {
          click: handler,
          keydown: handler
        },
        key: `slide_${i}`
      });
    }));
    const on = {
      mouseenter: noHoverPause ? noop : pause,
      mouseleave: noHoverPause ? noop : restart,
      focusin: pause,
      focusout: restart,
      keydown: event => {
        /* istanbul ignore next */
        if (/input|textarea/i.test(event.target.tagName)) {
          return;
        }
        const {
          keyCode
        } = event;
        if (keyCode === CODE_LEFT || keyCode === CODE_RIGHT) {
          stopEvent(event);
          this[keyCode === CODE_LEFT ? 'prev' : 'next']();
        }
      }
    };
    // Touch support event handlers for environment
    if (HAS_TOUCH_SUPPORT && !noTouch) {
      // Attach appropriate listeners (prepend event name with '&' for passive mode)
      /* istanbul ignore next: JSDOM doesn't support touch events */
      if (HAS_POINTER_EVENT_SUPPORT) {
        on['&pointerdown'] = touchStart;
        on['&pointerup'] = touchEnd;
      } else {
        on['&touchstart'] = touchStart;
        on['&touchmove'] = this.touchMove;
        on['&touchend'] = touchEnd;
      }
    }

    // Return the carousel
    return h('div', {
      staticClass: 'carousel',
      class: {
        slide: !noAnimation,
        'carousel-fade': !noAnimation && this.fade,
        'pointer-event': HAS_TOUCH_SUPPORT && HAS_POINTER_EVENT_SUPPORT && !noTouch
      },
      style: {
        background
      },
      attrs: {
        role: 'region',
        id: this.safeId(),
        'aria-busy': isSliding ? 'true' : 'false'
      },
      on
    }, [$inner, $controls, $indicators]);
  }
});

export { BCarousel, props };
