let slideShowInterval = null

/**
 * Disables hiding of various child items 
 * once model has loaded
 */
modelLoaded = function(e) {
    $('.awaiting-model').css('display', 'flex').removeClass('awaiting-model')
    if (typeof enableMenu != 'undefined') {enableMenu()}
}

/**
 * Event listener callback to toggle the visibility
 * of a hotspot's annotation when the hotspot is 
 * clicked
 * 
 * @param {PointerEvent} e 
 */
onAnnotation = function(e) {
	e.stopPropagation()
    if (typeof isDeleting != 'undefined' && isDeleting()) {
        clickDeleteHotspot(e)
        return
    }
	let targetAnnotation = Number.parseInt(e.target.slot.split('-')[1])
	let targetModel = e.target.closest('model-viewer')
    selectAnnotation(targetModel, targetAnnotation)
}

/**
 * Event listener callback to hide all hotspot
 * annotations when the model-viewer receives
 * a click event
 */
clearAnnotations = function() {
	[...document.getElementsByClassName('HotspotAnnotation')].forEach( an => {
		an.classList.add('HiddenAnnotation')
	})
};

/**
 * Select the numbered hotspot of the given model
 * 
 * @param {ModelViewer} mView
 * @param {number} annotId
 * 
 * @return {bool} true if annotation selected false if unselected
 */
selectAnnotation = function(mView, annotId) {
    let anSelected = false;
    [...mView.querySelectorAll('.HotspotAnnotation')].forEach( (an, idx) => {
		if (idx + 1 == annotId && an.classList.contains('HiddenAnnotation')) {
			an.classList.remove('HiddenAnnotation');
			if (an.parentElement.dataset.target) {mView.cameraTarget = an.parentElement.dataset.target}
			if (an.parentElement.dataset.orbit) {mView.cameraOrbit = an.parentElement.dataset.orbit}
            const anFov = an.parentElement.getAttribute('field-of-view')
			if (anFov) {mView.fieldOfView = anFov}
            anSelected = true
		} else {
			an.classList.add('HiddenAnnotation');
		}        
	});
    return anSelected
}

/**
 * Select the next numbered hotspot
 * 
 * @param {ModelViewer} mView
 * 
 * @return {number} ID number of the newly selected hotspot
 */
nextAnnotation = function(mView) {
    let incrAnnotation = 0
    const numSpots = [...mView.querySelectorAll('Button:not([seq-skip])')].length
    const currentAnnotation = mView.querySelectorAll('Button:has(.HotspotAnnotation:not(.HiddenAnnotation))')[0]
    if (!currentAnnotation) {
        incrAnnotation = 1
    } else {
        const annotationId = Number.parseInt(currentAnnotation.slot.split('-')[1])
        incrAnnotation = (annotationId >= numSpots)
            ? 1
            : annotationId + 1
    }
    selectAnnotation(mView, incrAnnotation)
    return incrAnnotation
}

/**
 * Select the previous numbered hotspot
 * 
 * @param {ModelViewer} mView
 * 
 * @return {number} ID number of the newly selected hotspot
 */
prevAnnotation = function(mView) {
    let decrAnnotation = 0
    const numSpots = [...mView.querySelectorAll('Button:not([seq-skip])')].length
    const currentAnnotation = mView.querySelectorAll('Button:has(.HotspotAnnotation:not(.HiddenAnnotation))')[0]
    if (!currentAnnotation) {
        decrAnnotation = numSpots
    } else {
        const annotationId = Number.parseInt(currentAnnotation.slot.split('-')[1])
        decrAnnotation = (annotationId <= 1)
            ? numSpots
            : annotationId - 1
    }
    selectAnnotation(mView, decrAnnotation)
    return decrAnnotation
}

/**
 * Cycle through the available annotations
 * 
 * @param {ModelViewer} mView
 * 
 * @param {Number} [slideDuration = 5000]
 * 
 * @return {intervalID} ID of the created interval timer
 */
slideshowAnnotations = function(mView, slideDuration = 3000) {
    if (slideShowInterval) {
        clearInterval(slideShowInterval)
    } else {
        nextAnnotation(mView)
        slideShowInterval = setInterval(nextAnnotation, slideDuration, mView)
    }
}

/**
 * Toggle visibility of all annotations
 * 
 * @param {ModelViewer} mView 
 */
toggleAnnotations = function(mView) {
    if (slideShowInterval) {
        clearInterval(slideShowInterval)
        const slideButton = mView.parentElement.querySelector('[toggled]')
        if (slideButton) slideButton.toggleAttribute('toggled')
    }
    [...mView.querySelectorAll('button')].forEach( hs => {
        hs.toggleAttribute('hidden')
    })
    const hsButtons = [...mView.parentElement.querySelectorAll('.disable-on-hide')]
    hsButtons.forEach( mb => {
        mb.toggleAttribute('disabled')
    })
}

/**
 * Respond to full screen changes on the gl container
 * 
 * @param {Element} glCont container element to enlarge or reduce
 */
toggleFullScreen = function(glCont) {
    if (document.fullscreenElement) {
        document.exitFullscreen()
    } else {
        glCont.requestFullscreen()
    }
}

/**
 * Reset view to initial position
 * 
 * @param {ModelViewer} mView
 */
resetView = function(mView) {
    const resetOrb = mView.getAttribute('camera-orbit') || 'auto auto auto'
    const resetTarg = mView.getAttribute('camera-target') || 'auto auto auto'
    const resetFov = mView.getAttribute('field-of-view') || 'auto'
    mView.cameraOrbit = resetOrb
    mView.cameraTarget = resetTarg
    mView.fieldOfView = resetFov
}