
/* Methods for rendering SEGMENTS, pieces of content that live on the view
 ( this file is no longer just for events )
----------------------------------------------------------------------------------------------------------------------*/

TimeGrid.mixin({

	colContainerEls: null, // containers for each column

	// inner-containers for each column where different types of segs live
	fgContainerEls: null,
	bgContainerEls: null,
	helperContainerEls: null,
	highlightContainerEls: null,
	businessContainerEls: null,

	// arrays of different types of displayed segments
	fgSegs: null,
	bgSegs: null,
	helperSegs: null,
	highlightSegs: null,
	businessSegs: null,


	// Renders the DOM that the view's content will live in
	renderContentSkeleton: function() {
		var cellHtml = '';
		var i;
		var skeletonEl;

		for (i = 0; i < this.colCnt; i++) {
			cellHtml +=
				'<td>' +
					'<div class="fc-content-col">' +
						'<div class="fc-event-container fc-helper-container"></div>' +
						'<div class="fc-event-container"></div>' +
						'<div class="fc-highlight-container"></div>' +
						'<div class="fc-bgevent-container"></div>' +
						'<div class="fc-business-container"></div>' +
					'</div>' +
				'</td>';
		}

		skeletonEl = $(
			'<div class="fc-content-skeleton">' +
				'<table>' +
					'<tr>' + cellHtml + '</tr>' +
				'</table>' +
			'</div>'
		);

		this.colContainerEls = skeletonEl.find('.fc-content-col');
		this.helperContainerEls = skeletonEl.find('.fc-helper-container');
		this.fgContainerEls = skeletonEl.find('.fc-event-container:not(.fc-helper-container)');
		this.bgContainerEls = skeletonEl.find('.fc-bgevent-container');
		this.highlightContainerEls = skeletonEl.find('.fc-highlight-container');
		this.businessContainerEls = skeletonEl.find('.fc-business-container');

		this.bookendCells(skeletonEl.find('tr')); // TODO: do this on string level
		this.el.append(skeletonEl);
	},


	/* Foreground Events
	------------------------------------------------------------------------------------------------------------------*/


	renderFgSegs: function(segs) {
		segs = this.renderFgSegsIntoContainers(segs, this.fgContainerEls);
		this.fgSegs = segs;
		return segs; // needed for Grid::renderEvents
	},


	unrenderFgSegs: function() {
		this.unrenderNamedSegs('fgSegs');
	},


	/* Foreground Helper Events
	------------------------------------------------------------------------------------------------------------------*/


	renderHelperSegs: function(segs, sourceSeg) {
		var i, seg;
		var sourceEl;

		segs = this.renderFgSegsIntoContainers(segs, this.helperContainerEls);

		// Try to make the segment that is in the same row as sourceSeg look the same
		for (i = 0; i < segs.length; i++) {
			seg = segs[i];
			if (sourceSeg && sourceSeg.col === seg.col) {
				sourceEl = sourceSeg.el;
				seg.el.css({
					left: sourceEl.css('left'),
					right: sourceEl.css('right'),
					'margin-left': sourceEl.css('margin-left'),
					'margin-right': sourceEl.css('margin-right')
				});
			}
		}

		this.helperSegs = segs;
	},


	unrenderHelperSegs: function() {
		this.unrenderNamedSegs('helperSegs');
	},


	/* Background Events
	------------------------------------------------------------------------------------------------------------------*/


	renderBgSegs: function(segs) {
		segs = this.renderFillSegEls('bgEvent', segs); // TODO: old fill system
		this.updateSegVerticals(segs);
		this.attachSegsByCol(this.groupSegsByCol(segs), this.bgContainerEls);
		this.bgSegs = segs;
		return segs; // needed for Grid::renderEvents
	},


	unrenderBgSegs: function() {
		this.unrenderNamedSegs('bgSegs');
	},


	/* Highlight
	------------------------------------------------------------------------------------------------------------------*/


	renderHighlightSegs: function(segs) {
		segs = this.renderFillSegEls('highlight', segs); // TODO: old fill system
		this.updateSegVerticals(segs);
		this.attachSegsByCol(this.groupSegsByCol(segs), this.highlightContainerEls);
		this.highlightSegs = segs;
	},


	unrenderHighlightSegs: function() {
		this.unrenderNamedSegs('highlightSegs');
	},


	/* Business Hours
	------------------------------------------------------------------------------------------------------------------*/


	renderBusinessSegs: function(segs) {
		segs = this.renderFillSegEls('businessHours', segs); // TODO: old fill system
		this.updateSegVerticals(segs);
		this.attachSegsByCol(this.groupSegsByCol(segs), this.businessContainerEls);
		this.businessSegs = segs;
	},


	unrenderBusinessSegs: function() {
		this.unrenderNamedSegs('businessSegs');
	},


	/* Seg Rendering Utils
	------------------------------------------------------------------------------------------------------------------*/


	// Given a flat array of segments, return an array of sub-arrays, grouped by each segment's col
	groupSegsByCol: function(segs) {
		var segsByCol = [];
		var i;

		for (i = 0; i < this.colCnt; i++) {
			segsByCol.push([]);
		}

		for (i = 0; i < segs.length; i++) {
			segsByCol[segs[i].col].push(segs[i]);
		}

		return segsByCol;
	},


	// Given segments grouped by column, insert the segments' elements into a parallel array of container
	// elements, each living within a column.
	attachSegsByCol: function(segsByCol, containerEls) {
		var col;
		var segs;
		var i;

		for (col = 0; col < this.colCnt; col++) { // iterate each column grouping
			segs = segsByCol[col];

			for (i = 0; i < segs.length; i++) {
				containerEls.eq(col).append(segs[i].el);
			}
		}
	},


	// Given the name of a property of `this` object, assumed to be an array of segments,
	// loops through each segment and removes from DOM. Will null-out the property afterwards.
	unrenderNamedSegs: function(propName) {
		var segs = this[propName];
		var i;

		if (segs) {
			for (i = 0; i < segs.length; i++) {
				segs[i].el.remove();
			}
			this[propName] = null;
		}
	},



	/* Foreground Event Rendering Utils
	------------------------------------------------------------------------------------------------------------------*/


	// Given an array of foreground segments, render a DOM element for each, computes position,
	// and attaches to the column inner-container elements.
	renderFgSegsIntoContainers: function(segs, containerEls) {
		var segsByCol;
		var col;

		segs = this.renderFgSegEls(segs); // will call fgSegHtml
		segsByCol = this.groupSegsByCol(segs);

		for (col = 0; col < this.colCnt; col++) {
			this.updateFgSegCoords(segsByCol[col]);
		}

		this.attachSegsByCol(segsByCol, containerEls);

		return segs;
	},


	// Renders the HTML for a single event segment's default rendering
	fgSegHtml: function(seg, disableResizing) {
		var view = this.view;
		var event = seg.event;
		var isDraggable = view.isEventDraggable(event);
		var isResizableFromStart = !disableResizing && seg.isStart && view.isEventResizableFromStart(event);
		var isResizableFromEnd = !disableResizing && seg.isEnd && view.isEventResizableFromEnd(event);
		var classes = this.getSegClasses(seg, isDraggable, isResizableFromStart || isResizableFromEnd);
		var skinCss = cssToStr(this.getEventSkinCss(event));
		var timeText;
		var fullTimeText; // more verbose time text. for the print stylesheet
		var startTimeText; // just the start time text

		classes.unshift('fc-time-grid-event', 'fc-v-event');

		if (view.isMultiDayEvent(event)) { // if the event appears to span more than one day...
			// Don't display time text on segments that run entirely through a day.
			// That would appear as midnight-midnight and would look dumb.
			// Otherwise, display the time text for the *segment's* times (like 6pm-midnight or midnight-10am)
			if (seg.isStart || seg.isEnd) {
				timeText = this.getEventTimeText(seg);
				fullTimeText = this.getEventTimeText(seg, 'LT');
				startTimeText = this.getEventTimeText(seg, null, false); // displayEnd=false
			}
		} else {
			// Display the normal time text for the *event's* times
			timeText = this.getEventTimeText(event);
			fullTimeText = this.getEventTimeText(event, 'LT');
			startTimeText = this.getEventTimeText(event, null, false); // displayEnd=false
		}

		return '<a class="' + classes.join(' ') + '"' +
			(event.url ?
				' href="' + htmlEscape(event.url) + '"' :
				''
				) +
			(skinCss ?
				' style="' + skinCss + '"' :
				''
				) +
			'>' +
				'<div class="fc-content">' +
					(timeText ?
						'<div class="fc-time"' +
						' data-start="' + htmlEscape(startTimeText) + '"' +
						' data-full="' + htmlEscape(fullTimeText) + '"' +
						'>' +
							'<span>' + htmlEscape(timeText) + '</span>' +
						'</div>' :
						''
						) +
					(event.title ?
						'<div class="fc-title">' +
							htmlEscape(event.title) +
						'</div>' :
						''
						) +
				'</div>' +
				'<div class="fc-bg"/>' +
				/* TODO: write CSS for this
				(isResizableFromStart ?
					'<div class="fc-resizer fc-start-resizer" />' :
					''
					) +
				*/
				(isResizableFromEnd ?
					'<div class="fc-resizer fc-end-resizer" />' :
					''
					) +
			'</a>';
	},


	/* Seg Position Utils
	------------------------------------------------------------------------------------------------------------------*/


	// Refreshes the CSS top/bottom coordinates for each segment element.
	// Works when called after initial render, after a window resize/zoom for example.
	updateSegVerticals: function(segs) {
		this.computeSegVerticals(segs);
		this.assignSegVerticals(segs);
	},


	// For each segment in an array, computes and assigns its top and bottom properties
	computeSegVerticals: function(segs) {
		var i, seg;

		for (i = 0; i < segs.length; i++) {
			seg = segs[i];
			seg.top = this.computeDateTop(seg.start, seg.start);
			seg.bottom = this.computeDateTop(seg.end, seg.start);
		}
	},


	// Given segments that already have their top/bottom properties computed, applies those values to
	// the segments' elements.
	assignSegVerticals: function(segs) {
		var i, seg;

		for (i = 0; i < segs.length; i++) {
			seg = segs[i];
			seg.el.css(this.generateSegVerticalCss(seg));
		}
	},


	// Generates an object with CSS properties for the top/bottom coordinates of a segment element
	generateSegVerticalCss: function(seg) {
		return {
			top: seg.top,
			bottom: -seg.bottom // flipped because needs to be space beyond bottom edge of event container
		};
	},


	/* Foreground Event Positioning Utils
	------------------------------------------------------------------------------------------------------------------*/


	// Given segments that are assumed to all live in the *same column*,
	// compute their verical/horizontal coordinates and assign to their elements.
	updateFgSegCoords: function(segs) {
		this.computeSegVerticals(segs); // horizontals relies on this
		this.computeFgSegHorizontals(segs); // compute horizontal coordinates, z-index's, and reorder the array
		this.assignSegVerticals(segs);
		this.assignFgSegHorizontals(segs);
	},


	// Given an array of segments that are all in the same column, sets the backwardCoord and forwardCoord on each.
	// NOTE: Also reorders the given array by date!
	computeFgSegHorizontals: function(segs) {
		var levels;
		var level0;
		var i;

		this.sortEventSegs(segs); // order by certain criteria
		levels = buildSlotSegLevels(segs);
		computeForwardSlotSegs(levels);

		if ((level0 = levels[0])) {

			for (i = 0; i < level0.length; i++) {
				computeSlotSegPressures(level0[i]);
			}

			for (i = 0; i < level0.length; i++) {
				this.computeFgSegForwardBack(level0[i], 0, 0);
			}
		}
	},


	// Calculate seg.forwardCoord and seg.backwardCoord for the segment, where both values range
	// from 0 to 1. If the calendar is left-to-right, the seg.backwardCoord maps to "left" and
	// seg.forwardCoord maps to "right" (via percentage). Vice-versa if the calendar is right-to-left.
	//
	// The segment might be part of a "series", which means consecutive segments with the same pressure
	// who's width is unknown until an edge has been hit. `seriesBackwardPressure` is the number of
	// segments behind this one in the current series, and `seriesBackwardCoord` is the starting
	// coordinate of the first segment in the series.
	computeFgSegForwardBack: function(seg, seriesBackwardPressure, seriesBackwardCoord) {
		var forwardSegs = seg.forwardSegs;
		var i;

		if (seg.forwardCoord === undefined) { // not already computed

			if (!forwardSegs.length) {

				// if there are no forward segments, this segment should butt up against the edge
				seg.forwardCoord = 1;
			}
			else {

				// sort highest pressure first
				this.sortForwardSegs(forwardSegs);

				// this segment's forwardCoord will be calculated from the backwardCoord of the
				// highest-pressure forward segment.
				this.computeFgSegForwardBack(forwardSegs[0], seriesBackwardPressure + 1, seriesBackwardCoord);
				seg.forwardCoord = forwardSegs[0].backwardCoord;
			}

			// calculate the backwardCoord from the forwardCoord. consider the series
			seg.backwardCoord = seg.forwardCoord -
				(seg.forwardCoord - seriesBackwardCoord) / // available width for series
				(seriesBackwardPressure + 1); // # of segments in the series

			// use this segment's coordinates to computed the coordinates of the less-pressurized
			// forward segments
			for (i=0; i<forwardSegs.length; i++) {
				this.computeFgSegForwardBack(forwardSegs[i], 0, seg.forwardCoord);
			}
		}
	},


	sortForwardSegs: function(forwardSegs) {
		forwardSegs.sort(proxy(this, 'compareForwardSegs'));
	},


	// A cmp function for determining which forward segment to rely on more when computing coordinates.
	compareForwardSegs: function(seg1, seg2) {
		// put higher-pressure first
		return seg2.forwardPressure - seg1.forwardPressure ||
			// put segments that are closer to initial edge first (and favor ones with no coords yet)
			(seg1.backwardCoord || 0) - (seg2.backwardCoord || 0) ||
			// do normal sorting...
			this.compareEventSegs(seg1, seg2);
	},


	// Given foreground event segments that have already had their position coordinates computed,
	// assigns position-related CSS values to their elements.
	assignFgSegHorizontals: function(segs) {
		var i, seg;

		for (i = 0; i < segs.length; i++) {
			seg = segs[i];
			seg.el.css(this.generateFgSegHorizontalCss(seg));

			// if the height is short, add a className for alternate styling
			if (seg.bottom - seg.top < 30) {
				seg.el.addClass('fc-short');
			}
		}
	},


	// Generates an object with CSS properties/values that should be applied to an event segment element.
	// Contains important positioning-related properties that should be applied to any event element, customized or not.
	generateFgSegHorizontalCss: function(seg) {
		var shouldOverlap = this.view.opt('slotEventOverlap');
		var backwardCoord = seg.backwardCoord; // the left side if LTR. the right side if RTL. floating-point
		var forwardCoord = seg.forwardCoord; // the right side if LTR. the left side if RTL. floating-point
		var props = this.generateSegVerticalCss(seg); // get top/bottom first
		var left; // amount of space from left edge, a fraction of the total width
		var right; // amount of space from right edge, a fraction of the total width

		if (shouldOverlap) {
			// double the width, but don't go beyond the maximum forward coordinate (1.0)
			forwardCoord = Math.min(1, backwardCoord + (forwardCoord - backwardCoord) * 2);
		}

		if (this.isRTL) {
			left = 1 - forwardCoord;
			right = backwardCoord;
		}
		else {
			left = backwardCoord;
			right = 1 - forwardCoord;
		}

		props.zIndex = seg.level + 1; // convert from 0-base to 1-based
		props.left = left * 100 + '%';
		props.right = right * 100 + '%';

		if (shouldOverlap && seg.forwardPressure) {
			// add padding to the edge so that forward stacked events don't cover the resizer's icon
			props[this.isRTL ? 'marginLeft' : 'marginRight'] = 10 * 2; // 10 is a guesstimate of the icon's width
		}

		return props;
	}

});


// Builds an array of segments "levels". The first level will be the leftmost tier of segments if the calendar is
// left-to-right, or the rightmost if the calendar is right-to-left. Assumes the segments are already ordered by date.
function buildSlotSegLevels(segs) {
	var levels = [];
	var i, seg;
	var j;

	for (i=0; i<segs.length; i++) {
		seg = segs[i];

		// go through all the levels and stop on the first level where there are no collisions
		for (j=0; j<levels.length; j++) {
			if (!computeSlotSegCollisions(seg, levels[j]).length) {
				break;
			}
		}

		seg.level = j;

		(levels[j] || (levels[j] = [])).push(seg);
	}

	return levels;
}


// For every segment, figure out the other segments that are in subsequent
// levels that also occupy the same vertical space. Accumulate in seg.forwardSegs
function computeForwardSlotSegs(levels) {
	var i, level;
	var j, seg;
	var k;

	for (i=0; i<levels.length; i++) {
		level = levels[i];

		for (j=0; j<level.length; j++) {
			seg = level[j];

			seg.forwardSegs = [];
			for (k=i+1; k<levels.length; k++) {
				computeSlotSegCollisions(seg, levels[k], seg.forwardSegs);
			}
		}
	}
}


// Figure out which path forward (via seg.forwardSegs) results in the longest path until
// the furthest edge is reached. The number of segments in this path will be seg.forwardPressure
function computeSlotSegPressures(seg) {
	var forwardSegs = seg.forwardSegs;
	var forwardPressure = 0;
	var i, forwardSeg;

	if (seg.forwardPressure === undefined) { // not already computed

		for (i=0; i<forwardSegs.length; i++) {
			forwardSeg = forwardSegs[i];

			// figure out the child's maximum forward path
			computeSlotSegPressures(forwardSeg);

			// either use the existing maximum, or use the child's forward pressure
			// plus one (for the forwardSeg itself)
			forwardPressure = Math.max(
				forwardPressure,
				1 + forwardSeg.forwardPressure
			);
		}

		seg.forwardPressure = forwardPressure;
	}
}


// Find all the segments in `otherSegs` that vertically collide with `seg`.
// Append into an optionally-supplied `results` array and return.
function computeSlotSegCollisions(seg, otherSegs, results) {
	results = results || [];

	for (var i=0; i<otherSegs.length; i++) {
		if (isSlotSegCollision(seg, otherSegs[i])) {
			results.push(otherSegs[i]);
		}
	}

	return results;
}


// Do these segments occupy the same vertical space?
function isSlotSegCollision(seg1, seg2) {
	return seg1.bottom > seg2.top && seg1.top < seg2.bottom;
}
