dojo.provide("dojox.charting.plot2d.common");

dojo.require("dojo.colors");
dojo.require("dojox.gfx");
dojo.require("dojox.lang.functional");

(function(){
	var df = dojox.lang.functional, dc = dojox.charting.plot2d.common;

	dojo.mixin(dojox.charting.plot2d.common, {
		makeStroke: function(stroke){
			if(!stroke){ return stroke; }
			if(typeof stroke == "string" || stroke instanceof dojo.Color){
				stroke = {color: stroke};
			}
			return dojox.gfx.makeParameters(dojox.gfx.defaultStroke, stroke);
		},
		augmentColor: function(target, color){
			var t = new dojo.Color(target),
				c = new dojo.Color(color);
			c.a = t.a;
			return c;
		},
		augmentStroke: function(stroke, color){
			var s = dc.makeStroke(stroke);
			if(s){
				s.color = dc.augmentColor(s.color, color);
			}
			return s;
		},
		augmentFill: function(fill, color){
			var fc, c = new dojo.Color(color);
			if(typeof fill == "string" || fill instanceof dojo.Color){
				return dc.augmentColor(fill, color);
			}
			return fill;
		},

		defaultStats: {hmin: Number.POSITIVE_INFINITY, hmax: Number.NEGATIVE_INFINITY,
			vmin: Number.POSITIVE_INFINITY, vmax: Number.NEGATIVE_INFINITY},

		collectSimpleStats: function(series){
			var stats = dojo.clone(dc.defaultStats);
			for(var i = 0; i < series.length; ++i){
				var run = series[i];
				if(!run.data.length){ continue; }
				if(typeof run.data[0] == "number"){
					// 1D case
					var old_vmin = stats.vmin, old_vmax = stats.vmax;
					if(!("ymin" in run) || !("ymax" in run)){
						dojo.forEach(run.data, function(val, i){
							var x = i + 1, y = val;
							if(isNaN(y)){ y = 0; }
							stats.hmin = Math.min(stats.hmin, x);
							stats.hmax = Math.max(stats.hmax, x);
							stats.vmin = Math.min(stats.vmin, y);
							stats.vmax = Math.max(stats.vmax, y);
						});
					}
					if("ymin" in run){ stats.vmin = Math.min(old_vmin, run.ymin); }
					if("ymax" in run){ stats.vmax = Math.max(old_vmax, run.ymax); }
				}else{
					// 2D case
					var old_hmin = stats.hmin, old_hmax = stats.hmax,
						old_vmin = stats.vmin, old_vmax = stats.vmax;
					if(!("xmin" in run) || !("xmax" in run) || !("ymin" in run) || !("ymax" in run)){
						dojo.forEach(run.data, function(val, i){
							var x = val.x, y = val.y;
							if(isNaN(x)){ x = 0; }
							if(isNaN(y)){ y = 0; }
							stats.hmin = Math.min(stats.hmin, x);
							stats.hmax = Math.max(stats.hmax, x);
							stats.vmin = Math.min(stats.vmin, y);
							stats.vmax = Math.max(stats.vmax, y);
						});
					}
					if("xmin" in run){ stats.hmin = Math.min(old_hmin, run.xmin); }
					if("xmax" in run){ stats.hmax = Math.max(old_hmax, run.xmax); }
					if("ymin" in run){ stats.vmin = Math.min(old_vmin, run.ymin); }
					if("ymax" in run){ stats.vmax = Math.max(old_vmax, run.ymax); }
				}
			}
			return stats;
		},

		calculateBarSize: function(/* Number */ availableSize, /* Object */ opt, /* Number? */ clusterSize){
			if(!clusterSize){
				clusterSize = 1;
			}
			var gap = opt.gap, size = (availableSize - 2 * gap) / clusterSize;
			if("minBarSize" in opt){
				size = Math.max(size, opt.minBarSize);
			}
			if("maxBarSize" in opt){
				size = Math.min(size, opt.maxBarSize);
			}
			size = Math.max(size, 1);
			gap = (availableSize - size * clusterSize) / 2;
			return {size: size, gap: gap};	// Object
		},

		collectStackedStats: function(series){
			// collect statistics
			var stats = dojo.clone(dc.defaultStats);
			if(series.length){
				// 1st pass: find the maximal length of runs
				stats.hmin = Math.min(stats.hmin, 1);
				stats.hmax = df.foldl(series, "seed, run -> Math.max(seed, run.data.length)", stats.hmax);
				// 2nd pass: stack values
				for(var i = 0; i < stats.hmax; ++i){
					var v = series[0].data[i];
					if(isNaN(v)){ v = 0; }
					stats.vmin = Math.min(stats.vmin, v);
					for(var j = 1; j < series.length; ++j){
						var t = series[j].data[i];
						if(isNaN(t)){ t = 0; }
						v += t;
					}
					stats.vmax = Math.max(stats.vmax, v);
				}
			}
			return stats;
		},

		curve: function(/* Number[] */a, /* Number|String */tension){
			//	FIX for #7235, submitted by Enzo Michelangeli.
			//	Emulates the smoothing algorithms used in a famous, unnamed spreadsheet
			//		program ;)
			var arr = a.slice(0);
			if(tension == "x") {
				arr[arr.length] = arr[0];   // add a last element equal to the first, closing the loop
			}
			var p=dojo.map(arr, function(item, i){
				if(i==0){ return "M" + item.x + "," + item.y; }
				if(!isNaN(tension)) { // use standard Dojo smoothing in tension is numeric
					var dx=item.x-arr[i-1].x, dy=arr[i-1].y;
					return "C"+(item.x-(tension-1)*(dx/tension))+","+dy+" "+(item.x-(dx/tension))+","+item.y+" "+item.x+","+item.y;
				} else if(tension == "X" || tension == "x" || tension == "S") {
					// use Excel "line smoothing" algorithm (http://xlrotor.com/resources/files.shtml)
					var p0, p1 = arr[i-1], p2 = arr[i], p3;
					var bz1x, bz1y, bz2x, bz2y;
					var f = 1/6;
					if(i==1) {
						if(tension == "x") {
							p0 = arr[arr.length-2];
						} else { // "tension == X || tension == "S"
							p0 = p1;
						}
						f = 1/3;
					} else {
						p0 = arr[i-2];
					}
					if(i==(arr.length-1)) {
						if(tension == "x") {
							p3 = arr[1];
						} else { // "tension == X || tension == "S"
							p3 = p2;
						}
						f = 1/3;
					} else {
						p3 = arr[i+1];
					}
					var p1p2 = Math.sqrt((p2.x-p1.x)*(p2.x-p1.x)+(p2.y-p1.y)*(p2.y-p1.y));
					var p0p2 = Math.sqrt((p2.x-p0.x)*(p2.x-p0.x)+(p2.y-p0.y)*(p2.y-p0.y));
					var p1p3 = Math.sqrt((p3.x-p1.x)*(p3.x-p1.x)+(p3.y-p1.y)*(p3.y-p1.y));

					var p0p2f = p0p2 * f;
					var p1p3f = p1p3 * f;

					if(p0p2f > p1p2/2 && p1p3f > p1p2/2) {
						p0p2f = p1p2/2;
						p1p3f = p1p2/2;
					} else if(p0p2f > p1p2/2) {
						p0p2f = p1p2/2;
						p1p3f = p1p2/2 * p1p3/p0p2;
					} else if(p1p3f > p1p2/2) {
						p1p3f = p1p2/2;
						p0p2f = p1p2/2 * p0p2/p1p3;
					}

					if(tension == "S") {
						if(p0 == p1) { p0p2f = 0; }
						if(p2 == p3) { p1p3f = 0; }
					}

					bz1x = p1.x + p0p2f*(p2.x - p0.x)/p0p2;
					bz1y = p1.y + p0p2f*(p2.y - p0.y)/p0p2;
					bz2x = p2.x - p1p3f*(p3.x - p1.x)/p1p3;
					bz2y = p2.y - p1p3f*(p3.y - p1.y)/p1p3;
				}
				return "C"+(bz1x+","+bz1y+" "+bz2x+","+bz2y+" "+p2.x+","+p2.y);
			});
			return p.join(" ");
		}
	});
})();