namespace SvgDrawing {
	export interface Rect {
		x: number;
		y: number;
		width: number;
		height: number;
	}
	
	export interface Point {
		x: number;
		y: number;
	}
	
	export class Point {
		public static add(a: Point, b: Point, out_result: Point) {
			out_result.x = a.x + b.x;
			out_result.y = a.y + b.y;
		}
		
		public static subtract(a: Point, b: Point, out_result: Point) {
			out_result.x = a.x - b.x;
			out_result.y = a.y - b.y;
		}
		
		public static normalize(v: Point) {
			let invN = 1.0 / Math.sqrt(v.x*v.x + v.y*v.y);
			v.x *= invN;
			v.y *= invN;
		}
		
		public static dot(a: Point, b: Point) {
			return a.x*b.x + a.y*b.y;
		}
		
		public static normalizedDot(a: Point, b: Point) {
			let NA = Math.sqrt(a.x*a.x + a.y*a.y);
			let NB = Math.sqrt(b.x*b.x + b.y*b.y);
			return (a.x*b.x + a.y*b.y) / NA / NB;
		}
	}
	
	export class Viewport {
		private invDataW: number = 0;
		private invDataH: number = 0;
		
		constructor(private data: Rect, private view: Rect) { this.update(); }
		
		setData(r: Rect) { this.data = r; this.update(); }
		setView(r: Rect) { this.view = r; this.update(); }
		
		xDataToView(x: number) { return (x - this.data.x) / this.data.width * this.view.width + this.view.x; }
		yDataToView(y: number) { return (y - this.data.y) / this.data.height * this.view.height + this.view.y; }
		
		dataToView(p: Point, out_point: Point) {
			out_point.x = (p.x - this.data.x) * this.invDataW * this.view.width + this.view.x;
			out_point.y = (p.y - this.data.y) * this.invDataH * this.view.height + this.view.y;
		}
		
		private update() {
			this.invDataW = 1.0 / this.data.width;
			this.invDataH = 1.0 / this.data.height;
		}
	}
	
	export interface LineStyle {
		className: string;
	}
	
	export class SvgElement {
		public viewport: Viewport;
		public width: number;
		public height: number;
		
		constructor(private htmlElement: HTMLElement) {
			let viewBox = htmlElement.getAttribute('viewBox').split(' ');
			let r: Rect = { x: Number(viewBox[0]), y: Number(viewBox[1]), width: Number(viewBox[2]), height: Number(viewBox[3]) };
			this.viewport = new Viewport(r, { x: r.x, y: r.y + r.height, width: r.width, height: -r.height });
			this.width = r.width;
			this.height = r.height;
		}
		
		clear() {
			this.htmlElement.querySelectorAll('*').forEach(elt => elt.remove());
		}
		
		line(start: Point, end: Point): SVGLineElement {
			let line = document.createElementNS('http://www.w3.org/2000/svg','line');
			line.setAttribute('x1', this.viewport.xDataToView(start.x).toString());
			line.setAttribute('y1', this.viewport.yDataToView(start.y).toString());
			line.setAttribute('x2', this.viewport.xDataToView(end.x).toString());
			line.setAttribute('y2', this.viewport.yDataToView(end.y).toString());
			this.htmlElement.append(line);
			return line;
		}
		
		text(position: Point, value: string, anchor?: string, verticalAlign?: number): SVGTextElement {
			let text = document.createElementNS('http://www.w3.org/2000/svg','text');
			text.setAttribute('x', this.viewport.xDataToView(position.x).toString());
			text.setAttribute('y', this.viewport.yDataToView(position.y).toString());
			if(anchor !== undefined) text.setAttribute('text-anchor', anchor);
			if(verticalAlign !== undefined) text.setAttribute('dy', (1.0-verticalAlign) + 'em');
			text.appendChild(document.createTextNode(value));
			this.htmlElement.append(text);
			return text;
		}
		
		graph(y: number[]): SVGPathElement[];
		graph(x: number[], y: number[]): SVGPathElement[];
		graph(y: number[], indices: number[], styles: LineStyle[]): SVGPathElement[];
		graph(x: number[], y: number[], indices: number[], styles: LineStyle[]): SVGPathElement[];
		graph(arg1: number[], arg2?: number[], arg3?: number[] | LineStyle[], arg4?: LineStyle[]): SVGPathElement[] {
			let indices: number[] | null = null;
			let styles: LineStyle[] | null = null;
			if(arg3) {
				if(arg4) {
					indices = <number[]>arg3;
					styles = arg4;
				}
				else {
					indices = arg2;
					styles = <LineStyle[]>arg3;
				}
			}
			
			if(styles == null) {
				styles = [{className: ''}];
			}
			
			let read = (idx: number, out_point: Point) => {
				out_point.x = arg1[idx];
				out_point.y = arg2[idx];
				return true;
			};
			
			let reset = (idx: number) => {};
			
			if(!arg2 || (arg3 && typeof(arg3[0]) !== 'number')) {
				read = (idx: number, out_point: Point) => {
					out_point.x = idx;
					out_point.y = arg1[idx];
					return true;
				};
			}
			
			let num = arg1.length;
			console.assert(!arg2 || num == arg2.length);
			
			if(num <= 1) return null;
			
			let optimizeCurveDist = 5;
			let optimizeCurveAngle = 45.0;
			if(optimizeCurveDist > 0 || optimizeCurveAngle < 0.0) {
				let rawRead = read;
				
				let dp = Math.cos(optimizeCurveAngle/180*Math.PI);
				
				let lastDrawnPoint: Point = { x: 0, y: 0 };
				
				let nextPoint: Point = { x: 0, y: 0 };
				let dir: Point = { x: 0, y: 0 };
				let nextDir: Point = { x: 0, y: 0 };
				let nextSegDir: Point = { x: 0, y: 0 };
				let perp: Point = { x: 0, y: 0 };
				
				let rawReset = reset;
				reset = (idx: number) => {
					rawReset(idx);
					read(idx, lastDrawnPoint);
				};
				
				read = (idx: number, out_point: Point) => {
					rawRead(idx, out_point);
					if(idx == 0 || idx == num - 1) return true;
					
					rawRead(idx + 1, nextPoint);
					Point.subtract(out_point, lastDrawnPoint, dir);
					Point.subtract(nextPoint, out_point, nextSegDir);
					
					if(Point.normalizedDot(dir, nextSegDir) < dp) {
						lastDrawnPoint = { ...out_point };
						return true;
					}
					
					Point.subtract(nextPoint, lastDrawnPoint, nextDir);
					
					perp.x = -nextDir.y;
					perp.y = nextDir.x;
					Point.normalize(perp);
					
					let d = Math.abs(Point.dot(perp, dir));
					if(d > optimizeCurveDist) {
						lastDrawnPoint = { ...out_point };
						return true;
					}
					
					return false;
				}
			}
			
			let startTime = performance.now();
			let count = 0;
			
			let paths = [];
			
			for(let styleIdx = 0; styleIdx < styles.length; ++styleIdx) {
				let dataPoint: Point = { x: 0, y: 0 };
				let viewPoint: Point = { x: 0, y: 0 };
				
				let coordinates = '';
				
				let open = false;
				for(let idx = 0; idx < num; ++idx) {
					let includePoint = !indices || indices[idx] == styleIdx;
					
					if(!open && includePoint) {
						reset(idx);
						read(idx, dataPoint);
						this.viewport.dataToView(dataPoint, viewPoint);
						let space = coordinates == '' ? '' : ' ';
						coordinates += space+'M'+Math.round(viewPoint.x)+','+Math.round(viewPoint.y) + ' L';
						count += 1;
					}
					else if(open && (read(idx, dataPoint) || !includePoint)) {
						this.viewport.dataToView(dataPoint, viewPoint);
						coordinates += ' '+Math.round(viewPoint.x)+','+Math.round(viewPoint.y);
						count += 1;
					}
					
					open = includePoint;
				}
				
				let style = styles[styleIdx];
				let path = document.createElementNS('http://www.w3.org/2000/svg','path');
				path.setAttribute('class', 'graph' + (style.className == '' ? '' : ' ' + style.className));
				path.setAttribute('d', coordinates);
				this.htmlElement.append(path);
				
				paths.push(path);
			}
			
			let endTime = performance.now();
			console.log("graph: " + count + " points, " + (endTime - startTime) + "ms");
			
			return paths;
		}
	}
}