//
// draw track
//

const RAILWAY_NOTHING = 0;
const RAILWAY_NORMAL = 1;
const RAILWAY_CROSSING = 2;
const RAILWAY_TURNOUT = 3;
const RAILWAY_SENSOR = 4;
const RAILWAY_CONNECTOR = 5;
const RAILWAY_BUTTON = 6;
const RAILWAY_TEXT = 7;
const RAILWAY_BLOCK = 8;

var track = { 
		size: {x: -1, y: -1}, 
		scale: 32, 
		dbuf: {}, 
		elements: []
	};

var trackMouse = {
		pos: {x: -1, y: -1, subx: 0.5, suby: 0.5},
		down: {x :-1 , y: -1, subx: 0.5, suby: 0.5}
	};


//
// mode: 0 = normal
// mode: 1 = selected
// mode: 2 = mouseover
//
// direktion (object type)
//
//  +---+   +---+   +---+   +---+
//  |   |   | | |   |   |   |/  |
// 0|   |  1| | |  2|---|  3|   |
//  |   |   | | |   |   |   |   |
//  +---+   +---+   +---+   +---+
//
//  +---+   +---+   +---+   +---+
//  |  \|   |   |   |   |   |   |
// 4|   |  5|   |  6|   |  7|   |
//  |   |   |  /|   |\  |   |   |
//  +---+   +---+   +---+   +---+
//
// direction (arrow type)
//
//      0  
//    7 | 1
//     \|/
//   6--+--2
//     /|\
//    5 | 3
//      4
//

function trackDrawTrack(ctx, pos, dirtype) {
	var s = { x:0 , y:0 };
	var e = { x:0 , y:0 };

	if (dirtype == 1) {
		s = { x: 0.5, y: 0.0 };
		e = { x: 0.5, y: 1.0 };
	}
	else if (dirtype == 2) {
		s = { x: 0.0, y: 0.5 };
		e = { x: 1.0, y: 0.5 };
	}
	else if (dirtype == 3) {
		s = { x: 0.5, y: 0.0 };
		e = { x: 0.0, y: 0.5 };
	}
	else if (dirtype == 4) {
		s = { x: 0.5, y: 0.0 };
		e = { x: 1.0, y: 0.5 };
	}
	else if (dirtype == 5) {
		s = { x: 0.5, y: 1.0 };
		e = { x: 1.0, y: 0.5 };
	}
	else if (dirtype == 6) {
		s = { x: 0.5, y: 1.0 };
		e = { x: 0.0, y: 0.5 };
	}
	else {
		s = { x: 0, y: 0 };
		e = { x: 0, y: 0 };
	}
	
	if (s.x != e.x || s.y != e.x) {
		ctx.beginPath();
		ctx.moveTo(0.5+(pos.x+s.x) * track.scale, 0.5+(pos.y+s.y) * track.scale);
		ctx.lineTo(0.5+(pos.x+e.x) * track.scale, 0.5+(pos.y+e.y) * track.scale);
		ctx.stroke();
	}
}


function cssVar(name,value){
    if(name[0]!='-') name = '--'+name //allow passing with or without --
    if(value) document.documentElement.style.setProperty(name, value)
    return getComputedStyle(document.documentElement).getPropertyValue(name);
}


function trackDrawElement(ctx, element, mode) {
	var dx = 0, dy = 0;
	var modcol = cssVar('--track-color');
	
	if (element) {
	
		if (mode == 1) modcol = cssVar('--track-color-select');
	
		if (element.type) {
			if (element.type == RAILWAY_TURNOUT) {
				//
				// turnout
				var	dir = element.dir;
				var	altdir = element.altdir;
				
				if (element.name != "")	if (turnout_IsTurnoutActive(element.name)) {
					// debug ("draw element:" + element.name + " isActive:" + 	turnout_IsActive(element.name));
					altdir = element.dir;
					dir = element.altdir;
				}
				ctx.lineWidth = 4;
				ctx.setLineDash([0,0]);
                if (element.lockedby && element.lockedby != "")  
                    ctx.strokeStyle = cssVar('--track-color-locked');
				else                         
				    ctx.strokeStyle = ctx.strokeStyle = cssVar('--turnout-this');
				trackDrawTrack (ctx, {x: element.x, y: element.y}, dir);
				ctx.setLineDash([0,0]);
				if (element.name == "") ctx.strokeStyle = cssVar('--track-color-error');
				else 					ctx.strokeStyle = cssVar('--turnout-other');

				trackDrawTrack (ctx, {x: element.x, y: element.y}, altdir);
			}
			else if (element.type == RAILWAY_BUTTON) {
                let bi;
				ctx.beginPath();
				ctx.lineWidth = 2;
				ctx.setLineDash([0,0]);
            
       			ctx.strokeStyle = cssVar('--button-inactive');
                for (bi = 0; bi < turnouts.length; bi++) {
                    if (turnouts[bi].name == element.name) {
                    	if ((turnouts[bi].flags & TURNOUT_F_OUTPUTACTIVE) != 0)
	            			ctx.strokeStyle = cssVar('--button-active');
                    }
                }
				ctx.moveTo((element.x+0.1) * track.scale, (element.y+0.1) * track.scale);
				ctx.lineTo((element.x+0.9) * track.scale, (element.y+0.1) * track.scale);
				ctx.lineTo((element.x+0.9) * track.scale, (element.y+0.9) * track.scale);
				ctx.lineTo((element.x+0.1) * track.scale, (element.y+0.9) * track.scale);
				ctx.lineTo((element.x+0.1) * track.scale, (element.y+0.1) * track.scale);
				ctx.stroke();
			}
			else if (element.type == RAILWAY_NORMAL || element.type == RAILWAY_SENSOR || element.type == RAILWAY_BLOCK) {
				//
				// normal
				ctx.lineWidth = 2;
				ctx.setLineDash([0,0]);
				ctx.strokeStyle = modcol;
                if (element.lockedby && element.lockedby != "")  
                    ctx.strokeStyle = cssVar('--track-color-locked');
				trackDrawTrack (ctx, {x: element.x, y: element.y}, element.dir);
			}
			else if (element.type == RAILWAY_CROSSING) {
				//
				// crossing
				ctx.lineWidth = 2;
				ctx.setLineDash([0,0]);
				ctx.strokeStyle = modcol;
                if (element.lockedby && element.lockedby != "")  
                    ctx.strokeStyle = cssVar('--track-color-locked');
				trackDrawTrack (ctx, {x: element.x, y: element.y}, element.dir);
				trackDrawTrack (ctx, {x: element.x, y: element.y}, element.altdir);
			}
			else if (element.type == RAILWAY_TEXT) {
				ctx.font = "14px Arial";
				ctx.textAlign = "left";
				if (element.name != "")	{
					ctx.fillStyle = cssVar('--track-text');
					ctx.fillText(element.name, (element.x+0.5) * track.scale, 6+(element.y+0.5) * track.scale);
				}
				else {
					ctx.fillStyle = cssVar('--track-color-error');
					ctx.fillText("------", (element.x+0.5) * track.scale, (element.y+0.5) * track.scale);
				}
			}
			else if (element.type == RAILWAY_CONNECTOR) {
				ctx.font = "bold 12px Arial";
				ctx.textAlign = "center";
				if (element.name != "")	{
					ctx.fillStyle = cssVar('--track-connector');
					ctx.fillText(element.name, (element.x+0.5) * track.scale, 6+(element.y+0.5) * track.scale);
				}
				else {
					ctx.fillStyle = cssVar('--track-color-error');
					ctx.fillText("------", (element.x+0.5) * track.scale, (element.y+0.5) * track.scale);
				}
			}
			else if (element.type != RAILWAY_NOTHING) {
				ctx.beginPath();
				ctx.lineWidth = 2;
				ctx.setLineDash([0,0]);
				ctx.strokeStyle = cssVar('--track-color-error');
				ctx.moveTo((element.x+0.25) * track.scale, (element.y+0.25) * track.scale);
				ctx.lineTo((element.x+0.75) * track.scale, (element.y+0.75) * track.scale);
				ctx.moveTo((element.x+0.75) * track.scale, (element.y+0.25) * track.scale);
				ctx.lineTo((element.x+0.25) * track.scale, (element.y+0.75) * track.scale);
				ctx.stroke();
			}
			
			//
			// additional draing of elements
			if (element.type == RAILWAY_SENSOR) {
   				ctx.beginPath();
				ctx.arc((element.x+0.5) * track.scale, (element.y+0.5) * track.scale, track.scale*0.25, 0, 2 * Math.PI);
				if (element.name == "") 				ctx.fillStyle = cssVar('--track-color-error');
				else if (sensor_IsActive(element.name)) ctx.fillStyle = cssVar('--sensor-active');
				else 									ctx.fillStyle = cssVar('--sensor-inactive');
				
				ctx.fill();
      			ctx.lineWidth = 2;
				ctx.strokeStyle = cssVar('--track-border');
				ctx.stroke();
			}
			
			//
			// draw ref. name
			if (element.name && sideBtnCmdGet() == "cmd-track-detail") {
				if (element.type != RAILWAY_TEXT && element.type != RAILWAY_CONNECTOR 
				       && element.type != RAILWAY_BLOCK) {
					ctx.font = "10px Arial";
					ctx.textAlign = "left";
					if (element.name != "")	{
						ctx.fillStyle = cssVar('--track-element-fgborder');
						ctx.fillText(element.name, (element.x) * track.scale -1, 6+(element.y+0.5) * track.scale   );
						ctx.fillText(element.name, (element.x) * track.scale +1, 6+(element.y+0.5) * track.scale   );
						ctx.fillText(element.name, (element.x) * track.scale   , 6+(element.y+0.5) * track.scale -1);
						ctx.fillText(element.name, (element.x) * track.scale   , 6+(element.y+0.5) * track.scale +1);
						ctx.fillText(element.name, (element.x) * track.scale +1, 6+(element.y+0.5) * track.scale +1);
						ctx.fillText(element.name, (element.x) * track.scale -1, 6+(element.y+0.5) * track.scale -1);
						ctx.fillText(element.name, (element.x) * track.scale +1, 6+(element.y+0.5) * track.scale -1);
						ctx.fillText(element.name, (element.x) * track.scale +1, 6+(element.y+0.5) * track.scale +1);
						ctx.fillText(element.name, (element.x) * track.scale -1, 6+(element.y+0.5) * track.scale +1);
						ctx.fillStyle = cssVar('--track-element-fg');
						ctx.fillText(element.name, (element.x) * track.scale , 6+(element.y+0.5) * track.scale );
					}
				}			
			}
		}
	}
};



function trackDrawBlock(ctx, blockelm) {

	if (blockelm.dir == 1 || blockelm.dir == 2) {           //  1 .. | 2.. -
	    let x1, y1, x2, y2, a, b;
	    let text, color;
        let block;

	    // select color depending on referecedBy
    	for (var i = 0; i < blocks.length; i++) {
	    	if (blockelm.name == blocks[i].name) {
	    		block = blocks[i];
	    		break;
	    	}
    	}

	    // Fill Box
		x1 = 0 * track.scale + 2;
		y1 = (-1) * track.scale + 2;
		x2 = ( 1) * track.scale - 2;
		y2 = ( 2) * track.scale - 2;

	    if (blockelm.dir == 2) {
	    	a = y1; y1 = x1; x1 = a;
	    	b = y2; y2 = x2; x2 = b;
   	    }

        x1 = x1 + (blockelm.x) * track.scale;
        x2 = x2 + (blockelm.x) * track.scale;
        y1 = y1 + (blockelm.y) * track.scale;
        y2 = y2 + (blockelm.y) * track.scale;

        // debug ("Flags:" + Number(blockelm.flags) + " Res:" + (Number(blockelm.flags) & BLOCK_F_OFF));
		if (block && Number(block.flags) & BLOCK_F_OFF) ctx.fillStyle = cssVar('--block-bg-closed');
		else if (blockelm.lockedby && blockelm.lockedby != "") ctx.fillStyle = cssVar('--block-bg-locked');
		else                         ctx.fillStyle = cssVar('--block-bg');
	    ctx.fillRect (x1, y1, (x2-x1), (y2-y1));

		ctx.beginPath();
		ctx.lineWidth = 2;
		ctx.setLineDash([0,0]);
		ctx.strokeStyle = cssVar('--track-border');
		ctx.moveTo(x1+0.5, y1+0.5);
		ctx.lineTo(x2+0.5, y1+0.5);
		ctx.lineTo(x2+0.5, y2+0.5);
		ctx.lineTo(x1+0.5, y2+0.5);
		ctx.lineTo(x1+0.5, y1+0.5);
		ctx.stroke();
    
	    if (blockelm.dir == 2) {
			x1 = (0.5 + blockelm.x) * track.scale;
			y1 = (0.5 + blockelm.y) * track.scale + 5;

			ctx.font = "10px Arial";
			ctx.textAlign = "center";
			if (block && Number(block.flags) & BLOCK_F_OFF) ctx.fillStyle = cssVar('--block-fg-closed');
			else if (blockelm.lockedby && blockelm.lockedby != "") ctx.fillStyle = cssVar('--block-fg-locked');
			else                         ctx.fillStyle = cssVar('--block-fg');

            let li;
            text = blockelm.name;

            for (li = 0; li < locomotives.length; li++)
                if (locomotives[li].name == blockelm.lockedby) {
                   	if (locomotives[li].blockassign.substring(2,2+blockelm.lockedby.length) == blockelm.name) {
                    	if (locomotives[li].blockassign.substring(0,1) == "-") text = "<= "+blockelm.lockedby;
                    	else text = blockelm.lockedby + " =>";
                	}
                	else {
                		text = blockelm.lockedby;
                	}
                }

			ctx.fillText(text, x1, y1);
	    } else  {
			x1 = (0.5 + blockelm.x) * track.scale + 5;
			y1 = (0.5 + blockelm.y) * track.scale;

	    	ctx.save();
	    	ctx.translate(x1, y1);
	    	ctx.rotate(-Math.PI/2);
			ctx.font = "10px Arial";
			ctx.textAlign = "center";
			if (block && Number(block.flags) & BLOCK_F_OFF) ctx.fillStyle = cssVar('--block-fg-closed');
			else if (blockelm.lockedby && blockelm.lockedby != "") ctx.fillStyle = cssVar('--block-fg-locked');
			else                         ctx.fillStyle = cssVar('--block-fg');

            let li;
            text = blockelm.name;
            
            for (li = 0; li < locomotives.length; li++)
                if (locomotives[li].name == blockelm.lockedby) {                	
                   	if (locomotives[li].blockassign.substring(2,2+blockelm.lockedby.length) == blockelm.name) {
                    	if (locomotives[li].blockassign.substring(0,1) == "-") text = blockelm.lockedby + " =>";
                    	else text = "<= " + blockelm.lockedby;
                    }
                    else text = blockelm.lockedby;
                }
                
			ctx.fillText(text, 0, 0);
			ctx.restore();
	    }
	}
	else {
		ctx.beginPath();
		ctx.lineWidth = 1;
		ctx.setLineDash([0,0]);
		ctx.strokeStyle = cssVar('--track-color-error');
		ctx.moveTo((blockelm.x+0.25) * track.scale, (blockelm.y+0.25) * track.scale);
		ctx.lineTo((blockelm.x+0.75) * track.scale, (blockelm.y+0.75) * track.scale);
		ctx.moveTo((blockelm.x+0.75) * track.scale, (blockelm.y+0.25) * track.scale);
		ctx.lineTo((blockelm.x+0.25) * track.scale, (blockelm.y+0.75) * track.scale);
		ctx.stroke();
	}
};


function trackDraw() {
	var ctx = track.dbuf.getContext("2d");
	var elm = {};
	var tmpblocks = new Array();

	//	debug ("trackDraw pos: " + trackMouse.pos.x + "," + trackMouse.pos.y + 
	//		   "  down: " + trackMouse.down.x + "," + trackMouse.down.y);

	
	//
	// clear screen
	ctx.fillStyle = cssVar('--track-bg');
	ctx.fillRect(0, 0, track.size.x * track.scale, track.size.y * track.scale);

	//
	// draw elements
	for (var i = 0; i < track.elements.length; i++) if (track.elements[i]) {
		if (track.elements[i].type == RAILWAY_BLOCK) {
			tmpblocks.push (track.elements[i]);
		}
		trackDrawElement(ctx, track.elements[i], 0);
	}

	//
	// draw block
	for (var i = 0; i < tmpblocks.length; i++) {
		trackDrawBlock(ctx, tmpblocks[i]);
	}
	tmpblocks.length = 0;
	
	//
	// draw down position
	if (trackMouse.down.x >= 0) {
		var p1 = {};
		var p2 = {};
		
		if (trackMouse.pos.x < trackMouse.down.x) {
			p1.x = trackMouse.pos.x;
			p2.x = trackMouse.down.x;
		}			
		else {
			p1.x = trackMouse.down.x;
			p2.x = trackMouse.pos.x;
		}
		
		if (trackMouse.pos.y < trackMouse.down.y) {
			p1.y = trackMouse.pos.y;
			p2.y = trackMouse.down.y;
		}			
		else {
			p1.y = trackMouse.down.y;
			p2.y = trackMouse.pos.y;
		}
				
		ctx.lineWidth = 1;
		ctx.lineJoin="round";
		ctx.miterLimit = 1;
		ctx.setLineDash([2,2]);
		ctx.strokeStyle = cssVar('--track-color-selectframe');
		ctx.beginPath();
		ctx.moveTo(0.5+(p1.x + 0) * track.scale, 0.5+(p1.y+0) * track.scale);
		ctx.lineTo(0.5+(p2.x + 1) * track.scale, 0.5+(p1.y+0) * track.scale);
		ctx.lineTo(0.5+(p2.x + 1) * track.scale, 0.5+(p2.y+1) * track.scale);
		ctx.lineTo(0.5+(p1.x + 0) * track.scale, 0.5+(p2.y+1) * track.scale);
		ctx.lineTo(0.5+(p1.x + 0) * track.scale, 0.5+(p1.y+0) * track.scale);
		ctx.stroke();
	}

	//
	// draw mouse cursor
	ctx.lineWidth = 1;
	ctx.lineJoin="round";
	ctx.miterLimit = 1;
	ctx.setLineDash([2,2]);
	ctx.strokeStyle = cssVar('--track-element-fgborder');
	ctx.beginPath();
	ctx.moveTo(0.5+(trackMouse.pos.x + 0) * track.scale, 0.5+(trackMouse.pos.y+0) * track.scale);
	ctx.lineTo(0.5+(trackMouse.pos.x + 1) * track.scale, 0.5+(trackMouse.pos.y+0) * track.scale);
	ctx.lineTo(0.5+(trackMouse.pos.x + 1) * track.scale, 0.5+(trackMouse.pos.y+1) * track.scale);
	ctx.lineTo(0.5+(trackMouse.pos.x + 0) * track.scale, 0.5+(trackMouse.pos.y+1) * track.scale);
	ctx.lineTo(0.5+(trackMouse.pos.x + 0) * track.scale, 0.5+(trackMouse.pos.y+0) * track.scale);
	ctx.stroke();
	
	//
	// draw mouseselection
	var mode = sideBtnCmdGet();
	
	if ((mode == "cmd-track-rail" || mode == "cmd-track-delete") &&
			trackMouse.down.x >= 0 && trackMouse.down.y >= 0) {
		var selected = new Array();
		
		selected.length = 0;
		selected = trackGetElementList(trackMouse.down, trackMouse.pos, trackMouse.direction);
		for (i = 0; i < selected.length; i++) {
			trackDrawElement(ctx, selected[i], 1);
		}
		selected.length = 0;
		var infoline = document.getElementById("infoline");
		if (infoline) infoline.innerHTML =  trackMouse.direction;
	}

    else if (!mode == "cmd-track-none") alert("track.js: unknown mode:" + mode);

	//
	// flip screen - double buffering
	trackFlipScreen();
};


function trackFlipScreen() {
	var c = document.getElementById("TrackCanvas");
	var ctx = c.getContext("2d");

	ctx.drawImage(track.dbuf, 0, 0);
};



////////////////////////////////////////////////////////////////////////
//
// callback functionen
//

function trackMouseGetPos(event) {
	var p = { x: 0, y: 0, subx: 0.5, suby: 0.5 };
	var x, dx;
	var y, dy;
		
	p.x = Math.floor((event.pageX - 1 - $('#TrackCanvas').offset().left) / track.scale);
	p.y = Math.floor((event.pageY - 1 - $('#TrackCanvas').offset().top) / track.scale);

	x = (event.pageX - 1 - $('#TrackCanvas').offset().left) / track.scale;
	y = (event.pageY - 1 - $('#TrackCanvas').offset().top) / track.scale;
	p.subx = x - p.x;
	p.suby = y - p.y;
	
	return p;
}


function trackMousemove(event) {
	var mode = sideBtnCmdGet();
	
	trackMouse.pos = trackMouseGetPos(event);
// 	debug ("trackMousemove pos: " + trackMouse.pos.x + "," + trackMouse.pos.y + 
// 		" subx: " + trackMouse.pos.subx + " suby:" + trackMouse.pos.suby);

	trackDraw();
};


function trackMousedown(event) {
	var mode = sideBtnCmdGet();
	var tmp = trackMouseGetPos(event);
	
	if (mode == "cmd-track-rail" || mode == "cmd-track-delete") {
		trackMouse.down = trackMouseGetPos(event);
	}

//	debug ("trackMousedown pos: " + tmp.x + "," + tmp.y + " subx: " + tmp.subx + " suby:" + tmp.suby);

	trackDraw();
};


//
//
//
function trackMouseup(event) {
	var mode = sideBtnCmdGet();
	var tmp = trackMouseGetPos(event);

	debug ("trackMouseup  tmp: " + tmp.x + "," + tmp.y + " mode:" + mode);
	debug ("trackMouseup down: " + trackMouse.down.x + "," + trackMouse.down.y);
	debug ("trackMouseup  pos: " + trackMouse.pos.x + "," + trackMouse.pos.y);

    gContextmenuClose();

	if (mode == "cmd-track-rail") {
		var pos = {};
		var selected = new Array();
		
		selected.length = 0;
		selected = trackGetElementList(trackMouse.down, trackMouse.pos, trackMouse.direction);
		serverinout_addTrack(selected);
		selected.length = 0;
	}

	else if (mode == "cmd-track-detail") {
		rwdetail_show(trackMouse.pos.x, trackMouse.pos.y);
	}

	else if (mode == "cmd-track-delete") {
		var pos = {};
		var xs, ys, xe ,ye;
		var selected = new Array();

		selected.length = 0;
		
		//
		// determine which direction to count.
		if (trackMouse.down.x <= trackMouse.pos.x) {
			xs = trackMouse.down.x;
			xe = trackMouse.pos.x;
		}
		else {
			xs = trackMouse.pos.x;
			xe = trackMouse.down.x;
		}
		
		if (trackMouse.down.y <= trackMouse.pos.y) {
			ys = trackMouse.down.y;
			ye = trackMouse.pos.y;
		}
		else {
			ys = trackMouse.pos.y;
			ye = trackMouse.down.y;
		}
	
		debug ("delete: xs: " + xs + " , " + ys + " xe: "  + xe + " , " + ye);
	
		for (x = xs; x <= xe; x++) for (y = ys; y <= ye; y++)  {
			selected.push({x: x, y: y, dir: 1, type: 0});
		}

		serverinout_delTrack(selected);
		selected.length = 0;
	}
	else {
		debug ("rw_Click was das?");
		rw_Click(trackMouse.pos.x, trackMouse.pos.y);
	}
	
	trackMouse.down.x = -1;
	trackMouse.down.y = -1;
	trackMouse.step = 0;

	trackDraw();
};


//
// add/or delete element
// fill in element
function trackAddElement(elm) {
	// debug ("trackAddElement: pos:" + elm.x + "," + elm.y + " d: " + elm.dir + " name:" + elm.name + " type:" + elm.type);

	if (track.size.x > 0 && track.size.y > 0) {
		track.elements[elm.x + track.size.y * elm.y] = elm;
	}
};


////////////////////////////////////////////////////////////////////////
//
// init the track view screen
// bind callback functions
function trackCreate(sizex, sizey) {
	debug ("trackCreate " + sizex + " , " + sizey);
	var canvas = document.createElement("canvas");
	
	track.size.x = sizex;
	track.size.y = sizey;

	canvas.setAttribute("id", "TrackCanvas");
	canvas.height = track.size.y * track.scale;
	canvas.width = track.size.x * track.scale;
	canvas.addEventListener('mousemove', trackMousemove);
	canvas.addEventListener('mousedown', trackMousedown);
	canvas.addEventListener('mouseup', trackMouseup);
	track.dbuf = document.createElement("canvas");
	track.dbuf.setAttribute("id", "TrackCanvasDBUF");
	track.dbuf.height = track.size.y * track.scale;
	track.dbuf.width = track.size.x * track.scale;

	track.array = new Array();

	return canvas;
};


//
// get the size fo track from server, setup all data
function trackSetup(tracksetup) {
	debug ("trackSetup");

	var client = document.getElementById("page_main");
	var oldc = document.getElementById("TrackCanvas");
	var olddbuf = document.getElementById("TrackCanvasDBUF");
	
	if (oldc)    oldc.remove();
	if (olddbuf) olddbuf.remove();
	
//	client.removeChild(oldc);

	var canvas = trackCreate (tracksetup.width, tracksetup.height);
	client.appendChild (canvas);

	trackDraw();

};


//
// return a new list of railways elements
// this list can be added to the server or deleted from.
// or useing this list for drawing preview
// START: will contain the position with the sub position (clockwise: 0, 3, 6, 9)
//
function trackGetElementList(start, end) {
	var list = new Array();
	
	var pstart;
	var pend;

	if (start.x > end.x) {
		pstart = {x: end.x, y:end.y, subx: end.subx, suby: end.suby};
		pend = {x: start.x, y:start.y, subx: start.subx, suby: start.suby};
	}
	else {
		pstart = {x: start.x, y:start.y, subx: start.subx, suby: start.suby};
		pend = {x: end.x, y:end.y, subx: end.subx, suby: end.suby};
	}
		
	//
	// clicked on a singlke field.
	if (pstart.x == pend.x && pstart.y == pend.y) {
		x = pstart.x;
		y = pstart.y;
		if (pstart.subx <= 0.33 && pstart.suby <= 0.33) 
			list.push ({x: x, y: y, dir: 3, type: 1});
		if (pstart.subx <= 0.33 && pstart.suby >= 0.66) 
			list.push ({x: x, y: y, dir: 6, type: 1});

		if (pstart.subx >= 0.66 && pstart.suby <= 0.33) 
			list.push ({x: x, y: y, dir: 4, type: 1});
		if (pstart.subx >= 0.66 && pstart.suby >= 0.66) 
			list.push ({x: x, y: y, dir: 5, type: 1});

		if (pstart.subx >= 0.33 && pstart.subx <= 0.66 && (pstart.suby <= 0.33 || pstart.suby >= 0.66))
			list.push ({x: x, y: y, dir: 1, type: 1});
		if (pstart.suby >= 0.33 && pstart.suby <= 0.66 && (pstart.subx <= 0.33 || pstart.subx >= 0.66))
			list.push ({x: x, y: y, dir: 2, type: 1});
	}
	else {
		var	dx = pend.x - pstart.x;
		var dy = pend.y - pstart.y;
		var m, x, y;

		if (dx != 0 && dy != 0) m = dy / dx;
		else if (dx == 0) m = 100;				// Y
		else m = 0;								// X

		x = pstart.x;
		y = pstart.y;
		if (Math.abs(m) > 0.5 && Math.abs(m) < 2) {
			var elm;			// save last element

			if (m < 0) {	//   	"/"
				// select starting point
				if (pstart.suby < 0.5) elm = 3;
				else elm = 5;
				
				for (; x <= pend.x && y >= pend.y;) {
					if (elm == 3) {
						list.push ({x: x, y: y, dir: elm, type: 1});
						elm = 5;
						y = y - 1;
					}
					else if (elm == 5) {
						list.push ({x: x, y: y, dir: elm, type: 1});
						elm = 3;
						x = x + 1;
					}
					else {
						// should not possible but somehow we ended up here	
						debug ("trackGetElementList: ERROR elm 3 or 5 expected");
						break;
					}
				}
			}
			else {			// 		"\"
				// select starting point
				if (pstart.suby < 0.5) elm = 4;
				else elm = 6;
				
				for (; x <= pend.x && y <= pend.y;) {
					if (elm == 4) {
						list.push ({x: x, y: y, dir: elm, type: 1});
						elm = 6;
						x = x + 1;
					}
					else if (elm == 6) {
						list.push ({x: x, y: y, dir: elm, type: 1});
						elm = 4;
						y = y + 1;
					}
					else {
						// should not possible but somehow we ended up here	
						debug ("trackGetElementList: ERROR elm 4 or 6 expected");
						break;
					}
				}
			}
		}
		else if (Math.abs(m) >= 2) {
			if (m > 0) {
				dirtype = 1;
				for (; y <= pend.y; y++) 
					list.push ({x: x, y: y, dir: dirtype, type: 1});
			}
			else {
				dirtype = 1;
				for (; y >= pend.y; y--) 
					list.push ({x: x, y: y, dir: dirtype, type: 1});
			}
		}
		else {		// m < 0.5
			if (m >= 0) {
				dirtype = 2;
				for (; x <= pend.x; x++) 
					list.push ({x: x, y: y, dir: dirtype, type: 1});
			}
			else {
				dirtype = 2;
				for (; x >= pend.x; x--) 
					list.push ({x: x, y: y, dir: dirtype, type: 1});
			}
		}
	}

	
	return list;
};

//
// returns the element at the givin point
function trackGetTurnout(mousepos) {
	var pos = {x: mousepos.x, y: mousepos.y};
	var elm = {};
	
	for (var i = 0; i < track.elements.length; i++) {
		if (track.elements[i]) {
			if (track.elements[i].x == pos.x && track.elements[i].y == pos.y) elm = track.elements[i];
		}
	}
	
	return elm;
};