var fs = require('fs');
var express = require('express');
var Canvas = require('canvas');

var Fox = require('./js/fox.js');

var renderFox = function (canvas, opts) {
    var width = opts.canvas.width;
    var height = opts.canvas.height;
    var ctx = canvas.getContext('2d');

    ctx.fillStyle = opts.canvas.color;
    ctx.fillRect(0, 0, width, height);
    // draw ears
    renderEars(ctx, opts.ears);
    // draw head
    renderHead(ctx, opts.head);
    // draw eyes
    renderEyes(ctx, opts.eyes);
    // draw cheeks
    // draw eyes
    // draw nose
    renderNose(ctx, opts.nose);
    // draw mouth
    renderMouth(ctx, opts.mouth);
};

function renderHead(ctx, opts) {

    ctx.save();
    ctx.translate(ctx.canvas.width/2, ctx.canvas.height/2);
    ctx.rotate(Math.PI / 4);
    drawEllipseByCenter(ctx, 0, 0, opts.width, opts.height, opts.color, null, opts.kappa);
    ctx.restore();
    ctx.clip();
    drawEllipseByCenter(ctx, ctx.canvas.width / 2, ctx.canvas.height, opts.maskWidth, opts.maskHeight, '#fff', '#fff', 0.5);
}

function renderEars(ctx, opts) {
    var offset = {
        x: ctx.canvas.width/2,
        y: ctx.canvas.height/2
    }
    ctx.save();
    ctx.translate(offset.x, offset.y);
    ctx.rotate(-opts.left.angle);
    drawEllipseByCenter(ctx, opts.left.x - offset.x, opts.left.y - offset.y, opts.left.width, opts.left.height, opts.color, null, opts.kappa);
    ctx.restore();

    ctx.save();
    ctx.translate(offset.x, offset.y);
    ctx.rotate(-opts.right.angle);
    drawEllipseByCenter(ctx, opts.right.x - offset.x, opts.right.y - offset.y, opts.right.width, opts.right.height, opts.color, null, opts.kappa);
    ctx.restore();
}

function renderEyes(ctx, opts) {
    switch (opts.style) {
      case "ellipse":
        drawEllipseByCenter(ctx, opts.left.x, opts.left.y, opts.width, opts.height, "black", null, 0.5);
        drawEllipseByCenter(ctx, opts.right.x, opts.right.y, opts.width, opts.height, "black", null, 0.5);
        break;
      case "smiley":
        ctx.strokeStyle = "black";
        ctx.beginPath();
        ctx.moveTo(opts.left.x - opts.width, opts.left.y + opts.height);
        ctx.bezierCurveTo(opts.left.x - opts.width, opts.left.y + opts.height, opts.left.x, opts.left.y, opts.left.x + opts.width, opts.left.y + opts.height);
        ctx.lineWidth = 2;
        ctx.stroke();
        ctx.closePath();

        ctx.beginPath();
        ctx.moveTo(opts.right.x - opts.width, opts.right.y + opts.height);
        ctx.bezierCurveTo(opts.right.x - opts.width, opts.right.y + opts.height, opts.right.x, opts.right.y, opts.right.x + opts.width, opts.right.y + opts.height);
        ctx.lineWidth = 2;
        ctx.stroke();
        ctx.closePath();
        break;
      case "none":
        break;
    }
}

function renderNose(ctx, opts) {

  ctx.strokeStyle = "black";
  ctx.beginPath();
  ctx.moveTo(opts.x - opts.width/2, opts.y - opts.height/2);
  ctx.bezierCurveTo(opts.x - opts.width/2, opts.y - opts.height/2, opts.x, opts.y - opts.height, opts.x + opts.width/2, opts.y - opts.height/2);
  ctx.bezierCurveTo(opts.x + opts.width/2, opts.y - opts.height/2, opts.x + opts.width/2, opts.y + opts.height/2, opts.x, opts.y + opts.height/2);
  ctx.bezierCurveTo(opts.x, opts.y + opts.height/2, opts.x - opts.width/2, opts.y + opts.height/2, opts.x - opts.width/2, opts.y - opts.height/2);
  ctx.fillStyle = "black";
  ctx.fill();
  ctx.stroke();
}

function renderMouth(ctx, opts) {
  ctx.strokeStyle = "black";
  ctx.lineWidth = 2;
  ctx.beginPath();
  switch (opts.style) {
    case "smirk":
      ctx.moveTo(opts.x - opts.width/2, opts.y - opts.height/2);
      ctx.bezierCurveTo(opts.x - opts.width/2, opts.y - opts.height/2,
        opts.x - opts.width/2, opts.y + opts.height/2,
        opts.x + opts.width/2, opts.y
      )
      break;
    case "cat":
      ctx.moveTo(opts.x - opts.width/2, opts.y + opts.height/2);
      ctx.lineTo(opts.x, opts.y - opts.height/2);
      ctx.lineTo(opts.x + opts.width/2, opts.y + opts.height/2);
      break;
  }
  ctx.stroke();
}

function drawEllipseByCenter(ctx, cx, cy, w, h, color, fillColor, kappa) {
  console.log("ellipse coords", cx, cy, w, h);
  drawEllipse(ctx, cx - w/2.0, cy - h/2.0, w, h, color, fillColor, kappa);
}

function drawEllipse(ctx, x, y, w, h, color, fillColor, kappa) {
  var kappa = kappa || 0.3,
      ox = (w / 2) * kappa, // control point offset horizontal
      oy = (h / 2) * kappa, // control point offset vertical
      xe = x + w,           // x-end
      ye = y + h,           // y-end
      xm = x + w / 2,       // x-middle
      ym = y + h / 2;       // y-middle

  if (color) {
    ctx.strokeStyle = color;
  }
  ctx.beginPath();
  ctx.moveTo(x, ym);
  ctx.bezierCurveTo(x, ym - oy, xm - ox, y, xm, y);
  ctx.bezierCurveTo(xm + ox, y, xe, ym - oy, xe, ym);
  ctx.bezierCurveTo(xe, ym + oy, xm + ox, ye, xm, ye);
  ctx.bezierCurveTo(xm - ox, ye, x, ym + oy, x, ym);
  var fillColor = fillColor || color;
  if (fillColor) {
    ctx.fillStyle = fillColor;
    ctx.fill();
  }
  //ctx.closePath(); // not used correctly, see comments (use to close off open path)
  ctx.stroke();
}

var circle = function(c){
    var ctx= c.context || false;
    var x=c.x || 500;
    var y=c.y || x;
    var r=c.r || 10;
    var cr=ctx.canvas.width/2;
    var lineWidth=c.lineWidth || 1;
    ctx.beginPath();
    ctx.arc(x,y,r,0,2*Math.PI);
    ctx.lineWidth=lineWidth;

    ctx.fillStyle="red";
    ctx.fill();
    ctx.stroke();


    return true;
};

function writeFoxesToDisk (width, height, n=10) {
    var fileNames = [];
    for (var i = 0; i < n; i++) {
        var Image = Canvas.Image;
        var canvas = new Canvas(width, height);
        var ctx = canvas.getContext('2d');
        var fox = Fox(width, height);
        renderFox(canvas, fox);
        var img = new Buffer(canvas.toDataURL(), 'base64');
        var fileName = "fox" + Math.floor(Math.random() * 10000) + ".png";
        var filePath = __dirname + '/images/' + fileName;

        fs.writeFile(filePath, canvas.toBuffer(), function(err) {
            if (err) console.log('error', err);
        });

        fileNames.push(fileName);
    }
    return fileNames;
};

var app = express();

app.use(express.static(__dirname + '/images'));

app.get('/', function(req, res) {
    var fileNames = writeFoxesToDisk(300, 300, 30);
    var images = fileNames.map(fileName => '<img src="/' + fileName + '"/>');
    res.send(images.join(''));
});

app.listen(process.env.PORT || 3000);
console.log('listening on http://localhost:3000');