let width;
let height;
let margin;
let no_of_nodes;
let matrix_rows;
let matrix_columns;
let min;
let max;
let nodes_list = [];

function preload() {
  edges_table = loadTable('3980.edges.csv','csv');
}

function setup() {
  width  = 1000;
  height = 1000;
  margin = 100;

  for(var j=0;j<edges_table.getRowCount();j++)
  {
    nodes_list.push(edges_table.getNum(j,0));
    nodes_list.push(edges_table.getNum(j,1));
  }
  nodes_list = Array.from(new Set(nodes_list))
  nodes_list.sort(function(a, b){return a - b});
  no_of_nodes = nodes_list.length;
  min = Math.min(...nodes_list);
  max = Math.max(...nodes_list);
  matrix_size = no_of_nodes;

  matrix_cell_width = (width - 2*margin)/matrix_size;
  matrix_cell_height = (height - 2*margin)/matrix_size;

  createCanvas(width,height);
  background(245,255,250);

}

function draw() {
  clear();

  push();
  translate(margin,margin);
  push();
  for(var j=0;j<matrix_size;j++)
  {
    for(var i=0;i<matrix_size;i++)
    {
      push();
      translate(matrix_cell_width*(j),matrix_cell_height*(i));
      push();
      fill(250,235,215);
      strokeWeight(0);
      rect(0,0,matrix_cell_width,matrix_cell_height);
      pop();
      pop();
    }
  }
  pop();
  pop();
  push();
  translate(margin,margin);
  for(var i=0;i<edges_table.getRowCount();i++)
  {
    push();
    translate(matrix_cell_width*(nodes_list.indexOf(edges_table.getNum(i,1))),
              matrix_cell_height*(nodes_list.indexOf(edges_table.getNum(i,0))));
    push();
    fill(11,211,211);
    strokeWeight(0);
    rect(0,0,matrix_cell_width,matrix_cell_height);
    pop();
    pop();
  }
  pop();

  drawMatrixCells();
  setPlotArea();
  plotYTicks();
  plotXTicks();

  push();
  translate(margin,margin);
  for(var i=0;i<edges_table.getRowCount();i++)
  {
    push();
    translate(matrix_cell_width*(nodes_list.indexOf(edges_table.getNum(i,1))),
              matrix_cell_height*(nodes_list.indexOf(edges_table.getNum(i,0))));
    if(mouseX > margin +matrix_cell_width*(nodes_list.indexOf(edges_table.getNum(i,1))) &&
       mouseX < margin +matrix_cell_width*(nodes_list.indexOf(edges_table.getNum(i,1))) + matrix_cell_width &&
       mouseY < margin +matrix_cell_height*(nodes_list.indexOf(edges_table.getNum(i,0))) + matrix_cell_height &&
       mouseY > margin +matrix_cell_height*(nodes_list.indexOf(edges_table.getNum(i,0))))
    {
      stroke(139,0,139);
      text("("+edges_table.getNum(i,1) +","+edges_table.getNum(i,0)+")",-6,0);
    }
    pop();
  }
  pop();

  push();
  translate(margin,margin);
  for(var j=0;j<matrix_size;j++)
  {
    for(var i=0;i<matrix_size;i++)
    {
      push();
      translate(matrix_cell_width*(j),matrix_cell_height*(i));
      if(mouseX > margin +matrix_cell_width*j &&
         mouseX < margin +matrix_cell_width*j + matrix_cell_width &&
         mouseY < margin +matrix_cell_height*i + matrix_cell_height &&
         mouseY > margin +matrix_cell_height*i)
      {
        push();
        stroke(255,0,0);
        textSize(10);
        textStyle(BOLD);
        text(nodes_list[i],-matrix_cell_width*(j)-margin/2,matrix_cell_height/2);
        pop();
        push();
        stroke(255,0,0);
        textSize(10);
        textStyle(BOLD);
        textAlign(CENTER);
        rotate(-PI/2.0);
        text(nodes_list[j],margin/4 + matrix_cell_height*i,matrix_cell_width/2);
        pop();
      }
      pop();
    }
  }
  pop();

}

function setPlotArea() {

  push();
  textSize(25);
  textStyle(BOLD);
  textAlign(CENTER);
  text('Matrix Layout - Facebook data',(width)/2,margin/2);
  translate(margin, margin);
  line(0,0,0,(height-(2*margin)));

  translate(0,(height-(2*margin)));
  line(0,0,(width-(2*margin)),0);

  translate((width-(2*margin)),0);
  line(0,0,0,-(height-(2*margin)));

  translate(0,-(height-(2*margin)));
  line(0,0,-(width-(2*margin)),0);
  pop();

}

function drawMatrixCells() {
  push();
  translate(margin,margin);
  for(var i=1;i<matrix_size;i++)
  {
    push();
    translate(matrix_cell_width*(i),0);
    strokeWeight(1);
    stroke(245,222,179);
    line(0,0,0,(height - 2*margin));
    pop();
  }
  pop();

  push();
  translate(margin,margin);
  for(var j=1;j<matrix_size;j++)
  {
    push();
    translate(0,matrix_cell_height*(j));
    strokeWeight(1);
    stroke(245,222,179);
    line(0,0,(width - 2*margin),0)
    pop();
  }
  pop();

}

function plotYTicks() {

  push();
  translate(margin, margin);
  for(var i=1;i<=no_of_nodes;i++)
  {
    push();
    translate(0,matrix_cell_height*(i-1));
    textSize(10);
    textStyle(BOLD);
    text(nodes_list[i-1].toString(),(0-margin)/2,matrix_cell_height/2);
    pop();
  }
  pop();

}

function plotXTicks() {

  push();
  translate(margin,margin);
  for(var i=1;i<=no_of_nodes;i++)
  {
    push();
    translate(matrix_cell_width*(i-1),0);
    textSize(10);
    textStyle(BOLD);
    textAlign(CENTER);
    rotate(-PI/2.0);
    text(nodes_list[i-1].toString(),margin/4,matrix_cell_width/2);
    pop();
  }
  pop();
}