/*
 *  plugin for jsPsych based in Qisheng Li 11/2019. /// https://github.com/QishengLi/virtual_chinrest
    
    Modified by Gustavo Juantorena 08/2020 // https://github.com/GEJ1

    Contributions from Peter J. Kohler: https://github.com/pjkohler
 */

jsPsych.plugins['virtual-chinrest'] = (function() {

  var plugin = {};

  plugin.info = {
    name: "virtual-chinrest", 
    parameters: {
      resize_units: {
        type: jsPsych.plugins.parameterType.STRING,
        default: "none",
        description: 'What units to resize to? ["none"/"cm"/"inch"/"deg"]. If "none", no resize will be done.'
      },
      pixels_per_unit: {
        type: jsPsych.plugins.parameterType.INT,
        pretty_name: 'Pixels per unit',
        default: 100,
        description: 'After the scaling factor is applied, this many pixels will equal one unit of measurement.'
      },
      mouse_adjustment: {
        type: jsPsych.plugins.parameterType.BOOL,
        pretty_name: 'Adjust Using Mouse?',
        default: true
      },
      adjustment_prompt: {
        type: jsPsych.plugins.parameterType.STRING,
        default: '<b> Let’s find out how big your monitor is! </b>'+
                  '<p>Please use any credit card that you have available.<br>' +
                  'It can also be a grocery store membership card,<br>'+
                  'your drivers license or anything else of the same format.<br>'+
                  '<b>Place your card flat onto the screen, and adjust the slider below to match its size.</b></p>'+
                  '<p>If you do not have access to a real card <br>'+
                  'you can use a ruler to measure the image width to 3.37 inches or 85.6 mm.<br>'
      },
      adjustment_button_prompt: {
        type: jsPsych.plugins.parameterType.STRING,
        default: 'Click here when the card has the right size!'
      },
      item_path: {
        type: jsPsych.plugins.parameterType.STRING,
        default: "img/card.png"
      },
      item_height_mm: {
        type: jsPsych.plugins.parameterType.INT,
        pretty_name: 'Item height',
        default: 53.98,
        description: 'The height of the item to be measured.'
      },
      item_width_mm: {
        type: jsPsych.plugins.parameterType.INT,
        pretty_name: 'Item width',
        default: 85.60,
        description: 'The width of the item to be measured.'
      },
      item_init_size: {
        type: jsPsych.plugins.parameterType.INT,
        pretty_name: 'Initial Size',
        default: 250,
        description: 'The initial size of the card, in pixels, along the largest dimension.'
      },
      blindspot_reps: {
        type: jsPsych.plugins.parameterType.INT,
        pretty_name: 'Blindspot measurement repetitions',
        default: 5,
        description: 'How many times to measure the blindspot location? If 0, blindspot will not detected and viewing distance not computed.'
      },
      blindspot_prompt: {
        type: jsPsych.plugins.parameterType.STRING,
        default: '<b>Now, let’s quickly test how far away you are sitting.</b>'+
                  '<p>You might know that vision tests at a doctor’s practice often involve chinrests.<br>'+
                  'The doctor basically asks you to sit away from a screen in a specific distance.<br>'+
                  'We do this here with a “virtual chinrest”.</p><br>'+
                  '<b>Instructions</b>'+
                  '<div style="text-align: left">'+
                  '<ol><li>Put your finger on <b>space bar</b> on the keyboard.</li>'+
                  '<li>Close your right eye. <em>(Tips: it might be easier to cover your right eye by hand!)</em></li>'+
                  '<li>Using your left eye, focus on the black square.</li>'+
                  '<li>Click the button below to start the animation of the red ball. The <b style="color: red">red ball </b>'+
                  'will disappear as it moves from right to left. Press the “Space” key as soon as the ball disappears from your eye sight.</li>'+
                  '</div><br> Keep your right eye closed and hit the “Space” key fast!</p><br>'
      },
      blindspot_start_prompt: {
        type: jsPsych.plugins.parameterType.STRING,
        default: 'Start'
      },
      blindspot_done_prompt: {
        type: jsPsych.plugins.parameterType.STRING,
        default: 'Done'
      },
      blindspot_measurements_prompt: {
        type: jsPsych.plugins.parameterType.STRING,
        default: 'Remaining measurements: '
      },
      viewing_distance_report: {
        type: jsPsych.plugins.parameterType.STRING,
        default: 'Estimated viewing distance (cm):',
        description: 'If "none" is given, viewing distance will not be reported to the participant'
      }
    }
  }
  
  // Get screen size
  var w = window.innerWidth;
  var h = window.innerHeight;

  const screen_size_px = []
  screen_size_px.push(w)
  screen_size_px.push('x')
  screen_size_px.push(h)

  let trial_data = {} // declare trial data as empty so we have access to it across functions

  let config_data = {
    "ball_pos": [],
    "slider_clck": false
  }

  plugin.trial = function(display_element, trial) {
    /*try {*/
      if ( !( trial.blindspot_reps > 0 ) && ( (trial.resize_units == "deg" ) || (trial.resize_units == "degrees" ) ) ) {
        throw Error("Blindspot repetitions set to 0, so resizing to degrees of visual angle is not possible!")
      } else {
        const start_time = performance.now();

        trial_data = {
          "item_width_mm": trial.item_width_mm,
          "item_height_mm": trial.item_height_mm //card dimension: 85.60 × 53.98 mm (3.370 × 2.125 in)
        };

        let button_str = '<button id=blind_spot class="btn btn-primary">'
        if (!( trial.blindspot_reps > 0 )) {
          button_str = '<button id=proceed class="btn btn-primary">'
        }

        let report_str = ''
        if ( !(trial.viewing_distance_report == "none" ) ) {
          report_str = '<div id="info" style="visibility:hidden">'+
                        '<b id="info-h">' + trial.viewing_distance_report + ' </b>'+
                        '</div>'
        }

        let pagesize_content = '<div id="page-size"><br><br>' + trial.adjustment_prompt

        // variables to determine div size
        let aspect_ratio = 1
        
        if ( trial.mouse_adjustment ) {
          aspect_ratio = trial.item_width_mm / trial.item_height_mm
          const start_div_height = ((aspect_ratio < 1 ) ? trial.item_init_size : Math.round(trial.item_init_size / aspect_ratio));
          const start_div_width = ((aspect_ratio < 1 ) ? Math.round(trial.item_init_size * aspect_ratio) : trial.item_init_size ); 
          const adjust_size = Math.round(start_div_width*.1)
          pagesize_content +=
              '<br>' + button_str + trial.adjustment_button_prompt + '</button><br>' +
              '<div id="item" style="border: none; '+
                'height: '+ start_div_height+'px; width:'+start_div_width+'px; '+
                'margin: 5px auto; background-color: none; position: relative; '+
                'background-image: url(' + trial.item_path + '); '+
                'background-size: 100% auto; background-repeat: no-repeat">'+
                '<div id="jspsych-resize-handle" style="cursor: nwse-resize; '+
                  'background-color: none; width: ' + adjust_size + 'px; height: ' + adjust_size + 'px; '+
                  'border: 5px solid red; border-left: 0; border-top: 0; position: absolute; bottom: 0; right: 0;">'+
                '</div>'+
              '</div>'+
            '</div>'
        } else {
          pagesize_content += 
            '<div id="container">'+
                '<div id="slider"></div><br>'+
                button_str + trial.adjustment_button_prompt + '</button><br><br>'+
                '<img id="item" src="' + trial.item_path + '" style="width: 50%">'+
              '</div>'+
            '</div>'
        }

        const blindspot_content = 
          '<div id="blind-spot" style="visibility: hidden">' +
            trial.blindspot_prompt +
            '<div id="svgDiv" style="width:1000px;height:200px;"></div>'+
            '<button class="btn btn-primary" id="start_ball">' + trial.blindspot_start_prompt + '</button>'+
            '<button class="btn btn-primary" id="proceed" style="display:none">' + trial.blindspot_done_prompt + '</button><br>'+
            `<b> ${trial.blindspot_measurements_prompt} <div id="click" style="display:inline; color: red"> ${trial.blindspot_reps} </div> <b><br>` +
            report_str+
          '</div>'
        
        display_element.innerHTML = 
          '<div id="content" style="width: 900px; margin: 0 auto;">'+
            pagesize_content + 
            blindspot_content +
          '</div>'

        // Event listeners for mouse-based resize
        if ( trial.mouse_adjustment ) {
          let dragging = false;
          let origin_x, origin_y;
          let cx, cy;
          
          const mouseupevent = function(e){
            dragging = false;
          }
          display_element.addEventListener('mouseup', mouseupevent);

          const mousedownevent = function(e){
            e.preventDefault();
            dragging = true;
            origin_x = e.pageX;
            origin_y = e.pageY;
            cx = parseInt(scale_div.style.width);
            cy = parseInt(scale_div.style.height);
          }
          display_element.querySelector('#jspsych-resize-handle').addEventListener('mousedown', mousedownevent);

          const scale_div = display_element.querySelector('#item');

          function resizeevent(e){
            if(dragging){
              let dx = (e.pageX - origin_x);
              let dy = (e.pageY - origin_y);

              if(Math.abs(dx) >= Math.abs(dy)){
                scale_div.style.width = Math.round(Math.max(20, cx+dx*2)) + "px";
                scale_div.style.height = Math.round(Math.max(20, cx+dx*2) / aspect_ratio ) + "px";
              } else {
                scale_div.style.height = Math.round(Math.max(20, cy+dy*2)) + "px";
                scale_div.style.width = Math.round(aspect_ratio * Math.max(20, cy+dy*2)) + "px";
              }
            }
          }

          display_element.addEventListener('mousemove', resizeevent)
        }

        //Event listeners for buttons
        if ( trial.blindspot_reps > 0 ) {
          display_element.querySelector('#blind_spot').addEventListener('click', function(){    
            configureBlindSpot()
          })
          display_element.querySelector('#start_ball').addEventListener('click', function(){    
            animateBall()
          })
        } else {
          // run the two relevant functions to get item_width_mm and px2mm
          distanceSetup.px2mm(get_item_width())
        }

        display_element.querySelector('#proceed').addEventListener('click', function(){

          // finish trial
          trial_data.rt = performance.now() - start_time;
          display_element.innerHTML = '';

          trial_data.item_width_deg = 2*(Math.atan((trial_data["item_width_mm"]/2)/trial_data["view_dist_mm"])) * 180/Math.PI
          trial_data.px2deg = trial_data["item_width_px"] / trial_data.item_width_deg  // size of item in pixels divided by size of item in degrees of visual angle

          let px2unit_scr = 0
          switch (trial.resize_units) {
            case "cm":
            case "centimeters": 
              px2unit_scr = trial_data["px2mm"]*10 // pixels per centimeter
              break;
            case "inch":
            case "inches":
              px2unit_scr = trial_data["px2mm"]*25.4 // pixels per inch
              break;
            case "deg":
            case "degrees":
              px2unit_scr = trial_data["px2deg"] // pixels per degree of visual angle
              break;
          }
          if (px2unit_scr > 0) {
            // scale the window
            scale_factor = px2unit_scr / trial.pixels_per_unit;
            document.getElementById("jspsych-content").style.transform = "scale(" + scale_factor + ")";
            // pixels have been scaled, so pixels per degree, pixels per mm and pixels per item_width needs to be updated
            trial_data.px2deg = trial_data.px2deg / scale_factor
            trial_data.px2mm = trial_data.px2mm / scale_factor
            trial_data.item_width_px = trial_data.item_width_px / scale_factor
            trial_data.scale_factor = scale_factor
          }

          if ( trial.blindspot_reps > 0 ) {
            trial_data.win_width_deg = window.innerWidth/trial_data.px2deg
            trial_data.win_height_deg = window.innerHeight/trial_data.px2deg
          } else {
            // delete degree related properties
             delete trial_data.px2deg
             delete trial_data.item_width_deg
          }
          jsPsych.finishTrial(trial_data);
          jsPsych.pluginAPI.cancelAllKeyboardResponses();
        })
      }
    /*} catch (e) {
      console.error(e)
    }*/
  };

  (function ( distanceSetup, $ ) {  // jQuery short-hand for $(document).ready(function() { ... });

      distanceSetup.round = function(value, decimals) {
          return Number(Math.round(value+'e'+decimals)+'e-'+decimals);
      };

      distanceSetup.px2mm = function(item_width_px) {
          const px2mm = item_width_px/trial_data["item_width_mm"];
          trial_data["px2mm"] = distanceSetup.round(px2mm, 2);
          return px2mm; 
      };

  }( window.distanceSetup = window.distanceSetup || {}, jQuery))

  function get_item_width() {
      const item_width_px = $('#item').width();
      trial_data["item_width_px"] = distanceSetup.round(item_width_px,2);
      return item_width_px
  }

  function configureBlindSpot() {
      drawBall();
      $('#page-size').remove();
      $('#blind-spot').css({'visibility':'visible'});
      // $(document).on('keydown', recordPosition);
      $(document).on('keydown', recordPosition);
  }

  $( function() {
      $( "#slider" ).slider({value:"50"});
  } );

  $(document).ready(function() {
      $( "#slider" ).on("slide", function (event, ui) {
          const item_width = ui.value + "%";
          $("#item").css({"width":item_width});
      });

      $('#slider').on('slidechange', function(event, ui){
          config_data["slider_clck"] = true;
      });

  });

  //=============================
  //Ball Animation

  function drawBall(pos=180){
      // pos: define where the fixation square should be.
      var mySVG = SVG("svgDiv");
      const item_width_px = get_item_width()
      const rectX = distanceSetup.px2mm(item_width_px)*pos;
      const ballX = rectX*0.6 // define where the ball is
      var ball = mySVG.circle(30).move(ballX, 50).fill("#f00"); 
      window.ball = ball;
      var square = mySVG.rect(30, 30).move(Math.min(rectX - 50, 950), 50); //square position
      config_data["square_pos"] = distanceSetup.round(square.cx(),2);
      config_data['rectX'] = rectX
      config_data['ballX'] = ballX
  };


  function animateBall(){
      ball.animate(7000).during(
          function(pos){
              moveX = - pos*config_data['ballX'];
              window.moveX = moveX;
              moveY = 0;
              ball.attr({transform:"translate("+moveX+","+moveY+")"});

          }
      ).loop(true, false).
      after(function(){
          animateBall();
      });

      //disable the button after clicked once.
      $("#start_ball").attr("disabled", true);
      $('#start_ball').css("display", "none");
  };

  function recordPosition(event, angle=13.5) {
      // angle: define horizontal blind spot entry point position in degrees.
      if (event.keyCode == '32') { //Press "Space"

          config_data["ball_pos"].push(distanceSetup.round((ball.cx() + moveX),2));
          var sum = config_data["ball_pos"].reduce((a, b) => a + b, 0);
          var ballPosLen = config_data["ball_pos"].length;
          config_data["avg_ball_pos"] = distanceSetup.round(sum/ballPosLen, 2);
          var ball_sqr_distance = (config_data["square_pos"]-config_data["avg_ball_pos"])/trial_data["px2mm"];
          var viewDistance = ball_sqr_distance/Math.radians(angle)
          trial_data["view_dist_mm"] = distanceSetup.round(viewDistance, 2);

          //counter and stop
          var counter = Number($('#click').text());
          counter = counter - 1;
          $('#click').text(Math.max(counter, 0));
          if (counter <= 0) {
              ball.stop();

              // Disable space key
              $('html').bind('keydown', function(e)
              {
                 if (e.keyCode == 32) {return false;}
              });

              // Display data
              $('#info').css("visibility", "visible");
              $('#info-h').append(trial_data["view_dist_mm"]/10)

              $('#proceed').css("display", "inline");
                           
              return //trial_data.viewing_distance_cm;  
          }

          ball.stop();
          animateBall();
      }
  };

  //helper function for radians
  // Converts from degrees to radians.
  Math.radians = function(degrees) {
    return degrees * Math.PI / 180;
  };
  
  return plugin;

})();