const getStepUtils = require('./util/getStep.js');

function Run(ref, json_q, callback, ind, progressObj) {
  if (!progressObj) progressObj = { stop: function() { } };

  function drawStep(drawarray, pos) {
    if (pos == drawarray.length && drawarray[pos - 1] !== undefined) {
      var image = drawarray[pos - 1].image;
      if (ref.objTypeOf(callback) == "Function" && ref.images[image].steps.slice(-1)[0].output) {
        var steps = ref.images[image].steps;
        var out = steps[steps.length - 1].output.src;
        callback(out);
        return true;
      }
    }

    // so we don't run on the loadImage module:
    if (drawarray[pos] !== undefined) {
      var image = drawarray[pos].image;
      var i = drawarray[pos].i;
      var input = ref.images[image].steps[i - 1].output;

      ref.images[image].steps[i].getStep = function getStep(offset) {
        if (i + offset >= ref.images[image].steps.length) return { options: { name: undefined } };
        else return ref.images[image].steps.slice(i + offset)[0];
      };
      ref.images[image].steps[i].getIndex = function getIndex() {
        return i;
      }

      for (var util in getStepUtils) {
        if (getStepUtils.hasOwnProperty(util)) {
          ref.images[image].steps[i][util] = getStepUtils[util];
        }
      }

      // Tell UI that a step is being drawn.
      ref.images[image].steps[i].UI.onDraw(ref.images[image].steps[i].options.step);

      // provides a set of standard tools for each step
      var inputForNextStep = require('./RunToolkit')(ref.copy(input));

      ref.images[image].steps[i].draw(
        inputForNextStep,
        function onEachStep() {

          // This output is accessible by UI
          ref.images[image].steps[i].options.step.output = ref.images[image].steps[i].output.src;

          // Tell UI that step has been drawn.
          ref.images[image].steps[i].UI.onComplete(ref.images[image].steps[i].options.step);

          drawStep(drawarray, ++pos);
        },
        progressObj
      );
    }
  }

  function drawSteps(json_q) {
    var drawarray = [];
    for (var image in json_q) {
      var no_steps = ref.images[image].steps.length;
      var init = json_q[image];
      for (var i = 0; i < no_steps - init; i++) {
        drawarray.push({ image: image, i: init + i });
      }
    }
    drawStep(drawarray, ind);
  }

  function filter(json_q) {
    for (var image in json_q) {
      if (json_q[image] == 0 && ref.images[image].steps.length == 1)
        delete json_q[image];
      else if (json_q[image] == 0) json_q[image]++;
    }
    for (var image in json_q) {
      var prevstep = ref.images[image].steps[json_q[image] - 1];
      while (
        typeof prevstep == "undefined" ||
        typeof prevstep.output == "undefined"
      ) {
        prevstep = ref.images[image].steps[--json_q[image] - 1];
      }
    }
    return json_q;
  }

  var json_q = filter(json_q);
  return drawSteps(json_q);
}
module.exports = Run;