function nn_activate(x) {
  var result = 1 / (1 + Math.pow(Math.E, (-1*x)));
  return result;
}

function cmpArray(a, b) {
  if(a.length == b.length
    && a.every(function(u, i) {
      return u === b[i];
    })
  ){
    return true;
  } else {
    return false;
  }
}

function shuffle(array) {
  let currentIndex = array.length,  randomIndex;

  // While there remain elements to shuffle...
  while (currentIndex != 0) {

    // Pick a remaining element...
    randomIndex = Math.floor(Math.random() * currentIndex);
    currentIndex--;

    // And swap it with the current element.
    [array[currentIndex], array[randomIndex]] = [
      array[randomIndex], array[currentIndex]];
  }

  return array;
}

class Perceptron {
  constructor() {
    this.detectors = undefined;
    this.data = undefined;
    this.weights = [];
    this.rezultat = 0;
    this.treshold = 0.8;
    this.learningRate = 0.1;
    console.log("Ustvarjen nov perceptron");
  }

  percept() {
    var i;
    this.rezultat = 0;
    for (i = 0; i < this.detectors; i++) {
      this.rezultat += this.data[i] * this.weights[i];
    }
  }

  activate(data) {
    this.data = data;
    if(this.detectors === undefined) {
      this.detectors = data.length;
      for (var i = 0; i < this.detectors; i++) {
        // return Math.floor(Math.random() * (max - min) + min);
        this.weights[i] = (Math.random() * (10.0 - (0.0)) + (0.0));
      }
    }
    this.percept();
    //console.log("Rezultat: " + this.rezultat + " : " + "Prag: " + this.treshold);
    if (nn_activate(this.rezultat) >= this.treshold) {
    //if (this.rezultat >= this.treshold) {
      return 1;
    } else {
      return 0;
    }
  }

  updateWeights(expectedOutput) {
    var i;
    var actualOutput;
    var error;
    if(expectedOutput == 1) {
      expectedOutput = 5;
    } else {
      expectedOutput = -5;
    }
    for (i = 0; i < this.detectors; i++) {
      actualOutput = this.weights[i] * this.data[i];
      error = expectedOutput - actualOutput;
      this.weights[i] = this.weights[i] + (this.learningRate * this.data[i] * error);
    }
  }

  train(trainingData, expectedResult) {
    var result = this.activate(trainingData);
    if(result != expectedResult) {
      this.updateWeights(expectedResult);
    }
  }
}

class Layer {
  constructor(perceptrons) {
    this.perceptrons = perceptrons;
    this.data = undefined;
    this.layerPerceptrons = [];
    this.rezultat = [];
  }

  activate(data) {
    this.data = data;
    this.rezultat = [];
    if(this.layerPerceptrons.length != this.perceptrons) {
      for (var i = 0; i < this.perceptrons; i++) {
        this.layerPerceptrons[i] = new Perceptron();
      }
    }
    for (var j = 0; j < this.perceptrons; j++) {
      this.rezultat[j] = this.layerPerceptrons[j].activate(this.data);
    }
    return this.rezultat;
  }

  trainPerceptrons(data, expectedResult) {
    this.data = data;
    this.rezultat = [];
    if(this.layerPerceptrons.length != this.perceptrons) {
      for (var i = 0; i < this.perceptrons; i++) {
        this.layerPerceptrons[i] = new Perceptron();
      }
    }
    for (var j = 0; j < this.perceptrons; j++) {
      this.layerPerceptrons[j].train(this.data, expectedResult[j]);
    }
  }

  train(trainingData, expectedResult) {
    //this.expectedOutput = expectedOutput;
    var result = this.activate(trainingData);
    if(cmpArray(result, expectedResult) != true) {
      console.log('updating weights ...');
      this.trainPerceptrons(trainingData, expectedResult);
    }
    return result;
  }
}

class Network {
  constructor(inputLayer, hiddenLayer, outputLayer) {
    this.inputLayer = new Layer(inputLayer);
    this.hiddenLayer = new Layer(hiddenLayer);
    this.outputLayer = new Layer(outputLayer);
  }

  train(trainingData, expectedResult) {
    var inputLayerResult = this.inputLayer.activate(trainingData);
    var hiddenLayerResult = this.hiddenLayer.activate(inputLayerResult);
    var networkResult = this.outputLayer.activate(hiddenLayerResult);

    if(cmpArray(networkResult, expectedResult) != true) {
      for(var i = 0; i < networkResult.length; i++) {
        if(networkResult[i] < expectedResult[i]) {
          var trainInput = this.inputLayer.train(trainingData, [1,1]);
          var trainHidden = this.hiddenLayer.train(trainInput, [1,1,1,1,1]);
          var trainOutput = this.outputLayer.train(trainHidden, expectedResult);
        } else if(networkResult[i] > expectedResult[i]) {
          var trainInput1 = this.inputLayer.train(trainingData, [0,0]);
          var trainHidden1 = this.hiddenLayer.train(trainInput1, [0,0,0,0,0]);
          var trainOutput1 = this.outputLayer.train(trainHidden1, expectedResult);
        }
      }
    }
  }

  activate(data) {
    var inputLayerResult = this.inputLayer.activate(data);
    var hiddenLayerResult = this.hiddenLayer.activate(inputLayerResult);
    var networkResult = this.outputLayer.activate(hiddenLayerResult);
    return networkResult;
  }
}

console.log("Hello World!");

mm_training_data = [
  { input: [1, 0], output: [1, 0, 0] },
  { input: [0, 1], output: [0, 1, 0] },
  { input: [1, 1], output: [0, 0, 1] },
  { input: [0, 0], output: [0, 0, 0] }
];

// const network = new Network(2, 2, 2);


const layer = new Layer(3);
layer.activate([1, 0]);
for(var xx = 0; xx < 10000; xx++) {
  shuffle(mm_training_data);
  layer.train(mm_training_data[0].input, mm_training_data[0].output);
  layer.train(mm_training_data[1].input, mm_training_data[1].output);
  layer.train(mm_training_data[2].input, mm_training_data[2].output);
  layer.train(mm_training_data[3].input, mm_training_data[3].output);
}

console.log(layer.activate([1, 0]));
console.log(layer.activate([0, 1]));
console.log(layer.activate([1, 1]));
console.log(layer.activate([0, 0]));

console.log('Tu smo');