<!DOCTYPE html>
<html>
<head>
  <script src="face-api.js"></script>
  <script src="commons.js"></script>
  <link rel="stylesheet" href="styles.css">
  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/materialize/0.100.2/css/materialize.css">
  <script type="text/javascript" src="https://code.jquery.com/jquery-2.1.1.min.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/materialize/0.100.2/js/materialize.min.js"></script>
</head>
<body>
  <div id="navbar"></div>
  <div class="center-content page-container">
    <div class="progress" id="loader">
      <div class="indeterminate"></div>
    </div>
    <div style="position: relative" class="margin">
      <video onplay="onPlay(this)" id="inputVideo" autoplay muted></video>
      <canvas id="overlay" />
    </div>
    <div class="row side-by-side">
      <div class="row input-field" style="margin-right: 20px;">
        <select id="sizeType">
          <option value="" disabled selected>Input Size:</option>
          <option value="160">160 x 160</option>
          <option value="224">224 x 224</option>
          <option value="320">320 x 320</option>
          <option value="416">416 x 416</option>
          <option value="608">608 x 608</option>
        </select>
        <label>Input Size</label>
      </div>
      <div class="row">
        <label for="scoreThreshold">Score Threshold:</label>
        <input disabled value="0.5" id="scoreThreshold" type="text" class="bold">
      </div>
      <button
        class="waves-effect waves-light btn"
        onclick="onDecreaseThreshold()"
      >
        <i class="material-icons left">-</i>
      </button>
      <button
        class="waves-effect waves-light btn"
        onclick="onIncreaseThreshold()"
      >
        <i class="material-icons left">+</i>
      </button>
    </div>
    <div class="row side-by-side">
      <div class="row">
        <label for="time">Time:</label>
        <input disabled value="-" id="time" type="text" class="bold">
      </div>
      <div class="row">
        <label for="fps">Estimated Fps:</label>
        <input disabled value="-" id="fps" type="text" class="bold">
      </div>
    </div>
  </div>

  <script>
    let scoreThreshold = 0.5
    let sizeType = '160'
    let modelLoaded = false

    let forwardTimes = []

    function updateTimeStats(timeInMs) {
      forwardTimes = [timeInMs].concat(forwardTimes).slice(0, 30)
      const avgTimeInMs = forwardTimes.reduce((total, t) => total + t) / forwardTimes.length
      $('#time').val(`${Math.round(avgTimeInMs)} ms`)
      $('#fps').val(`${faceapi.round(1000 / avgTimeInMs)}`)
    }

    function onIncreaseThreshold() {
      scoreThreshold = Math.min(faceapi.round(scoreThreshold + 0.1), 1.0)
      $('#scoreThreshold').val(scoreThreshold)
    }

    function onDecreaseThreshold() {
      scoreThreshold = Math.max(faceapi.round(scoreThreshold - 0.1), 0.1)
      $('#scoreThreshold').val(scoreThreshold)
    }

    function onSizeTypeChanged(e, c) {
      sizeType = e.target.value
      $('#sizeType').val(sizeType)
    }

    async function onPlay(videoEl) {
      if(videoEl.paused || videoEl.ended || !modelLoaded)
        return false

      const { width, height } = faceapi.getMediaDimensions(videoEl)
      const canvas = $('#overlay').get(0)
      canvas.width = width
      canvas.height = height

      const forwardParams = {
        inputSize: parseInt(sizeType),
        scoreThreshold
      }

      const ts = Date.now()
      result = await faceapi.tinyYolov2(videoEl, forwardParams)
      updateTimeStats(Date.now() - ts)

      faceapi.drawDetection('overlay', result.map(det => det.forSize(width, height)))
      setTimeout(() => onPlay(videoEl))
    }
    async function loadNetWeights(uri) {
      return new Float32Array(await (await fetch(uri)).arrayBuffer())
    }
    async function run() {
      await faceapi.loadTinyYolov2Model('/')
      modelLoaded = true

      const videoEl = $('#inputVideo').get(0)
      navigator.getUserMedia(
        { video: {} },
        stream => videoEl.srcObject = stream,
        err => console.error(err)
      )

      onPlay($('#inputVideo').get(0))
      $('#loader').hide()
    }

    $(document).ready(function() {
      renderNavBar('#navbar', 'tiny_yolov2_face_detection_webcam')

      const sizeTypeSelect = $('#sizeType')
      sizeTypeSelect.val(sizeType)
      sizeTypeSelect.on('change', onSizeTypeChanged)
      sizeTypeSelect.material_select()
      run()
    })
  </script>
</body>
</html>