(async function() {
  const chartData = {
    datasets: [{
      label: 'Air Temperature',
      data: [{"x":0,"y":-11.3},{"x":-1,"y":-10.8},{"x":-2,"y":-10.2},{"x":-3,"y":-9.9},{"x":-4,"y":-10.6},{"x":-5,"y":-10.1},{"x":-6,"y":-9.2},{"x":-7,"y":-8.3},{"x":-8,"y":-7.6},{"x":-9,"y":-7.1},{"x":-10,"y":-7.1},{"x":-11,"y":-7.6},{"x":-12,"y":-8},{"x":-13,"y":-8.4},{"x":-14,"y":-9.2},{"x":-15,"y":-9.9},{"x":-16,"y":-10.5},{"x":-17,"y":-11.3},{"x":-18,"y":-11.8},{"x":-19,"y":-11.5},{"x":-20,"y":-11.9},{"x":-21,"y":-12.2},{"x":-22,"y":-12.6},{"x":-23,"y":-11.9}],
      backgroundColor: '#D5202A'
    }]
  }
  
  ctx = document.getElementById('airTemp').getContext('2d');
  chart = new Chart(ctx, {
    type: 'scatter',
    data: chartData,
    showLine: true,
    options: {
      scales: {
        x: {
          title: {
            display: true,
            text: 'Hours',
            font: {
              size: 16
            },
          }
        },
        y: {
          title: {
            display: true,
            text: '°C',
            font: {
              size: 16
            },
          }
        }
      }
    }
  })
  if(chartData.datasets[0].data.length === 0) {
    const width = chart.width
    const height = chart.height
    const chart_ctx = chart.ctx;
    var fontSize = (height / 114).toFixed(2);
    chart_ctx.font = fontSize + "em sans-serif";
    chart_ctx.fillStyle = "red";
    chart_ctx.textBaseline = "middle";

    var text = 'No Data',
        textX = Math.round((width - ctx.measureText(text).width) / 2),
        textY = height / 2;

    ctx.fillText(text, textX, textY);
  }
})();