Graph.razor

@page "/graph"
@using Public_API.Shared.Models
@inject HttpClient http

<h3>Graph</h3>

<!-- TODO : List of sensors here-->
<label for="sensor">Sensor: </label>
@if (sensors == null)
{
    <p><em>Loading...</em></p>
}
else
{

    <select name="sensor" @onchange="@OnSensorSelectChange">
        <option disabled selected> Select...</option>
        @foreach (Sensor s in sensors)
        {
            <option value="@s.sensorID">@s.friendlyName</option>
        }
    </select>
}

<!-- TODO : Show data for each sensor here -->
@if (@targetSensor != null)
{
    <h3>Sensor Selected: @targetSensor.friendlyName</h3>
}

<!-- TODO Graphs here! -->
@{<LineChart @ref="lineChart" TItem="decimal?" />}

@code {
    private Sensor[] sensors;
    private Sensor targetSensor;

    LineChart<decimal?> lineChart;
    private vw_SensorData[] sensorData;

    protected override async Task OnInitializedAsync()
    {
        sensors = await http.GetFromJsonAsync<Sensor[]>("api/GetSensorList");
    }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender)
        {
            //await HandleChartRedraw(lineChart, new List<string>(), new LineChartDataset<decimal?>(), new LineChartDataset<decimal?>());
        }
    }

    async void OnSensorSelectChange(ChangeEventArgs e)
    {
        await getSensor(e.Value.ToString());
        await getSensorData(e.Value.ToString());

        await HandleChartRedraw(lineChart, generateLabels(),
            GetLineChartDataset(),
            GetLineChartDatasetHumidity()
        );

        StateHasChanged();
    }

    async Task HandleChartRedraw(LineChart<decimal?> chart, List<string> labels,
        LineChartDataset<decimal?> dataset,
        LineChartDataset<decimal?> dataset2)
    {
        await chart.Clear();
        await chart.AddLabelsDatasetsAndUpdate(labels, dataset);
        await chart.AddDatasetsAndUpdate(dataset2);
    }

    LineChartDataset<decimal?> GetLineChartDataset()
    {
        return new LineChartDataset<decimal?>
        {
            Label = "Temperature",
            Data = extractTemperature(),
            BorderColor = new List<string> { ChartColor.FromRgba(255, 99, 132, 1f) },
            Fill = false,
            PointRadius = 2,
            BorderDash = new List<int> { }
        };
    }

    LineChartDataset<decimal?> GetLineChartDatasetHumidity()
    {
        return new LineChartDataset<decimal?>
        {
            Label = "Humidity",
            Data = extractHumidity(),
            BorderColor = new List<string> { ChartColor.FromRgba(99, 132, 99, 1f) },
            Fill = false,
            PointRadius = 2,
            BorderDash = new List<int> { }
        };
    }

    protected async Task getSensor(string sensorID)
    {
        targetSensor = await http.GetFromJsonAsync<Sensor>("api/GetSensorByID/" + sensorID);
    }

    protected async Task getSensorData(string sensorID)
    {
        sensorData = await http.GetFromJsonAsync<vw_SensorData[]>("api/LatestData/" + sensorID);
    }

    private List<decimal?> extractTemperature()
    {
        List<decimal?> l = new List<decimal?>();

        foreach (vw_SensorData data in sensorData)
        {
            l.Add(data.temperature);
        }

        return l;
    }

    private List<decimal?> extractHumidity()
    {
        List<decimal?> l = new List<decimal?>();

        foreach (vw_SensorData data in sensorData)
        {
            l.Add(data.humidity);
        }

        return l;
    }

    private List<string> generateLabels()
    {
        List<string> labels = new List<string>();

        foreach (vw_SensorData data in sensorData)
        {
            labels.Add(data.dateTime.ToShortDateString() + " " + data.dateTime.ToShortTimeString());
        }

        return labels;
    }
}