@using System.Drawing
@using System.Runtime.InteropServices
@using System.Diagnostics

@if (Data is { Count: > 0 })
{
    @*                                                      12*5=60 *@
    <div style="display: grid; grid-template-columns: 35px repeat(60, 1.5em); grid-template-rows: 1.5em repeat(7, 1.5em); gap: 0;">
        @* row 0: month labels with colspan *@
        @* @foreach (var month in Enumerable.Range(1, 12)) *@
        @* { *@
        @*     <div style="grid-row: 1; grid-column: @((int)(month * 4.3) + 1);"> *@
        @*         <span aria-hidden="true">@(new DateTime(2021, month, 1).ToString("MMM")[..3])</span> *@
        @*     </div> *@
        @* } *@

        @* column 0: day labels *@
        @* @for (var i = 0; i < 7; i++) *@
        @* { *@
        @*     <div style="text-align: left; grid-column: 1; grid-row: @(i + 2)"> *@
        @*         @(((DayOfWeek)i).ToString()[..3]) *@
        @*     </div> *@
        @* } *@


        <div style="grid-row: 1; grid-column: 5;">Jan</div>
        <div style="grid-row: 1; grid-column: 9;">Feb</div>
        <div style="grid-row: 1; grid-column: 13;">Mar</div>
        <div style="grid-row: 1; grid-column: 18;">Apr</div>
        <div style="grid-row: 1; grid-column: 22;">May</div>
        <div style="grid-row: 1; grid-column: 26;">Jun</div>
        <div style="grid-row: 1; grid-column: 31;">Jul</div>
        <div style="grid-row: 1; grid-column: 35;">Aug</div>
        <div style="grid-row: 1; grid-column: 39;">Sep</div>
        <div style="grid-row: 1; grid-column: 44;">Oct</div>
        <div style="grid-row: 1; grid-column: 48;">Nov</div>
        <div style="grid-row: 1; grid-column: 52;">Dec</div>
        <div style="text-align: left; grid-column: 1; grid-row: 2">Sun</div>
        <div style="text-align: left; grid-column: 1; grid-row: 3">Mon</div>
        <div style="text-align: left; grid-column: 1; grid-row: 4">Tue</div>
        <div style="text-align: left; grid-column: 1; grid-row: 5">Wed</div>
        <div style="text-align: left; grid-column: 1; grid-row: 6">Thu</div>
        <div style="text-align: left; grid-column: 1; grid-row: 7">Fri</div>
        <div style="text-align: left; grid-column: 1; grid-row: 8">Sat</div>


        @* pad activity cell dates... *@
        <div style="grid-column: 2; grid-row: 2 / span @((int)(new DateOnly(Data.Keys.First().Year, 1, 1).DayOfWeek));"></div>

        @* the actual activity cells *@

        @code{
            bool needsBorder = false;
        }

        @for (DateOnly date = new DateOnly(Data.Keys.First().Year, 1, 1); date <= new DateOnly(Data.Keys.First().Year, 1, 1).AddYears(1).AddDays(-1); date = date.AddDays(1))
        {
            var hasData = Data.TryGetValue(date, out var color);
            var needsTopBorder = date.Day == 1 && date.Month != 1 && date.DayOfWeek != DayOfWeek.Sunday;
            if (date.DayOfWeek == DayOfWeek.Sunday)
                needsBorder = date.AddDays(7).Day <= 7 && date.Month != 12;
            var needsLeftBorder = date.Day <= 7;

            <div class="activity-cell-container"
                 style="grid-row: @((int)date.DayOfWeek + 2); border-@(needsLeftBorder ? "left" : "right"): @(needsBorder ? "2px solid white" : "none"); border-top: @(needsTopBorder ? "2px solid white" : "none");">
                @if (hasData)
                {
                    <div class="activity-cell"
                         style="background-color: rgb(@(color.R / GlobalMax.R * 255), @(color.G / GlobalMax.G * 255), @(color.B / GlobalMax.B * 255));"
                         title="@($"{color.R} {RLabel}, {color.G} {GLabel}, and {color.B} {BLabel} on {date.ToString("D")}")">
                    </div>
                }
                else
                {
                    <div class="activity-cell"
                         title="@($"No data on {date.ToString("D")}")">
                    </div>
                }
            </div>
        }
    </div>
}


@code {
    private Dictionary<DateOnly, RGB> _data = new();
    private RGB? _globalMax = null;

    [Parameter]
    public Dictionary<DateOnly, RGB> Data
    {
        get => _data;
        set
        {
            // var sw = Stopwatch.StartNew();
            if (value is not { Count: > 0 }) return;
            // Console.WriteLine($"Recalculating activity graph ({value.Count} datapoints)...");


            // var year = (int)value.Keys.Average(x => x.Year);
            // value = value
            // .Where(x => x.Key.Year == year)
            // .OrderBy(x => x.Key)
            // .ToDictionary(x => x.Key, x => x.Value);

            _data = value;
            // Console.WriteLine($"Recalculated activity graph in {sw.Elapsed}");
            // StateHasChanged();
        }
    }

    [Parameter]
    public RGB GlobalMax
    {
        get
        {
            if (_globalMax is not null) return _globalMax.Value;
            if (Data is not { Count: > 0 }) return new RGB() { R = 255, G = 255, B = 255 };
            return new RGB()
            {
                R = Data.Values.Max(x => x.R),
                G = Data.Values.Max(x => x.G),
                B = Data.Values.Max(x => x.B)
            };
        }
        set => _globalMax = value;
    }

    [Parameter] public string RLabel { get; set; } = "R";
    [Parameter] public string GLabel { get; set; } = "G";
    [Parameter] public string BLabel { get; set; } = "B";

    [StructLayout(LayoutKind.Sequential, Size = sizeof(float) * 3, Pack = 1)]
    public struct RGB()
    {
        public float R = 0;
        public float G = 0;
        public float B = 0;

        public RGB(float r, float g, float b) : this()
        {
            R = r;
            G = g;
            B = b;
        }
    }

}