namespace Htmx.ApiDemo.Templates.Components;

/// <summary>
/// shadcn-style TimePicker. Syncs hour+minute inputs to a hidden HH:MM field via inline JS.
/// </summary>
public sealed class TimePicker : TimePickerBase
{
    private readonly byte[] _uniqueIdData;
    private readonly byte[] _nameData;
    private readonly byte[] _use12hData;
    private readonly byte[] _labelData;
    private readonly byte[] _descriptionData;
    private readonly byte[] _defaultHourData;
    private readonly byte[] _defaultMinuteData;
    private readonly byte[] _defaultValueData;
    private readonly byte[] _hourMinData;
    private readonly byte[] _hourMaxData;
    private readonly byte[] _amPmToggleData;

    public TimePicker(
        string name        = "time",
        TimeOnly? selected = null,
        string label       = "",
        string description = "",
        bool use12h        = false)
    {
        var time = selected ?? TimeOnly.FromDateTime(DateTime.Now);
        var uid  = Guid.NewGuid().ToString("N")[..8];   // short unique suffix

        _uniqueIdData    = uid.ToUtf8Bytes();
        _nameData        = name.ToUtf8Bytes();
        _use12hData      = (use12h ? "true" : "false").ToUtf8Bytes();
        _defaultValueData = time.ToString("HH:mm").ToUtf8Bytes();

        _labelData = string.IsNullOrEmpty(label)
            ? []
            : $"""<span class="text-sm font-medium leading-none">{label}</span>""".ToUtf8Bytes();

        _descriptionData = string.IsNullOrEmpty(description)
            ? []
            : $"""<p class="text-xs text-muted-foreground">{description}</p>""".ToUtf8Bytes();

        if (use12h)
        {
            int hour12 = time.Hour % 12;
            if (hour12 == 0) hour12 = 12;
            bool isPm = time.Hour >= 12;

            _defaultHourData   = hour12.ToString().ToUtf8Bytes();
            _defaultMinuteData = time.Minute.ToString("D2").ToUtf8Bytes();
            _hourMinData       = "1".ToUtf8Bytes();
            _hourMaxData       = "12".ToUtf8Bytes();
            _amPmToggleData    = BuildAmPmToggle(isPm);
        }
        else
        {
            _defaultHourData   = time.Hour.ToString("D2").ToUtf8Bytes();
            _defaultMinuteData = time.Minute.ToString("D2").ToUtf8Bytes();
            _hourMinData       = "0".ToUtf8Bytes();
            _hourMaxData       = "23".ToUtf8Bytes();
            _amPmToggleData    = [];
        }
    }

    private static byte[] BuildAmPmToggle(bool isPm)
    {
        var amSel = isPm ? "" : " selected";
        var pmSel = isPm ? " selected" : "";
        return $"""
            <select class="timepicker-ampm h-10 rounded-md border border-input bg-background px-2 text-sm
                           focus:outline-none focus:ring-2 focus:ring-ring">
              <option value="AM"{amSel}>AM</option>
              <option value="PM"{pmSel}>PM</option>
            </select>
            """.ToUtf8Bytes();
    }

    protected override void RenderUniqueId(HtmxRenderContext ctx)      => ctx.Writer.WriteUtf8(_uniqueIdData);
    protected override void RenderName(HtmxRenderContext ctx)          => ctx.Writer.WriteUtf8(_nameData);
    protected override void RenderUse12h(HtmxRenderContext ctx)        => ctx.Writer.WriteUtf8(_use12hData);
    protected override void RenderLabel(HtmxRenderContext ctx)         => ctx.Writer.WriteUtf8(_labelData);
    protected override void RenderDescription(HtmxRenderContext ctx)   => ctx.Writer.WriteUtf8(_descriptionData);
    protected override void RenderDefaultHour(HtmxRenderContext ctx)   => ctx.Writer.WriteUtf8(_defaultHourData);
    protected override void RenderDefaultMinute(HtmxRenderContext ctx) => ctx.Writer.WriteUtf8(_defaultMinuteData);
    protected override void RenderDefaultValue(HtmxRenderContext ctx)  => ctx.Writer.WriteUtf8(_defaultValueData);
    protected override void RenderHourMin(HtmxRenderContext ctx)       => ctx.Writer.WriteUtf8(_hourMinData);
    protected override void RenderHourMax(HtmxRenderContext ctx)       => ctx.Writer.WriteUtf8(_hourMaxData);
    protected override void RenderAmPmToggle(HtmxRenderContext ctx)    => ctx.Writer.WriteUtf8(_amPmToggleData);
}