using System.Globalization;
using Blog.Models;
using Blog.Services;
using Microsoft.AspNetCore.Components;
using Microsoft.Extensions.Options;

namespace Blog.Components.Pages;

public partial class Rvrb : ComponentBase
{
    [Inject]
    public required RvrbService Service { get; set; }

    [Inject]
    public required IOptions<RvrbOptions> Settings { get; set; }

    private RvrbStatus Status { get; set; } = RvrbStatus.Unreachable("not read yet");

    private RvrbSnapshot? Snapshot => Status.Snapshot;

    private RvrbOptions Options => Settings.Value;

    /// <summary>
    /// How stale the snapshot is by the time it reaches the browser. Snapshots are cached and
    /// shared, so the track that was 40 seconds in when it was taken is further along by now — this
    /// is what lets the page pick the counter up where the bot left it.
    /// </summary>
    private TimeSpan Age => DateTimeOffset.UtcNow - Status.FetchedAt;

    private string StatusLabel => Status switch
    {
        { Snapshot: null } => "offline",
        { Snapshot.Live: null } => "up, not in the room",
        _ => "up, in the room"
    };

    private string StatusClass => Status switch
    {
        { Snapshot: null } => "status-down",
        { Snapshot.Live: null } => "status-idle",
        _ => "status-up"
    };

    protected override async Task OnInitializedAsync()
    {
        Status = await Service.GetStatusAsync().ConfigureAwait(true);
        await base.OnInitializedAsync().ConfigureAwait(true);
    }

    /// <summary>The hover label on a bar: which day it is, and what it counts.</summary>
    private static string BarTitle(RvrbDay day) => $"{day.Date:yyyy-MM-dd}: {day.Plays} plays";

    /// <summary>
    /// The weekday under a bar, so a fortnight of counts reads as weeks rather than as a row of
    /// numbers. Invariant rather than the request's culture: the rest of the page is in English,
    /// and a per-visitor abbreviation would change how wide the column has to be.
    /// </summary>
    private static string DayLabel(RvrbDay day) => day.Date.ToString("ddd", CultureInfo.InvariantCulture);

    /// <summary>
    /// A day's bar height as a percentage of the busiest day in the window, floored at something
    /// visible so a day with one play doesn't render as nothing at all.
    /// </summary>
    private int BarHeight(int plays)
    {
        if (plays == 0) return 0;

        var busiest = Snapshot?.PlaysPerDay.Max(day => day.Plays) ?? 0;
        return busiest == 0 ? 0 : Math.Max(4, (int)Math.Round(plays * 100.0 / busiest));
    }
}