using System.Globalization;
using Microsoft.Extensions.Options;
using SQLInsight.Core.Findings;
using SQLInsight.Core.Instances;

namespace SQLInsight.Web;

/// <summary>
/// Formatting for the UI: times in the configured time zone, Danish number format, severity names.
/// </summary>
public sealed class Display(IOptions<WebOptions> options)
{
    private static readonly CultureInfo Danish = CultureInfo.GetCultureInfo("da-DK");

    private readonly TimeZoneInfo _zone = options.Value.TimeZone is { Length: > 0 } id
        ? TimeZoneInfo.FindSystemTimeZoneById(id)
        : TimeZoneInfo.Local;

    public string Time(DateTime? utc) => utc is { } value
        ? TimeZoneInfo.ConvertTimeFromUtc(DateTime.SpecifyKind(value, DateTimeKind.Utc), _zone).ToString("dd-MM-yyyy HH:mm", Danish)
        : "–";

    public string Ago(DateTime? utc)
    {
        if (utc is not { } value)
        {
            return "aldrig";
        }

        var age = DateTime.UtcNow - value;
        return age.TotalMinutes < 2 ? "lige nu"
            : age.TotalHours < 2 ? $"{age.TotalMinutes:0} min. siden"
            : age.TotalDays < 2 ? $"{age.TotalHours:0} timer siden"
            : $"{age.TotalDays:0} dage siden";
    }

    public static string Number(double value, int decimals = 0) => value.ToString("N" + decimals, Danish);

    public static string SeverityName(Severity severity) => severity switch
    {
        Severity.Critical => "Kritisk",
        Severity.High => "Høj",
        Severity.Medium => "Middel",
        Severity.Low => "Lav",
        _ => "Info",
    };

    public static string SeverityClass(Severity? severity) => severity switch
    {
        Severity.Critical => "sev-critical",
        Severity.High => "sev-high",
        Severity.Medium => "sev-medium",
        Severity.Low => "sev-low",
        Severity.Info => "sev-info",
        _ => "sev-ok",
    };

    public static string Release(string? productVersion, int? engineEdition = null) =>
        engineEdition == (int)EngineEdition.AzureSqlManagedInstance ? SqlServerRelease.AzureSqlManagedInstance.DisplayName()
        : SqlServerVersion.TryParse(productVersion, out var version) ? version.Release.DisplayName() : "Ukendt version";
}