ModStatusTracker.cs

using System.Collections.Generic;
using System.Text;

namespace ModUpdater
{
    public class ModStatusTracker
    {
        private readonly object lockObj = new object();
        private readonly List<ModStatusEntry> entries = new List<ModStatusEntry>();
        private readonly StringBuilder sb = new StringBuilder();
        private string cachedText = "No mods found.";
        private bool dirty = true;

        public bool HasUpdate { get { lock (lockObj) return dirty; } }

        public void Clear()
        {
            lock (lockObj)
            {
                entries.Clear();
                dirty = true;
            }
        }

        public void SetMod(string name, string version, ModStatus status)
        {
            lock (lockObj)
            {
                for (int i = 0; i < entries.Count; i++)
                {
                    if (entries[i].Name == name)
                    {
                        var entry = entries[i];
                        entry.Version = version;
                        entry.Status = status;
                        entries[i] = entry;
                        dirty = true;
                        return;
                    }
                }
                entries.Add(new ModStatusEntry { Name = name, Version = version, Status = status });
                dirty = true;
            }
        }

        public string BuildDisplayText()
        {
            lock (lockObj)
            {
                if (!dirty)
                    return cachedText;

                if (entries.Count == 0)
                {
                    cachedText = "No mods found.";
                    dirty = false;
                    return cachedText;
                }

                sb.Clear();
                foreach (var entry in entries)
                {
                    if (entry.Status == ModStatus.Installed)
                        sb.Append("<b><color=green>OK</color>  ");
                    else if (entry.Status == ModStatus.Skipped)
                        sb.Append("<b><color=yellow>-</color>   ");
                    else
                        sb.Append("<b><color=red>X</color>   ");

                    sb.Append(entry.Name);
                    sb.Append("</b> ... ");
                    sb.Append(entry.Version);

                    if (entry.Status != ModStatus.Installed)
                    {
                        sb.Append(" .... ");
                        sb.Append(StatusLabel(entry.Status));
                    }

                    sb.AppendLine();
                }

                cachedText = sb.ToString().TrimEnd();
                dirty = false;
                return cachedText;
            }
        }

        public string StatusSummary
        {
            get
            {
                lock (lockObj)
                {
                    int downloading = 0;
                    bool anyDownloaded = false;

                    foreach (var entry in entries)
                    {
                        if (entry.Status == ModStatus.Downloading || entry.Status == ModStatus.Queued)
                            downloading++;
                        else if (entry.Status == ModStatus.Downloaded)
                            anyDownloaded = true;
                    }

                    if (downloading > 0)
                        return $"Downloading {downloading}";
                    if (anyDownloaded)
                        return "NEED RESTART";
                    return "Up to date";
                }
            }
        }

        public void GetDownloadProgress(out int completed, out int total, out bool isDownloading)
        {
            lock (lockObj)
            {
                completed = 0;
                total = 0;
                isDownloading = false;
                foreach (var entry in entries)
                {
                    switch (entry.Status)
                    {
                        case ModStatus.Downloaded:
                            completed++;
                            total++;
                            break;
                        case ModStatus.Downloading:
                            total++;
                            isDownloading = true;
                            break;
                        case ModStatus.Queued:
                        case ModStatus.Failed:
                            total++;
                            break;
                        case ModStatus.Skipped:
                            break;
                    }
                }
            }
        }

        private static string StatusLabel(ModStatus status)
        {
            switch (status)
            {
                case ModStatus.Downloading: return "Downloading";
                case ModStatus.Queued:      return "Queued";
                case ModStatus.Downloaded:  return "Updated";
                case ModStatus.Skipped:     return "Skipped";
                case ModStatus.Failed:      return "Failed";
                default:                    return "";
            }
        }

        private struct ModStatusEntry
        {
            public string Name;
            public string Version;
            public ModStatus Status;
        }
    }
}