namespace MarketAlly.GitCommitEditor.Models;

public sealed class ImproverState
{
    private const int DefaultMaxHistorySize = 1000;
    private const int DefaultMaxHistoryAgeDays = 90;

    public List<ManagedRepo> Repos { get; set; } = [];
    public List<RewriteOperation> History { get; set; } = [];
    public Dictionary<string, string> LastAnalyzedCommits { get; set; } = [];
    public DateTimeOffset LastUpdated { get; set; } = DateTimeOffset.UtcNow;

    /// <summary>
    /// Prunes history to keep only recent entries within size and age limits.
    /// </summary>
    /// <param name="maxSize">Maximum number of history entries to retain.</param>
    /// <param name="maxAgeDays">Maximum age in days for history entries.</param>
    /// <returns>Number of entries removed.</returns>
    public int PruneHistory(int maxSize = DefaultMaxHistorySize, int maxAgeDays = DefaultMaxHistoryAgeDays)
    {
        var initialCount = History.Count;
        var cutoffDate = DateTimeOffset.UtcNow.AddDays(-maxAgeDays);

        // Remove entries older than max age
        History.RemoveAll(h => h.CreatedAt < cutoffDate);

        // If still over size limit, keep only the most recent entries
        if (History.Count > maxSize)
        {
            var sorted = History.OrderByDescending(h => h.CreatedAt).ToList();
            History.Clear();
            History.AddRange(sorted.Take(maxSize));
        }

        return initialCount - History.Count;
    }

    /// <summary>
    /// Removes history entries for repositories that are no longer registered.
    /// </summary>
    /// <returns>Number of orphaned entries removed.</returns>
    public int RemoveOrphanedHistory()
    {
        var repoIds = Repos.Select(r => r.Id).ToHashSet();
        var initialCount = History.Count;

        History.RemoveAll(h => !repoIds.Contains(h.RepoId));

        return initialCount - History.Count;
    }
}