using Spectre.Console;

namespace AnchorCli;

/// <summary>
/// Manages session persistence, including auto-load on startup and auto-save on exit.
/// </summary>
internal sealed class SessionManager
{
    private readonly ChatSession _session;
    private readonly string _sessionPath;

    public SessionManager(ChatSession session, string sessionPath = ".anchor/session.json")
    {
        _session = session;
        _sessionPath = sessionPath;
    }

    /// <summary>
    /// Attempts to load a session from disk. Returns true if successful.
    /// </summary>
    public async Task<bool> TryLoadAsync(CancellationToken cancellationToken = default)
    {
        if (!File.Exists(_sessionPath))
        {
            return false;
        }

        try
        {
            await _session.LoadAsync(_sessionPath, cancellationToken);
            AnsiConsole.MarkupLine($"[dim grey]Auto-loaded previous session.[/]");

            // Print the last message if there is one
            if (_session.History.Count > 1)
            {
                var lastMessage = _session.History[^1];
                var preview = lastMessage.Text.Length > 280
                    ? lastMessage.Text[..277] + "..."
                    : lastMessage.Text;
                AnsiConsole.MarkupLine($"[dim grey]  Last message: {Markup.Escape(preview)}[/]");
            }

            return true;
        }
        catch
        {
            // Ignore load errors
            return false;
        }
    }

    /// <summary>
    /// Attempts to save the session to disk. Returns true if successful.
    /// </summary>
    public async Task<bool> TrySaveAsync(CancellationToken cancellationToken = default)
    {
        try
        {
            var directory = Path.GetDirectoryName(_sessionPath);
            if (!string.IsNullOrEmpty(directory) && !Directory.Exists(directory))
            {
                Directory.CreateDirectory(directory);
            }

            await _session.SaveAsync(_sessionPath, cancellationToken);
            return true;
        }
        catch
        {
            // Ignore save errors
            return false;
        }
    }

    /// <summary>
    /// Saves the session after an LLM turn completes.
    /// </summary>
    public async Task SaveAfterTurnAsync(CancellationToken cancellationToken = default)
    {
        await TrySaveAsync(cancellationToken);
    }
}