using HanaToolbox.Config;
using HanaToolbox.Logging;
using HanaToolbox.Services.Interfaces;

namespace HanaToolbox.Services;

/// <summary>
/// Deletes backup and log files older than their configured retention period.
/// Runs as root (no user switching needed for file deletion).
/// </summary>
public sealed class CleanerService(AppLogger logger) : ICleanerService
{
    public Task RunAsync(CleanerConfig config, CancellationToken ct = default)
    {
        logger.Step($"Cleaning tenant backup path: {config.TenantBackupPath} "
                  + $"(retention: {config.TenantRetentionDays}d)");
        CleanDirectory(config.TenantBackupPath, config.TenantRetentionDays);

        foreach (var logPath in config.LogBackupPaths)
        {
            ct.ThrowIfCancellationRequested();
            logger.Step($"Cleaning log backup path: {logPath} "
                      + $"(retention: {config.LogRetentionDays}d)");
            CleanDirectory(logPath, config.LogRetentionDays);
        }

        logger.Success("Cleanup complete.");
        return Task.CompletedTask;
    }

    private void CleanDirectory(string directory, int retentionDays)
    {
        if (!Directory.Exists(directory))
        {
            logger.Warning($"Directory not found, skipping: {directory}");
            return;
        }

        var cutoff = DateTime.UtcNow.AddDays(-retentionDays);
        int deleted = 0;

        try
        {
            foreach (var file in Directory.EnumerateFiles(directory, "*", SearchOption.TopDirectoryOnly))
            {
                try
                {
                    if (File.GetLastWriteTimeUtc(file) < cutoff)
                    {
                        File.Delete(file);
                        deleted++;
                        logger.Info($"Deleted: {file}");
                    }
                }
                catch (Exception ex)
                {
                    logger.Warning($"Could not delete '{file}': {ex.Message}");
                }
            }
        }
        catch (Exception ex)
        {
            logger.Error($"Error enumerating '{directory}': {ex.Message}");
        }

        logger.Info($"Deleted {deleted} file(s) from '{directory}'.");
    }
}