using System.Diagnostics;
using System.Text;
using ZA.CoreService.ESBCertificateManager.Models;

namespace ZA.CoreService.ESBCertificateManager.Services;

/// <summary>
/// Neustart über die offiziellen Sonic-Bin-Scripts (laut Doku):
///   SonicHome\bin\stopcontainer.bat Domain.Container
///   SonicHome\bin\startcontainer.bat Domain.Container
/// Die Scripts setzen selbst JAVA_HOME – kein separates System-Java nötig.
/// </summary>
public sealed class SonicBinRestartExecutor
{
    private readonly SonicConnection _connection;

    public SonicBinRestartExecutor(SonicConnection connection)
    {
        _connection = connection;
    }

    public (bool Ok, string? Error, string? Detail) Probe()
    {
        string sonicHome = _connection.SonicHome?.Trim() ?? string.Empty;
        if (string.IsNullOrWhiteSpace(sonicHome))
        {
            return (false, "SonicHome ist leer – in appsettings setzen.", null);
        }

        if (!Directory.Exists(sonicHome))
        {
            return (false, $"SonicHome existiert nicht: '{sonicHome}'", null);
        }

        string stop = Path.Combine(sonicHome, "bin", "stopcontainer.bat");
        string start = Path.Combine(sonicHome, "bin", "startcontainer.bat");
        if (!File.Exists(stop) || !File.Exists(start))
        {
            return (false,
                $"stopcontainer.bat/startcontainer.bat fehlen unter '{Path.Combine(sonicHome, "bin")}'.",
                $"stop={File.Exists(stop)}; start={File.Exists(start)}");
        }

        return (true, null, $"SonicHome={sonicHome}");
    }

    public async Task<(bool Success, string Status, string? Detail)> RestartAsync(
        string containerName,
        CancellationToken cancellationToken = default)
    {
        (bool probeOk, string? probeError, string? probeDetail) = Probe();
        if (!probeOk)
        {
            return (false, "Neustart fehlgeschlagen (SonicBin)",
                $"{probeError}\n{probeDetail}");
        }

        string sonicHome = _connection.SonicHome.Trim();
        string bin = Path.Combine(sonicHome, "bin");
        string stopBat = Path.Combine(bin, "stopcontainer.bat");
        string startBat = Path.Combine(bin, "startcontainer.bat");

        string shortName = containerName.Contains('.')
            ? containerName[(containerName.IndexOf('.') + 1)..]
            : containerName;
        string fullName = containerName.Contains('.')
            ? containerName
            : $"{_connection.DomainName}.{containerName}";

        StringBuilder log = new();
        log.AppendLine($"SonicHome={sonicHome}");
        log.AppendLine($"Container={fullName} (kurz={shortName})");

        (bool stopOk, string stopOut, string stopErr, int stopCode) =
            await RunBatAsync(stopBat, fullName, bin, cancellationToken);
        log.AppendLine($"STOP ExitCode={stopCode}");
        if (stopOut.Length > 0) log.AppendLine("STOP out: " + Truncate(stopOut));
        if (stopErr.Length > 0) log.AppendLine("STOP err: " + Truncate(stopErr));

        // stopcontainer kann ExitCode!=0 liefern wenn Container schon down – trotzdem starten
        await Task.Delay(TimeSpan.FromSeconds(5), cancellationToken);

        (bool startOk, string startOut, string startErr, int startCode) =
            await RunBatAsync(startBat, fullName, bin, cancellationToken);
        log.AppendLine($"START ExitCode={startCode}");
        if (startOut.Length > 0) log.AppendLine("START out: " + Truncate(startOut));
        if (startErr.Length > 0) log.AppendLine("START err: " + Truncate(startErr));

        if (!startOk || startCode != 0)
        {
            // Fallback: Kurzname ohne Domain
            if (!string.Equals(shortName, fullName, StringComparison.OrdinalIgnoreCase))
            {
                log.AppendLine($"Retry START mit Kurzname '{shortName}'…");
                (startOk, startOut, startErr, startCode) =
                    await RunBatAsync(startBat, shortName, bin, cancellationToken);
                log.AppendLine($"START(short) ExitCode={startCode}");
                if (startOut.Length > 0) log.AppendLine("START out: " + Truncate(startOut));
                if (startErr.Length > 0) log.AppendLine("START err: " + Truncate(startErr));
            }
        }

        await Task.Delay(
            TimeSpan.FromSeconds(Math.Clamp(_connection.PostRestartDelaySeconds, 0, 120)),
            cancellationToken);

        if (startCode != 0)
        {
            return (false, "Neustart fehlgeschlagen (SonicBin)",
                $"startcontainer ExitCode={startCode} (stop ExitCode={stopCode}).\n{log}");
        }

        return (true, $"Container '{fullName}' neugestartet (SonicBin)", log.ToString());
    }

    private static async Task<(bool Started, string StdOut, string StdErr, int ExitCode)> RunBatAsync(
        string batPath,
        string argument,
        string workingDirectory,
        CancellationToken cancellationToken)
    {
        ProcessStartInfo psi = new()
        {
            FileName = "cmd.exe",
            Arguments = $"/c \"\"{batPath}\" \"{argument}\"\"",
            WorkingDirectory = workingDirectory,
            UseShellExecute = false,
            RedirectStandardOutput = true,
            RedirectStandardError = true,
            CreateNoWindow = true,
            StandardOutputEncoding = Encoding.UTF8,
            StandardErrorEncoding = Encoding.UTF8
        };

        using Process process = new() { StartInfo = psi };
        if (!process.Start())
        {
            return (false, string.Empty, "cmd.exe konnte nicht gestartet werden.", -1);
        }

        Task<string> stdoutTask = process.StandardOutput.ReadToEndAsync(cancellationToken);
        Task<string> stderrTask = process.StandardError.ReadToEndAsync(cancellationToken);

        await process.WaitForExitAsync(cancellationToken);
        return (true, (await stdoutTask).Trim(), (await stderrTask).Trim(), process.ExitCode);
    }

    private static string Truncate(string value, int max = 500)
        => value.Length <= max ? value : value[..max] + "…";
}