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

namespace ZA.CoreService.ESBCertificateManager.Services;

public sealed class LocalSetupSelectionStore
{
    private static readonly JsonSerializerOptions JsonOptions =
        new()
        {
            WriteIndented = true
        };

    private readonly string _filePath;

    public LocalSetupSelectionStore()
    {
        string directory = Path.Combine(
            Environment.GetFolderPath(
                Environment.SpecialFolder.LocalApplicationData),
            "ZA.CoreService.ESBCertificateManager");

        _filePath = Path.Combine(
            directory,
            "setup-selection.json");
    }

    public LocalSetupSelection? Load()
    {
        if (!File.Exists(_filePath))
        {
            return null;
        }

        try
        {
            string json =
                File.ReadAllText(_filePath);

            return JsonSerializer.Deserialize<LocalSetupSelection>(
                json,
                JsonOptions);
        }
        catch
        {
            // Eine beschädigte lokale Auswahl darf den Start
            // nicht verhindern. Die Einstellungen werden erneut angezeigt.
            return null;
        }
    }

    public void Save(
        LocalSetupSelection selection)
    {
        ArgumentNullException.ThrowIfNull(selection);

        string? directory =
            Path.GetDirectoryName(_filePath);

        if (string.IsNullOrWhiteSpace(directory))
        {
            throw new InvalidOperationException(
                "Der lokale Einstellungen-Ordner konnte nicht bestimmt werden.");
        }

        Directory.CreateDirectory(directory);

        string json =
            JsonSerializer.Serialize(
                selection,
                JsonOptions);

        File.WriteAllText(
            _filePath,
            json);
    }

    public void Clear()
    {
        if (File.Exists(_filePath))
        {
            File.Delete(_filePath);
        }
    }
}