using System;
using System.IO;
using System.Text.Json;
using System.Threading.Tasks;

namespace Harmonia.WinUI.Session;

public sealed class JsonSessionService : ISessionService
{
    private static readonly JsonSerializerOptions Options = new()
    {
        WriteIndented = true
    };

    private readonly string _filePath = Path.Combine(
        Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
        "Harmonia",
        "session.json"
    );

    public ApplicationSession Session { get; private set; } = new();

    public async Task LoadAsync()
    {
        try
        {
            if (File.Exists(_filePath))
            {
                await using var stream = File.OpenRead(_filePath);
                Session = await JsonSerializer.DeserializeAsync<ApplicationSession>(stream) ?? new();
            }
        }
        catch
        {
            Session = new();
        }
    }

    public async Task SaveAsync()
    {
        string directoryName = Path.GetDirectoryName(_filePath)!;
        Directory.CreateDirectory(directoryName);

        await using var stream = File.Create(_filePath);
        await JsonSerializer.SerializeAsync(stream, Session, Options);
    }
}