using System.Text;
using System.Text.Json;
using SharepointToolbox.Web.Core.Models;

namespace SharepointToolbox.Web.Infrastructure.Persistence;

public class SettingsRepository
{
    private readonly string _filePath;
    private readonly SemaphoreSlim _writeLock = new(1, 1);

    public SettingsRepository(string filePath) { _filePath = filePath; }

    public async Task<AppSettings> LoadAsync()
    {
        if (!File.Exists(_filePath)) return new AppSettings();
        try
        {
            var json = await File.ReadAllTextAsync(_filePath, Encoding.UTF8);
            return JsonSerializer.Deserialize<AppSettings>(json,
                new JsonSerializerOptions { PropertyNameCaseInsensitive = true }) ?? new AppSettings();
        }
        catch { return new AppSettings(); }
    }

    public async Task SaveAsync(AppSettings settings)
    {
        await _writeLock.WaitAsync();
        try
        {
            var json = JsonSerializer.Serialize(settings, new JsonSerializerOptions
            {
                WriteIndented = true, PropertyNamingPolicy = JsonNamingPolicy.CamelCase
            });
            var dir = Path.GetDirectoryName(_filePath);
            if (!string.IsNullOrEmpty(dir)) Directory.CreateDirectory(dir);
            var tmp = _filePath + ".tmp";
            await File.WriteAllTextAsync(tmp, json, Encoding.UTF8);
            File.Move(tmp, _filePath, overwrite: true);
        }
        finally { _writeLock.Release(); }
    }
}