using MongoDB.Driver;
using WorkTracker.Domain;

namespace WorkTracker.Services.Settings;

public sealed class MongoAppSettingsService : IAppSettingsService
{
    private const string DefaultSettingsId = "global";
    private readonly IMongoCollection<AppSettingsDocument> appSettingsCollection;

    public MongoAppSettingsService(IMongoDatabase database)
    {
        appSettingsCollection = database.GetCollection<AppSettingsDocument>("app_settings");
    }

    public async Task<AppSettingsDocument> GetAsync(CancellationToken cancellationToken = default)
    {
        var filter = Builders<AppSettingsDocument>.Filter.Eq(x => x.Id, DefaultSettingsId);
        var settings = await appSettingsCollection.Find(filter).FirstOrDefaultAsync(cancellationToken);

        if (settings is not null)
        {
            return settings;
        }

        var defaults = new AppSettingsDocument();
        await appSettingsCollection.InsertOneAsync(defaults, cancellationToken: cancellationToken);
        return defaults;
    }

    public async Task<AppSettingsDocument> SaveAsync(AppSettingsDocument settings, CancellationToken cancellationToken = default)
    {
        var existing = await GetAsync(cancellationToken);

        settings.Id = DefaultSettingsId;
        settings.CreatedAtUtc = existing.CreatedAtUtc;
        settings.UpdatedAtUtc = DateTimeOffset.UtcNow;

        var filter = Builders<AppSettingsDocument>.Filter.Eq(x => x.Id, DefaultSettingsId);
        await appSettingsCollection.ReplaceOneAsync(filter, settings, new ReplaceOptions { IsUpsert = true }, cancellationToken);

        return settings;
    }
}