using Microsoft.Extensions.Configuration;
using MongoDB.Bson;
using MongoDB.Bson.Serialization;
using MongoDB.Bson.Serialization.Serializers;
using MongoDB.Driver;

namespace data;

public static class MongoFactory
{
    private static IConfiguration? _config;

    /// <summary>
    /// Sets up the configuration, must be called before using GetDatabase()
    /// </summary>
    /// <param name="config"></param>
    public static void InitConfig(IConfiguration config)
    {
        //set up the use of guids globally for the mongo connection
        BsonSerializer.RegisterSerializer(new GuidSerializer(GuidRepresentation.Standard));
        _config = config;
    }
    
    /// <summary>
    /// Sets up the connection to Mongo and returns the database from Configuration
    /// </summary>
    /// <returns></returns>
    /// <exception cref="NullReferenceException"></exception>
    /// <exception cref="Exception"></exception>
    public static IMongoDatabase GetDatabase()
    {
        if (_config == null)
        {
            throw new NullReferenceException("Configuration is not set");
        }

        if (String.IsNullOrEmpty(_config.GetSection("Mongo:ConnectionString").Value))
        {
            throw new Exception("No MongoDB connection string");
        }

        var client = new MongoClient(_config.GetSection("Mongo:ConnectionString").Value);
        return client.GetDatabase(_config.GetSection("Mongo:Database").Value);
    }
}