using System;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;
using MongoDB.Driver;

namespace StellaOps.Graph.Indexer.Infrastructure;

public static class MongoServiceCollectionExtensions
{
    public static IServiceCollection AddGraphMongoDatabase(
        this IServiceCollection services,
        Action<MongoDatabaseOptions> configure)
    {
        ArgumentNullException.ThrowIfNull(services);
        ArgumentNullException.ThrowIfNull(configure);

        services.Configure(configure);

        services.AddSingleton<IMongoClient>(sp =>
        {
            var opts = sp.GetRequiredService<IOptions<MongoDatabaseOptions>>().Value;
            Validate(opts);
            return new MongoClient(opts.ConnectionString);
        });

        services.AddSingleton<IMongoDatabase>(sp =>
        {
            var opts = sp.GetRequiredService<IOptions<MongoDatabaseOptions>>().Value;
            Validate(opts);
            return sp.GetRequiredService<IMongoClient>().GetDatabase(opts.DatabaseName);
        });

        return services;
    }

    private static void Validate(MongoDatabaseOptions options)
    {
        if (string.IsNullOrWhiteSpace(options.ConnectionString))
        {
            throw new InvalidOperationException("Mongo connection string must be provided.");
        }

        if (string.IsNullOrWhiteSpace(options.DatabaseName))
        {
            throw new InvalidOperationException("Mongo database name must be provided.");
        }
    }
}