using System.Reflection;
using DBConnection.Contexts;
using DBConnection.Repositories.Interfaces;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

namespace DBConnection.Extensions;

public static class BuilderExtensions
{
    /// <summary>
    /// Adds dbcontext and all repositories in repository namespace
    /// </summary>
    /// <param name="collection">service collection</param>
    /// <param name="config">configuration</param>
    public static void AddDbServices(this IServiceCollection collection, IConfiguration config)
    {
        // Add appropriate DbContext
        // Contexts are linked to providers by trimming the 'AppDbContext' portion of their name.
        // So 'PostgresSqlAppDbContext' is selected with provider 'PostgresSql'
        var providerTypes = Assembly.GetExecutingAssembly().GetTypes()
            .Where(t => (t.Namespace?.Contains(nameof(Contexts)) ?? false) && typeof(AppDbContext).IsAssignableFrom(t) && !t.IsAbstract && t.Name.EndsWith(nameof(AppDbContext)));
        var providers = providerTypes.ToDictionary(t => t.Name.Replace(nameof(AppDbContext), ""), t => t);
        var selectedProvider = config["DatabaseProvider"];
        
        //add dboptions
        collection.AddSingleton(new DbContextOptions<AppDbContext>());
        collection.AddSingleton<DbContextOptions>(p => p.GetRequiredService<DbContextOptions<AppDbContext>>());
        
        // add our provider dbcontext
        collection.AddScoped(typeof(AppDbContext), providers[selectedProvider]);
        
        // Add db repositories
        Type[] repositories = Assembly.GetExecutingAssembly().GetTypes()
            .Where(t => t.IsClass && !t.IsAbstract && (t.Namespace?.Contains(nameof(DBConnection.Repositories)) ?? false) && typeof(IRepository).IsAssignableFrom(t)).ToArray();
        foreach (var repo in repositories)
        {
            var repoInterface = repo.GetInterfaces()
                .FirstOrDefault(repoInterface => typeof(IRepository).IsAssignableFrom(repoInterface) && repoInterface != typeof(IRepository) && !repoInterface.IsGenericType);
            if (repoInterface != null)
            {
                collection.AddScoped(repoInterface, repo);
            }
            else
            {
                collection.AddScoped(repo);
            }
        }
        
    }
}