using System;
using AutoMapper;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;
using Volo.Abp.Auditing;
using Volo.Abp.Modularity;
using Volo.Abp.ObjectExtending;
using Volo.Abp.ObjectMapping;

namespace Volo.Abp.AutoMapper
{
    [DependsOn(
        typeof(AbpObjectMappingModule),
        typeof(AbpObjectExtendingModule),
        typeof(AbpAuditingModule)
    )]
    public class AbpAutoMapperModule : AbpModule
    {
        public override void PreConfigureServices(ServiceConfigurationContext context)
        {
            context.Services.AddConventionalRegistrar(new AbpAutoMapperConventionalRegistrar());
        }

        public override void ConfigureServices(ServiceConfigurationContext context)
        {
            context.Services.AddAutoMapperObjectMapper();

            context.Services.AddSingleton<MapperAccessor>(CreateMappings);
            context.Services.AddSingleton<IMapperAccessor>(provider => provider.GetRequiredService<MapperAccessor>());
        }

        private MapperAccessor CreateMappings(IServiceProvider serviceProvider)
        {
            using (var scope = serviceProvider.CreateScope())
            {
                var options = scope.ServiceProvider.GetRequiredService<IOptions<AbpAutoMapperOptions>>().Value;

                void ConfigureAll(IAbpAutoMapperConfigurationContext ctx)
                {
                    foreach (var configurator in options.Configurators)
                    {
                        configurator(ctx);
                    }
                }

                options.Configurators.Insert(0, ctx => ctx.MapperConfiguration.ConstructServicesUsing(serviceProvider.GetService));

                void ValidateAll(IConfigurationProvider config)
                {
                    foreach (var profileType in options.ValidatingProfiles)
                    {
                        config.AssertConfigurationIsValid(((Profile) Activator.CreateInstance(profileType)).ProfileName);
                    }
                }

                var mapperConfiguration = new MapperConfiguration(mapperConfigurationExpression =>
                {
                    ConfigureAll(new AbpAutoMapperConfigurationContext(mapperConfigurationExpression, scope.ServiceProvider));
                });

                ValidateAll(mapperConfiguration);

                return new MapperAccessor
                {
                    Mapper = new Mapper(mapperConfiguration)
                };
            }
        }
    }
}