using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WIDESEA_Core.Core
{
    public static class ConfigurableOptions
    {
        /// <summary>添加选项配置</summary>
        /// <typeparam name="TOptions">选项类型</typeparam>
        /// <param name="services">服务集合</param>
        /// <returns>服务集合</returns>
        public static IServiceCollection AddConfigurableOptions<TOptions>(this IServiceCollection services)
            where TOptions : class, IConfigurableOptions
        {
            Type optionsType = typeof(TOptions);
            string path = GetConfigurationPath(optionsType);
            services.Configure<TOptions>(App.Configuration.GetSection(path));

            return services;
        }

        public static IServiceCollection AddConfigurableOptions(this IServiceCollection services, Type type)
        {
            string path = GetConfigurationPath(type);
            var config = App.Configuration.GetSection(path);

            Type iOptionsChangeTokenSource = typeof(IOptionsChangeTokenSource<>);
            Type iConfigureOptions = typeof(IConfigureOptions<>);
            Type configurationChangeTokenSource = typeof(ConfigurationChangeTokenSource<>);
            Type namedConfigureFromConfigurationOptions = typeof(NamedConfigureFromConfigurationOptions<>);
            iOptionsChangeTokenSource = iOptionsChangeTokenSource.MakeGenericType(type);
            iConfigureOptions = iConfigureOptions.MakeGenericType(type);
            configurationChangeTokenSource = configurationChangeTokenSource.MakeGenericType(type);
            namedConfigureFromConfigurationOptions = namedConfigureFromConfigurationOptions.MakeGenericType(type);

            services.AddOptions();
            services.AddSingleton(iOptionsChangeTokenSource,
                Activator.CreateInstance(configurationChangeTokenSource, Options.DefaultName, config) ?? throw new InvalidOperationException());
            return services.AddSingleton(iConfigureOptions,
                Activator.CreateInstance(namedConfigureFromConfigurationOptions, Options.DefaultName, config) ?? throw new InvalidOperationException());
        }

        /// <summary>获取配置路径</summary>
        /// <param name="optionsType">选项类型</param>
        /// <returns></returns>
        public static string GetConfigurationPath(Type optionsType)
        {
            var endPath = new[] { "Option", "Options" };
            var configurationPath = optionsType.Name;
            foreach (var s in endPath)
            {
                if (configurationPath.EndsWith(s))
                {
                    return configurationPath[..^s.Length];
                }
            }

            return configurationPath;
        }
    }
}