using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Options;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;

namespace Znyc.Recruitment.Admin.Commons.Core.App
{
    /// <summary>
    ///     全局应用类
    /// </summary>
    public static class App
    {
        /// <summary>
        ///     全局配置选项
        /// </summary>
        public static IConfiguration Configuration;

        /// <summary>
        ///     应用服务
        /// </summary>
        public static IServiceCollection Services;

        /// <summary>
        ///     全局配置构建器
        /// </summary>
        private static IConfigurationBuilder ConfigurationBuilder;

        /// <summary>
        ///     私有环境变量，避免重复解析
        /// </summary>
        private static IWebHostEnvironment _webHostEnvironment;

        /// <summary>
        ///     应用有效程序集
        /// </summary>
        public static readonly IEnumerable<Assembly> Assemblies;

        /// <summary>
        ///     有效程序集类型
        /// </summary>
        public static readonly IEnumerable<Type> EffectiveTypes;

        /// <summary>
        ///     构造函数
        /// </summary>
        static App()
        {
            // 编译配置
            // Configuration =ConfigurationBuilder.Build();
        }

        /// <summary>
        ///     应用环境，如，是否是开发环境，生产环境等
        /// </summary>
        public static IWebHostEnvironment WebHostEnvironment =>
            _webHostEnvironment ??= GetService<IWebHostEnvironment>();

        /// <summary>
        ///     服务提供器
        /// </summary>
        public static IServiceProvider ServiceProvider =>
            HttpContext?.RequestServices ?? Services.BuildServiceProvider();

        /// <summary>
        ///     获取请求上下文
        /// </summary>
        public static HttpContext HttpContext => HttpContextLocal.Current();

        /// <summary>
        ///     获取请求生命周期的服务
        /// </summary>
        /// <typeparam name="TService"></typeparam>
        /// <returns></returns>
        public static TService GetService<TService>()
            where TService : class
        {
            return GetService(typeof(TService)) as TService;
        }

        /// <summary>
        ///     获取请求生命周期的服务
        /// </summary>
        /// <param name="type"></param>
        /// <returns></returns>
        public static object GetService(Type type)
        {
            return ServiceProvider.GetService(type);
        }

        /// <summary>
        ///     获取请求生命周期的服务
        /// </summary>
        /// <typeparam name="TService"></typeparam>
        /// <returns></returns>
        public static TService GetRequiredService<TService>()
            where TService : class
        {
            return GetRequiredService(typeof(TService)) as TService;
        }

        /// <summary>
        ///     获取请求生命周期的服务
        /// </summary>
        /// <param name="type"></param>
        /// <returns></returns>
        public static object GetRequiredService(Type type)
        {
            return ServiceProvider.GetRequiredService(type);
        }

        /// <summary>
        ///     获取选项
        /// </summary>
        /// <typeparam name="TOptions">强类型选项类</typeparam>
        /// <returns>TOptions</returns>
        public static TOptions GetOptions<TOptions>()
            where TOptions : class, new()
        {
            return GetService<IOptions<TOptions>>()?.Value;
        }

        /// <summary>
        ///     获取选项
        /// </summary>
        /// <typeparam name="TOptions">强类型选项类</typeparam>
        /// <returns>TOptions</returns>
        public static TOptions GetOptionsMonitor<TOptions>()
            where TOptions : class, new()
        {
            return GetService<IOptionsMonitor<TOptions>>()?.CurrentValue;
        }

        /// <summary>
        ///     获取选项
        /// </summary>
        /// <typeparam name="TOptions">强类型选项类</typeparam>
        /// <returns>TOptions</returns>
        public static TOptions GetOptionsSnapshot<TOptions>()
            where TOptions : class, new()
        {
            return GetService<IOptionsSnapshot<TOptions>>()?.Value;
        }

        #region

        /// <summary>
        ///     添加配置文件
        /// </summary>
        /// <param name="config"></param>
        /// <param name="env"></param>
        internal static void AddConfigureFiles(IConfigurationBuilder config, IHostEnvironment env)
        {
            // 读取忽略的配置文件
            string[] ignoreConfigurationFiles = config.Build()
                                               .GetSection("IgnoreConfigurationFiles").Get<string[]>()
                                           ?? Array.Empty<string>();

            // 加载配置
            AutoAddJsonFiles(config, env, ignoreConfigurationFiles);
            AutoAddXmlFiles(config, env, ignoreConfigurationFiles);

            // 存储配置
            ConfigurationBuilder = config;
        }

        /// <summary>
        ///     自动加载自定义 .json 配置文件
        /// </summary>
        /// <param name="config"></param>
        /// <param name="env"></param>
        /// <param name="ignoreConfigurationFiles"></param>
        public static void AutoAddJsonFiles(IConfigurationBuilder config, IHostEnvironment env,
            string[] ignoreConfigurationFiles)
        {
            // 获取程序目录下的所有配置文件
            IEnumerable<string> jsonFiles = Directory.GetFiles(AppContext.BaseDirectory, "*.json", SearchOption.TopDirectoryOnly)
                .Union(
                    Directory.GetFiles(Directory.GetCurrentDirectory(), "*.json", SearchOption.TopDirectoryOnly)
                )
                .Where(u => !excludeJsons.Contains(Path.GetFileName(u)) &&
                            !ignoreConfigurationFiles.Contains(Path.GetFileName(u)) &&
                            !runtimeJsonSuffixs.Any(j => u.EndsWith(j)));

            if (!jsonFiles.Any())
            {
                return;
            }

            // 获取环境变量名
            string envName = env.EnvironmentName;
            List<string> envFiles = new List<string>();

            // 自动加载配置文件
            foreach (string jsonFile in jsonFiles)
            {
                // 处理带环境的配置文件
                if (Path.GetFileNameWithoutExtension(jsonFile).EndsWith($".{envName}"))
                {
                    envFiles.Add(jsonFile);
                    continue;
                }

                config.AddJsonFile(jsonFile, true, true);
            }

            // 配置带环境的配置文件
            envFiles.ForEach(u => config.AddJsonFile(u, true, true));
        }

        /// <summary>
        ///     自动加载自定义 .xml 配置文件
        /// </summary>
        /// <param name="config"></param>
        /// <param name="env"></param>
        /// <param name="ignoreConfigurationFiles"></param>
        public static void AutoAddXmlFiles(IConfigurationBuilder config, IHostEnvironment env,
            string[] ignoreConfigurationFiles)
        {
            // 获取程序目录下的所有配置文件，必须以 .config.xml 结尾
            IEnumerable<string> xmlFiles = Directory.GetFiles(AppContext.BaseDirectory, "*.xml", SearchOption.TopDirectoryOnly)
                .Union(
                    Directory.GetFiles(Directory.GetCurrentDirectory(), "*.xml", SearchOption.TopDirectoryOnly)
                )
                .Where(u => !ignoreConfigurationFiles.Contains(Path.GetFileName(u)) &&
                            u.EndsWith(".config.xml", StringComparison.OrdinalIgnoreCase));

            if (!xmlFiles.Any())
            {
                return;
            }

            // 获取环境变量名
            string envName = env.EnvironmentName;
            List<string> envFiles = new List<string>();

            // 自动加载配置文件
            foreach (string xmlFile in xmlFiles)
            {
                // 处理带环境的配置文件
                if (Path.GetFileNameWithoutExtension(xmlFile).EndsWith($".{envName}.config"))
                {
                    envFiles.Add(xmlFile);
                    continue;
                }

                config.AddXmlFile(xmlFile, true, true);
            }

            // 配置带环境的配置文件
            envFiles.ForEach(u => config.AddXmlFile(u, true, true));
        }

        /// <summary>
        ///     默认排除配置项
        /// </summary>
        private static readonly string[] excludeJsons =
        {
            "appsettings.json",
            "appsettings.Development.json",
            "appsettings.Production.json",
            "bundleconfig.json",
            "bundleconfig.Development.json",
            "bundleconfig.Production.json",
            "compilerconfig.json",
            "compilerconfig.Development.json",
            "compilerconfig.Production.json"
        };

        /// <summary>
        ///     排除运行时 Json 后缀
        /// </summary>
        private static readonly string[] runtimeJsonSuffixs =
        {
            "deps.json",
            "runtimeconfig.dev.json",
            "runtimeconfig.prod.json",
            "runtimeconfig.json"
        };

        #endregion
    }
}