using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using DS.Module.Core.Extensions;
using DS.Module.Core.Reflection;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;

namespace DS.Module.Core.Modules;

public class ModuleApplicationBase : IModuleApplication
{
    public Type StartupModuleType { get; set; }

    public IServiceCollection Services { get; set; }

    public IServiceProvider ServiceProvider { get; set; }

    /// <summary>
    /// 模块接口容器
    /// </summary>
    public IReadOnlyList<IDSAppModule> Modules { get; set; }

    public List<IDSAppModule> Source { get; protected set; }

    public ModuleApplicationBase(Type startupModuleType, IServiceCollection services)
    {
        StartupModuleType = startupModuleType;
        Services = services;
        services.TryAddSingleton<IAssemblyFinder, AssemblyFinder>();
        services.TryAddSingleton<ITypeFinder, TypeFinder>();
        services.AddSingleton<IModuleApplication>(this);
        services.TryAddObjectAccessor<IServiceProvider>();
        Source = this.GetAllModule(services);
        Modules = this.LoadModules();
    }

    protected virtual List<IDSAppModule> GetAllModule(IServiceCollection services)
    {
        var typeFinder = services.GetOrAddSingletonService<ITypeFinder, TypeFinder>();
        var typs = typeFinder.Find(o => DSAppModule.IsAppModule(o));
        var modules = typs.Select(o => CreateModule(services, o)).Distinct();
        return modules.ToList();
    }

    protected virtual void SetServiceProvider(IServiceProvider serviceProvider)
    {
        ServiceProvider = serviceProvider;
        ServiceProvider.GetRequiredService<ObjectAccessor<IServiceProvider>>().Value = ServiceProvider;
    }

    /// <summary>
    /// 获取所有需要加载的模块
    /// </summary>
    /// <returns></returns>
    protected virtual IReadOnlyList<IDSAppModule> LoadModules()
    {
        List<IDSAppModule> modules = new List<IDSAppModule>();

        var module = Source.FirstOrDefault(o => o.GetType() == StartupModuleType);
        //if (module == null)
        //{
        //    throw new Exception($"类型为“{StartupModuleType.FullName}”的模块实例无法找到");
        //}
        Console.WriteLine("当前启动模块:",module);
        modules.Add(module);
        var dependeds = module.GetDependedTypes();
        foreach (var dependType in dependeds.Where(o => DSAppModule.IsAppModule(o)))
        {
            var dependModule = Source.ToList().Find(m => m.GetType() == dependType);
            if (dependModule == null)
            {
                throw new Exception($"加载模块{module.GetType().FullName}时无法找到依赖模块{dependType.FullName}");
            }

            modules.AddIfNotContains(dependModule);
        }

        return modules;
    }

    /// <summary>
    /// 创建模块
    /// </summary>
    /// <param name="services"></param>
    /// <param name="moduleType"></param>
    /// <returns></returns>
    private IDSAppModule CreateModule(IServiceCollection services, Type moduleType)
    {
        var module = (IDSAppModule)Expression.Lambda(Expression.New(moduleType)).Compile().DynamicInvoke();
        services.AddSingleton(moduleType, module);
        return module;
    }

    public virtual void Dispose()
    {
    }
}