using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.ActionConstraints;
using Microsoft.AspNetCore.Mvc.ApplicationModels;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.AspNetCore.Mvc.Routing;
using Microsoft.AspNetCore.Routing.Template;
using SqlSugar;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Wood.Util;

namespace Wood.Admin.WebApi
{
	/// <summary>
	/// 自动扫描所有带service名称的程序集
	/// 扫描程序集中所有带service后缀的类
	/// 给类中所有public 方法注册路由
	/// </summary>
	public class AutoRouteConvention : IApplicationModelConvention
	{
		private readonly string _baseRoutePrefix = "api";

		/// <summary>
		/// 应用路由规则
		/// get 开头为 get
		/// 其他为post
		/// </summary>
		/// <param name="application"></param>
		public void Apply(ApplicationModel application)
		{
			foreach (var controller in application.Controllers)
			{
				var controllerName = controller.ControllerName.ToLowerInvariant().Replace("service", "");

				foreach (var action in controller.Actions)
				{
					var actionName = action.ActionName.ToLowerInvariant();
					var httpMethod = "POST";
					var isGetMethod = false;
					if (!action.Selectors.Any() || !action.Selectors[0].ActionConstraints.Any())
					{
						if (actionName.StartsWith("get"))
						{
							httpMethod = "GET";
							actionName = actionName.Substring(3);
							isGetMethod = true;
						}
						else if (actionName.StartsWith("post"))
						{
							httpMethod = "POST";
							actionName = actionName.Substring(4);
						}

						// 构建路由模板
						var routeTemplate = $"{_baseRoutePrefix}/{controllerName}/{actionName}";

						if (action.Selectors.Any())
						{
							//当前已经有了 Selectors 信息则直接设置
							action.Selectors[0].AttributeRouteModel = new AttributeRouteModel { Template = routeTemplate };
							action.Selectors[0].ActionConstraints.Add(new HttpMethodActionConstraint(new[] { httpMethod }));
						}
						else
						{
							//当前没有 Selectors 信息则直接新增
							var selectorModel = new SelectorModel
							{
								AttributeRouteModel = new AttributeRouteModel { Template = routeTemplate },
							};
							selectorModel.ActionConstraints.Add(new HttpMethodActionConstraint(new[] { httpMethod }));

							action.Selectors.Add(selectorModel);
						}
					}
					else
					{
						// 构建路由模板
						var routeTemplate = $"{_baseRoutePrefix}/{controllerName}/{actionName}";
						//重新指定路由路径
						action.Selectors[0].AttributeRouteModel = new AttributeRouteModel { Template = routeTemplate };
						//是否get请求
						isGetMethod = action.Attributes.Any(it => it.GetType() == typeof(HttpGetAttribute));
					}

					//查找所有没有绑定来源的参数
					IEnumerable<ParameterModel> noBindModels = action.Parameters.Where(it => it.BindingInfo == null);

					if (noBindModels.Any())
					{
						// 设置参数来源：GET 请求的参数来自 URL，POST 请求的参数来自请求体
						// 只会设置没有明确指定来源的参数
						// Get 会加上 FromQuery
						// Post 会加上 FromBody （只有第一个参数加上 Frombody 多个参数会报错！）
						if (isGetMethod)
						{
							foreach (var parameter in noBindModels)
							{
								var bindId = parameter.BindingInfo?.BindingSource?.Id;
								if (string.IsNullOrEmpty(bindId))
								{
									// 对于 GET 请求，默认情况下参数应该来自于查询字符串或路径
									parameter.BindingInfo = new BindingInfo() { BindingSource = BindingSource.Query };
									// 对于 GET 请求，默认情况下参数应该来自于 URL
									//parameter.BindingInfo = new BindingInfo() { BindingSource = BindingSource.Path }; 
								}
							}
						}
						else
						{
							if (noBindModels.Count() > 1)
								throw Oops.Oh($"系统不支持Post请求FromBody绑定多个参数，请改成一个。路径：Controller({controller.ControllerName})Action({action.ActionName})");
							else
							{
								if (action.Parameters.Any(it => it.BindingInfo?.BindingSource?.Id == "Body"))
									throw Oops.Oh($"系统不支持Post请求FromBody绑定多个参数，请改成一个。路径：Controller({controller.ControllerName})Action({action.ActionName})");
								noBindModels.First().BindingInfo = new BindingInfo() { BindingSource = BindingSource.Body };
							}
						}
					}

				}
			}
		}
	}
}