package gee

import (
	"fmt"
	"log"
	"net/http"
)

// HandlerFunc 路由匹配到后的具体函数
type HandlerFunc func(w http.ResponseWriter, r *http.Request)

// Engine 路由表 实现了ServeHTTP接口
type Engine struct {
	router map[string]HandlerFunc
}

// ServeHTTP 实现了ServeHTTP接口
func (engine *Engine) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	// 获取连接的请求方式和路径
	key := r.Method + "-" + r.URL.Path
	// 对比和匹配路由
	handler, ok := engine.router[key]
	if ok {
		handler(w, r)
	} else {
		w.WriteHeader(http.StatusNotFound)
		_, _ = fmt.Fprintf(w, "404 NOT FOUND: %s", r.URL)
	}
	// 这里我们加上时间,容易理解
	log.Println("请求方式:", r.Method, r.URL.Path, "对应:", key, "是否对应上:", ok)
}

// Run 启动服务
func (engine *Engine) Run(addr string) (err error) {
	return http.ListenAndServe(addr, engine)
}

// 封装路由规则和具体的处理函数
// addRoute 添加路由规则
func (engine *Engine) addRoute(method string, pattern string, handler HandlerFunc) {
	key := method + "-" + pattern
	engine.router[key] = handler
	// 打印对应的 key
	fmt.Println("请求方式:", method, pattern, " 对应: ", key)
}

// GET 添加GET路由规则
func (engine *Engine) GET(pattern string, handler HandlerFunc) {
	engine.addRoute("GET", pattern, handler)
}

// POST 添加POST路由规则
func (engine *Engine) POST(pattern string, handler HandlerFunc) {
	engine.addRoute("POST", pattern, handler)
}

// New 实例化Engine
func New() *Engine {
	return &Engine{router: make(map[string]HandlerFunc)}
}