core.go

package mserver

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

type Server interface {
	http.Handler
	// Start 启动服务器
	// addr 是监听地址。如果只指定端口，可以使用 ":8081"
	// 或者 "localhost:8082"
	Start(addr string) error

	// addRoute 注册一个路由
	// method 是 HTTP 方法
	addRoute(method string, path string, handler HandleFunc, mws ...Middleware)
}

var _ Server = &Core{}

type Core struct {
	router
	middlewares []Middleware

	log       func(msg string, args ...any)
	tplEngine TemplateEngine

	pool sync.Pool
}
type CoreOption func(c *Core)

func CoreWithTemplateEngine(tplEngine TemplateEngine) CoreOption {
	return func(c *Core) {
		c.tplEngine = tplEngine
	}
}

func NewCore(opts ...CoreOption) *Core {
	c := &Core{
		router:      newRouter(),
		middlewares: []Middleware{},
		log: func(msg string, args ...any) {
			fmt.Printf(msg, args...)
		},
	}
	c.pool.New = func() any {
		return newContext()
	}
	for _, opt := range opts {
		opt(c)
	}
	return c
}

// ServeHTTP 处理请求的入口
func (c *Core) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
	ctx := c.pool.Get().(*Context)
	ctx.reset()
	ctx.req = request
	ctx.resp = writer
	ctx.tplEngine = c.tplEngine
	root := c.serve
	for i := len(c.middlewares) - 1; i >= 0; i-- {
		root = c.middlewares[i](root)
	}
	// 第一个应该是回写响应的
	// 因为它在调用next之后才回写响应，
	// 所以实际上 flashResp 是最后一个步骤
	var m Middleware = func(next HandleFunc) HandleFunc {
		return func(ctx *Context) error {
			next(ctx)
			c.flashResp(ctx)
			return nil
		}
	}
	root = m(root)
	root(ctx)
	c.pool.Put(ctx)
}

func (c *Core) serve(ctx *Context) error {
	// 寻找路由
	mn, ok := c.FindRouteNodeByRequest(ctx.GetRequest())
	if !ok {
		// 未到路由 直接返回
		ctx.SetStatus(http.StatusNotFound).Text("%s not found", ctx.GetRequest().URL)
		return fmt.Errorf("未找到路由")
	}
	ctx.SetParams(mn.pathParams)
	ctx.MatchedRoute = mn.n.path
	handler := mn.n.handler
	for i := len(mn.matchMiddlewares) - 1; i >= 0; i-- {
		handler = mn.matchMiddlewares[i](handler)
	}
	handler(ctx)
	return nil
}

// flashResp 回写响应
func (c *Core) flashResp(ctx *Context) {
	if ctx.respStatusCode > 0 {
		ctx.resp.WriteHeader(ctx.respStatusCode)
	}
	_, err := ctx.resp.Write(ctx.respData)
	if err != nil {
		c.log("回写响应失败", err)
	}
}

// Start 启动服务
func (c *Core) Start(addr string) error {
	return http.ListenAndServe(addr, c)
}

func (c *Core) StartTLS(addr, certFile, keyFile string) error {
	return http.ListenAndServeTLS(addr, certFile, keyFile, c)
}

func (c *Core) addRoute(method string, path string, handler HandleFunc, mws ...Middleware) {
	if err := c.router.addRoute(method, path, handler, mws...); err != nil {
		panic(fmt.Sprintf("add route err:%v", err))
	}
}

// 匹配路由
func (c *Core) FindRouteNodeByRequest(request *http.Request) (*matchNode, bool) {
	path := request.URL.Path
	method := request.Method
	return c.router.findRoute(method, path)
}

func (c *Core) Post(path string, handler HandleFunc) {
	c.addRoute(http.MethodPost, path, handler)
}
func (c *Core) Get(path string, handler HandleFunc) {
	c.addRoute(http.MethodGet, path, handler)
}
func (c *Core) Put(path string, handler HandleFunc) {
	c.addRoute(http.MethodPut, path, handler)
}
func (c *Core) Delete(path string, handler HandleFunc) {
	c.addRoute(http.MethodDelete, path, handler)
}

var anyMethods = []string{http.MethodGet, http.MethodPost, http.MethodPut, http.MethodPatch,
	http.MethodHead, http.MethodOptions, http.MethodDelete, http.MethodConnect, http.MethodTrace}

func (c *Core) Any(path string, handler HandleFunc) {
	for _, method := range anyMethods {
		c.addRoute(method, path, handler)
	}
}

// 注册中间件
func (c *Core) Use(middlewares ...Middleware) {
	if c.middlewares == nil {
		c.middlewares = middlewares
		return
	}
	c.middlewares = append(c.middlewares, middlewares...)
}

func (c *Core) UsePath(method string, path string, mws ...Middleware) {
	c.addRoute(method, path, nil, mws...)
}
func (c *Core) Group(prefix string) Grouper {
	return NewGroup(c, prefix)
}