go.sdls.io/sin@v0.0.9/pkg/sin/routergroup.go

// Copyright 2014 Manu Martinez-Almeida.  All rights reserved.
// Use of this source code is governed by a MIT style
// license that can be found in the LICENSE file.

package sin

import (
	"net/http"
	"regexp"
)

// reg match english letters for http method name
var regEnLetter = regexp.MustCompile("^[A-Z]+$")

// IRouter defines all router handle interface includes single and group router.
type IRouter interface {
	IRoutes
	Group(string, ...HandlerFunc) *RouterGroup
}

// IRoutes defines all router handle interface.
type IRoutes interface {
	Use(...HandlerFunc) IRoutes

	Handle(string, string, ...HandlerFunc) IRoutes
	Any(string, ...HandlerFunc) IRoutes
	GET(string, ...HandlerFunc) IRoutes
	POST(string, ...HandlerFunc) IRoutes
	DELETE(string, ...HandlerFunc) IRoutes
	PATCH(string, ...HandlerFunc) IRoutes
	PUT(string, ...HandlerFunc) IRoutes
	OPTIONS(string, ...HandlerFunc) IRoutes
	HEAD(string, ...HandlerFunc) IRoutes
}

// RouterGroup is used internally to configure router, a RouterGroup is associated with
// a prefix and an array of handlers (middleware).
type RouterGroup struct {
	engine   *Engine
	basePath string
	Handlers HandlersChain
	root     bool
}

var _ IRouter = &RouterGroup{}

// Use adds middleware to the group, see example code in GitHub.
func (group *RouterGroup) Use(middleware ...HandlerFunc) IRoutes {
	group.Handlers = append(group.Handlers, middleware...)
	return group.returnObj()
}

// Group creates a new router group. You should add all the routes that have common middlewares or the same path prefix.
// For example, all the routes that use a common middleware for authorization could be grouped.
func (group *RouterGroup) Group(relativePath string, handlers ...HandlerFunc) *RouterGroup {
	return &RouterGroup{
		Handlers: group.combineHandlers(handlers),
		basePath: group.calculateAbsolutePath(relativePath),
		engine:   group.engine,
	}
}

// BasePath returns the base path of router group.
// For example, if v := router.Group("/rest/n/v1/api"), v.BasePath() is "/rest/n/v1/api".
func (group *RouterGroup) BasePath() string {
	return group.basePath
}

func (group *RouterGroup) handle(httpMethod, relativePath string, handlers HandlersChain) IRoutes {
	absolutePath := group.calculateAbsolutePath(relativePath)
	handlers = group.combineHandlers(handlers)
	group.engine.addRoute(httpMethod, absolutePath, handlers)
	return group.returnObj()
}

// Handle registers a new request handle and middleware with the given path and method.
// The last handler should be the real handler, the other ones should be middleware that can and should be shared among different routes.
// See the example code in GitHub.
//
// For GET, POST, PUT, PATCH and DELETE requests the respective shortcut
// functions can be used.
//
// This function is intended for bulk loading and to allow the usage of less
// frequently used, non-standardized or custom methods (e.g. for internal
// communication with a proxy).
func (group *RouterGroup) Handle(httpMethod, relativePath string, handlers ...HandlerFunc) IRoutes {
	if matched := regEnLetter.MatchString(httpMethod); !matched {
		panic("http method " + httpMethod + " is not valid")
	}
	return group.handle(httpMethod, relativePath, handlers)
}

// POST is a shortcut for router.Handle("POST", path, handle).
func (group *RouterGroup) POST(relativePath string, handlers ...HandlerFunc) IRoutes {
	return group.handle(http.MethodPost, relativePath, handlers)
}

// GET is a shortcut for router.Handle("GET", path, handle).
func (group *RouterGroup) GET(relativePath string, handlers ...HandlerFunc) IRoutes {
	return group.handle(http.MethodGet, relativePath, handlers)
}

// DELETE is a shortcut for router.Handle("DELETE", path, handle).
func (group *RouterGroup) DELETE(relativePath string, handlers ...HandlerFunc) IRoutes {
	return group.handle(http.MethodDelete, relativePath, handlers)
}

// PATCH is a shortcut for router.Handle("PATCH", path, handle).
func (group *RouterGroup) PATCH(relativePath string, handlers ...HandlerFunc) IRoutes {
	return group.handle(http.MethodPatch, relativePath, handlers)
}

// PUT is a shortcut for router.Handle("PUT", path, handle).
func (group *RouterGroup) PUT(relativePath string, handlers ...HandlerFunc) IRoutes {
	return group.handle(http.MethodPut, relativePath, handlers)
}

// OPTIONS is a shortcut for router.Handle("OPTIONS", path, handle).
func (group *RouterGroup) OPTIONS(relativePath string, handlers ...HandlerFunc) IRoutes {
	return group.handle(http.MethodOptions, relativePath, handlers)
}

// HEAD is a shortcut for router.Handle("HEAD", path, handle).
func (group *RouterGroup) HEAD(relativePath string, handlers ...HandlerFunc) IRoutes {
	return group.handle(http.MethodHead, relativePath, handlers)
}

// Any registers a route that matches all the HTTP methods.
// GET, POST, PUT, PATCH, HEAD, OPTIONS, DELETE, CONNECT, TRACE.
func (group *RouterGroup) Any(relativePath string, handlers ...HandlerFunc) IRoutes {
	group.handle(http.MethodGet, relativePath, handlers)
	group.handle(http.MethodPost, relativePath, handlers)
	group.handle(http.MethodPut, relativePath, handlers)
	group.handle(http.MethodPatch, relativePath, handlers)
	group.handle(http.MethodHead, relativePath, handlers)
	group.handle(http.MethodOptions, relativePath, handlers)
	group.handle(http.MethodDelete, relativePath, handlers)
	group.handle(http.MethodConnect, relativePath, handlers)
	group.handle(http.MethodTrace, relativePath, handlers)
	return group.returnObj()
}

func (group *RouterGroup) combineHandlers(handlers HandlersChain) HandlersChain {
	finalSize := len(group.Handlers) + len(handlers)
	if finalSize >= int(abortIndex) {
		panic("too many handlers")
	}
	mergedHandlers := make(HandlersChain, finalSize)
	copy(mergedHandlers, group.Handlers)
	copy(mergedHandlers[len(group.Handlers):], handlers)
	return mergedHandlers
}

func (group *RouterGroup) calculateAbsolutePath(relativePath string) string {
	return joinPaths(group.basePath, relativePath)
}

func (group *RouterGroup) returnObj() IRoutes {
	if group.root {
		return group.engine
	}
	return group
}