router.go

package minima

/**
* Minima is a free and open source software under Mit license

Copyright (c) 2024 gominima

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

* Authors @apoorvcodes @megatank58
* Maintainers @Panquesito7 @savioxavier @Shubhaankar-Sharma @apoorvcodes @megatank58
* Thank you for showing interest in minima and for this beautiful community
*/

import (
	"fmt"
	"net/http"
)

type Handler func(res *Response, req *Request)

/**
 * @info The cache routes struct
 * @property {string} [method] The route method
 * @property {Handler} [handler] The handler for the cached route
 * @property {string} [path] The path of the cached route
 */
type cacheRoute struct {
	method  string
	path    string
	handler Handler
}

/**
 * @info The router structure
 * @property {map[string][]*tree} [routes] The radix-tree based routes
 * @property {Handler} [notfound] The handler for the non matching routes
 * @property {[]Handler} [minmiddleware] The minima handler middleware stack
 * @property {[]func(http.Handler)http.Handler} [middleware] The http.Handler middleware stack
 * @property {bool} [isCache] Whether the router is cache or not
 * @property {[]*cacheRoute} [cacheRoute] Slice of cached routes
 * @property {http.Handler} [handler] The single http.Handler built on chaining the whole middleware stack
 */
type Router struct {
	notfound    http.Handler
	handler     http.Handler
	isCache     bool
	middlewares []func(http.Handler) http.Handler
	cacheRoute  []*cacheRoute
	routes      map[string]*tree
}

/*
*
  - @info Make new default router interface

return {Router}
*/
func NewRouter() *Router {
	r := &Router{
		routes: map[string]*tree{
			"GET":     NewTree(),
			"POST":    NewTree(),
			"PUT":     NewTree(),
			"DELETE":  NewTree(),
			"PATCH":   NewTree(),
			"OPTIONS": NewTree(),
			"HEAD":    NewTree(),
		},
		isCache:    true,
		notfound:   nil,
		middlewares: make([]func(http.Handler) http.Handler, 0),
		cacheRoute: make([]*cacheRoute, 0),
	}
	return r
}

/*
*
  - @info Registers a new route to router interface
  - @param {string} [path] The route path

return {string, []string}
*/
func (r *Router) Register(method string, path string, handler Handler) error {
	if r.handler == nil {
		r.buildHandler()
	}
	if r.isCache {
		r.cacheRoute = append(r.cacheRoute, &cacheRoute{
			method:  method,
			path:    path,
			handler: handler,
		})
		return nil
	}
	routes, ok := r.routes[method]
	if !ok {
		return fmt.Errorf("method %s not valid", method)
	}

	routes.InsertNode(path, handler)
	return nil
}

func (r *Router) NotFound(handler Handler) *Router {
	r.notfound = buildHandler(handler, nil)
	return r
}

/**
 * @info Adds route with Get method
 * @param {string} [path] The route path
 * @param {...Handler} [handler] The handler for the given route
 * @returns {*Router}
 */
func (r *Router) Get(path string, handler Handler) *Router {
	r.Register("GET", path, handler)
	return r
}

/**
 * @info Adds route with Post method
 * @param {string} [path] The route path
 * @param {...Handler} [handler] The handler for the given route
 * @returns {*Router}
 */
func (r *Router) Post(path string, handler Handler) *Router {
	r.Register("POST", path, handler)
	return r
}

/**
 * @info Adds route with Put method
 * @param {string} [path] The route path
 * @param {...Handler} [handler] The handler for the given route
 * @returns {*Router}
 */
func (r *Router) Put(path string, handler Handler) *Router {
	r.Register("PUT", path, handler)
	return r
}

/**
 * @info Adds route with Patch method
 * @param {string} [path] The route path
 * @param {...Handler} [handler] The handler for the given route
 * @returns {*Router}
 */
func (r *Router) Patch(path string, handler Handler) {
	r.Register("PATCH", path, handler)
}

/**
 * @info Adds route with Options method
 * @param {string} [path] The route path
 * @param {...Handler} [handler] The handler for the given route
 * @returns {*Router}
 */
func (r *Router) Options(path string, handler Handler) *Router {
	r.Register("OPTIONS", path, handler)
	return r
}

/**
 * @info Adds route with Head method
 * @param {string} [path] The route path
 * @param {...Handler} [handler] The handler for the given route
 * @returns {*Router}
 */
func (r *Router) Head(path string, handler Handler) *Router {
	r.Register("HEAD", path, handler)
	return r
}

/**
 * @info Adds route with Delete method
 * @param {string} [path] The route path
 * @param {...Handler} [handler] The handler for the given route
 * @returns {*Router}
 */
func (r *Router) Delete(path string, handler Handler) *Router {
	r.Register("DELETE", path, handler)
	return r
}

/**
 * @info Returns all the routes in router
 * @returns {map[string][]*mux}
 */
func (r *Router) GetCacheRoutes() []*cacheRoute {
	return r.cacheRoute
}

/**
 * @info Appends all routes to core router instance
 * @param {Router} [Router] The router instance to append
 * @returns {Router}
 */
func (r *Router) UseRouter(Router *Router) {
	routes := Router.GetCacheRoutes()
	if !r.isCache {
		for _, v := range routes {
			err := r.Register(v.method, v.path, v.handler); if err != nil {
				panic(err)
			}
		}
		return
	}
	r.cacheRoute = append(r.cacheRoute, routes...)
}

/**
 * @info Injects net/http middleware to the stack
 * @param {...func(http.Handler)http.Handler} [handler] The handler stack to append
 * @returns {}
 */
func (r *Router) use(handler ...func(http.Handler) http.Handler) {
	if r.handler != nil {
		panic("Minima: Middlewares can't go after the routes are mounted")
	}
	r.middlewares = append(r.middlewares, handler...)
}

// A dummy function that runs at the end of the middleware stack
func (r *Router) middlewareHTTP(w http.ResponseWriter, rq *http.Request) {}

/**
 * @info Builds whole middleware stack chain into single handler
 */
func (r *Router) buildHandler() {
	r.handler = chain(r.middlewares, http.HandlerFunc(r.middlewareHTTP))
}