cgi.go

package main

import (
	"fmt"
	"net/http"
	"net/http/cgi"
	"os"
)

type Handler func(http.ResponseWriter, *http.Request)

type Params map[string]string

func (p Params) Matches(req *http.Request) bool {
	values := req.URL.Query()
	for k, v := range p {
		if values.Get(k) != v {
			return false
		}
	}
	return true
}

type Route struct {
	Method  string
	Params  Params
	Handler Handler
}

func (r *Route) Matches(req *http.Request) bool {
	if r.Method != "" && r.Method != req.Method {
		return false
	}
	if r.Params != nil {
		return r.Params.Matches(req)
	}
	return true
}

type Router struct {
	Routes   []Route
	NotFound Handler
}

var DefaultNotFound = func(w http.ResponseWriter, _ *http.Request) {
	http.Error(w, "not found", http.StatusNotFound)
}

func NewRouter() *Router {
	return &Router{NotFound: DefaultNotFound}
}

func (r *Router) Method(name string, h Handler, p Params) {
	r.Routes = append(r.Routes, Route{name, p, h})
}

func (r *Router) Get(h Handler, p Params)    { r.Method("GET", h) }
func (r *Router) Post(h Handler, p Params)   { r.Method("POST", h, p) }
func (r *Router) Put(h Handler, p Params)    { r.Method("PUT", h, p) }
func (r *Router) Delete(h Handler, p Params) { r.Method("DELETE", h, p) }
func (r *Router) Any(h Handler, p Params)    { r.Method("", h, p) }

func (r *Router) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
	for _, rt := range r.Routes {
		if rt.Matches(req) {
			rt.Handler(rw, req)
			return
		}
	}
	r.NotFound(rw, req)
}

func main() {
	mux := NewRouter()

	mux.Post(func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintln(w, "hello world")
	}, Params{"thing": "foo"})

	mux.Delete(func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintln(w, "what what in the butt")
	}, Params{"thing": "bar"})

	mux.Put(func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintln(w, "put it somewhere else")
	}, nil)

	if err := cgi.Serve(mux); err != nil {
		fmt.Println(os.Stderr, err)
	}
}