// Package to manage routing of urls in net/http
// URLs type is the main thing of interest
package gispatcho

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

// Represent a single URL with a name, a pattern and supported protocol
type URL struct {
	Handler  func(http.ResponseWriter, *http.Request)
	Path     string
	Protocol string
}

// Return the corresponding net/http pattern for a URL
func (url *URL) GetPattern() string {
	return fmt.Sprintf("%s %s", url.Protocol, url.Path)
}

// Represent a set of URLs at a prefix
type URLs struct {
	URLs   map[string]URL
	Prefix string
}

type Repl map[string]string

// Given a name and replacements, return a rendered path component of a URL
func (urls URLs) Reverse(name string, replacements Repl) string {
	pattern := urls.URLs[name].Path

	for key, val := range replacements {
		re := regexp.MustCompile("{" + key + "}")
		pattern = re.ReplaceAllString(pattern, val)
	}
	return urls.Prefix + pattern
}

// Return router for the urls
func (urls URLs) GetRouter() *http.ServeMux {
	router := http.NewServeMux()
	for _, url := range urls.URLs {
		router.HandleFunc(url.GetPattern(), url.Handler)
	}
	return router
}