package redirection

import (
	"fmt"
	"log"
	"net/http"
	"strings"
)

/*
	handler.go

	This script store the handlers use for handling
	redirection request
*/

//Check if a request URL is a redirectable URI
func (t *RuleTable) IsRedirectable(r *http.Request) bool {
	requestPath := r.Host + r.URL.Path
	rr := t.MatchRedirectRule(requestPath)
	return rr != nil
}

//Handle the redirect request, return after calling this function to prevent
//multiple write to the response writer
func (t *RuleTable) HandleRedirect(w http.ResponseWriter, r *http.Request) {
	requestPath := r.Host + r.URL.Path
	rr := t.MatchRedirectRule(requestPath)
	if rr != nil {
		redirectTarget := rr.TargetURL
		//Always pad a / at the back of the target URL
		if redirectTarget[len(redirectTarget)-1:] != "/" {
			redirectTarget += "/"
		}
		if rr.ForwardChildpath {
			//Remove the first / in the path
			redirectTarget += r.URL.Path[1:]
		}

		if !strings.HasPrefix(redirectTarget, "http://") && !strings.HasPrefix(redirectTarget, "https://") {
			redirectTarget = "http://" + redirectTarget
		}

		fmt.Println(redirectTarget)
		http.Redirect(w, r, redirectTarget, rr.StatusCode)
	} else {
		//Invalid usage
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte("500 - Internal Server Error"))
		log.Println("Target request URL do not have matching redirect rule. Check with IsRedirectable before calling HandleRedirect!")
	}
}