package main

import (
	"context"
	"encoding/json"
	"log"
	"net/http"
	"time"
)

const VTT_URL string = "http://73.188.175.49:30000"

// If a url is publically reachable during a context
func isOnline(ctx context.Context, url string) bool {
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
	if err != nil {
		panic(err)
	}

	_, err = http.DefaultClient.Do(req)
	if err != nil {
		log.Println("Error occured while checking status of", url)
		return false
	}

	return true
}

func remoteStatus(w http.ResponseWriter, url string, status bool) {
	resp_body := struct {
		Online bool   `json:"online"`
		Site   string `json:"url"`
	}{status, url}

	jsonData, err := json.Marshal(resp_body)
	if err != nil {
		http.Error(w, "Error constructing response", http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	w.Write(jsonData)
}

func logStatus(name string, status bool) {
	statusText := "offline"
	if status {
		statusText = "online"
	}

	log.Println(name, "is", statusText)
}

// Check if the vtt is online
func vttStatus(w http.ResponseWriter, req *http.Request) {
	ctx, cancel := context.WithTimeout(req.Context(), 3*time.Second)
	defer cancel()

	status := isOnline(ctx, VTT_URL)
	logStatus("Foundry VTT", status)
	remoteStatus(w, VTT_URL, status)

}

// Redirect to vtt
func vttRedirect(w http.ResponseWriter, req *http.Request) {
	http.Redirect(w, req, VTT_URL, http.StatusMovedPermanently)
}

// Check if the campaign website is online
func siteStatus(w http.ResponseWriter, req *http.Request) {
	ctx, cancel := context.WithTimeout(req.Context(), 3*time.Second)
	defer cancel()

	const URL string = "https://dnd.jpappel.xyz"
	status := isOnline(ctx, URL)
	logStatus("Campaign Website", status)
	remoteStatus(w, URL, status)
}

func main() {
	mux := http.NewServeMux()

	mux.HandleFunc("GET /vtt/status", vttStatus)
    mux.HandleFunc("GET /vtt", vttRedirect)
	mux.HandleFunc("GET /site/status", siteStatus)

	log.Println("Listening on Port 8080")
	http.ListenAndServe(":8080", mux)
}