package main

import (
	"encoding/json"
	"flag"
	"html/template"
	"log"
	"net/http"
)

// Server configs.
var (
	listenAddr = flag.String("listen", "0.0.0.0:80", "Listen address for server, in the form addr:port")
	scriptPath = flag.String("script", "./pajen.pl", "The relative path to pajen.pl. Must be executable!")
	apiQty     = flag.Int("quantity", 5, "The number of names returned at a time from the API")
)

var (
	pajen     *Pajen
	indexTmpl = template.Must(template.ParseFiles("index.gohtml"))
)

func logRequest(response int, r *http.Request) {
	log.Printf("[%s] %s %s %d", r.RemoteAddr, r.Method, r.RequestURI, response)
}

func handleRoot(w http.ResponseWriter, r *http.Request) {
	if r.RequestURI != "/" {
		logRequest(404, r)

		w.WriteHeader(http.StatusNotFound)
		w.Write([]byte("404 not found"))
		return
	}

	logRequest(200, r)
	indexTmpl.Execute(w, nil)
}

func handleAPI(w http.ResponseWriter, r *http.Request) {
	if r.Method != "GET" || r.RequestURI != "/api" {
		logRequest(404, r)

		w.WriteHeader(http.StatusNotFound)
		w.Write([]byte("404 not found"))
		return
	}

	a := make([]string, 0, *apiQty)
	for i := 0; i < *apiQty; i++ {
		a = append(a, <-pajen.Chan)
	}

	b, err := json.Marshal(a)
	if err != nil {
		logRequest(500, r)

		w.WriteHeader(http.StatusInternalServerError)
		b, _ = json.Marshal(map[string]any{
			"status": "Failed",
			"error":  err,
		})
	}

	logRequest(200, r)
	w.Write(b)
}

func main() {
	log.Println("Starting pajen.pl frontend - the famous indian name generator")
	flag.Parse()

	p, err := NewPajen(*scriptPath)
	if err != nil {
		log.Fatal(err)
	}
	pajen = p

	http.HandleFunc("/", handleRoot)
	http.HandleFunc("/api", handleAPI)
	http.HandleFunc("/index.css", func(w http.ResponseWriter, r *http.Request) {
		logRequest(200, r)
		http.ServeFile(w, r, "index.css")
	})
	http.HandleFunc("/index.js", func(w http.ResponseWriter, r *http.Request) {
		logRequest(200, r)
		http.ServeFile(w, r, "index.js")
	})

	if err := http.ListenAndServe(*listenAddr, nil); err != nil {
		log.Fatalln(err)
	}
}