package main

import (
	"embed"
	"github.com/gorilla/mux"
	"html/template"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"sort"
)

//go:embed *.json *.css *.js *.svg
var content embed.FS

//go:embed *.tmpl
var internal embed.FS

var templates *template.Template

var root string

func main() {
	initRoot()

	port := os.Getenv("DERELICTPORT")
	if port == "" {
		port = "8080"
	}

	templates = template.Must(template.ParseFS(internal, "*.tmpl"))

	router := mux.NewRouter()
	router.HandleFunc("/", handleRecent).Methods("GET")
	router.HandleFunc("/view/{id:[_0-9]+}", handleView).Methods("GET")
	router.HandleFunc("/battles/", handleBattlesPost).Methods("POST")
	router.HandleFunc("/battles/{id:[_0-9]+}", handleBattlesId).Methods("GET")
	router.PathPrefix("/").Handler(http.FileServer(http.FS(content)))

	log.Fatal(http.ListenAndServe(":"+port, router))
}

func initRoot() {
	root = os.Getenv("DERELICTROOT")
	if root == "" {
		root = ".derelict"
	}
	os.Mkdir(root, 0755)
	os.Mkdir(root+"/battles", 0755)
}

func handleBattlesPost(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusNotImplemented)
}

func handleBattlesId(w http.ResponseWriter, r *http.Request) {
	id := mux.Vars(r)["id"]
	w.Header().Add("Content-Type", "application/json")
	http.ServeFile(w, r, root+"/battles/"+id)
}

func handleRecent(w http.ResponseWriter, r *http.Request) {
	files, err := ioutil.ReadDir(root + "/battles")
	if err != nil {
		panic(err)
	}
	sort.Slice(files, func(lhs, rhs int) bool {
		return files[lhs].ModTime().After(files[rhs].ModTime())
	})
	count := 10
	if count > len(files) {
		count = len(files)
	}
	templates.ExecuteTemplate(w, "recent", files[:count])
}

func handleView(w http.ResponseWriter, r *http.Request) {
	id := mux.Vars(r)["id"]
	templates.ExecuteTemplate(w, "view", id)
}