package main

import (
	"cmp"
	"embed"
	"io/fs"
	"log"
	"net/http"
	"os"
	"strings"
	"github.com/joho/godotenv"
)

/* environment */
var debug  = false
var apiKey = ""
var host   = ""
var port   = ""

/* embeded filesystem */
//go:embed static templates README.md
var embedded embed.FS

func assetsFS() fs.FS {
	if debug {
		return os.DirFS(".")
	}
	return embedded
}

var Assets = assetsFS()

/* api key */
func getAPIKey() {
	if path := os.Getenv("API_KEY_FILE"); path != "" {
		b, err := os.ReadFile(path)
		if err != nil {
			log.Fatalf("Failed to read API_KEY_FILE: %v", err)
		}
		apiKey = strings.TrimSpace(string(b))
	} else {
		apiKey = os.Getenv("API_KEY")
	}
	if apiKey == "" {
		log.Println("Warning: neither API_KEY and API_KEY_FILE are set. Endpoints that rely on the API key will return 500")
	}
}

/* root handler */
func rootHandler(w http.ResponseWriter, r *http.Request) {
	path := strings.Trim(r.URL.Path, "/")
	if path == "" {
		//http.ServeFile(w, r, "static/index.html")
		renderIndexTemplate(w)
	} else {
		renderWatchTemplate(w, path, r.URL.RawQuery) // FIXME just redirect this one to /watch for simplicity
	}
}

/* main */
func main() {
	// load .env file if it exists
	godotenv.Load()
	// setup environment
	debug = os.Getenv("DEBUG") != ""
	host  = cmp.Or(os.Getenv("HOST"), "127.0.0.1")
	port  = cmp.Or(os.Getenv("PORT"), "8080")
	getAPIKey()

	// setup routes
	mux := http.NewServeMux()
	registerRoutesAPI(mux, &APISourceOfficial{})
	registerRoutesWatch(mux)
	setupHome()
	static, _ := fs.Sub(Assets, "static")
	mux.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.FS(static))))
	mux.HandleFunc("/", rootHandler)

	// start http server
	log.Println("Listening on http://" + host + ":" + port)
	err := http.ListenAndServe(host + ":" + port, mux)
	if err != nil {
		log.Fatal(err)
	}
}