Initial commit with user management

main.go

@@ -0,0 +1,202 @@
+package main
+
+import (
+	// External
+
+	// Internal
+	"notes2/authentication"
+	"notes2/html_template"
+	"os"
+
+	// Standard
+	"bufio"
+	"embed"
+	"flag"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"path"
+	"strings"
+	"text/template"
+)
+
+const VERSION = "v1"
+
+var (
+	FlagDev            bool
+	FlagConfig         string
+	FlagCreateUser     string
+	FlagChangePassword string
+	Webengine          HTMLTemplate.Engine
+	config             Config
+	Log                *slog.Logger
+	AuthManager        authentication.Manager
+
+	//go:embed views
+	ViewFS embed.FS
+
+	//go:embed static
+	StaticFS embed.FS
+
+	//go:embed sql
+	SqlFS embed.FS
+)
+
+func init() { // {{{
+	// Configuration filename to use with a somewhat sane default.
+	cfgDir, err := os.UserConfigDir()
+	if err != nil {
+		panic(err)
+	}
+	cfgFilename := path.Join(cfgDir, "notes2.json")
+
+	flag.StringVar(&FlagConfig, "config", cfgFilename, "Configuration file")
+	flag.BoolVar(&FlagDev, "dev", false, "Use local files instead of embedded files")
+	flag.StringVar(&FlagCreateUser, "create-user", "", "Username for creating a new user")
+	flag.StringVar(&FlagChangePassword, "change-password", "", "Change the password for the given username")
+	flag.Parse()
+} // }}}
+func initLog() { // {{{
+	opts := slog.HandlerOptions{}
+	opts.Level = slog.LevelDebug
+	Log = slog.New(slog.NewJSONHandler(os.Stdout, &opts))
+} // }}}
+func main() { // {{{
+	initLog()
+	err := readConfig()
+	if err != nil {
+		Log.Error("config", "error", err)
+		os.Exit(1)
+	}
+
+	// dbschema uses the embedded SQL files to keep the database schema up to date.
+	err = initDB()
+	if err != nil {
+		Log.Error("database", "error", err)
+		os.Exit(1)
+	}
+
+	// The session manager contains authentication, authorization and session settings.
+	AuthManager, err = authentication.NewManager(db, Log, config.JWT.Secret, config.JWT.ExpireDays)
+
+	// A new user?
+	if FlagCreateUser != "" {
+		createNewUser(FlagCreateUser)
+		return
+	}
+
+	// Forgotten the password?
+	if FlagChangePassword != "" {
+		changePassword(FlagChangePassword)
+		return
+	}
+
+
+	// The webengine takes layouts, pages and components and renders them into HTML.
+	Webengine, err = HTMLTemplate.NewEngine(ViewFS, StaticFS, FlagDev)
+	if err != nil {
+		panic(err)
+	}
+
+	http.HandleFunc("/", rootHandler)
+	http.HandleFunc("/authenticate", AuthManager.AuthenticationHandler)
+	http.HandleFunc("/service_worker.js", pageServiceWorker)
+	listen := fmt.Sprintf("%s:%d", config.Network.Address, config.Network.Port)
+	http.ListenAndServe(listen, nil)
+} // }}}
+
+func rootHandler(w http.ResponseWriter, r *http.Request) { // {{{
+	// All URLs not specifically handled are routed to this function.
+	// Everything going here should be a static resource.
+	if r.URL.Path != "/" {
+		Webengine.StaticResource(w, r)
+		return
+	}
+
+	pageIndex(w, r)
+} // }}}
+func pageServiceWorker(w http.ResponseWriter, r *http.Request) { // {{{
+	w.Header().Add("Content-Type", "text/javascript; charset=utf-8")
+
+	var tmpl *template.Template
+	var err error
+	if FlagDev {
+		tmpl, err = template.ParseFiles("static/service_worker.js")
+	} else {
+		tmpl, err = template.ParseFS(StaticFS, "static/service_worker.js")
+	}
+	if err != nil {
+		w.Write([]byte(err.Error()))
+		return
+	}
+
+	err = tmpl.Execute(w, struct{ VERSION string }{VERSION})
+	if err != nil {
+		w.Write([]byte(err.Error()))
+		return
+	}
+} // }}}
+func pageIndex(w http.ResponseWriter, r *http.Request) { // {{{
+	// Index page is rendered since everything
+	// else are specifically handled.
+	page := HTMLTemplate.SimplePage{
+		Layout:  "main",
+		Page:    "index",
+		Version: VERSION,
+	}
+
+	err := Webengine.Render(page, w, r)
+	if err != nil {
+		w.Write([]byte(err.Error()))
+		return
+	}
+} // }}}
+func sessionFilter(fn func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) { // {{{
+	return func(w http.ResponseWriter, r *http.Request) {
+		fmt.Printf("Filtered ")
+		fn(w, r)
+	}
+} // }}}
+
+func createNewUser(username string) { // {{{
+	reader := bufio.NewReader(os.Stdin)
+
+	fmt.Print("\nPassword: ")
+	pwd, _ := reader.ReadString('\n')
+	pwd = strings.Trim(pwd, "\r\n")
+
+	fmt.Print("Name: ")
+	name, _ := reader.ReadString('\n')
+	name = strings.Trim(name, "\r\n")
+
+	alreadyExists, err := AuthManager.CreateUser(username, pwd, name)
+	if alreadyExists {
+		fmt.Printf("\nUser '%s' already exists\n", username)
+		return
+	}
+	if err != nil {
+		Log.Error("create_user", "error", err)
+		return
+	}
+
+	fmt.Printf("\nUser '%s' with username '%s' is created.\n", name, username)
+} // }}}
+func changePassword(username string) { // {{{
+	reader := bufio.NewReader(os.Stdin)
+
+	fmt.Print("\nPassword: ")
+	newPwd, _ := reader.ReadString('\n')
+	newPwd = strings.Trim(newPwd, "\r\n")
+
+	hasChanged, err := AuthManager.ChangePassword(username, "", newPwd, true)
+	if !hasChanged {
+		fmt.Printf("Invalid user\n")
+		return
+	}
+	if err != nil {
+		Log.Error("change_password", "error", err)
+		return
+	}
+
+	fmt.Printf("\nPassword changed\n")
+} // }}}