ch17

cmd/web/context.go

@@ -0,0 +1,5 @@
+package main
+
+type contextKey string
+
+const isAuthenticatedContextKey = contextKey("isAuthenticated")

cmd/web/handlers.go

@@ -4,12 +4,51 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"io/fs"
 	"net/http"
 	"strconv"
+	"strings"
 
 	"gitea.local.lab/Lbenedar/snippetbox/internal/models"
+	"gitea.local.lab/Lbenedar/snippetbox/internal/validator"
+	"gitea.local.lab/Lbenedar/snippetbox/ui"
+	"github.com/julienschmidt/httprouter"
 )
 
+type snippetCreateForm struct {
+	Title               string `form:"title"`
+	Content             string `form:"content"`
+	Expires             int    `form:"expires"`
+	validator.Validator `form:"-"`
+}
+
+type userSignupForm struct {
+	Name                string `form:"name"`
+	Email               string `form:"email"`
+	Password            string `form:"password"`
+	validator.Validator `form:"-"`
+}
+
+type userLoginForm struct {
+	Email               string `form:"email"`
+	Password            string `form:"password"`
+	validator.Validator `form:"-"`
+}
+
+type accountViewForm struct {
+	Name                string `form:"name"`
+	Email               string `form:"email"`
+	Joined              string `form:"joined"`
+	validator.Validator `form:"-"`
+}
+
+type passwordChangeForm struct {
+	CurrentPassword     string `form:"curr_pass"`
+	NewPassword         string `form:"new_pass"`
+	ConfirmPassword     string `form:"conf_pass"`
+	validator.Validator `form:"-"`
+}
+
 func (app *application) render(w http.ResponseWriter, status int, page string, data *templateData) {
 	ts, ok := app.templateCache[page]
 	if !ok {
@@ -46,7 +85,8 @@ func (app *application) home(w http.ResponseWriter, r *http.Request) {
 }
 
 func (app *application) snippetView(w http.ResponseWriter, r *http.Request) {
-	id, err := strconv.Atoi(r.URL.Query().Get("id"))
+	params := httprouter.ParamsFromContext(r.Context())
+	id, err := strconv.Atoi(params.ByName("id"))
 	if err != nil || id < 1 {
 		app.notFound(w)
 		return
@@ -68,19 +108,227 @@ func (app *application) snippetView(w http.ResponseWriter, r *http.Request) {
 }
 
 func (app *application) snippetCreate(w http.ResponseWriter, r *http.Request) {
-	if r.Method != http.MethodPost {
+	data := app.newTemplateData(r)
-		w.Header().Set("Allow", http.MethodPost)
+
-		app.clientError(w, http.StatusMethodNotAllowed)
+	data.Form = snippetCreateForm{
+		Expires: 365,
+	}
+
+	app.render(w, http.StatusOK, "create.tmpl", data)
+}
+
+func (app *application) snippetCreatePost(w http.ResponseWriter, r *http.Request) {
+	var form snippetCreateForm
+	err := app.decodePostForm(r, &form)
+	if err != nil {
+		app.clientError(w, http.StatusBadRequest)
 		return
 	}
-	title := "0 snail"
-	content := "0 snail\nClimb Mount Fuji,\nBut slowly, slowly!\n\n-Kobayshi Issa"
-	expires := 7
 
-	id, err := app.snippets.Insert(title, content, expires)
+	form.CheckField(validator.NotBlank(form.Title), "title", "This field cannot be blank")
+	form.CheckField(validator.MaxChars(form.Title, 100), "title", "This field cannot be more than 100 character long")
+	form.CheckField(validator.NotBlank(form.Content), "content", "This field cannot be blank")
+	form.CheckField(validator.PermittedValue(form.Expires, 1, 7, 365), "expires", "This field must equal 1, 7 and 365")
+
+	if !form.Valid() {
+		data := app.newTemplateData(r)
+		data.Form = form
+		app.render(w, http.StatusUnprocessableEntity, "create.tmpl", data)
+		return
+	}
+
+	id, err := app.snippets.Insert(form.Title, form.Content, form.Expires)
 	if err != nil {
 		app.serverError(w, err)
 		return
 	}
-	http.Redirect(w, r, fmt.Sprintf("/snippet/view?id=%d", id), http.StatusSeeOther)
+
+	app.sessionManager.Put(r.Context(), "flash", "Snippet successfully created!")
+
+	http.Redirect(w, r, fmt.Sprintf("/snippet/view/%d", id), http.StatusSeeOther)
+}
+
+func (app *application) userSignupPost(w http.ResponseWriter, r *http.Request) {
+	var form userSignupForm
+	err := app.decodePostForm(r, &form)
+
+	if err != nil {
+		app.notFound(w)
+		return
+	}
+
+	form.CheckField(validator.NotBlank(form.Name), "name", "This field cannot be blank")
+	form.CheckField(validator.NotBlank(form.Email), "email", "This field cannot be blank")
+	form.CheckField(validator.Matches(form.Email, validator.EmailRX), "email", "This field must be a valid email address")
+	form.CheckField(validator.NotBlank(form.Password), "password", "This field cannot be blank")
+	form.CheckField(validator.MinChars(form.Password, 8), "password", "This field must be at least 8 character long")
+
+	if !form.Valid() {
+		data := app.newTemplateData(r)
+		data.Form = form
+		app.render(w, http.StatusUnprocessableEntity, "signup.tmpl", data)
+		return
+	}
+
+	err = app.users.Insert(form.Name, form.Email, form.Password)
+	if err != nil {
+		if errors.Is(err, models.ErrDuplicateEmail) {
+			form.AddFieldError("email", "Email address already in use")
+
+			data := app.newTemplateData(r)
+			data.Form = form
+			app.render(w, http.StatusUnprocessableEntity, "signup.tmpl", data)
+		} else {
+			app.serverError(w, err)
+		}
+		return
+	}
+	app.sessionManager.Put(r.Context(), "flash", "Your singup was successful. Please log in.")
+	http.Redirect(w, r, "/user/login", http.StatusSeeOther)
+}
+
+func (app *application) userLoginPost(w http.ResponseWriter, r *http.Request) {
+	var form userLoginForm
+
+	err := app.decodePostForm(r, &form)
+	if err != nil {
+		app.clientError(w, http.StatusBadRequest)
+		return
+	}
+
+	form.CheckField(validator.NotBlank(form.Email), "email", "This field cannot be blank")
+	form.CheckField(validator.Matches(form.Email, validator.EmailRX), "email", "This field must be a valid email address")
+	form.CheckField(validator.NotBlank(form.Password), "password", "This field cannot be blank")
+
+	if !form.Valid() {
+		data := app.newTemplateData(r)
+		data.Form = form
+		app.render(w, http.StatusUnprocessableEntity, "login.tmpl", data)
+		return
+	}
+
+	id, err := app.users.Authenticate(form.Email, form.Password)
+	if err != nil {
+		if errors.Is(err, models.ErrInvalidCredentials) {
+			form.AddNonFieldError("Email or password is incorrect")
+
+			data := app.newTemplateData(r)
+			data.Form = form
+			app.render(w, http.StatusUnprocessableEntity, "login.tmpl", data)
+		} else {
+			app.serverError(w, err)
+		}
+		return
+	}
+	err = app.sessionManager.RenewToken(r.Context())
+	if err != nil {
+		app.serverError(w, err)
+		return
+	}
+
+	app.sessionManager.Put(r.Context(), "authenticatedUserID", id)
+	redirectPath := app.sessionManager.PopString(r.Context(), "redirectParent")
+	if redirectPath != "" {
+		http.Redirect(w, r, redirectPath, http.StatusSeeOther)
+		return
+	}
+	http.Redirect(w, r, "/snippet/create", http.StatusSeeOther)
+}
+
+func (app *application) userLogoutPost(w http.ResponseWriter, r *http.Request) {
+	err := app.sessionManager.RenewToken(r.Context())
+	if err != nil {
+		app.serverError(w, err)
+		return
+	}
+	app.sessionManager.Remove(r.Context(), "authenticatedUserID")
+	app.sessionManager.Put(r.Context(), "flash", "You've been logged out succefully!")
+
+	http.Redirect(w, r, "/", http.StatusSeeOther)
+}
+
+func (app *application) userSignup(w http.ResponseWriter, r *http.Request) {
+	data := app.newTemplateData(r)
+	data.Form = userSignupForm{}
+	app.render(w, http.StatusOK, "signup.tmpl", data)
+}
+
+func (app *application) userLogin(w http.ResponseWriter, r *http.Request) {
+	data := app.newTemplateData(r)
+	data.Form = userLoginForm{}
+	app.render(w, http.StatusOK, "login.tmpl", data)
+}
+
+func ping(w http.ResponseWriter, r *http.Request) {
+	w.Write([]byte("OK"))
+}
+
+func (app *application) about(w http.ResponseWriter, r *http.Request) {
+	data := app.newTemplateData(r)
+	text, err := fs.ReadFile(ui.Files, "static/text/about.txt")
+	if err != nil {
+		app.serverError(w, err)
+		return
+	}
+	data.AboutText = string(text)
+	app.render(w, http.StatusOK, "about.tmpl", data)
+}
+
+func (app *application) accountView(w http.ResponseWriter, r *http.Request) {
+	data := app.newTemplateData(r)
+	id := app.sessionManager.Get(r.Context(), "authenticatedUserID").(int)
+
+	user, err := app.users.GetById(id)
+	if err != nil {
+		app.serverError(w, err)
+		return
+	}
+	data.Form = accountViewForm{Name: user.Name, Email: user.Email, Joined: humanDate(user.Created)}
+	app.render(w, http.StatusOK, "account.tmpl", data)
+}
+
+func (app *application) accountChangePassword(w http.ResponseWriter, r *http.Request) {
+	data := app.newTemplateData(r)
+	data.Form = passwordChangeForm{}
+	app.render(w, http.StatusOK, "password.tmpl", data)
+}
+
+func (app *application) accountChangePasswordPost(w http.ResponseWriter, r *http.Request) {
+	form := passwordChangeForm{}
+	err := app.decodePostForm(r, &form)
+	if err != nil {
+		app.clientError(w, http.StatusBadRequest)
+		return
+	}
+
+	form.CheckField(validator.NotBlank(form.CurrentPassword), "curr_pass", "This field cannot be blank")
+	form.CheckField(validator.NotBlank(form.NewPassword), "new_pass", "This field cannot be blank")
+	form.CheckField(validator.MinChars(form.NewPassword, 8), "new_pass", "Minimum password length is 8 symbols")
+	form.CheckField(validator.NotBlank(form.ConfirmPassword), "conf_pass", "This field cannot be blank")
+	form.CheckField(strings.Compare(form.NewPassword, form.ConfirmPassword) == 0, "conf_pass", "Confirm password does not match")
+
+	if !form.Valid() {
+		data := app.newTemplateData(r)
+		data.Form = form
+		app.render(w, http.StatusUnprocessableEntity, "password.tmpl", data)
+		return
+	}
+
+	id := app.sessionManager.Get(r.Context(), "authenticatedUserID").(int)
+	err = app.users.ChangePassword(id, form.CurrentPassword, form.NewPassword)
+	if err != nil {
+		if errors.Is(err, models.ErrInvalidCredentials) {
+			form.AddNonFieldError("Password is incorrect")
+
+			data := app.newTemplateData(r)
+			data.Form = form
+			app.render(w, http.StatusUnprocessableEntity, "password.tmpl", data)
+		} else {
+			app.serverError(w, err)
+		}
+		return
+	}
+
+	app.sessionManager.Put(r.Context(), "flash", "Password successfully changed!")
+	http.Redirect(w, r, "/account/view", http.StatusSeeOther)
 }

cmd/web/handlers_test.go

@@ -0,0 +1,228 @@
+package main
+
+import (
+	"net/http"
+	"net/url"
+	"testing"
+
+	"gitea.local.lab/Lbenedar/snippetbox/internal/assert"
+)
+
+func TestPing(t *testing.T) {
+	app := newTestApplication(t)
+
+	ts := newTestServer(t, app.routes())
+	defer ts.Close()
+
+	statusCode, _, body := ts.get(t, "/ping")
+
+	assert.Equal(t, statusCode, http.StatusOK)
+	assert.Equal(t, body, "OK")
+}
+
+func TestSnippetView(t *testing.T) {
+	app := newTestApplication(t)
+
+	ts := newTestServer(t, app.routes())
+	defer ts.Close()
+
+	tests := []struct {
+		name     string
+		urlPath  string
+		wantCode int
+		wantBody string
+	}{
+		{
+			name:     "Valid ID",
+			urlPath:  "/snippet/view/1",
+			wantCode: http.StatusOK,
+			wantBody: "An old silent pond...",
+		},
+		{
+			name:     "Non-existend ID",
+			urlPath:  "/snippet/view/2",
+			wantCode: http.StatusNotFound,
+		},
+		{
+			name:     "Negative ID",
+			urlPath:  "/snippet/view/-1",
+			wantCode: http.StatusNotFound,
+		},
+		{
+			name:     "Decimal ID",
+			urlPath:  "/snippet/view/1.23",
+			wantCode: http.StatusNotFound,
+		},
+		{
+			name:     "String ID",
+			urlPath:  "/snippet/view/foo",
+			wantCode: http.StatusNotFound,
+		},
+		{
+			name:     "Empty ID",
+			urlPath:  "/snippet/view/",
+			wantCode: http.StatusNotFound,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			code, _, body := ts.get(t, tt.urlPath)
+
+			assert.Equal(t, code, tt.wantCode)
+
+			if tt.wantBody != "" {
+				assert.StringContains(t, body, tt.wantBody)
+			}
+		})
+	}
+}
+
+func TestUserSignup(t *testing.T) {
+	app := newTestApplication(t)
+	ts := newTestServer(t, app.routes())
+	defer ts.Close()
+
+	_, _, body := ts.get(t, "/user/signup")
+	validCsrfToken := extractCSRFToken(t, body)
+	t.Logf("CsrfToken: %s", validCsrfToken)
+
+	const (
+		validName     = "Bob"
+		validPassword = "validPa$$word"
+		validEmail    = "bob@example.com"
+		formTag       = "<form action='/user/signup' method='POST' novalidate>"
+	)
+
+	tests := []struct {
+		name         string
+		userName     string
+		userEmail    string
+		userPassword string
+		csrfToken    string
+		wantCode     int
+		wantFormTag  string
+	}{
+		{
+			name:         "Valid submission",
+			userName:     validName,
+			userEmail:    validEmail,
+			userPassword: validPassword,
+			csrfToken:    validCsrfToken,
+			wantCode:     http.StatusSeeOther,
+		},
+		{
+			name:         "Invalid CSRF Token",
+			userName:     validName,
+			userEmail:    validEmail,
+			userPassword: validPassword,
+			csrfToken:    "wrongToken",
+			wantCode:     http.StatusBadRequest,
+		},
+		{
+			name:         "Empty name",
+			userName:     "",
+			userEmail:    validEmail,
+			userPassword: validPassword,
+			csrfToken:    validCsrfToken,
+			wantCode:     http.StatusUnprocessableEntity,
+			wantFormTag:  formTag,
+		},
+		{
+			name:         "Empty email",
+			userName:     validName,
+			userEmail:    "",
+			userPassword: validPassword,
+			csrfToken:    validCsrfToken,
+			wantCode:     http.StatusUnprocessableEntity,
+			wantFormTag:  formTag,
+		},
+		{
+			name:         "Empty password",
+			userName:     validName,
+			userEmail:    validEmail,
+			userPassword: "",
+			csrfToken:    validCsrfToken,
+			wantCode:     http.StatusUnprocessableEntity,
+			wantFormTag:  formTag,
+		},
+		{
+			name:         "Invalid email",
+			userName:     validName,
+			userEmail:    "bob@example.",
+			userPassword: validPassword,
+			csrfToken:    validCsrfToken,
+			wantCode:     http.StatusUnprocessableEntity,
+			wantFormTag:  formTag,
+		},
+		{
+			name:         "Short password",
+			userName:     validName,
+			userEmail:    validEmail,
+			userPassword: "pa$$",
+			csrfToken:    validCsrfToken,
+			wantCode:     http.StatusUnprocessableEntity,
+			wantFormTag:  formTag,
+		},
+		{
+			name:         "Duplicate email",
+			userName:     validName,
+			userEmail:    "dupe@example.com",
+			userPassword: validPassword,
+			csrfToken:    validCsrfToken,
+			wantCode:     http.StatusUnprocessableEntity,
+			wantFormTag:  formTag,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			form := url.Values{}
+			form.Add("name", tt.userName)
+			form.Add("email", tt.userEmail)
+			form.Add("password", tt.userPassword)
+			form.Add("csrf_token", tt.csrfToken)
+
+			code, _, body := ts.postForm(t, "/user/signup", form)
+
+			assert.Equal(t, code, tt.wantCode)
+			if tt.wantFormTag != "" {
+				assert.StringContains(t, body, tt.wantFormTag)
+			}
+		})
+	}
+}
+
+func TestSnippetCreate(t *testing.T) {
+	app := newTestApplication(t)
+	ts := newTestServer(t, app.routes())
+	defer ts.Close()
+
+	const (
+		validPassword = "validPa$$word"
+		validEmail    = "bob@example.com"
+	)
+
+	t.Run("Unauthenticated", func(t *testing.T) {
+		code, head, _ := ts.get(t, "/snippet/create")
+		assert.Equal(t, code, http.StatusSeeOther)
+		assert.Equal(t, head.Get("Location"), "/user/login")
+	})
+
+	t.Run("Authenticated", func(t *testing.T) {
+		_, _, body := ts.get(t, "/user/login")
+		validCsrfToken := extractCSRFToken(t, body)
+		t.Logf("CsrfToken: %s", validCsrfToken)
+
+		form := url.Values{}
+		form.Add("email", validEmail)
+		form.Add("password", validPassword)
+		form.Add("csrf_token", validCsrfToken)
+		code, _, _ := ts.postForm(t, "/user/login", form)
+		t.Logf("Auth result: %d", code)
+
+		code, _, body = ts.get(t, "/snippet/create")
+		assert.Equal(t, code, http.StatusOK)
+		assert.StringContains(t, body, "<form action='/snippet/create' method='POST'>")
+	})
+}

cmd/web/helpers.go

@@ -1,16 +1,25 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 	"net/http"
 	"runtime/debug"
+
+	"github.com/go-playground/form/v4"
 )
 
 func (app *application) serverError(w http.ResponseWriter, err error) {
 	trace := fmt.Sprintf("%s\n%s", err.Error(), debug.Stack())
 	app.errorLog.Output(2, trace)
 
-	http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+	var errorText string
+	if app.debug {
+		errorText = trace
+	} else {
+		errorText = http.StatusText(http.StatusInternalServerError)
+	}
+	http.Error(w, errorText, http.StatusInternalServerError)
 }
 
 func (app *application) clientError(w http.ResponseWriter, status int) {
@@ -20,3 +29,28 @@ func (app *application) clientError(w http.ResponseWriter, status int) {
 func (app *application) notFound(w http.ResponseWriter) {
 	app.clientError(w, http.StatusNotFound)
 }
+
+func (app *application) decodePostForm(r *http.Request, templateForm any) error {
+	err := r.ParseForm()
+	if err != nil {
+		return err
+	}
+
+	err = app.formDecoder.Decode(&templateForm, r.PostForm)
+	if err != nil {
+		var invalidDecoderError *form.InvalidDecoderError
+		if errors.As(err, &invalidDecoderError) {
+			panic("Invalid decoder error")
+		}
+		return err
+	}
+	return nil
+}
+
+func (app *application) isAuthenticated(r *http.Request) bool {
+	isAuthenticated, ok := r.Context().Value(isAuthenticatedContextKey).(bool)
+	if !ok {
+		return false
+	}
+	return isAuthenticated
+}

cmd/web/main.go

@@ -1,29 +1,39 @@
 package main
 
 import (
+	"crypto/tls"
 	"database/sql"
 	"flag"
 	"html/template"
 	"log"
 	"net/http"
 	"os"
+	"time"
 
 	"gitea.local.lab/Lbenedar/snippetbox/internal/models"
 
+	"github.com/alexedwards/scs/mysqlstore"
+	"github.com/alexedwards/scs/v2"
+	"github.com/go-playground/form/v4"
 	_ "github.com/go-sql-driver/mysql"
 )
 
 type application struct {
-	errorLog      *log.Logger
+	errorLog       *log.Logger
-	infoLog       *log.Logger
+	infoLog        *log.Logger
-	snippets      *models.SnippetModel
+	snippets       models.SnippetModelInterface
-	templateCache map[string]*template.Template
+	users          models.UserModelInterface
+	templateCache  map[string]*template.Template
+	formDecoder    *form.Decoder
+	sessionManager *scs.SessionManager
+	debug          bool
 }
 
 type config struct {
 	addr      string
 	staticDir string
 	dsn       string
+	debug     bool
 }
 
 func main() {
@@ -31,6 +41,7 @@ func main() {
 	flag.StringVar(&cfg.addr, "addr", ":4000", "HTTP network address")
 	flag.StringVar(&cfg.staticDir, "static-dir", "./ui/static", "Path to static assets")
 	flag.StringVar(&cfg.dsn, "dsn", "web:pass@/snippetbox?parseTime=true", "MySQL data source name")
+	flag.BoolVar(&cfg.debug, "debug", false, "Option to enable debug mode")
 	flag.Parse()
 
 	errorLog := log.New(os.Stderr, "ERROR\t", log.Ldate|log.Ltime|log.Lshortfile)
@@ -47,21 +58,38 @@ func main() {
 		errorLog.Fatal(err)
 	}
 
+	formDecoder := form.NewDecoder()
+	sessionManager := scs.New()
+	sessionManager.Store = mysqlstore.New(db)
+	sessionManager.Lifetime = 12 * time.Hour
+
 	app := &application{
-		errorLog:      errorLog,
+		errorLog:       errorLog,
-		infoLog:       infoLog,
+		infoLog:        infoLog,
-		snippets:      &models.SnippetModel{DB: db},
+		snippets:       &models.SnippetModel{DB: db},
-		templateCache: templateCache,
+		users:          &models.UserModel{DB: db},
+		templateCache:  templateCache,
+		formDecoder:    formDecoder,
+		sessionManager: sessionManager,
+		debug:          cfg.debug,
+	}
+
+	tlsConfig := &tls.Config{
+		CurvePreferences: []tls.CurveID{tls.X25519, tls.CurveP256}, // TODO: read about CurvePreferences
 	}
 
 	srv := &http.Server{
-		Addr:     cfg.addr,
+		Addr:         cfg.addr,
-		ErrorLog: errorLog,
+		ErrorLog:     errorLog,
-		Handler:  app.routes(),
+		Handler:      app.routes(),
+		TLSConfig:    tlsConfig,
+		IdleTimeout:  time.Minute,
+		ReadTimeout:  5 * time.Second,
+		WriteTimeout: 10 * time.Second,
 	}
 
 	infoLog.Printf("Starting server on %s", cfg.addr)
-	err = srv.ListenAndServe()
+	err = srv.ListenAndServeTLS("./tls/cert.pem", "./tls/key.pem")
 	errorLog.Fatal(err)
 }
 

cmd/web/middleware.go

@@ -0,0 +1,88 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+
+	"github.com/justinas/nosurf"
+)
+
+func secureHeaders(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Security-Policy",
+			"default-src 'self'; style-src 'self' fonts.googleapis.com; font-src fonts.gstatic.com")
+		w.Header().Set("Referrer-Policy", "origin-when-cross-origin")
+		w.Header().Set("X-Content-Type-Options", "deny")
+		w.Header().Set("X-Frame-Options", "nosniff")
+		w.Header().Set("X-XSS-Protection", "0")
+
+		next.ServeHTTP(w, r)
+	})
+}
+
+func noSurf(next http.Handler) http.Handler {
+	csrfHanlder := nosurf.New(next)
+	csrfHanlder.SetBaseCookie(http.Cookie{
+		HttpOnly: false,
+		Path:     "/",
+		Secure:   false,
+	})
+
+	return csrfHanlder
+}
+
+func (app *application) logRequest(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		app.infoLog.Printf("%s - %s %s %s", r.RemoteAddr, r.Proto, r.Method, r.URL.RequestURI())
+
+		next.ServeHTTP(w, r)
+	})
+}
+
+func (app *application) recoverPanic(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		defer func() {
+			if err := recover(); err != nil {
+				w.Header().Set("Connection", "close")
+				app.serverError(w, fmt.Errorf("%s", err))
+			}
+		}()
+
+		next.ServeHTTP(w, r)
+	})
+}
+
+func (app *application) requireAuthentication(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if !app.isAuthenticated(r) {
+			app.sessionManager.Put(r.Context(), "redirectParent", r.URL.Path)
+			http.Redirect(w, r, "/user/login", http.StatusSeeOther)
+			return
+		}
+		w.Header().Set("Cache-Control", "no-store")
+		next.ServeHTTP(w, r)
+	})
+}
+
+func (app *application) authenticate(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		id := app.sessionManager.GetInt(r.Context(), "authenticatedUserID")
+		if id == 0 {
+			next.ServeHTTP(w, r)
+			return
+		}
+
+		exists, err := app.users.Exists(id)
+		if err != nil {
+			app.serverError(w, err)
+			return
+		}
+
+		if exists {
+			ctx := context.WithValue(r.Context(), isAuthenticatedContextKey, true)
+			r = r.WithContext(ctx)
+		}
+		next.ServeHTTP(w, r)
+	})
+}

cmd/web/middleware_test.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"bytes"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"gitea.local.lab/Lbenedar/snippetbox/internal/assert"
+)
+
+func TestSecureHeaders(t *testing.T) {
+	rr := httptest.NewRecorder()
+
+	r, err := http.NewRequest(http.MethodGet, "/", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte("OK"))
+	})
+	secureHeaders(next).ServeHTTP(rr, r)
+
+	rs := rr.Result()
+
+	expectedValue := "default-src 'self'; style-src 'self' fonts.googleapis.com; font-src fonts.gstatic.com"
+	assert.Equal(t, rs.Header.Get("Content-Security-Policy"), expectedValue)
+
+	expectedValue = "nosniff"
+	assert.Equal(t, rs.Header.Get("X-Frame-Options"), expectedValue)
+
+	expectedValue = "0"
+	assert.Equal(t, rs.Header.Get("X-XSS-Protection"), expectedValue)
+
+	assert.Equal(t, rs.StatusCode, http.StatusOK)
+
+	defer rs.Body.Close()
+	body, err := io.ReadAll(rs.Body)
+	if err != nil {
+		t.Fatal(err)
+	}
+	bytes.TrimSpace(body)
+
+	assert.Equal(t, string(body), "OK")
+}

cmd/web/routes.go

@@ -1,16 +1,46 @@
 package main
 
-import "net/http"
+import (
+	"net/http"
 
-func (app *application) routes() *http.ServeMux {
+	"gitea.local.lab/Lbenedar/snippetbox/ui"
-	mux := http.NewServeMux()
 
-	fileServer := http.FileServer(http.Dir("./ui/static/"))
+	"github.com/julienschmidt/httprouter"
-	mux.Handle("/static/", http.StripPrefix("/static", fileServer))
+	"github.com/justinas/alice"
+)
 
-	mux.HandleFunc("/", app.home)
+func (app *application) routes() http.Handler {
-	mux.HandleFunc("/snippet/view", app.snippetView)
+	router := httprouter.New()
-	mux.HandleFunc("/snippet/create", app.snippetCreate)
 
-	return mux
+	router.NotFound = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		app.notFound(w)
+	})
+
+	fileServer := http.FileServer(http.FS(ui.Files))
+	router.Handler(http.MethodGet, "/static/*filepath", fileServer)
+
+	router.HandlerFunc(http.MethodGet, "/ping", ping)
+
+	dynamic := alice.New(app.sessionManager.LoadAndSave, noSurf, app.authenticate)
+
+	router.Handler(http.MethodGet, "/", dynamic.ThenFunc(app.home))
+	router.Handler(http.MethodGet, "/about", dynamic.ThenFunc(app.about))
+	router.Handler(http.MethodGet, "/snippet/view/:id", dynamic.ThenFunc(app.snippetView))
+
+	router.Handler(http.MethodGet, "/user/signup", dynamic.ThenFunc(app.userSignup))
+	router.Handler(http.MethodPost, "/user/signup", dynamic.ThenFunc(app.userSignupPost))
+	router.Handler(http.MethodGet, "/user/login", dynamic.ThenFunc(app.userLogin))
+	router.Handler(http.MethodPost, "/user/login", dynamic.ThenFunc(app.userLoginPost))
+
+	protected := dynamic.Append(app.requireAuthentication)
+
+	router.Handler(http.MethodGet, "/account/view", protected.ThenFunc(app.accountView))
+	router.Handler(http.MethodGet, "/account/password", protected.ThenFunc(app.accountChangePassword))
+	router.Handler(http.MethodPost, "/account/password", protected.ThenFunc(app.accountChangePasswordPost))
+	router.Handler(http.MethodGet, "/snippet/create", protected.ThenFunc(app.snippetCreate))
+	router.Handler(http.MethodPost, "/snippet/create", protected.ThenFunc(app.snippetCreatePost))
+	router.Handler(http.MethodPost, "/user/logout", protected.ThenFunc(app.userLogoutPost))
+
+	standard := alice.New(app.recoverPanic, app.logRequest, secureHeaders)
+	return standard.Then(router)
 }

cmd/web/templates.go

@@ -2,21 +2,32 @@ package main
 
 import (
 	"html/template"
+	"io/fs"
 	"net/http"
 	"path/filepath"
 	"time"
 
 	"gitea.local.lab/Lbenedar/snippetbox/internal/models"
+	"gitea.local.lab/Lbenedar/snippetbox/ui"
+	"github.com/justinas/nosurf"
 )
 
 type templateData struct {
-	CurrentYear int
+	CurrentYear     int
-	Snippet     *models.Snippet
+	Snippet         *models.Snippet
-	Snippets    []*models.Snippet
+	Snippets        []*models.Snippet
+	Form            any
+	Flash           string
+	IsAuthenticated bool
+	CSRFToken       string
+	AboutText       string
 }
 
 func humanDate(t time.Time) string {
-	return t.Format("02 Jan 2006 at 15:04")
+	if t.IsZero() {
+		return ""
+	}
+	return t.UTC().Format("02 Jan 2006 at 15:04")
 }
 
 var functions = template.FuncMap{
@@ -25,31 +36,30 @@ var functions = template.FuncMap{
 
 func (app *application) newTemplateData(r *http.Request) *templateData {
 	return &templateData{
-		CurrentYear: time.Now().Year(),
+		CurrentYear:     time.Now().Year(),
+		Flash:           app.sessionManager.PopString(r.Context(), "flash"),
+		IsAuthenticated: app.isAuthenticated(r),
+		CSRFToken:       nosurf.Token(r),
 	}
 }
 
 func newTemplateCache() (map[string]*template.Template, error) {
 	cache := map[string]*template.Template{}
 
-	pages, err := filepath.Glob("./ui/html/pages/*.tmpl")
+	pages, err := fs.Glob(ui.Files, "html/pages/*.tmpl")
 	if err != nil {
 		return nil, err
 	}
 
 	for _, page := range pages {
 		name := filepath.Base(page)
-		ts, err := template.New(name).Funcs(functions).ParseFiles("./ui/html/base.tmpl")
-		if err != nil {
-			return nil, err
-		}
 
-		ts, err = ts.ParseGlob("./ui/html/partials/nav.tmpl")
+		patterns := []string{
-		if err != nil {
+			"html/base.tmpl",
-			return nil, err
+			"html/partials/*.tmpl",
+			page,
 		}
-
+		ts, err := template.New(name).Funcs(functions).ParseFS(ui.Files, patterns...)
-		ts, err = ts.ParseFiles(page)
 		if err != nil {
 			return nil, err
 		}

cmd/web/templates_test.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"testing"
+	"time"
+
+	"gitea.local.lab/Lbenedar/snippetbox/internal/assert"
+)
+
+func TestHumanDate(t *testing.T) {
+	tests := []struct {
+		name string
+		tm   time.Time
+		want string
+	}{
+		{
+			name: "UTC",
+			tm:   time.Date(2022, 3, 17, 10, 15, 0, 0, time.UTC),
+			want: "17 Mar 2022 at 10:15",
+		},
+		{
+			name: "Empty",
+			tm:   time.Time{},
+			want: "",
+		},
+		{
+			name: "CET",
+			tm:   time.Date(2022, 3, 17, 10, 15, 0, 0, time.FixedZone("CET", 1*60*60)),
+			want: "17 Mar 2022 at 09:15",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			hd := humanDate(tt.tm)
+			assert.Equal(t, hd, tt.want)
+		})
+	}
+}

cmd/web/testutils_test.go

@@ -0,0 +1,104 @@
+package main
+
+import (
+	"bytes"
+	"html"
+	"io"
+	"log"
+	"net/http"
+	"net/http/cookiejar"
+	"net/http/httptest"
+	"net/url"
+	"regexp"
+	"testing"
+	"time"
+
+	"gitea.local.lab/Lbenedar/snippetbox/internal/models/mocks"
+	"github.com/alexedwards/scs/v2"
+	"github.com/go-playground/form/v4"
+)
+
+var csrfTokenRX = regexp.MustCompile(`<input type='hidden' name='csrf_token' value='(.+)'>`)
+
+func extractCSRFToken(t *testing.T, body string) string {
+	t.Logf("Body: %s", body)
+	matches := csrfTokenRX.FindStringSubmatch(body)
+	if len(matches) < 2 {
+		t.Fatal("no csrf token found in body")
+	}
+
+	return html.UnescapeString(string(matches[1]))
+}
+
+func newTestApplication(t *testing.T) *application {
+	templateCache, err := newTemplateCache()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	formDecoder := form.NewDecoder()
+
+	sessionManager := scs.New()
+	sessionManager.Lifetime = 12 * time.Hour
+	sessionManager.Cookie.Secure = true
+
+	return &application{
+		errorLog:       log.New(io.Discard, "", 0),
+		infoLog:        log.New(io.Discard, "", 0),
+		snippets:       &mocks.SnippetModel{},
+		users:          &mocks.UserModel{},
+		templateCache:  templateCache,
+		formDecoder:    formDecoder,
+		sessionManager: sessionManager,
+	}
+}
+
+type testServer struct {
+	*httptest.Server
+}
+
+func newTestServer(t *testing.T, h http.Handler) *testServer {
+	ts := httptest.NewTLSServer(h)
+	jar, err := cookiejar.New(nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ts.Client().Jar = jar
+
+	ts.Client().CheckRedirect = func(req *http.Request, via []*http.Request) error {
+		return http.ErrUseLastResponse
+	}
+	return &testServer{ts}
+}
+
+func (ts *testServer) get(t *testing.T, urlPath string) (int, http.Header, string) {
+	rs, err := ts.Client().Get(ts.URL + urlPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	defer rs.Body.Close()
+	body, err := io.ReadAll(rs.Body)
+	if err != nil {
+		t.Fatal(err)
+	}
+	bytes.TrimSpace(body)
+
+	return rs.StatusCode, rs.Header, string(body)
+}
+
+func (ts *testServer) postForm(t *testing.T, urlPath string, form url.Values) (int, http.Header, string) {
+	rs, err := ts.Client().PostForm(ts.URL+urlPath, form)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	defer rs.Body.Close()
+	body, err := io.ReadAll(rs.Body)
+	if err != nil {
+		t.Fatal(err)
+	}
+	bytes.TrimSpace(body)
+	return rs.StatusCode, rs.Header, string(body)
+}

go.mod

@@ -4,5 +4,12 @@ go 1.25.0
 
 require (
 	filippo.io/edwards25519 v1.1.0 // indirect
+	github.com/alexedwards/scs/mysqlstore v0.0.0-20251002162104-209de6e426de // indirect
+	github.com/alexedwards/scs/v2 v2.9.0 // indirect
+	github.com/go-playground/form/v4 v4.3.0 // indirect
 	github.com/go-sql-driver/mysql v1.9.3 // indirect
+	github.com/julienschmidt/httprouter v1.3.0 // indirect
+	github.com/justinas/alice v1.2.0 // indirect
+	github.com/justinas/nosurf v1.2.0 // indirect
+	golang.org/x/crypto v0.48.0 // indirect
 )

go.sum

@@ -1,4 +1,19 @@
 filippo.io/edwards25519 v1.1.0 h1:FNf4tywRC1HmFuKW5xopWpigGjJKiJSV0Cqo0cJWDaA=
 filippo.io/edwards25519 v1.1.0/go.mod h1:BxyFTGdWcka3PhytdK4V28tE5sGfRvvvRV7EaN4VDT4=
+github.com/alexedwards/scs/mysqlstore v0.0.0-20251002162104-209de6e426de h1:/Y/iIFgV1Ofvk4Euv5gUQ74vgqFZOQ1wlJQ3yz/zYGs=
+github.com/alexedwards/scs/mysqlstore v0.0.0-20251002162104-209de6e426de/go.mod h1:p8jK3D80sw1PFrCSdlcJF1O75bp55HqbgDyyCLM0FrE=
+github.com/alexedwards/scs/v2 v2.9.0 h1:xa05mVpwTBm1iLeTMNFfAWpKUm4fXAW7CeAViqBVS90=
+github.com/alexedwards/scs/v2 v2.9.0/go.mod h1:ToaROZxyKukJKT/xLcVQAChi5k6+Pn1Gvmdl7h3RRj8=
+github.com/go-playground/form/v4 v4.3.0 h1:OVttojbQv2WNCs4P+VnjPtrt/+30Ipw4890W3OaFlvk=
+github.com/go-playground/form/v4 v4.3.0/go.mod h1:Cpe1iYJKoXb1vILRXEwxpWMGWyQuqplQ/4cvPecy+Jo=
+github.com/go-sql-driver/mysql v1.7.1/go.mod h1:OXbVy3sEdcQ2Doequ6Z5BW6fXNQTmx+9S1MCJN5yJMI=
 github.com/go-sql-driver/mysql v1.9.3 h1:U/N249h2WzJ3Ukj8SowVFjdtZKfu9vlLZxjPXV1aweo=
 github.com/go-sql-driver/mysql v1.9.3/go.mod h1:qn46aNg1333BRMNU69Lq93t8du/dwxI64Gl8i5p1WMU=
+github.com/julienschmidt/httprouter v1.3.0 h1:U0609e9tgbseu3rBINet9P48AI/D3oJs4dN7jwJOQ1U=
+github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
+github.com/justinas/alice v1.2.0 h1:+MHSA/vccVCF4Uq37S42jwlkvI2Xzl7zTPCN5BnZNVo=
+github.com/justinas/alice v1.2.0/go.mod h1:fN5HRH/reO/zrUflLfTN43t3vXvKzvZIENsNEe7i7qA=
+github.com/justinas/nosurf v1.2.0 h1:yMs1bSRrNiwXk4AS6n8vL2Ssgpb9CB25T/4xrixaK0s=
+github.com/justinas/nosurf v1.2.0/go.mod h1:ALpWdSbuNGy2lZWtyXdjkYv4edL23oSEgfBT1gPJ5BQ=
+golang.org/x/crypto v0.48.0 h1:/VRzVqiRSggnhY7gNRxPauEQ5Drw9haKdM0jqfcCFts=
+golang.org/x/crypto v0.48.0/go.mod h1:r0kV5h3qnFPlQnBSrULhlsRfryS2pmewsg+XfMgkVos=

internal/assert/assert.go

@@ -0,0 +1,30 @@
+package assert
+
+import (
+	"strings"
+	"testing"
+)
+
+func Equal[T comparable](t *testing.T, actual, expected T) {
+	t.Helper()
+
+	if actual != expected {
+		t.Errorf("got: %v; want: %v", actual, expected)
+	}
+}
+
+func StringContains(t *testing.T, actual, expectedString string) {
+	t.Helper()
+
+	if !strings.Contains(actual, expectedString) {
+		t.Errorf("got: %q; expected to contain: %q", actual, expectedString)
+	}
+}
+
+func NilError(t *testing.T, actual error) {
+	t.Helper()
+
+	if actual != nil {
+		t.Errorf("got: %v; expected: nil", actual)
+	}
+}

internal/models/errors.go

@@ -2,4 +2,8 @@ package models
 
 import "errors"
 
-var ErrNoRecord = errors.New("models: no matching record found")
+var (
+	ErrNoRecord           = errors.New("models: no matching record found")
+	ErrInvalidCredentials = errors.New("models: invalid credentials")
+	ErrDuplicateEmail     = errors.New("models: duplicate email")
+)

internal/models/mocks/snippets.go

@@ -0,0 +1,34 @@
+package mocks
+
+import (
+	"time"
+
+	"gitea.local.lab/Lbenedar/snippetbox/internal/models"
+)
+
+var mockSnippet = &models.Snippet{
+	ID:      1,
+	Title:   "An old silent pond",
+	Content: "An old silent pond...",
+	Created: time.Now(),
+	Expires: time.Now(),
+}
+
+type SnippetModel struct{}
+
+func (m *SnippetModel) Insert(title string, content string, expires int) (int, error) {
+	return 2, nil
+}
+
+func (m *SnippetModel) Get(id int) (*models.Snippet, error) {
+	switch id {
+	case 1:
+		return mockSnippet, nil
+	default:
+		return nil, models.ErrNoRecord
+	}
+}
+
+func (m *SnippetModel) Latest() ([]*models.Snippet, error) {
+	return []*models.Snippet{mockSnippet}, nil
+}

internal/models/mocks/users.go

@@ -0,0 +1,39 @@
+package mocks
+
+import "gitea.local.lab/Lbenedar/snippetbox/internal/models"
+
+type UserModel struct{}
+
+func (m *UserModel) Insert(name, email, password string) error {
+	switch email {
+	case "dupe@example.com":
+		return models.ErrDuplicateEmail
+	default:
+		return nil
+	}
+}
+
+func (m *UserModel) Authenticate(email, password string) (int, error) {
+	if email == "alice@example.com" && password == "pa$$word" {
+		return 1, nil
+	}
+
+	return 0, models.ErrInvalidCredentials
+}
+
+func (m *UserModel) Exists(id int) (bool, error) {
+	switch id {
+	case 1:
+		return true, nil
+	default:
+		return false, nil
+	}
+}
+
+func (m *UserModel) GetById(id int) (*models.User, error) {
+	return nil, nil
+}
+
+func (a *UserModel) ChangePassword(id int, curr_pass, new_pass string) error {
+	return nil
+}

internal/models/snippets.go

@@ -13,7 +13,11 @@ type Snippet struct {
 	Created time.Time
 	Expires time.Time
 }
-
+type SnippetModelInterface interface {
+	Insert(title string, content string, expires int) (int, error)
+	Get(id int) (*Snippet, error)
+	Latest() ([]*Snippet, error)
+}
 type SnippetModel struct {
 	DB *sql.DB
 }

internal/models/testdata/setup.sql

@@ -0,0 +1,26 @@
+CREATE TABLE snippets (
+    id INTEGER NOT NULL PRIMARY KEY AUTO_INCREMENT,
+    title VARCHAR(100) NOT NULL,
+    content TEXT NOT NULL,
+    created DATETIME NOT NULL,
+    expires DATETIME NOT NULL
+);
+
+CREATE INDEX idx_snippets_created ON snippets(created);
+
+CREATE TABLE users (
+    id INTEGER NOT NULL PRIMARY KEY AUTO_INCREMENT,
+    name VARCHAR(255) NOT NULL,
+    email VARCHAR(255) NOT NULL,
+    hashed_password CHAR(60) NOT NULL,
+    created DATETIME NOT NULL
+);
+
+ALTER TABLE users ADD CONSTRAINT users_uc_email UNIQUE (email);
+
+INSERT INTO users (name, email, hashed_password, created) VALUES (
+    'Alice Jones',
+    'alice@example.com',
+    '$2a$12$NuTjWXm3KKntReFwyBVHyuf/to.HEwTy.eS206TNfkGfr6HzGJSWG',
+    '2022-01-01 10:00:00'
+);

internal/models/testdata/teardown.sql

@@ -0,0 +1,3 @@
+DROP TABLE users;
+
+DROP TABLE snippets;

internal/models/testutils_test.go

@@ -0,0 +1,37 @@
+package models
+
+import (
+	"database/sql"
+	"os"
+	"testing"
+)
+
+func newTestDB(t *testing.T) *sql.DB {
+	db, err := sql.Open("mysql", "test_web:pass@/test_snippetbox?parseTime=true&multiStatements=true")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	script, err := os.ReadFile("./testdata/setup.sql")
+	if err != nil {
+		t.Fatal(err)
+	}
+	_, err = db.Exec(string(script))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	t.Cleanup(func() {
+		script, err := os.ReadFile("./testdata/teardown.sql")
+		if err != nil {
+			t.Fatal(err)
+		}
+		_, err = db.Exec(string(script))
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		db.Close()
+	})
+	return db
+}

internal/models/users.go

@@ -0,0 +1,129 @@
+package models
+
+import (
+	"database/sql"
+	"errors"
+	"strings"
+	"time"
+
+	"github.com/go-sql-driver/mysql"
+	"golang.org/x/crypto/bcrypt"
+)
+
+type User struct {
+	ID             int
+	Name           string
+	Email          string
+	HashedPassword []byte
+	Created        time.Time
+}
+
+type UserModelInterface interface {
+	Insert(name, email, password string) error
+	Authenticate(email, password string) (int, error)
+	Exists(id int) (bool, error)
+	GetById(id int) (*User, error)
+	ChangePassword(id int, curr_pass, new_pass string) error
+}
+
+type UserModel struct {
+	DB *sql.DB
+}
+
+func (m *UserModel) Insert(name, email, password string) error {
+	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(password), 12)
+	if err != nil {
+		return err
+	}
+
+	stmt := `INSERT INTO users (name, email, hashed_password, created) 
+	VALUES(?, ?, ?, UTC_TIMESTAMP())`
+
+	_, err = m.DB.Exec(stmt, name, email, string(hashedPassword))
+	if err != nil {
+		var mySQLError *mysql.MySQLError
+		if errors.As(err, &mySQLError) {
+			if mySQLError.Number == 1062 && strings.Contains(mySQLError.Message, "users_uc_email") {
+				return ErrDuplicateEmail
+			}
+		}
+		return err
+	}
+	return nil
+}
+
+func (m *UserModel) Authenticate(email, password string) (int, error) {
+	var id int
+	var hashedPassword []byte
+
+	stmt := `SELECT id, hashed_password FROM users WHERE email = ?`
+
+	err := m.DB.QueryRow(stmt, email).Scan(&id, &hashedPassword)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return 0, ErrInvalidCredentials
+		}
+		return 0, err
+	}
+	err = bcrypt.CompareHashAndPassword(hashedPassword, []byte(password))
+	if err != nil {
+		if errors.Is(err, bcrypt.ErrMismatchedHashAndPassword) {
+			return 0, ErrInvalidCredentials
+		}
+		return 0, err
+	}
+
+	return id, nil
+}
+
+func (m *UserModel) Exists(id int) (bool, error) {
+	var exists bool
+
+	stmt := `SELECT EXISTS(SELECT true FROM users WHERE id = ?)`
+
+	err := m.DB.QueryRow(stmt, id).Scan(&exists)
+	return exists, err
+}
+
+func (a *UserModel) GetById(id int) (*User, error) {
+	acc := User{}
+
+	stmt := `SELECT name, email, created FROM users WHERE id = ?`
+	err := a.DB.QueryRow(stmt, id).Scan(&acc.Name, &acc.Email, &acc.Created)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, ErrInvalidCredentials
+		}
+		return nil, err
+	}
+
+	return &acc, nil
+}
+
+func (a *UserModel) ChangePassword(id int, curr_pass, new_pass string) error {
+	hashedNewPassword, err := bcrypt.GenerateFromPassword([]byte(new_pass), 12)
+	if err != nil {
+		return err
+	}
+
+	var hashedDBPassword []byte
+	stmt := `SELECT hashed_password FROM users WHERE id = ?`
+	err = a.DB.QueryRow(stmt, id).Scan(&hashedDBPassword)
+	if err != nil {
+		return err
+	}
+	err = bcrypt.CompareHashAndPassword(hashedDBPassword, []byte(curr_pass))
+	if err != nil {
+		if errors.Is(err, bcrypt.ErrMismatchedHashAndPassword) {
+			return ErrInvalidCredentials
+		}
+		return err
+	}
+
+	stmt = `UPDATE users SET hashed_password = ? WHERE id = ?`
+	_, err = a.DB.Exec(stmt, hashedNewPassword, id)
+	if err != nil {
+		return err
+	}
+	return nil
+}

internal/models/users_test.go

@@ -0,0 +1,45 @@
+package models
+
+import (
+	"testing"
+
+	"gitea.local.lab/Lbenedar/snippetbox/internal/assert"
+)
+
+func TestUserModelExists(t *testing.T) {
+	if testing.Short() {
+		t.Skip("models: skipping integration test")
+	}
+
+	tests := []struct {
+		name   string
+		userID int
+		want   bool
+	}{
+		{
+			name:   "Valid ID",
+			userID: 1,
+			want:   true,
+		},
+		{
+			name:   "Zero ID",
+			userID: 0,
+			want:   false,
+		},
+		{
+			name:   "Non-existent ID",
+			userID: 2,
+			want:   false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			db := newTestDB(t)
+			m := UserModel{DB: db}
+
+			exists, err := m.Exists(tt.userID)
+			assert.Equal(t, exists, tt.want)
+			assert.NilError(t, err)
+		})
+	}
+}

internal/validator/validator.go

@@ -0,0 +1,62 @@
+package validator
+
+import (
+	"regexp"
+	"strings"
+	"unicode/utf8"
+)
+
+type Validator struct {
+	NonFieldErrors []string
+	FieldErrors    map[string]string
+}
+
+func (v *Validator) Valid() bool {
+	return len(v.FieldErrors) == 0 && len(v.NonFieldErrors) == 0
+}
+
+func (v *Validator) AddFieldError(key, message string) {
+	if v.FieldErrors == nil {
+		v.FieldErrors = make(map[string]string)
+	}
+	if _, exist := v.FieldErrors[key]; !exist {
+		v.FieldErrors[key] = message
+	}
+}
+
+func (v *Validator) AddNonFieldError(message string) {
+	v.NonFieldErrors = append(v.NonFieldErrors, message)
+}
+
+func (v *Validator) CheckField(ok bool, key, message string) {
+	if !ok {
+		v.AddFieldError(key, message)
+	}
+}
+
+func NotBlank(value string) bool {
+	return strings.TrimSpace(value) != ""
+}
+
+func MaxChars(value string, n int) bool {
+	return utf8.RuneCountInString(value) <= n
+}
+
+func PermittedValue[T comparable](value T, permittedValues ...T) bool {
+	for i := range permittedValues {
+		if value == permittedValues[i] {
+			return true
+		}
+	}
+	return false
+}
+
+var EmailRX = regexp.MustCompile("^[a-zA-Z0-9.!#$%&'*+\\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$")
+
+func MinChars(value string, n int) bool {
+	return utf8.RuneCountInString(value) >= n
+}
+
+func Matches(value string, rx *regexp.Regexp) bool {
+	return rx.MatchString(value)
+}

tls/cert.pem

@@ -0,0 +1,18 @@
+-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

tls/key.pem

@@ -0,0 +1,28 @@
+-----BEGIN PRIVATE KEY-----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+-----END PRIVATE KEY-----

ui/efs.go

@@ -0,0 +1,8 @@
+package ui
+
+import (
+	"embed"
+)
+
+//go:embed "html" "static"
+var Files embed.FS

ui/html/base.tmpl

@@ -14,6 +14,9 @@
         </header>
         {{template "nav" .}}
         <main>
+            {{with .Flash}}
+                <div class='flash'>{{.}}</div>
+            {{end}}
             {{template "main" .}}
         </main>
         <footer>

ui/html/pages/about.tmpl

@@ -0,0 +1,8 @@
+{{define "title"}}About{{end}}
+
+{{define "main"}}
+    <h2>About</h2>
+    <div class='about'>
+        {{.AboutText}}
+    </div>
+{{end}}

ui/html/pages/account.tmpl

@@ -0,0 +1,28 @@
+{{define "title"}}Account{{end}}
+
+{{define "main"}}
+    <h2>Account</h2>
+    {{if .Form}}
+    <table>
+        <tr>
+            <th>Name</th>
+            <th>{{.Form.Name}}</th>
+        </tr>
+        <tr>
+            <th>Email</th>
+            <th>{{.Form.Email}}</th>
+        </tr>
+        <tr>
+            <th>Joined</th>
+            <th>{{.Form.Joined}}</th>
+        </tr>
+    </table>
+    {{else}}
+        <p>There's nothing to see here... yet!</p>
+    {{end}}
+    <form action='/account/password' method='GET'>
+        <div>
+            <input type='submit' value='Change password'>
+        </div>
+    </form>
+{{end}}

ui/html/pages/create.tmpl

@@ -0,0 +1,33 @@
+{{define "title"}}Create a New Snippet{{end}}
+
+{{define "main"}}
+<form action='/snippet/create' method='POST'>
+    <input type='hidden' name='csrf_token' value='{{.CSRFToken}}'>
+    <div>
+        <label>Title:</label>
+        {{with .Form.FieldErrors.title}}
+            <label class='error'>{{.}}</label>
+        {{end}}
+        <input type='text' name='title' value='{{.Form.Title}}'>
+    </div>
+    <div>
+        <label>Content:</label>
+        {{with .Form.FieldErrors.content}}
+            <label class='error'>{{.}}</label>
+        {{end}}
+        <textarea name='content'>{{.Form.Content}}</textarea>
+    </div>
+    <div>
+        <label>Delete in:</label>
+        {{with .Form.FieldErrors.expires}}
+            <label class='error'>{{.}}</label>
+        {{end}}
+        <input type='radio' name='expires' value='365' {{if (eq .Form.Expires 365)}}checked{{end}}> One Year
+        <input type='radio' name='expires' value='7' {{if (eq .Form.Expires 7)}}checked{{end}}> One Week
+        <input type='radio' name='expires' value='1' {{if (eq .Form.Expires 1)}}checked{{end}}> One Day
+    </div>
+    <div>
+        <input type='submit' value='Publish snippet'>
+    </div>
+</form>
+{{end}}

ui/html/pages/home.tmpl

@@ -11,7 +11,7 @@
         </tr>
         {{range .Snippets}}
         <tr>
-            <td><a href='/snippet/view?id={{.ID}}'>{{.Title}}</a></td>
+            <td><a href='/snippet/view/{{.ID}}'>{{.Title}}</a></td>
             <td>{{humanDate .Created}}</td>
             <td>#{{.ID}}</td>
         </tr>

ui/html/pages/login.tmpl

@@ -0,0 +1,27 @@
+{{define "title"}}Login{{end}}
+
+{{define "main"}}
+<form action='/user/login' method='POST' novalidate>
+    <input type='hidden' name='csrf_token' value='{{.CSRFToken}}'>
+    {{range .Form.NonFieldErrors}}
+        <div class='error'>{{.}}</div>
+    {{end}}
+    <div>
+        <label>Email:</label>
+        {{with .Form.FieldErrors.email}}
+            <label class='error'>{{.}}</label>
+        {{end}}
+        <input type='email' name='email' value='{{.Form.Email}}'>
+    </div>
+    <div>
+        <label>Password:</label>
+        {{with .Form.FieldErrors.password}}
+            <label class='error'>{{.}}</label>
+        {{end}}
+        <input type='password' name='password'>
+    </div>
+    <div>
+        <input type='submit' value='Login'>
+    </div>
+</form>
+{{end}}

ui/html/pages/password.tmpl

@@ -0,0 +1,35 @@
+{{define "title"}}Change Password{{end}}
+
+{{define "main"}}
+    <h2>Change Password</h2>
+    <form action='/account/password' method='POST' novalidate>
+        <input type='hidden' name='csrf_token' value='{{.CSRFToken}}'>
+        {{range .Form.NonFieldErrors}}
+            <div class='error'>{{.}}</div>
+        {{end}}
+        <div>
+            <label>Current password:</label>
+            {{with .Form.FieldErrors.curr_pass}}
+                <label class='error'>{{.}}</label>
+            {{end}}
+            <input type='password' name='curr_pass' value=''>
+        </div>
+        <div>
+            <label>New password:</label>
+            {{with .Form.FieldErrors.new_pass}}
+                <label class='error'>{{.}}</label>
+            {{end}}
+            <input type='password' name='new_pass'>
+        </div>
+        <div>
+            <label>Confirm new password:</label>
+            {{with .Form.FieldErrors.conf_pass}}
+                <label class='error'>{{.}}</label>
+            {{end}}
+            <input type='password' name='conf_pass'>
+        </div>
+        <div>
+            <input type='submit' value='Change password'>
+        </div>
+    </form>
+{{end}}

ui/html/pages/signup.tmpl

@@ -0,0 +1,31 @@
+{{define "title"}}Signup{{end}}
+
+{{define "main"}}
+<form action='/user/signup' method='POST' novalidate>
+    <input type='hidden' name='csrf_token' value='{{.CSRFToken}}'>
+    <div>
+        <label>Name:</label>
+        {{with .Form.FieldErrors.name}}
+            <label class='error'>{{.}}</label>
+        {{end}}
+        <input type='text' name='name' value='{{.Form.Name}}'>
+    </div>
+    <div>
+        <label>Email:</label>
+        {{with .Form.FieldErrors.email}}
+            <label class='error'>{{.}}</label>
+        {{end}}
+        <input type='email' name='email' value='{{.Form.Email}}'>
+    </div>
+    <div>
+        <label>Password:</label>
+        {{with .Form.FieldErrors.password}}
+            <label class='error'>{{.}}</label>
+        {{end}}
+        <input type='password' name='password'>
+    </div>
+    <div>
+        <input type='submit' value='Signup'>
+    </div>
+</form>
+{{end}}

ui/html/partials/nav.tmpl

@@ -1,5 +1,23 @@
 {{define "nav"}}
 <nav>
-    <a href='/'>Home</a>
+    <div>
+        <a href='/'>Home</a>
+        <a href='/about'>About</a>
+        {{if .IsAuthenticated}}
+            <a href='/snippet/create'>Create snippet</a>
+        {{end}}
+    </div>
+    <div>
+        {{if .IsAuthenticated}}
+            <a href='/account/view'>Account</a>
+            <form action='/user/logout' method='POST'>
+                <input type='hidden' name='csrf_token' value='{{.CSRFToken}}'>
+                <button>Logout</button>
+            </form>
+        {{else}}
+            <a href='/user/signup'>Signup</a>
+            <a href='/user/login'>Login</a>
+        {{end}}
+    </div>
 </nav>
 {{end}}

ui/static/text/about.txt

@@ -0,0 +1 @@
+Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus magna quam, eleifend a metus at, tincidunt commodo enim. Integer ac mattis ipsum. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Maecenas non purus ullamcorper, tristique diam vel, sagittis neque. Fusce quam dolor, accumsan non leo sed, auctor rutrum felis. Duis semper tristique tellus, sed sagittis est lobortis nec. Curabitur porttitor lacus eget semper sodales. Duis diam nisl, maximus eu felis id, placerat pulvinar erat. Etiam elementum elit tellus, at auctor ante accumsan vitae. Nulla elit magna, molestie vitae nibh ut, vehicula accumsan ipsum. Ut id consequat ipsum, volutpat volutpat orci. Aenean rhoncus tellus lacus, nec tempor risus interdum sed. Proin quis quam in metus imperdiet lobortis. Duis euismod sem enim, volutpat mollis tortor posuere sed. Morbi condimentum eget dolor at accumsan.