From 4e6b789167266f312630101773867906d75bada8 Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Mon, 19 Feb 2024 01:19:56 +0100
Subject: [PATCH] Add page to create/update user

---
 db.go                     | 12 +++++++++++-
 entity.go                 | 15 ++++++++++-----
 main.go                   |  2 ++
 template/index.html       |  4 +++-
 template/update-user.html | 21 +++++++++++++++++++++
 user.go                   | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++--

diff --git a/db.go b/db.go
index c82dca8c118d5fd507ec9575f4b8413bc3e4f946..9198db2582880a8b5a2c1562c69bbb9ebe656f75 100644
--- a/db.go
+++ b/db.go
@@ -57,7 +57,17 @@ func (db *DB) Close() error {
 	return db.db.Close()
 }
 
-func (db *DB) FetchUser(ctx context.Context, username string) (*User, error) {
+func (db *DB) FetchUser(ctx context.Context, id ID[*User]) (*User, error) {
+	rows, err := db.db.QueryContext(ctx, "SELECT * FROM User WHERE id = ?", id)
+	if err != nil {
+		return nil, err
+	}
+	var user User
+	err = scanRow(&user, rows)
+	return &user, err
+}
+
+func (db *DB) FetchUserByUsername(ctx context.Context, username string) (*User, error) {
 	rows, err := db.db.QueryContext(ctx, "SELECT * FROM User WHERE username = ?", username)
 	if err != nil {
 		return nil, err
diff --git a/entity.go b/entity.go
index a36750b99156715f6cd98b0b98c367b3531a92a3..2958f9b7c433741ae3992289b24f8719a955c4c6 100644
--- a/entity.go
+++ b/entity.go
@@ -33,6 +33,14 @@ 	_ sql.Scanner   = (*ID[*User])(nil)
 	_ driver.Valuer = ID[*User](0)
 )
 
+func ParseID[T entity](s string) (ID[T], error) {
+	u, _ := strconv.ParseUint(s, 10, 63)
+	if u == 0 {
+		return 0, fmt.Errorf("invalid ID")
+	}
+	return ID[T](u), nil
+}
+
 func (ptr *ID[T]) Scan(v interface{}) error {
 	if v == nil {
 		*ptr = 0
@@ -207,11 +215,8 @@ }
 
 func UnmarshalSecret[T entity](s string) (id ID[T], secret string, err error) {
 	idStr, secret, _ := strings.Cut(s, ".")
-	u, _ := strconv.ParseUint(idStr, 10, 63)
-	if u == 0 {
-		return 0, "", fmt.Errorf("invalid ID")
-	}
-	return ID[T](int64(u)), secret, nil
+	id, err = ParseID[T](idStr)
+	return id, secret, err
 }
 
 func MarshalSecret[T entity](id ID[T], secret string) string {
diff --git a/main.go b/main.go
index e6d5e7e9b49df2756caa03580139b79c85909961..063c66500e938e47213622f7462593a85a994b3a 100644
--- a/main.go
+++ b/main.go
@@ -36,6 +36,8 @@ 	mux.Handle("/static/*", http.FileServer(http.FS(staticFS)))
 	mux.Get("/", index)
 	mux.Post("/client/new", createClient)
 	mux.HandleFunc("/login", login)
+	mux.HandleFunc("/user/new", updateUser)
+	mux.HandleFunc("/user/{id}", updateUser)
 	mux.HandleFunc("/authorize", authorize)
 	mux.Post("/token", exchangeToken)
 
diff --git a/template/index.html b/template/index.html
index 06c442c3dd5a9b4e13cdc6fd7809b0738bdf6abd..764be26d0efd6979d632c552d50f83308545df2d 100644
--- a/template/index.html
+++ b/template/index.html
@@ -5,10 +5,12 @@
 <h1>sinwon</h1>
 
 <form method="post" action="/client/new">
+	<a href="/user/new"><button type="button">Create user</button></a>
+	<a href="/user/{{ .Me }}"><button type="button">Edit user</button></a>
 	<button type="submit">Register new client</button>
 </form>
 
-{{ with . }}
+{{ with .Clients }}
 	<p>{{ . | len }} clients registered:</p>
 	<ul>
 		{{ range . }}
diff --git a/template/update-user.html b/template/update-user.html
new file mode 100644
index 0000000000000000000000000000000000000000..b1049728c4ea5135de8bd96cafa6c5f747259227
--- /dev/null
+++ b/template/update-user.html
@@ -0,0 +1,21 @@
+{{ template "head.html" }}
+
+<main>
+
+<h1>sinwon</h1>
+
+<form method="post" action="">
+	Username: <input type="text" name="username" value="{{ .Username }}" required><br>
+	Password: <input type="password" name="password"><br>
+	<button type="submit">
+		{{ if .Username }}
+			Update user
+		{{ else }}
+			Create user
+		{{ end }}
+	</button>
+</form>
+
+</main>
+
+{{ template "foot.html" }}
diff --git a/user.go b/user.go
index 87940917d3b207593d767d4356c284ca9124ed2c..1071fcfad3459a1cabe61095e087d9300f360abf 100644
--- a/user.go
+++ b/user.go
@@ -5,6 +5,8 @@ 	"fmt"
 	"log"
 	"net/http"
 	"net/url"
+
+	"github.com/go-chi/chi/v5"
 )
 
 func index(w http.ResponseWriter, req *http.Request) {
@@ -24,7 +26,14 @@ 		httpError(w, err)
 		return
 	}
 
-	if err := tpl.ExecuteTemplate(w, "index.html", clients); err != nil {
+	data := struct {
+		Clients []Client
+		Me      ID[*User]
+	}{
+		Clients: clients,
+		Me:      loginToken.User,
+	}
+	if err := tpl.ExecuteTemplate(w, "index.html", &data); err != nil {
 		panic(err)
 	}
 }
@@ -60,7 +69,7 @@ 		}
 		return
 	}
 
-	user, err := db.FetchUser(ctx, username)
+	user, err := db.FetchUserByUsername(ctx, username)
 	if err != nil && err != errNoDBRows {
 		httpError(w, fmt.Errorf("failed to fetch user: %v", err))
 		return
@@ -94,3 +103,59 @@
 	setLoginTokenCookie(w, &token, secret)
 	http.Redirect(w, req, redirectURI.String(), http.StatusFound)
 }
+
+func updateUser(w http.ResponseWriter, req *http.Request) {
+	ctx := req.Context()
+	db := dbFromContext(ctx)
+	tpl := templateFromContext(ctx)
+
+	user := new(User)
+	if idStr := chi.URLParam(req, "id"); idStr != "" {
+		id, err := ParseID[*User](idStr)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+
+		user, err = db.FetchUser(ctx, id)
+		if err != nil {
+			httpError(w, err)
+			return
+		}
+	}
+
+	loginToken := loginTokenFromContext(ctx)
+	if loginToken == nil {
+		http.Redirect(w, req, "/login", http.StatusFound)
+		return
+	}
+
+	if user.ID != 0 && loginToken.User != user.ID {
+		http.Error(w, "Access denied", http.StatusForbidden)
+		return
+	}
+
+	username := req.PostFormValue("username")
+	password := req.PostFormValue("password")
+	if username == "" {
+		if err := tpl.ExecuteTemplate(w, "update-user.html", user); err != nil {
+			panic(err)
+		}
+		return
+	}
+
+	user.Username = username
+	if password != "" {
+		if err := user.SetPassword(password); err != nil {
+			httpError(w, err)
+			return
+		}
+	}
+
+	if err := db.StoreUser(ctx, user); err != nil {
+		httpError(w, err)
+		return
+	}
+
+	http.Redirect(w, req, "/", http.StatusFound)
+}

-- 
2.48.1