Add login endpoint and generate a valid token

server/api/auth.go

@@ -1,10 +1,24 @@
 package api
 
 import (
-	"fmt"
 	"net/http"
 )
 
 func (a *API) Login(w http.ResponseWriter, r *http.Request) {
-	fmt.Fprintf(w, "FROM API")
+	body := ParseBody(r)
+	username := body.String("username")
+	password := body.String("password")
+
+	token, err := a.App.Login(username, password)
+	if err != nil {
+		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+		return
+	}
+
+	if token == "" {
+		http.Error(w, http.StatusText(http.StatusForbidden), http.StatusForbidden)
+		return
+	}
+
+	w.Write([]byte(token))
 }

server/app/auth.go

@@ -0,0 +1,28 @@
+package app
+
+import (
+	"database/sql"
+	"fmt"
+
+	"git.ctrlz.es/mgdelacroix/craban/utils"
+)
+
+func (a *App) Login(username, password string) (string, error) {
+	user, err := a.store.User().GetByUsername(username)
+	if err == sql.ErrNoRows {
+		return "", nil
+	} else if err != nil {
+		return "", fmt.Errorf("cannot get user by username: %w", err)
+	}
+
+	if !utils.CheckHash(user.Password, password) {
+		return "", nil
+	}
+
+	token, err := utils.GenerateToken(user.ID, *a.config.Secret)
+	if err != nil {
+		return "", fmt.Errorf("cannot generate token: %w", err)
+	}
+
+	return token, nil
+}

server/model/user.go

@@ -5,11 +5,11 @@ import (
 )
 
 type User struct {
-	ID       int
-	Name     string
-	Mail     string
-	Username string
-	Password string
+	ID       int    `json:"id"`
+	Name     string `json:"name"`
+	Mail     string `json:"mail"`
+	Username string `json:"username"`
+	Password string `json:"-"`
 }
 
 func (u *User) IsValid() error {

server/services/store/user.go

@@ -68,6 +68,29 @@ func (us *UserStore) GetByID(id int) (*model.User, error) {
 	return users[0], nil
 }
 
+func (us *UserStore) GetByUsername(username string) (*model.User, error) {
+	query := us.Q().Select(userColumns...).
+		From("users").
+		Where(sq.Eq{"username": username})
+
+	rows, err := query.Query()
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	users, err := us.usersFromRows(rows)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(users) == 0 {
+		return nil, sql.ErrNoRows
+	}
+
+	return users[0], nil
+}
+
 func (us *UserStore) Create(user *model.User) (*model.User, error) {
 	query := us.Q().Insert("users").
 		Columns(userColumns[1:]...).

webapp/src/client.js

@@ -5,7 +5,13 @@ export class Client {
       method: 'POST',
       headers: { 'Content-Type': 'application/json' },
       body: JSON.stringify({ username, password })
-    }).then(r => r.text()).then(token => {
+    }).then(r => {
+      if (r.status === 200) {
+        return r.text()
+      }
+      console.error("INVALID")
+      throw new Error("invalid credentials")
+    }).then(token => {
       localStorage.setItem('token', token)
       return token
     })

webapp/src/pages/login.js

@@ -18,12 +18,17 @@ const Login = () => {
 
   const [username, setUsername] = useState("")
   const [password, setPassword] = useState("")
+  const [error, setError] = useState("")
 
   const handleSubmit = (e) => {
     e.preventDefault()
-    client.login(username, password).then(token => {
+    client.login(username, password)
+      .then(token => {
         setToken(token)
       })
+      .catch(e => {
+        setError(e.toString())
+      })
   }
 
   const handleChange = (setFn) => {
@@ -52,6 +57,8 @@ const Login = () => {
         onChange={handleChange(setPassword)}
       />
 
+      {error !== "" && <p style={{color: 'red'}}>{error}</p>}
+
       <Button variant="contained" color="primary" onClick={handleSubmit}>Login</Button>
     </Box>
   )