hostname-service/auth/handlers.go

package auth

import (
	"database/sql"
	"net/http"

	"git.beisel.it/florian/hostname-service/db"
	"git.beisel.it/florian/hostname-service/models"
	"golang.org/x/crypto/bcrypt"

	"github.com/gin-gonic/gin"
)

//	LoginHandler godoc
//
//	@Summary		User login
//	@Description	Authenticate user and return JWT token
//	@Tags			Authentication
//	@Accept			json
//	@Produce		json
//	@Param			loginCredentials	body		models.LoginCredentials	true	"Login Credentials"
//	@Success		200					{object}	models.TokenResponse	"Successfully authenticated, JWT token returned"
//	@Failure		400					{object}	models.ErrorResponse	"Invalid request body"
//	@Failure		401					{object}	models.ErrorResponse	"Invalid login credentials"
//	@Failure		500					{object}	models.ErrorResponse	"Internal server error"
//	@Router			/login [post]
func LoginHandler(c *gin.Context) {
	var creds models.LoginCredentials

	// Bind JSON to creds
	if err := c.BindJSON(&creds); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid request body"})
		return
	}

	// Fetch user from the database
	var storedCreds models.User
	err := db.DB.QueryRow("SELECT username, password FROM users WHERE username = ?", creds.Username).Scan(&storedCreds.Username, &storedCreds.Password)
	if err != nil {
		if err == sql.ErrNoRows {
			// User not found
			c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid login credentials"})
			return
		}
		// Other errors
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Internal server error"})
		return
	}

	// Compare provided password with stored hashed password
	if err := bcrypt.CompareHashAndPassword([]byte(storedCreds.Password), []byte(creds.Password)); err != nil {
		// Password does not match
		c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid login credentials"})
		return
	}

	// If password matches, generate a JWT token
	token, err := GenerateToken(storedCreds.Username)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to generate token"})
		return
	}

	// Send the token in the response
	c.JSON(http.StatusOK, gin.H{"token": token})
}