From e35e8f8c3a8738eb1a3b4c3b6b0462c38638781d Mon Sep 17 00:00:00 2001
From: bkawk <email.will.in.china@gmail.com>
Date: Sat, 4 Feb 2023 21:40:37 +0000
Subject: [PATCH] check username

---
 api/email/welcome.go          |  8 ++++----
 api/handlers/checkUsername.go | 35 +++++++++++++++++++++++++++++++++++
 api/main.go                   |  1 +
 3 files changed, 40 insertions(+), 4 deletions(-)
 create mode 100644 api/handlers/checkUsername.go

diff --git a/api/email/welcome.go b/api/email/welcome.go
index 9e36a1b..ccc7bb2 100644
--- a/api/email/welcome.go
+++ b/api/email/welcome.go
@@ -13,11 +13,11 @@ func WelcomeEmail(u *models.User) error {
 	password := os.Getenv("SMTP_PASSWORD")
 	to := u.Email
 	message := `Subject: Welcome to Our System
+	<p>Dear ` + u.Username + `,</p>
+	<p>Welcome to our system!</p>
+	<p>Best regards,</p>
+	<p>Support Team</p>`
 
-<p>Dear ` + u.Username + `,</p>
-<p>Welcome to our system!</p>
-<p>Best regards,</p>
-<p>Support Team</p>`
 	smtpServer := os.Getenv("SMTP_SERVER")
 	auth := smtp.PlainAuth("", from, password, smtpServer)
 	err := smtp.SendMail(smtpServer, auth, from, []string{to}, []byte(message))
diff --git a/api/handlers/checkUsername.go b/api/handlers/checkUsername.go
new file mode 100644
index 0000000..c3c4eb7
--- /dev/null
+++ b/api/handlers/checkUsername.go
@@ -0,0 +1,35 @@
+package handlers
+
+import (
+	"bkawk/go-echo/api/models"
+	"context"
+	"net/http"
+	"time"
+
+	"github.com/labstack/echo/v4"
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/mongo"
+)
+
+func CheckUsernameGet(c echo.Context) error {
+
+	// Get the username from the query parameter
+	username := c.QueryParam("username")
+
+	// Get database connection from context
+	db := c.Get("db").(*mongo.Database)
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	// Check if username exists in the database
+	var existingUser models.User
+	collection := db.Collection("users")
+	err := collection.FindOne(ctx, bson.M{
+		"username": username,
+	}).Decode(&existingUser)
+	if err == nil {
+		return c.JSON(http.StatusOK, echo.Map{"message": "Username not available"})
+	}
+
+	return c.JSON(http.StatusOK, echo.Map{"message": "Username available"})
+}
diff --git a/api/main.go b/api/main.go
index 773e8b3..6b49d18 100644
--- a/api/main.go
+++ b/api/main.go
@@ -107,6 +107,7 @@ func main() {
 	// Routes
 	e.GET("/health", handlers.HealthGet)                            // Health Check
 	e.POST("/register", handlers.RegisterPost)                      // Register a new user
+	e.GET("/check-username", handlers.CheckUsernameGet)             // Check if a username is available
 	e.POST("/login", handlers.LoginPost)                            // Login with a username and password
 	e.POST("/refresh", handlers.RefreshPost)                        // Refresh the access token using a refresh token
 	e.DELETE("/refresh", handlers.RefreshDelete)                    // Invalidate the current refresh token, effectively logging the user out