Prompt Title: IoT User Service Implementation

To implement the forgot password functionality, you can use the following steps:

1. Generate a random token for the user when they request a password reset.
2. Save the token and its expiry time in the database.
3. Send the token via email to the user with a password reset link.
4. Create a route to handle the password reset request using the token.

Note that this example does not include the email sending part. You can use a package like github.com/sendgrid/sendgrid-go to send emails.

First, update the models/user.go file to add the password reset token and its expiry time:

goCopy code
package models

import (
	"time"
	// ... other imports ...
)

type User struct {
	ID                     uint      `gorm:"primaryKey;autoIncrement"`
	Email                  string    `gorm:"unique;not null"`
	Password               string    `gorm:"not null"`
	PasswordResetToken     string    `gorm:""`
	PasswordResetTokenExpiry time.Time `gorm:""`
	// ... other fields ...
}

// ... other functions ...

Next, update the main.go file to add the forgot password and reset password routes and handlers:

goCopy code
package main

import (
	// ... other imports ...
	"math/rand"
	"time"
)

func main() {
	// ... existing code ...

	r.POST("/forgot-password", forgotPassword)
	r.POST("/reset-password", resetPassword)

	r.Run(":8080")
}

func forgotPassword(c *gin.Context) {
	var user models.User
	if err := c.ShouldBindJSON(&user); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	var foundUser models.User
	if err := db.Where("email = ?", user.Email).First(&foundUser).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "User not found"})
		return
	}

	token := generateRandomToken()
	foundUser.PasswordResetToken = token
	foundUser.PasswordResetTokenExpiry = time.Now().Add(1 * time.Hour) // Token valid for 1 hour
	db.Save(&foundUser)

	// TODO: Send an email to the user with the token and a link to reset their password

	c.JSON(http.StatusOK, gin.H{"message": "Password reset email sent"})
}

func resetPassword(c *gin.Context) {
	var resetData struct {
		Token    string `json:"token" binding:"required"`
		Password string `json:"password" binding:"required"`
	}
	if err := c.ShouldBindJSON(&resetData); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	var user models.User
	if err := db.Where("password_reset_token = ? AND password_reset_token_expiry > ?", resetData.Token, time.Now()).First(&user).Error; err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid or expired token"})
		return
	}

	user.Password = resetData.Password
	user.PasswordResetToken = ""
	user.PasswordResetTokenExpiry = time.Time{}
	db.Save(&user)

	c.JSON(http.StatusOK,