Services

Updated on May 21, 2025

Services

Note

IMPORTANT!
The service file should be placed in directory app/services

Service is a relatively important component of an application. It holds all the main logic, determining the effectiveness and correctness of the application.

The service will be used by the Controller, Console (Command/Schedule/Queue) Or called from other Services.

The service will also help you call through external third-party used by the application.

So always think carefully and name the service files appropriately to suit your application. A small suggestion for naming and grouping services with the same purpose together. For example, there is a service auth_services.go that will contain logic:

SignIn(signIn dto.SignIn) to login to system.
SignUp(signUp dto.SignUp) to register new account.
SignOut(jwtToken string) to signout system.
RefreshJWTToken(jwtToken, refreshToken string) to refresh JWT token.

Or another example of actions forgot and reset password is password_services.go and will contain logic:

ForgotPassword(forgotPassword dto.ForgotPassword) to send email with a link have code to reset new password.
ChangePassword(resetPassword dto.ResetPassword) to update new password from reset link was sent.

Full source code

package services

import (
    "errors"
    "fmt"
    "gfly/app/domain/repository"
    "gfly/app/modules/auth/dto"
    "gfly/app/modules/auth/notifications"
    "github.com/gflydev/core/log"
    "github.com/gflydev/core/utils"
    mb "github.com/gflydev/db"
    dbNull "github.com/gflydev/db/null"
    "github.com/gflydev/notification"
    "time"
)

// ====================================================================
// ========================= Main functions ===========================
// ====================================================================

// ForgotPassword processes a forgot password request by generating a reset
// token and sending a password reset email.
//
// This function handles the forgot password flow by:
// 1. Looking up the user by their email address
// 2. Generating a secure reset token using SHA256 hash of email + timestamp
// 3. Saving the reset token to the user's record
// 4. Sending a password reset email with instructions
//
// Parameters:
//   - forgotPassword: dto.ForgotPassword struct containing the user's email address
//
// Returns:
//   - error: nil if successful, otherwise:
//   - "invalid input data" if user email is not found
//   - "service error" if database update or email notification fails
//
// Example usage:
//
//    err := ForgotPassword(dto.ForgotPassword{
//        Username: "user@example.com"
//    })
func ForgotPassword(forgotPassword dto.ForgotPassword) error {
    // Get user by ID.
    user := repository.Pool.GetUserByEmail(forgotPassword.Username)
    // Item not found error
    if user == nil {
        return errors.New("invalid input data")
    }

    // Create a new SHA256 hash.
    hash := utils.Sha256(user.Email, time.Now().Unix())

    user.Token = dbNull.String(interpolateToken(hash))
    user.UpdatedAt = time.Now()

    if err := mb.UpdateModel(user); err != nil {
        return errors.New("service error")
    }

    // Send notification via mail
    if err := notification.Send(notifications.ResetPassword{
        Email: user.Email,
    }); err != nil {
        log.Errorf("Service forgot password error '%v'", err)

        return errors.New("service error")
    }

    return nil
}

// ChangePassword processes a password reset request and updates the user's password.
//
// This function handles the password reset flow by:
// 1. Verifying the reset token and retrieving associated user
// 2. Clearing the reset token
// 3. Updating the password with a new hashed value
// 4. Sending email notification about password change
//
// Parameters:
//   - resetPassword: dto.ResetPassword struct containing the new password and reset token
//
// Returns:
//   - error: nil if successful, otherwise:
//   - "invalid input data" if token is invalid/expired
//   - "service error" if database update or email notification fails
//
// Example usage:
//
//    err := ChangePassword(dto.ResetPassword{
//        Password: "newpass123",
//        Token: "abc123token",
//    })
func ChangePassword(resetPassword dto.ResetPassword) error {
    // Get user by ID.
    user := repository.Pool.GetUserByToken(interpolateToken(resetPassword.Token))
    // Item not found error
    if user == nil {
        return errors.New("invalid input data")
    }

    user.Token = dbNull.String("")
    user.UpdatedAt = time.Now()
    user.Password = utils.GeneratePassword(resetPassword.Password)

    if err := mb.UpdateModel(user); err != nil {
        log.Errorf("Change password error '%v'", err)

        return errors.New("service error")
    }

    // Send notification via mail
    if err := notification.Send(notifications.ChangePassword{
        Email: user.Email,
        Name:  user.Fullname,
    }); err != nil {
        log.Errorf("Change password error '%v'", err)

        return errors.New("service error")
    }

    return nil
}

// ====================================================================
// ======================== Helper Functions ==========================
// ====================================================================

func interpolateToken(token string) string {
    return fmt.Sprintf("reset_password:%s", token)
}

Note

TIP
You should not create each processing logic as a file or combine too much logic into one file because it will not bring too many semantic benefits. This will be difficult to find. Let’s create a service file with a bit more open semantics.

Note

IMPORTANT!
The Service is used in the following cases:

Controller —> Service

Service <—> Service

Console —> Service