medium-introduction-go-part3-main.go

package main

import (
  "net/http"

  "golang.org/x/crypto/bcrypt"
  "github.com/labstack/echo"
)

type User struct {
  Email	    string `json:"email,omitempty" form:"email"`
  Password  string `json:"-" form:"password"`
  Name	    string `json:"name,omitempty" form:"name"`
  Role	    string `json:"role,omitempty" form:"role"`
}

var users []User

// Retorna a listagem de todos os usuários cadastrados
func getAllUsers (c echo.Context) error {
  return c.JSON(http.StatusOK, users)
}

// Retorna os dados de um usuário
func getUser (c echo.Context) error {
  email := c.Param("user")
  user := getUserByEmail(email)
  return c.JSON(http.StatusOK, user)
}

// Cadastra um novo usuário
func createUser (c echo.Context) error {
  password := c.FormValue("password")
  hashPassword, _ := bcrypt.GenerateFromPassword([]byte(password), 10)
  user := User{Email: c.FormValue("email"), Password: string(hashPassword), Name: c.FormValue("name"), Role: c.FormValue("role")}
  users = append(users, user)
  return c.JSON(http.StatusCreated, user)
}

// Atualiza um usuário existente
func updateUser (c echo.Context) error {
  email := c.Param("user")
  for index, user := range users {
    if (user.Email == email) {
	name := c.FormValue("name");
	if ( name != "") {
	  users[index].Name = name
	}

	role := c.FormValue("role");
	if ( role != "") {
	  users[index].Role = role
	}
	password := c.FormValue("password");
	if ( password != "") {
	  hashPassword, _ := bcrypt.GenerateFromPassword([]byte(password), 10)
	  users[index].Password = string(hashPassword)
	}
	return c.JSON(http.StatusOK, users[index])
      }
  }

  return c.JSONBlob(http.StatusBadRequest, []byte("{\"status\": \"error\"}"))
}

// Exclui um usuário existente
func deleteUser (c echo.Context) error {
  email := c.Param("user")
  for index, user := range users {
    if (user.Email == email) {
      users = append(users[:index], users[index+1:]...)
	return c.JSONBlob(http.StatusOK, []byte("{\"status\": \"success\"}"))
      }
    }

  return c.JSONBlob(http.StatusBadRequest, []byte("{\"status\": \"error\"}"))
}

// Faz a autenticação de um usuário
func authUser (c echo.Context) error {
  email := c.FormValue("email")
  password := c.FormValue("password")

  user := getUserByEmail(email)
  err := bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(password))
  if (err == nil) {
    return c.JSONBlob(http.StatusOK, []byte("{\"status\": \"success\"}"))
  }
	
  return c.JSONBlob(http.StatusUnauthorized, []byte("{\"status\": \"error\"}"))
}

// Retonar instancia do usuário apartir de um e-mail
func getUserByEmail(email string) User {
  var user User;
  for _, user = range users {
    if (user.Email == email) {
      return user
    }
  }
	
  return user;
}

func main() {
  // Inicia usuário
  password, _ := bcrypt.GenerateFromPassword([]byte("123456"), 10)
  users = append(users, User{Email:"ronaldo@test.com", Password: string(password), Name:"Ronaldo Meneguite", Role:"Admin"})
	
  router := echo.New()
  v1 := router.Group("/v1")
	
  // User API
  v1.GET("/users", getAllUsers)
  v1.GET("/users/:user", getUser)
  v1.POST("/users", createUser)
  v1.PUT("/users/:user", updateUser)
  v1.DELETE("/users/:user", deleteUser)

  // Auth API
  v1.POST("/auth", authUser)

  router.Logger.Fatal(router.Start(":8080"))
}