/* File responsible for owning the operations assigned to the user. */

package main

import (
	"fmt"
    	"gopkg.in/mgo.v2"
	"gopkg.in/mgo.v2/bson"
)

/* Structure responsible for representing the user. */

type User struct {
    UserName    string        `json: "username"`
    Email       string        `json: "email"`
    Password    string        `json: "password"`
}

/* Function responsible for including a user in the database. */

func InsertUser(u User) bool {

	session, err := mgo.Dial("localhost:27017")

	if err != nil {
		return false
	}

	defer session.Close()

	// The database is called "crud-go-mongodb" and the collection is called "user"

	c := session.DB("crud-go-mongodb").C("user")

	err = c.Insert(u)

	if err != nil {
		return false
	}

	return true

}

/* Function responsible for getting all users. */

func GetAllUsers() []User {

	session, err := mgo.Dial("localhost:27017")

	if err != nil {
		return nil
	}

	defer session.Close()

	// The database is called "crud-go-mongodb" and the collection is called "user"

	c := session.DB("crud-go-mongodb").C("user")

	var users []User

	err = c.Find(bson.M{}).All(&users)

	return users
}

/* Function responsible for validating a user through his username and password. */

func Login(username string, password string) User {

	session, err := mgo.Dial("localhost:27017")

	user := User{}

	if err != nil {
		return user
	}

	defer session.Close()

	// The database is called "crud-go-mongodb" and the collection is called "user"

	c := session.DB("crud-go-mongodb").C("user")

	w := bson.M{"username": username, "password": password}

	err = c.Find(w).One(&user)

	return user
}

/* Responsible for updating the user record in the database, using as input parameter your username. */

func UpdateUser(u User) bool {

	session, err := mgo.Dial("localhost:27017")

	if err != nil {
		return false
	}

	defer session.Close()

	// The database is called "crud-go-mongodb" and the collection is called "user"

	c := session.DB("crud-go-mongodb").C("user")

	w := bson.M{"username": "maxwellmoreira"}

	err = c.Update(w, u)

	if err != nil {
		return false
	}

	return true

}

/* Function responsible for delete a user in the database, using as input parameter his username. */

func DeleteUser(username string) bool {

	session, err := mgo.Dial("localhost:27017")

	if err != nil {
		return false
	}

	defer session.Close()

	// The database is called "crud-go-mongodb" and the collection is called "user"

	c := session.DB("crud-go-mongodb").C("user")

	w := bson.M{"username": username}

	err = c.Remove(w)

	return true

}


/* Function responsible for running the program. */

func main() {

	// 1- INSERT USER

	user1 := User{UserName: "maxwellmoreira", Email: "example@email.com", Password: "1234"}

	result1 := InsertUser(user1)

	_ = result1

	fmt.Printf("%+v\n", result1)

	// 2- SELECT ALL USERS

	result2 := GetAllUsers()

	_ = result2

	fmt.Printf("%+v\n", result2)

	// 3- UPDATE USER

	user3 := User{UserName: "maxwellmaxwell", Email: "example@email.com", Password: "1234"}

	result3 := UpdateUser(user3)

	_ = result3

	fmt.Printf("%+v\n", result3)

	// 4- LOGIN USER

	username_updated := "maxwellmaxwell"
	password := "1234"

	result4 := Login(username_updated, password)

	_ = result4

	fmt.Printf("%+v\n", result4)

	// 5- DELETE USER

	result5 := DeleteUser(username_updated)

	_ = result5

	fmt.Printf("%+v\n", result5)

}