feat: initial commit

Author: herculesgabriel

Dockerfile

@@ -0,0 +1,10 @@
+FROM golang:latest
+
+WORKDIR /usr/src/app
+
+COPY go.mod go.sum ./
+RUN go mod download && go mod verify
+
+COPY . .
+
+CMD [ "tail", "-f", "/dev/null" ]

Dockerfile.prod

@@ -0,0 +1,11 @@
+FROM golang:latest
+
+WORKDIR /usr/src/app
+
+COPY go.mod go.sum ./
+RUN go mod download && go mod verify
+
+COPY . .
+RUN go build -v -o /usr/local/bin/app
+
+CMD ["app"]

docker-compose.yml

@@ -0,0 +1,6 @@
+services:
+  go-app:
+    build: .
+    container_name: go-app
+    volumes:
+      - ./:/usr/src/app

go.mod

@@ -0,0 +1,5 @@
+module herculesgabriel/golang-playground
+
+go 1.20
+
+require github.com/google/uuid v1.3.0

go.sum

@@ -0,0 +1,2 @@
+github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
+github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=

main.go

@@ -0,0 +1,171 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"herculesgabriel/golang-playground/src/jobs"
+	"herculesgabriel/golang-playground/src/schemas"
+	mail "herculesgabriel/golang-playground/src/services/mail/implementations"
+	"herculesgabriel/golang-playground/src/usecases"
+	"herculesgabriel/golang-playground/src/utils"
+)
+
+func basicLearnings() {
+	divisionResult, err := utils.Divide(0, 2)
+	if err != nil {
+		utils.Logger("Error while dividing values")
+	}
+
+	sumResult := utils.Sum(1, 2)
+	sumAllResult := utils.SumAll(1, 2, 3)
+
+	fmt.Println("0 / 2 =", divisionResult)
+	fmt.Println("1 + 2 =", sumResult)
+	fmt.Println("1 + 2 + 3 =", sumAllResult)
+}
+
+func threads() {
+	go jobs.Countdown("second countdown", 5)
+	jobs.Countdown("first countdown", 10)
+}
+
+func channels() {
+	stringChannel := make(chan string)
+
+	go func() {
+		stringChannel <- "Hello,"
+		stringChannel <- "World!"
+		stringChannel <- "-"
+	}()
+
+	var endSignal string
+	for endSignal != "-" {
+		msg := <-stringChannel
+
+		if msg == "-" {
+			endSignal = msg
+			continue
+		}
+
+		time.Sleep(time.Second)
+		fmt.Println(msg)
+	}
+}
+
+func arraysAndSlices() {
+	var array [2]int = [2]int{1, 2}
+	fmt.Println(array)
+
+	var slice []int = []int{1, 2}
+	fmt.Println(slice)
+
+	var newSlice []int = make([]int, 2)
+	fmt.Println(newSlice)
+}
+
+func maps() {
+	var activeModules map[string]bool = make(map[string]bool)
+	activeModules["finances"] = true
+	activeModules["health"] = false
+
+	emails := map[string]string{
+		"bob":  "bob@mail.com",
+		"kate": "kate@mail.com",
+	}
+
+	fmt.Println(activeModules)
+	fmt.Println(emails["bob"])
+
+	delete(emails, "kate")
+	_, exists := activeModules["kate"]
+	fmt.Println(exists)
+}
+
+func structs() {
+	someone := schemas.Person{
+		Name: "Someone",
+		Age:  27,
+		Address: schemas.Address{
+			City:    "Curitiba",
+			Country: "Brasil",
+		},
+	}
+
+	city := schemas.Address{
+		City:    "Colombo",
+		Country: "Brasil",
+	}
+
+	someoneElse := schemas.Person{
+		Name:    "Someone Else",
+		Age:     26,
+		Address: city,
+	}
+
+	supermarket := schemas.Place{
+		Name:    "Menudo",
+		Code:    1,
+		Address: city,
+	}
+
+	fmt.Println(someone)
+	fmt.Println(someoneElse)
+	fmt.Println(supermarket)
+
+	fmt.Println(supermarket.Address.City)
+	fmt.Println(supermarket.City)
+
+	fmt.Println(someone.Greeting())
+}
+
+func serializer() {
+	team := schemas.NewTeam()
+
+	team.AddPlayer("Bob")
+	team.AddPlayer("Kate")
+
+	result, _ := json.Marshal(team)
+
+	data := []byte(result)
+	var parsedTeam schemas.Team
+	json.Unmarshal(data, &parsedTeam)
+
+	fmt.Println("JSON -> " + string(result))
+	fmt.Println()
+	fmt.Print("Team -> ")
+	fmt.Println(parsedTeam)
+}
+
+func interfaces() {
+	goodMail := mail.GoodMail{}
+	sendPromoEmail := usecases.NewSendPromoEmail(goodMail)
+
+	sendPromoEmail.Execute("bob@mail.com")
+}
+
+func Runner(funcs ...func()) {
+	for _, fn := range funcs {
+		fn()
+		fmt.Println()
+	}
+}
+
+func main() {
+	funcs := []func(){
+		basicLearnings,
+		threads,
+		channels,
+		arraysAndSlices,
+		maps,
+		structs,
+		serializer,
+		interfaces,
+	}
+
+	Runner(funcs...)
+
+
+	
+}

src/jobs/countdown.go

@@ -0,0 +1,14 @@
+package jobs
+
+import (
+	"fmt"
+	"time"
+)
+
+func Countdown(title string, seconds int) {
+	for ; seconds > 0; seconds-- {
+		fmt.Println(title, ":", seconds)
+		time.Sleep(time.Second)
+	}
+	fmt.Println(title, ":", seconds)
+}

src/schemas/address.go

@@ -0,0 +1,6 @@
+package schemas
+
+type Address struct {
+	City    string
+	Country string
+}

src/schemas/person.go

@@ -0,0 +1,11 @@
+package schemas
+
+type Person struct {
+	Name string
+	Age  int
+	Address
+}
+
+func (p Person) Greeting() string {
+	return "Hello" + " " + p.Name
+}

src/schemas/place.go

@@ -0,0 +1,7 @@
+package schemas
+
+type Place struct {
+	Name string
+	Code int
+	Address
+}

src/schemas/team.go

@@ -0,0 +1,47 @@
+package schemas
+
+import (
+	"errors"
+
+	"github.com/google/uuid"
+)
+
+type Player struct {
+	ID         int
+	Name       string `json:"Player"`
+	ExternalID string `json:"-"`
+}
+
+type Team struct {
+	ID      int
+	Name    string
+	Players []Player
+	lastID  int
+}
+
+func NewTeam() *Team {
+	return &Team{
+		ID:      1,
+		Name:    "Brazil",
+		Players: []Player{},
+		lastID:  0,
+	}
+}
+
+func (t *Team) AddPlayer(name string) error {
+	if t.lastID >= 11 {
+		return errors.New("team not accepting more players")
+	}
+
+	newID := t.lastID + 1
+
+	player := Player{
+		ID:         newID,
+		Name:       name,
+		ExternalID: uuid.NewString(),
+	}
+	t.lastID = newID
+	t.Players = append(t.Players, player)
+
+	return nil
+}

src/services/mail/implementations/good_mail.go

@@ -0,0 +1,9 @@
+package mail
+
+import "fmt"
+
+type GoodMail struct{}
+
+func (g GoodMail) Send(from string, to string, body string) {
+	fmt.Printf("Email from %s sent to %s: %s", from, to, body)
+}

src/services/mail/mail.go

@@ -0,0 +1,5 @@
+package mail
+
+type Mail interface {
+	Send(from string, to string, body string)
+}

src/usecases/send_promo_email.go

@@ -0,0 +1,29 @@
+package usecases
+
+import (
+	"errors"
+	"herculesgabriel/golang-playground/src/services/mail"
+)
+
+type SendPromoEmail struct {
+	mailService mail.Mail
+}
+
+func NewSendPromoEmail(mail mail.Mail) *SendPromoEmail {
+	return &SendPromoEmail{
+		mailService: mail,
+	}
+}
+
+func (s *SendPromoEmail) Execute(to string) error {
+	if len(to) < 10 {
+		return errors.New("invalid email")
+	}
+
+	from := "promo@mail.com"
+	body := "<h1>Hello!</h1><p>You've just got a huge discount! :)</p>"
+
+	s.mailService.Send(from, to, body)
+
+	return nil
+}

src/utils/divide.go

@@ -0,0 +1,11 @@
+package utils
+
+import "errors"
+
+func Divide(a int, b int) (int, error) {
+	if a == 0 {
+		privateLogger("There is an error!")
+		return 0, errors.New("first value cannot be zero")
+	}
+	return a / b, nil
+}

src/utils/logger.go

@@ -0,0 +1,52 @@
+package utils
+
+import (
+	"fmt"
+	"strings"
+)
+
+func Logger(msg string) {
+	title := createTitle("public", len(msg))
+	logTemplate(title, msg)
+}
+
+func privateLogger(msg string) {
+	title := createTitle("private", len(msg))
+	logTemplate(title, msg)
+}
+
+func logTemplate(title string, msg string) {
+	fmt.Println()
+	fmt.Println(title)
+	fmt.Println(msg)
+	fmt.Println(strings.Repeat("-", len(msg)))
+	fmt.Println()
+}
+
+func createTitle(title string, msgLen int) string {
+	baseStr := strings.Repeat("-", msgLen)
+	return strings.Map(transform(msgLen, title), baseStr)
+}
+
+func transform(msgLen int, title string) func(r rune) rune {
+	start := (msgLen - len(title)) / 2
+	end := msgLen - 5
+	titleIndex := 0
+	count := 0
+
+	return func(r rune) rune {
+		count += 1
+
+		if titleIndex >= len(title) {
+			return r
+		}
+
+		if count > start && count < end {
+			char := title[titleIndex]
+			titleIndex += 1
+			return rune(char)
+		}
+
+		return r
+	}
+}

src/utils/sum.go

@@ -0,0 +1,13 @@
+package utils
+
+func Sum(a int, b int) int {
+	return a + b
+}
+
+func SumAll(n ...int) (c int) {
+	for _, v := range n {
+		c += v
+	}
+
+	return
+}