🎉 first commit

app/config/.env.example

@@ -0,0 +1,10 @@
+DB=postgres
+POSTGRES_USER=
+POSTGRES_PASSWORD=
+POSTGRES_DB=
+POSTGRES_HOST=ohmyurl-postgresql
+POSTGRES_PORT=5432
+LISTEN_PORT_CREATE=8080
+LISTEN_PORT_FORWARD=8081
+FORWARD_DOMAIN=http://localhost/
+CREATE_DOMAIN=http://127.0.0.1

app/config/settings.go

@@ -0,0 +1,78 @@
+package config
+
+import (
+	"os"
+	"strings"
+)
+
+type DBName string
+
+const (
+	Postgres  DBName = "postgres"
+	MongoDB   DBName = "mongodb"
+	Cassandra DBName = "cassandra"
+)
+
+type AppConfig struct {
+	LISTEN_PORT_CREATE  string
+	LISTEN_PORT_FORWARD string
+	FORWARD_DOMAIN      string
+	CREATE_DOMAIN       string
+}
+
+type PostgresConfig struct {
+	USER     string
+	PASSWORD string
+	HOST     string
+	PORT     string
+	DBNAME   string
+}
+
+func GetAppConfig() *AppConfig {
+	return &AppConfig{
+		LISTEN_PORT_CREATE:  GetEnvOrPanic("LISTEN_PORT_CREATE"),
+		LISTEN_PORT_FORWARD: GetEnvOrPanic("LISTEN_PORT_FORWARD"),
+		FORWARD_DOMAIN:      GetEnvOrPanic("FORWARD_DOMAIN"),
+		CREATE_DOMAIN:       GetEnvOrPanic("CREATE_DOMAIN"),
+	}
+}
+
+func GetPostgresConfig() *PostgresConfig {
+	return &PostgresConfig{
+		USER:     GetEnvOrPanic("POSTGRES_USER"),
+		PASSWORD: GetEnvOrPanic("POSTGRES_PASSWORD"),
+		HOST:     GetEnvOrPanic("POSTGRES_HOST"),
+		PORT:     GetEnvOrDefault("POSTGRES_PORT", "5432"),
+		DBNAME:   GetEnvOrPanic("POSTGRES_DB"),
+	}
+}
+
+func GetDB() DBName {
+	dbName := strings.ToLower(GetEnvOrPanic("DB"))
+	switch dbName {
+	case "postgres":
+		return Postgres
+	case "mongodb":
+		return MongoDB
+	case "cassandra":
+		return Cassandra
+	default:
+		panic("Unknown database")
+	}
+}
+
+func GetEnvOrDefault(key, defaultValue string) string {
+	value := os.Getenv(key)
+	if value == "" {
+		return defaultValue
+	}
+	return value
+}
+
+func GetEnvOrPanic(key string) string {
+	value := os.Getenv(key)
+	if value == "" {
+		panic("Environment variable " + key + " is not set")
+	}
+	return value
+}

app/db/base.go

@@ -0,0 +1,48 @@
+package db
+
+import (
+	"fmt"
+	"github.com/aykhans/oh-my-url/app/config"
+	gormPostgres "gorm.io/driver/postgres"
+	"gorm.io/gorm"
+	"time"
+)
+
+type DB interface {
+	Init()
+	CreateURL(url string) (string, error)
+	GetURL(key string) (string, error)
+}
+
+func GetDB() DB {
+	db := config.GetDB()
+	switch db {
+	case "postgres":
+		postgresConf := config.GetPostgresConfig()
+		dsn := fmt.Sprintf(
+			"host=%s user=%s password=%s dbname=%s port=%s sslmode=%s TimeZone=%s",
+			postgresConf.HOST,
+			postgresConf.USER,
+			postgresConf.PASSWORD,
+			postgresConf.DBNAME,
+			postgresConf.PORT,
+			"disable",
+			"UTC",
+		)
+
+		var db *gorm.DB
+		var err error
+		for i := 0; i < 5; i++ {
+			db, err = gorm.Open(gormPostgres.Open(dsn), &gorm.Config{})
+			if err == nil {
+				break
+			}
+			time.Sleep(3 * time.Second)
+		}
+		if err != nil {
+			panic(err)
+		}
+		return &Postgres{gormDB: db}
+	}
+	return nil
+}

app/db/cassandra.go

@@ -0,0 +1 @@
+package db

app/db/mongodb.go

@@ -0,0 +1 @@
+package db

app/db/postgres.go

@@ -0,0 +1,72 @@
+package db
+
+import (
+	// "github.com/aykhans/oh-my-url/app/config"
+	"gorm.io/gorm"
+)
+
+type Postgres struct {
+	gormDB *gorm.DB
+}
+
+type url struct {
+	ID  uint   `gorm:"primaryKey"`
+	Key string `gorm:"unique;not null;size:15;default:null"`
+	URL string `gorm:"not null;default:null"`
+}
+
+func (p *Postgres) Init() {
+	err := p.gormDB.AutoMigrate(&url{})
+	if err != nil {
+		panic("failed to migrate database")
+	}
+	tx := p.gormDB.Exec(urlKeyCreateTrigger)
+	if tx.Error != nil {
+		panic("failed to create trigger")
+	}
+}
+
+func (p *Postgres) CreateURL(mainUrl string) (string, error) {
+	url := url{URL: mainUrl}
+	tx := p.gormDB.Create(&url)
+	if tx.Error != nil {
+		return "", tx.Error
+	}
+	return url.Key, nil
+}
+
+func (p *Postgres) GetURL(key string) (string, error) {
+	var result url
+	tx := p.gormDB.Where("key = ?", key).First(&result)
+	if tx.Error != nil {
+		return "", tx.Error
+	}
+	return result.URL, nil
+}
+
+const urlKeyCreateTrigger = `
+CREATE OR REPLACE FUNCTION generate_url_key()
+	RETURNS TRIGGER AS $$
+DECLARE
+	key_characters TEXT := 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
+	key TEXT := '';
+	base INT := LENGTH(key_characters);
+	n INT := NEW.id;
+BEGIN
+	WHILE n > 0 LOOP
+	n := n - 1;
+	key := SUBSTRING(key_characters FROM (n % base) + 1 FOR 1) || key;
+	n := n / base;
+	END LOOP;
+	NEW.key := key;
+	RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+DROP TRIGGER IF EXISTS trigger_generate_url_key on "public"."urls";
+
+CREATE TRIGGER trigger_generate_url_key
+	BEFORE INSERT ON urls
+	FOR EACH ROW
+	EXECUTE FUNCTION generate_url_key();
+`

app/http_handlers/base.go

@@ -0,0 +1,27 @@
+package httpHandlers
+
+import (
+	"github.com/aykhans/oh-my-url/app/db"
+	"github.com/aykhans/oh-my-url/app/utils"
+	"log"
+	"net/http"
+)
+
+type HandlerCreate struct {
+	DB            db.DB
+	ForwardDomain string
+}
+
+type HandlerForward struct {
+	DB           db.DB
+	CreateDomain string
+}
+
+func FaviconHandler(w http.ResponseWriter, r *http.Request) {
+	http.ServeFile(w, r, utils.GetTemplatePaths("favicon.ico")[0])
+}
+
+func InternalServerError(w http.ResponseWriter, err error) {
+	log.Fatal(err)
+	http.Error(w, "Internal Server Error", http.StatusInternalServerError)
+}

app/http_handlers/url_create.go

@@ -0,0 +1,75 @@
+package httpHandlers
+
+import (
+	"github.com/aykhans/oh-my-url/app/utils"
+	"html/template"
+	"net/http"
+	netUrl "net/url"
+	"regexp"
+)
+
+type CreateData struct {
+	ShortedURL string
+	MainURL    string
+	Error      string
+}
+
+func (hl *HandlerCreate) UrlCreate(w http.ResponseWriter, r *http.Request) {
+	if r.URL.Path != "/" {
+		http.NotFound(w, r)
+		return
+	}
+
+	tmpl, err := template.ParseFiles(utils.GetTemplatePaths("index.html")...)
+	if err != nil {
+		InternalServerError(w, err)
+		return
+	}
+
+	switch r.Method {
+	case http.MethodGet:
+		err = tmpl.Execute(w, nil)
+		if err != nil {
+			InternalServerError(w, err)
+			return
+		}
+	case http.MethodPost:
+		url := r.FormValue("url")
+		urlRegex := regexp.MustCompile(`^(http|https)://[a-zA-Z0-9.-]+(?:\:[0-9]+)?(?:/[^\s]*)?$`)
+		isValidUrl := urlRegex.MatchString(url)
+		if !isValidUrl {
+			data := CreateData{
+				MainURL: url,
+				Error:   "Invalid URL",
+			}
+			err = tmpl.Execute(w, data)
+			if err != nil {
+				InternalServerError(w, err)
+			}
+			return
+		}
+
+		key, err := hl.DB.CreateURL(url)
+		if err != nil {
+			InternalServerError(w, err)
+			return
+		}
+		shortedURL, err := netUrl.JoinPath(hl.ForwardDomain, key)
+		if err != nil {
+			InternalServerError(w, err)
+			return
+		}
+		data := CreateData{
+			ShortedURL: shortedURL,
+			MainURL:    url,
+		}
+		err = tmpl.Execute(w, data)
+		if err != nil {
+			InternalServerError(w, err)
+			return
+		}
+
+	default:
+		http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
+	}
+}

app/http_handlers/url_forward.go

@@ -0,0 +1,26 @@
+package httpHandlers
+
+import (
+	"net/http"
+	"strings"
+)
+
+func (hl *HandlerForward) UrlForward(w http.ResponseWriter, r *http.Request) {
+	path := r.URL.Path
+	segments := strings.Split(path, "/")
+	if len(segments) > 2 {
+		http.NotFound(w, r)
+		return
+	} else if segments[1] == "" {
+		http.Redirect(w, r, hl.CreateDomain, http.StatusMovedPermanently)
+		return
+	}
+
+	key := segments[1]
+	url, err := hl.DB.GetURL(key)
+	if err != nil {
+		http.NotFound(w, r)
+		return
+	}
+	http.Redirect(w, r, url, http.StatusMovedPermanently)
+}

app/main.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"github.com/aykhans/oh-my-url/app/config"
+	"github.com/aykhans/oh-my-url/app/db"
+	"github.com/aykhans/oh-my-url/app/http_handlers"
+	"net/http"
+	"sync"
+)
+
+func main() {
+	config := config.GetAppConfig()
+	dbCreate := db.GetDB()
+	dbCreate.Init()
+	handlerCreate := httpHandlers.HandlerCreate{DB: dbCreate, ForwardDomain: config.FORWARD_DOMAIN}
+	urlCreateMux := http.NewServeMux()
+	urlCreateMux.HandleFunc("/", handlerCreate.UrlCreate)
+	urlCreateMux.HandleFunc("/favicon.ico", httpHandlers.FaviconHandler)
+
+	dbRead := db.GetDB()
+	handlerForward := httpHandlers.HandlerForward{DB: dbRead, CreateDomain: config.CREATE_DOMAIN}
+	urlReadMux := http.NewServeMux()
+	urlReadMux.HandleFunc("/", handlerForward.UrlForward)
+	urlReadMux.HandleFunc("/favicon.ico", httpHandlers.FaviconHandler)
+
+	var wg sync.WaitGroup
+	wg.Add(2)
+	go func() {
+		defer wg.Done()
+		panic(http.ListenAndServe(":"+config.LISTEN_PORT_CREATE, urlCreateMux))
+	}()
+	go func() {
+		defer wg.Done()
+		panic(http.ListenAndServe(":"+config.LISTEN_PORT_FORWARD, urlReadMux))
+	}()
+	wg.Wait()
+}

app/templates/index.html

@@ -0,0 +1,82 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <title>Oh My URL</title>
+  <style>
+    body {
+      font-family: Arial, sans-serif;
+      margin: 0;
+      padding: 0;
+      background-color: #f4f4f4;
+    }
+
+    .container {
+      max-width: 600px;
+      margin: 50px auto;
+      background-color: #fff;
+      padding: 20px;
+      border-radius: 5px;
+      box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
+    }
+
+    h1 {
+      text-align: center;
+    }
+
+    form {
+      display: flex;
+      flex-direction: column;
+    }
+
+    label {
+      margin-bottom: 8px;
+    }
+
+    input[type="url"] {
+      padding: 8px;
+      margin-bottom: 15px;
+      border-radius: 3px;
+      border: 1px solid #ccc;
+    }
+
+    button {
+      padding: 10px 15px;
+      width: 20%;
+      margin: 0 auto;
+      font-size: medium;
+      border: none;
+      border-radius: 3px;
+      background-color: #007bff;
+      color: #fff;
+      cursor: pointer;
+      transition: background-color 0.3s ease;
+    }
+
+    button:hover {
+      background-color: #0056b3;
+    }
+
+    button:active {
+      transform: scale(0.98);
+    }
+  </style>
+</head>
+<body>
+
+  <div class="container">
+    <h1>Oh My URL!</h1>
+    <form action="/" method="post">
+      {{ if .Error }}
+        <label for="urlInput" style="color: red;">{{ .Error }}</label>
+      {{ end }}
+      <input type="url" id="urlInput" name="url" placeholder="https://example.com/" value="{{ if .MainURL }}{{ .MainURL }}{{ end }}" required>
+      {{ if .ShortedURL }}
+        <label for="urlOutput">Shortened URL: <a href="{{.ShortedURL}}" target="_blank">{{.ShortedURL}}</a></label>
+      {{ end }}
+      <button type="submit">Get URL</button>
+    </form>
+  </div>
+
+</body>
+</html>

app/utils/short_key.go

@@ -0,0 +1,26 @@
+package utils
+
+import (
+	"strings"
+)
+
+const keyCharacters string = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+
+func GenerateKey(n int) string {
+	var result strings.Builder
+	base := len(keyCharacters)
+
+	for n > 0 {
+		n--
+		result.WriteByte(keyCharacters[n%base])
+		n /= base
+	}
+
+	key := result.String()
+	runes := []rune(key)
+	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
+		runes[i], runes[j] = runes[j], runes[i]
+	}
+
+	return string(runes)
+}

app/utils/templates.go

@@ -0,0 +1,19 @@
+package utils
+
+import (
+	"os"
+	"path/filepath"
+)
+
+func GetTemplatePaths(filenames ...string) []string {
+	dir, err := os.Getwd()
+	if err != nil {
+		panic(err)
+	}
+
+	templatePath := filepath.Join(dir, "app", "templates")
+	for i, filename := range filenames {
+		filenames[i] = filepath.Join(templatePath, filename)
+	}
+	return filenames
+}