rework new app

app/app.go

@@ -0,0 +1,182 @@
+package app
+
+import (
+	"bufio"
+	"database/sql"
+	"embed"
+	"errors"
+	"fmt"
+	"gopher-toolbox/utils"
+	"log/slog"
+	"os"
+	"strings"
+	"time"
+
+	"aidanwoods.dev/go-paseto"
+	"github.com/golang-migrate/migrate/v4"
+	_ "github.com/golang-migrate/migrate/v4/database/postgres"
+	"github.com/golang-migrate/migrate/v4/source/iofs"
+	_ "github.com/jackc/pgx/v5/stdlib"
+)
+
+const (
+	// Handlers keys
+	InvalidRequest  string = "invalid_request"
+	InternalError   string = "internal_error"
+	RequestID       string = "request_id"
+	NotFound        string = "not_found"
+	Created         string = "created"
+	Updated         string = "updated"
+	Deleted         string = "deleted"
+	Enabled         string = "enabled"
+	Disabled        string = "disabled"
+	Retrieved       string = "retrieved"
+	ErrorCreating   string = "error_creating"
+	ErrorUpdating   string = "error_updating"
+	ErrorEnabling   string = "error_enabling"
+	ErrorDisabling  string = "error_disabling"
+	ErrorGetting    string = "error_getting"
+	ErrorGettingAll string = "error_getting_all"
+	InvalidEntityID string = "invalid_entity_id"
+	NotImplemented  string = "not_implemented"
+
+	// User keys
+	UserUsernameKey       string = "user_username_key"
+	UserEmailKey          string = "user_email_key"
+	UsernameAlReadyExists string = "username_already_exists"
+	EmailAlreadyExists    string = "email_already_exists"
+	IncorrectPassword     string = "incorrect_password"
+	ErrorGeneratingToken  string = "error_generating_token"
+	LoggedIn              string = "logged_in"
+)
+
+type App struct {
+	Database AppDatabase
+	Security AppSecurity
+	AppInfo  AppInfo
+}
+
+type AppDatabase struct {
+	DriverName string
+	DataSource string
+	Migrate    bool
+}
+
+type AppInfo struct {
+	Version string
+}
+
+type AppSecurity struct {
+	AsymmetricKey paseto.V4AsymmetricSecretKey
+	PublicKey     paseto.V4AsymmetricPublicKey
+	Duration      time.Duration
+}
+
+func New(version string) *App {
+	var err error
+
+	err = loadEnvFile()
+	if err != nil {
+		slog.Error("error loading env file", "error", err)
+		panic(err)
+	}
+
+	var durationTime time.Duration
+	var ak paseto.V4AsymmetricSecretKey
+
+	ak, err = paseto.NewV4AsymmetricSecretKeyFromHex(os.Getenv("ASYMMETRICKEY"))
+	if err != nil {
+		ak = paseto.NewV4AsymmetricSecretKey()
+	}
+	pk := ak.Public()
+
+	duration := os.Getenv("DURATION")
+	if duration != "" {
+		durationTime, err = time.ParseDuration(duration)
+		if err != nil {
+			durationTime = time.Hour * 24 * 7
+		}
+	}
+
+	return &App{
+		Database: AppDatabase{
+			Migrate:    utils.GetBool(os.Getenv("MIGRATE")),
+			DriverName: os.Getenv("DRIVERNAME"),
+			DataSource: os.Getenv("DATASOURCE"),
+		},
+		Security: AppSecurity{
+			AsymmetricKey: ak,
+			PublicKey:     pk,
+			Duration:      durationTime,
+		},
+		AppInfo: AppInfo{
+			Version: version,
+		},
+	}
+}
+
+// MigrateDB migrates the database. The migrations must stored in the
+// "database/migrations" directory inside cmd directory along with the main.go.
+//
+// cmd/main.go
+//
+// cmd/database/migrations/*.sql
+func (a *App) Migrate(database embed.FS) {
+	if a.Database.Migrate == false {
+		slog.Info("migration disabled")
+		return
+	}
+	dbConn, err := sql.Open(a.Database.DriverName, a.Database.DataSource)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	defer dbConn.Close()
+
+	d, err := iofs.New(database, "database/migrations")
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	m, err := migrate.NewWithSourceInstance("iofs", d, a.Database.DataSource)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	err = m.Up()
+	if err != nil && !errors.Is(err, migrate.ErrNoChange) {
+		slog.Error("cannot migrate", "error", err)
+		panic(err)
+	}
+	if errors.Is(err, migrate.ErrNoChange) {
+		slog.Info("migration has no changes")
+	}
+
+	slog.Info("migration done")
+}
+
+func loadEnvFile() error {
+	file, err := os.Open(".env")
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if len(line) == 0 || strings.HasPrefix(line, "#") {
+			continue
+		}
+		parts := strings.SplitN(line, "=", 2)
+		if len(parts) != 2 {
+			continue
+		}
+		key := strings.TrimSpace(parts[0])
+		value := strings.TrimSpace(parts[1])
+		os.Setenv(key, value)
+	}
+	return scanner.Err()
+}