feat: services: crus, migrations

internal/services/migrator.go

@@ -0,0 +1,116 @@
+package services
+
+import (
+	"app/internal/database"
+	"app/internal/models"
+	"context"
+	"crypto/sha256"
+	"fmt"
+	"github.com/wailsapp/wails/v3/pkg/application"
+	"io"
+	"log/slog"
+	"os"
+)
+
+type Migrator struct{}
+
+var MigratorService = application.NewService(&Migrator{})
+
+var db = database.GetInstance()
+
+func CalculateFileSha256Checksum(filePath string) (string, error) {
+	file, err := os.Open(filePath)
+	if err != nil {
+		return "", err
+	}
+	defer file.Close()
+
+	hasher := sha256.New()
+
+	if _, err := io.Copy(hasher, file); err != nil {
+		return "", err
+	}
+
+	return fmt.Sprintf("%x", hasher.Sum(nil)), nil
+}
+
+func dropDatabase() error {
+	_ = database.Shutdown()
+	if _, err := os.Stat(database.Path); err == nil {
+		err := os.Remove(database.Path)
+		if err != nil {
+
+			return err
+		}
+	}
+	return nil
+}
+
+func createDatabase(entities ...any) error {
+	// Close current connections and create new database
+	err := dropDatabase()
+	if err != nil {
+		return err
+	}
+
+	db = database.GetInstance()
+
+	err = db.AutoMigrate(entities...)
+	if err != nil {
+		return err
+	}
+
+	InsertDefaultData()
+	return nil
+}
+
+func Migrate(entities ...any) error {
+	hashBeforeMigration, err := CalculateFileSha256Checksum(database.Path)
+
+	slog.Info("Calculating hash...")
+
+	if err != nil {
+		return err
+	}
+
+	slog.Info("Apply migrations")
+	err = db.AutoMigrate(entities...)
+
+	if err != nil {
+		slog.Info("Error occurred while migrations: %s. Recreate database...", err)
+		if err = createDatabase(entities...); err != nil {
+			slog.Error("Error occurred again: %s. Panic!", err)
+			return err
+		}
+	} else {
+		slog.Info("Calculating hash after migrations...")
+		var hashAfterMigration string
+		hashAfterMigration, err = CalculateFileSha256Checksum(database.Path)
+		if err != nil {
+			slog.Error("Failed to calc hash: %s", err)
+			return err
+		}
+
+		if hashAfterMigration != hashBeforeMigration {
+			slog.Info("Hashes before and after migrations are different. Recreate database...")
+			err = createDatabase(entities...)
+			if err != nil {
+				slog.Error("Failed to create new database: %s", err)
+				return err
+			}
+		}
+	}
+	slog.Info("Migrations proceeded")
+	return nil
+}
+
+func (migrator *Migrator) OnStartup(ctx context.Context, options application.ServiceOptions) error {
+	return Migrate(models.Entities...)
+}
+
+func (migrator *Migrator) OnShutdown() {
+	err := database.Shutdown()
+	if err != nil {
+		panic(err)
+	}
+}