first commit

pkg/data/data.go

@@ -0,0 +1,58 @@
+package data
+
+import (
+	"database/sql"
+	"errors"
+	"log"
+	"path/filepath"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+type (
+	Repository struct {
+		path string
+		conn *sql.DB
+	}
+)
+
+func New(path string) *Repository {
+	dbPath := filepath.Join(path, "system.db")
+	conn, err := sql.Open("sqlite3", dbPath)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	r := &Repository{
+		path: path,
+		conn: conn,
+	}
+
+	if err := r.check(); err != nil {
+		log.Fatalf("[PANIC] %s", err)
+	}
+	return r
+}
+
+func (r *Repository) Close() error {
+	return r.conn.Close()
+}
+
+func (r *Repository) check() error {
+	rows, err := r.conn.Query("SELECT value FROM system WHERE key = 'db.version'")
+	if err != nil {
+		m := new(migratorVersion1)
+		m.conn = r.conn
+		return m.create()
+	}
+	defer rows.Close()
+	var version string
+	if !rows.Next() {
+		return errors.New("no version found in the system database")
+	}
+	if err := rows.Scan(&version); err != nil {
+		return err
+	}
+	log.Printf("[INFO] database loaded with version %s", version)
+	return nil
+}