初版功能完成

internal/database/db.go

@@ -0,0 +1,53 @@
+// Package database owns SQLite setup, migrations, and persistence repositories.
+package database
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	_ "modernc.org/sqlite"
+)
+
+// Open creates the parent directory, opens SQLite, enables required pragmas,
+// runs embedded migrations, and verifies connectivity.
+func Open(ctx context.Context, path string) (*sql.DB, error) {
+	if strings.TrimSpace(path) == "" {
+		return nil, errors.New("database path must not be empty")
+	}
+	if path != ":memory:" {
+		if err := os.MkdirAll(filepath.Dir(path), 0o750); err != nil {
+			return nil, fmt.Errorf("create database directory: %w", err)
+		}
+	}
+
+	dsn := path
+	if path != ":memory:" {
+		dsn = "file:" + filepath.ToSlash(path)
+	}
+	separator := "?"
+	if strings.Contains(dsn, "?") {
+		separator = "&"
+	}
+	dsn += separator + "_pragma=foreign_keys(1)&_pragma=busy_timeout(5000)&_pragma=journal_mode(WAL)"
+
+	db, err := sql.Open("sqlite", dsn)
+	if err != nil {
+		return nil, fmt.Errorf("open SQLite: %w", err)
+	}
+	db.SetMaxOpenConns(1)
+	db.SetMaxIdleConns(1)
+	if err := db.PingContext(ctx); err != nil {
+		db.Close()
+		return nil, fmt.Errorf("ping SQLite: %w", err)
+	}
+	if err := Migrate(ctx, db); err != nil {
+		db.Close()
+		return nil, err
+	}
+	return db, nil
+}