feat: scaffold files service

internal/migrate/migrate.go

@@ -0,0 +1,54 @@
+package migrate
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+func Run(ctx context.Context, pool *pgxpool.Pool, migrationsDir string) error {
+	_, err := pool.Exec(ctx, `
+		CREATE TABLE IF NOT EXISTS schema_migrations (
+			version VARCHAR(255) PRIMARY KEY,
+			applied_at TIMESTAMPTZ NOT NULL DEFAULT now()
+		)
+	`)
+	if err != nil {
+		return fmt.Errorf("create migrations table: %w", err)
+	}
+
+	files, err := filepath.Glob(filepath.Join(migrationsDir, "*.up.sql"))
+	if err != nil {
+		return fmt.Errorf("glob migrations: %w", err)
+	}
+	sort.Strings(files)
+
+	for _, f := range files {
+		version := strings.TrimSuffix(filepath.Base(f), ".up.sql")
+		var exists bool
+		if err := pool.QueryRow(ctx, `SELECT EXISTS(SELECT 1 FROM schema_migrations WHERE version = $1)`, version).Scan(&exists); err != nil {
+			return fmt.Errorf("check migration %s: %w", version, err)
+		}
+		if exists {
+			continue
+		}
+		sql, err := os.ReadFile(f)
+		if err != nil {
+			return fmt.Errorf("read migration %s: %w", version, err)
+		}
+		if _, err := pool.Exec(ctx, string(sql)); err != nil {
+			return fmt.Errorf("apply migration %s: %w", version, err)
+		}
+		if _, err := pool.Exec(ctx, `INSERT INTO schema_migrations (version) VALUES ($1)`, version); err != nil {
+			return fmt.Errorf("record migration %s: %w", version, err)
+		}
+		slog.Info("applied migration", "version", version)
+	}
+	return nil
+}