init

internal/db/db.go

@@ -0,0 +1,81 @@
+package db
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+const defaultDSN = "postgres://writekit:writekit@localhost:5432/writekit?sslmode=disable"
+
+type DB struct {
+	pool *pgxpool.Pool
+}
+
+func Connect(migrationsDir string) (*DB, error) {
+	dsn := os.Getenv("DATABASE_URL")
+	if dsn == "" {
+		dsn = defaultDSN
+	}
+
+	pool, err := pgxpool.New(context.Background(), dsn)
+	if err != nil {
+		return nil, fmt.Errorf("connect: %w", err)
+	}
+
+	if err := pool.Ping(context.Background()); err != nil {
+		pool.Close()
+		return nil, fmt.Errorf("ping: %w", err)
+	}
+
+	db := &DB{pool: pool}
+
+	if err := db.RunMigrations(migrationsDir); err != nil {
+		pool.Close()
+		return nil, fmt.Errorf("migrations: %w", err)
+	}
+
+	return db, nil
+}
+
+func (db *DB) RunMigrations(dir string) error {
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		return fmt.Errorf("read migrations dir: %w", err)
+	}
+
+	var files []string
+	for _, entry := range entries {
+		if entry.IsDir() || filepath.Ext(entry.Name()) != ".sql" {
+			continue
+		}
+		files = append(files, entry.Name())
+	}
+	sort.Strings(files)
+
+	for _, name := range files {
+		content, err := os.ReadFile(filepath.Join(dir, name))
+		if err != nil {
+			return fmt.Errorf("read %s: %w", name, err)
+		}
+
+		if _, err := db.pool.Exec(context.Background(), string(content)); err != nil {
+			return fmt.Errorf("run %s: %w", name, err)
+		}
+	}
+
+	return nil
+}
+
+func (db *DB) Close() {
+	db.pool.Close()
+}
+
+func (db *DB) Pool() *pgxpool.Pool {
+	return db.pool
+}
+