first commit

backend/internal/database/database.go

@@ -0,0 +1,77 @@
+package database
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+type DB struct {
+	Pool *pgxpool.Pool
+}
+
+func Connect(ctx context.Context, databaseURL string) (*DB, error) {
+	cfg, err := pgxpool.ParseConfig(databaseURL)
+	if err != nil {
+		return nil, fmt.Errorf("parse database url: %w", err)
+	}
+
+	cfg.MaxConns = 10
+	cfg.MinConns = 1
+	cfg.MaxConnLifetime = time.Hour
+	cfg.MaxConnIdleTime = 30 * time.Minute
+
+	pool, err := pgxpool.NewWithConfig(ctx, cfg)
+	if err != nil {
+		return nil, fmt.Errorf("create database pool: %w", err)
+	}
+
+	if err := pool.Ping(ctx); err != nil {
+		pool.Close()
+		return nil, fmt.Errorf("ping database: %w", err)
+	}
+
+	return &DB{Pool: pool}, nil
+}
+
+func (db *DB) Close() {
+	if db != nil && db.Pool != nil {
+		db.Pool.Close()
+	}
+}
+
+func (db *DB) Migrate(ctx context.Context, logger *slog.Logger, migrationsDir string) error {
+	files, err := filepath.Glob(filepath.Join(migrationsDir, "*.sql"))
+	if err != nil {
+		return fmt.Errorf("list migrations: %w", err)
+	}
+
+	sort.Strings(files)
+
+	for _, file := range files {
+		sql, err := os.ReadFile(file)
+		if err != nil {
+			return fmt.Errorf("read migration %s: %w", file, err)
+		}
+
+		statement := strings.TrimSpace(string(sql))
+		if statement == "" {
+			continue
+		}
+
+		if _, err := db.Pool.Exec(ctx, statement); err != nil {
+			return fmt.Errorf("run migration %s: %w", file, err)
+		}
+
+		logger.Info("migration applied", "file", filepath.Base(file))
+	}
+
+	return nil
+}