first commit

internal/db/postgres.go

@@ -0,0 +1,51 @@
+package db
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+
+	"a301_game_server/config"
+	"a301_game_server/pkg/logger"
+)
+
+// Pool wraps a pgx connection pool.
+type Pool struct {
+	*pgxpool.Pool
+}
+
+// NewPool creates a connection pool to PostgreSQL.
+func NewPool(ctx context.Context, cfg *config.DatabaseConfig) (*Pool, error) {
+	poolCfg, err := pgxpool.ParseConfig(cfg.DSN())
+	if err != nil {
+		return nil, fmt.Errorf("parse dsn: %w", err)
+	}
+
+	poolCfg.MaxConns = cfg.MaxConns
+	poolCfg.MinConns = cfg.MinConns
+
+	pool, err := pgxpool.NewWithConfig(ctx, poolCfg)
+	if err != nil {
+		return nil, fmt.Errorf("create pool: %w", err)
+	}
+
+	if err := pool.Ping(ctx); err != nil {
+		pool.Close()
+		return nil, fmt.Errorf("ping database: %w", err)
+	}
+
+	logger.Info("database connected", "host", cfg.Host, "db", cfg.DBName)
+	return &Pool{pool}, nil
+}
+
+// RunMigrations executes all schema migrations.
+func (p *Pool) RunMigrations(ctx context.Context) error {
+	for i, m := range migrations {
+		if _, err := p.Exec(ctx, m); err != nil {
+			return fmt.Errorf("migration %d failed: %w", i, err)
+		}
+	}
+	logger.Info("database migrations completed", "count", len(migrations))
+	return nil
+}