feat(gl): add immutable postgres ledger storage

infrastructure/postgres/database.go

@@ -0,0 +1,83 @@
+// Package postgres provides GL's PostgreSQL adapters.
+package postgres
+
+import (
+	"context"
+	"fmt"
+	"net/url"
+	"strconv"
+
+	"gl/infrastructure/config"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgconn"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+type Row interface {
+	Scan(dest ...any) error
+}
+
+type Tx interface {
+	Exec(context.Context, string, ...any) (pgconn.CommandTag, error)
+	QueryRow(context.Context, string, ...any) Row
+	Commit(context.Context) error
+	Rollback(context.Context) error
+}
+
+type Database interface {
+	Begin(context.Context) (Tx, error)
+	QueryRow(context.Context, string, ...any) Row
+	Ping(context.Context) error
+	Close()
+}
+
+type Pool struct {
+	pool *pgxpool.Pool
+}
+
+func Open(ctx context.Context, cfg config.DatabaseConfig) (*Pool, error) {
+	connectionURL := &url.URL{
+		Scheme: "postgres",
+		User:   url.UserPassword(cfg.User, cfg.Password),
+		Host:   cfg.Host + ":" + strconv.Itoa(cfg.Port),
+		Path:   cfg.Name,
+	}
+	query := connectionURL.Query()
+	query.Set("sslmode", cfg.SSLMode)
+	connectionURL.RawQuery = query.Encode()
+
+	pool, err := pgxpool.New(ctx, connectionURL.String())
+	if err != nil {
+		return nil, fmt.Errorf("create postgres pool: %w", err)
+	}
+	return &Pool{pool: pool}, nil
+}
+
+func (p *Pool) Begin(ctx context.Context) (Tx, error) {
+	tx, err := p.pool.BeginTx(ctx, pgx.TxOptions{})
+	if err != nil {
+		return nil, err
+	}
+	return txAdapter{Tx: tx}, nil
+}
+
+func (p *Pool) Ping(ctx context.Context) error {
+	return p.pool.Ping(ctx)
+}
+
+func (p *Pool) QueryRow(ctx context.Context, sql string, args ...any) Row {
+	return p.pool.QueryRow(ctx, sql, args...)
+}
+
+func (p *Pool) Close() {
+	p.pool.Close()
+}
+
+type txAdapter struct {
+	pgx.Tx
+}
+
+func (t txAdapter) QueryRow(ctx context.Context, sql string, args ...any) Row {
+	return t.Tx.QueryRow(ctx, sql, args...)
+}