package db

import (
	"context"
	"time"

	"github.com/jackc/pgx/v5/pgxpool"
)

func NewPool(ctx context.Context, dsn string, maxConns int32) (*pgxpool.Pool, error) {
	cfg, err := pgxpool.ParseConfig(dsn)
	if err != nil {
		return nil, err
	}
	if maxConns > 0 {
		cfg.MaxConns = maxConns
	}
	pool, err := pgxpool.NewWithConfig(ctx, cfg)
	if err != nil {
		return nil, err
	}

	// Fail fast if unreachable
	pctx, cancel := context.WithTimeout(ctx, 3*time.Second)
	defer cancel()
	if err := pool.Ping(pctx); err != nil {
		pool.Close()
		return nil, err
	}
	return pool, nil
}