package db

import (
	"context"
	"fmt"
	"log/slog"

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

// OpenPostgres creates a pgx connection pool and validates connectivity.
func OpenPostgres(ctx context.Context, dsn string) (*pgxpool.Pool, error) {
	cfg, err := pgxpool.ParseConfig(dsn)
	if err != nil {
		return nil, fmt.Errorf("parse postgres DSN: %w", err)
	}

	pool, err := pgxpool.NewWithConfig(ctx, cfg)
	if err != nil {
		return nil, fmt.Errorf("create postgres pool: %w", err)
	}
	if err := pool.Ping(ctx); err != nil {
		pool.Close()
		return nil, fmt.Errorf("ping postgres: %w", err)
	}
	slog.Info("postgres connected", "max_conns", cfg.MaxConns)
	return pool, nil
}