package db

import (
	"context"
	"fmt"

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

// Connect opens a connection pool to Postgres.
// pgxpool manages multiple connections automatically — you rarely need to
// think about it; just pass the pool around and pgx picks an idle connection.
func Connect(databaseURL string) (*pgxpool.Pool, error) {
	if databaseURL == "" {
		return nil, fmt.Errorf("DATABASE_URL is not set")
	}

	config, err := pgxpool.ParseConfig(databaseURL)
	if err != nil {
		return nil, fmt.Errorf("parse database url: %w", err)
	}

	// Pool settings — tune these later based on your load
	config.MaxConns = 25
	config.MinConns = 2

	pool, err := pgxpool.NewWithConfig(context.Background(), config)
	if err != nil {
		return nil, fmt.Errorf("create pool: %w", err)
	}

	// Ping to verify the connection works at startup
	if err := pool.Ping(context.Background()); err != nil {
		return nil, fmt.Errorf("ping database: %w", err)
	}

	return pool, nil
}