package dbretry

import (
	"context"
	"fmt"
	"time"

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

func Connect(ctx context.Context, databaseURL string, maxWait time.Duration) (*pgxpool.Pool, error) {
	deadline := time.Now().Add(maxWait)
	var lastErr error

	for attempt := 1; ; attempt++ {
		pool, err := pgxpool.New(ctx, databaseURL)
		if err == nil {
			if pingErr := pool.Ping(ctx); pingErr == nil {
				return pool, nil
			} else {
				err = fmt.Errorf("ping postgres: %w", pingErr)
				pool.Close()
			}
		} else {
			err = fmt.Errorf("connect postgres: %w", err)
		}
		lastErr = err

		if time.Now().After(deadline) {
			return nil, fmt.Errorf("connect postgres after retry: %w", lastErr)
		}
		sleep := time.Duration(attempt) * time.Second
		if sleep > 5*time.Second {
			sleep = 5 * time.Second
		}
		timer := time.NewTimer(sleep)
		select {
		case <-ctx.Done():
			timer.Stop()
			return nil, fmt.Errorf("connect postgres cancelled: %w", ctx.Err())
		case <-timer.C:
		}
	}
}