package retry

import "time"

type options struct {
	maxAttempts int     // default 3
	backoff     Backoff // default ExponentialBackoff(100ms, 5s, true)
	policy      Policy  // default: defaultPolicy (retry on 5xx and network errors)
	retryAfter  bool    // default true, respect Retry-After header
}

// Option configures the retry transport.
type Option func(*options)

func defaults() options {
	return options{
		maxAttempts: 3,
		backoff:     ExponentialBackoff(100*time.Millisecond, 5*time.Second, true),
		policy:      defaultPolicy{},
		retryAfter:  true,
	}
}

// WithMaxAttempts sets the maximum number of attempts (including the first).
// Values less than 1 are treated as 1 (no retries).
func WithMaxAttempts(n int) Option {
	return func(o *options) {
		if n < 1 {
			n = 1
		}
		o.maxAttempts = n
	}
}

// WithBackoff sets the backoff strategy used to compute delays between retries.
func WithBackoff(b Backoff) Option {
	return func(o *options) {
		o.backoff = b
	}
}

// WithPolicy sets the retry policy that decides whether to retry a request.
func WithPolicy(p Policy) Option {
	return func(o *options) {
		o.policy = p
	}
}

// WithRetryAfter controls whether the Retry-After response header is respected.
// When enabled and present, the Retry-After delay is used if it exceeds the
// backoff delay.
func WithRetryAfter(enable bool) Option {
	return func(o *options) {
		o.retryAfter = enable
	}
}