package activator

import (
	"context"
	"errors"
	"time"

	"github.com/carlosframework/platform/internal/hostwrite"
)

type probeWindow struct {
	policy startPolicy
	opened time.Time
	ready  bool
	now    func() time.Time
}

func (b *probeWindow) result(err error) error {
	if !b.policy.Probe || b.ready {
		return err
	}
	now := b.now()
	if (!b.policy.Deadline.IsZero() && !now.Before(b.policy.Deadline)) ||
		(!b.opened.IsZero() && !now.Before(b.opened.Add(b.policy.Window))) {
		return errors.Join(ErrAttemptOver, err)
	}
	return err
}

func (b *probeWindow) start(ctx context.Context, journal func(context.Context, time.Time) (time.Time, error)) error {
	if !b.policy.Probe {
		return ctx.Err()
	}
	if err := b.result(ctx.Err()); err != nil {
		return err
	}
	if journal == nil {
		return hostwrite.ErrUnavailable
	}
	proposed := b.now()
	opened, err := journal(ctx, proposed)
	if err != nil {
		return err
	}
	if opened.IsZero() || opened.After(proposed) || (!b.opened.IsZero() && !b.opened.Equal(opened)) {
		return hostwrite.ErrUnavailable
	}
	b.opened = opened
	return b.result(ctx.Err())
}