package buildstep

import (
	"encoding/json"
	"sync"
	"testing"
	"time"

	"git.novox.be/novox/mesh-sdk/go/delivery"
)

// keys is a steps state in memory: every value put, in order, per key, and a signal for each end.
type keys struct {
	mu    sync.Mutex
	puts  map[string][]delivery.Step
	ended chan string
}

func newKeys() *keys { return &keys{puts: map[string][]delivery.Step{}, ended: make(chan string, 16)} }

func (k *keys) put(key string, value any) (uint64, error) {
	step, err := delivery.DecodeStep(value.(json.RawMessage))
	if err != nil {
		return 0, err
	}
	k.mu.Lock()
	k.puts[key] = append(k.puts[key], step)
	n := uint64(len(k.puts[key]))
	k.mu.Unlock()
	if step.State != delivery.StepRunning {
		k.ended <- key
	}
	return n, nil
}

func (k *keys) last(key string) delivery.Step {
	k.mu.Lock()
	defer k.mu.Unlock()
	s := k.puts[key]
	return s[len(s)-1]
}

func (k *keys) waitEnd(t *testing.T) string {
	t.Helper()
	select {
	case key := <-k.ended:
		return key
	case <-time.After(3 * time.Second):
		t.Fatal("the step never ended on its key")
		return ""
	}
}

// 1471/AC5: ids made in one and the same millisecond differ, and each is one key token. The clock is fixed
// while no step runs, so no goroutine reads it meanwhile.
func TestTwoIDsInOneMillisecondDiffer(t *testing.T) {
	was := now
	defer func() { now = was }()
	at := time.Date(2026, 10, 20, 12, 0, 0, 0, time.UTC)
	now = func() time.Time { return at }
	seen := map[string]bool{}
	for i := 0; i < 50; i++ {
		id := NewID()
		if seen[id] {
			t.Fatalf("id %q handed out twice", id)
		}
		seen[id] = true
		if _, err := delivery.StepKey("ace", id); err != nil {
			t.Errorf("id %q: %v", id, err)
		}
	}
}