package observation

import (
	"testing"

	"gitea.maximumdirect.net/eric/promptkit/internal/domain"
)

func TestUsageAccumulatorPreservesPresenceAndNoAttemptSemantics(t *testing.T) {
	var empty UsageAccumulator
	zero := empty.Observed()
	if !zero.PromptTokens.Known || !zero.PromptTokens.Complete || zero.PromptTokens.Value != 0 ||
		!zero.CacheWriteTokens.Known || !zero.CacheWriteTokens.Complete || zero.CacheWriteTokens.Value != 0 {
		t.Fatalf("zero-attempt usage = %+v", zero)
	}

	var usage UsageAccumulator
	usage.Add(domain.TokenUsage{PromptTokens: 0}, &domain.TokenUsagePresence{PromptTokens: true})
	usage.Add(domain.TokenUsage{PromptTokens: 3}, &domain.TokenUsagePresence{PromptTokens: true})
	observed := usage.Observed()
	if observed.PromptTokens.Value != 3 || !observed.PromptTokens.Known || !observed.PromptTokens.Complete {
		t.Fatalf("reported prompt usage = %+v", observed.PromptTokens)
	}
	if observed.CompletionTokens.Known || observed.CompletionTokens.Complete {
		t.Fatalf("unreported completion usage = %+v", observed.CompletionTokens)
	}
}