package main

import (
	"context"
	"testing"

	"github.com/kami/maven/internal/decision"
	"github.com/kami/maven/internal/store"
)

// A real turn leaves a persisted trace, not only a ring entry. This is the whole
// of V-629: without one there is nothing to fit the routing heads from.
func TestTurnPersistsTrace(t *testing.T) {
	ring := decision.NewRing()
	h := traceHandler(t, ring)
	h.traces = traceSink(h.dataStore)
	h.encoderID = "hash-1024"

	if reply := h.handleText(context.Background(), "web", "сколько сейчас времени"); reply == "" {
		t.Fatal("turn produced no reply")
	}
	got, err := h.dataStore.RecentRoutingTraces(context.Background(), 5)
	if err != nil {
		t.Fatal(err)
	}
	if len(got) != 1 {
		t.Fatalf("persisted %d traces, want 1", len(got))
	}
	tr := got[0]
	if tr.Utterance != "сколько сейчас времени" {
		t.Errorf("utterance %q", tr.Utterance)
	}
	if tr.Source != string(sourceText) {
		t.Errorf("source %q, want %q", tr.Source, sourceText)
	}
	// A stage-0 clock rule answers this one, so the turn teaches the classifier
	// nothing and the trace has to say so.
	if !tr.ClaimedBeforeHead {
		t.Errorf("claimed_before_head false on winner %q", tr.Winner)
	}
	if tr.EncoderID != "hash-1024" {
		t.Errorf("encoder_id %q", tr.EncoderID)
	}
	if len(tr.Claims) < 3 {
		t.Errorf("claims %s: the losers and the never-asked are the point", tr.Claims)
	}
}

// No store, no trace, and no panic. A typed nil pointer in the interface would
// pass the nil check and die on the first turn.
func TestNoStoreNoTrace(t *testing.T) {
	ring := decision.NewRing()
	h := traceHandler(t, ring)
	h.traces = traceSink(nil)

	if reply := h.handleText(context.Background(), "web", "сколько сейчас времени"); reply == "" {
		t.Fatal("turn produced no reply")
	}
	if len(ring.Recent(5)) != 1 {
		t.Error("the ring is still the first sink and must still hold the turn")
	}
}

// An empty utterance writes nothing. A blank row carries no label and no
// diagnosis, and it is his words the retention bound exists for.
func TestEmptyUtteranceIsNotPersisted(t *testing.T) {
	h := traceHandler(t, decision.NewRing())
	h.traces = traceSink(h.dataStore)
	h.persistDecision(context.Background(), &decision.Record{Utterance: "  "}, sourceText)
	got, err := h.dataStore.RecentRoutingTraces(context.Background(), 5)
	if err != nil {
		t.Fatal(err)
	}
	if len(got) != 0 {
		t.Fatalf("persisted %d traces for a blank utterance", len(got))
	}
}

var _ traceWriter = (*store.Store)(nil)