package main

import (
	"context"
	"strings"
	"testing"
	"time"

	"github.com/kami/maven/internal/ipc"
	"github.com/kami/maven/internal/router"
)

// historyAPI serves a fixed set of recent facts.
type historyAPI struct {
	ipc.UnimplementedCoreAPI
	facts []ipc.Fact
	calls int
}

func (a *historyAPI) RecentFacts(context.Context, int) ([]ipc.Fact, error) {
	a.calls++
	return a.facts, nil
}

func historyHandler(now time.Time, facts ...ipc.Fact) (*reactiveHandler, *historyAPI) {
	api := &historyAPI{facts: facts}
	return &reactiveHandler{api: api, now: func() time.Time { return now }}, api
}

func askHistory(h *reactiveHandler, u string) (string, bool) {
	return h.queryHistory(context.Background(), &queryTurn{
		dec: router.Decision{Intent: router.IntentQuery, Utterance: u},
	})
}

func TestIsHistoryQuery(t *testing.T) {
	for _, tc := range []struct {
		text string
		want bool
	}{
		{"что я тебе говорил?", true},
		{"что ты записала сегодня?", true},
		{"что я отмечал?", true},
		// Forms the truncated prefixes did not reach. The dictionary answers
		// these because it lemmatises both sides (V-530).
		{"что я тебе рассказывал?", true},
		{"что я сказала вчера", true},
		{"что ты запомнила?", true},
		// The noun, not the verb. "рассказ" was a prefix of the old pair, so
		// this read as a history question — the same defect V-528 fixed in
		// complaint.go, where "лаг" matched "лагерь".
		{"что я читал рассказ", false},
		// A verb of saying with nobody saying it.
		{"что записать?", false},
		// A named topic is a recall question, and the notes pass answers it
		// better than a list of the last five facts does.
		{"что я говорил про сервер?", false},
		{"что у меня сегодня?", false},
		{"", false},
	} {
		if got := isHistoryQuery(tc.text); got != tc.want {
			t.Errorf("isHistoryQuery(%q) = %v, want %v", tc.text, got, tc.want)
		}
	}
}

func TestHistoryReadsOnlyWhatHeSaid(t *testing.T) {
	now := time.Date(2026, 8, 4, 20, 0, 0, 0, time.UTC)
	h, api := historyHandler(now,
		ipc.Fact{Key: "water", Value: "выпил", Source: "tap:voice", Ts: now.Add(-time.Hour)},
		// Learned, not said: a poller writing this back under "что я тебе
		// говорил?" would put words in his mouth.
		ipc.Fact{Key: "spent_today", Value: "1200", Source: "poll:zenmoney", Ts: now.Add(-time.Hour)},
		// Older than the window.
		ipc.Fact{Key: "shower", Value: "принял", Source: "tap:voice", Ts: now.Add(-30 * time.Hour)},
	)
	reply, ok := askHistory(h, "что я тебе говорил?")
	if !ok {
		t.Fatal("the history question must be claimed before the recall sources")
	}
	if !strings.Contains(reply, "water") {
		t.Errorf("reply = %q, want the fact he tapped in", reply)
	}
	if strings.Contains(reply, "spent_today") || strings.Contains(reply, "shower") {
		t.Errorf("reply = %q, want only what he said inside the window", reply)
	}
	if api.calls != 1 {
		t.Errorf("RecentFacts called %d times, want 1", api.calls)
	}
}

// The rows are the same either way, because a tapped fact is one act seen from
// two sides. The sentence is not: "что ты записала" answered with "ты говорил"
// hands the question back (Vikunja #456).
func TestHistoryAnswersTheSideItWasAsked(t *testing.T) {
	now := time.Date(2026, 8, 4, 20, 0, 0, 0, time.UTC)
	h, _ := historyHandler(now, ipc.Fact{Key: "water", Value: "выпил", Source: "tap:voice", Ts: now.Add(-time.Hour)})

	his, ok := askHistory(h, "что я тебе говорил?")
	if !ok || !strings.HasPrefix(his, "ты говорил") {
		t.Errorf("reply = %q, ok = %v, want his side", his, ok)
	}
	hers, ok := askHistory(h, "что ты записала сегодня?")
	if !ok || !strings.HasPrefix(hers, "я записала") {
		t.Errorf("reply = %q, ok = %v, want her side", hers, ok)
	}
	// "отмечать" is on both verb lists, so his subject has to win.
	if side, ok := historyAsks("что я отметил?"); !ok || side != historyAskedHim {
		t.Errorf("historyAsks(что я отметил) = %v, %v", side, ok)
	}

	empty, _ := historyHandler(now)
	none, ok := askHistory(empty, "что ты записала сегодня?")
	if !ok || !strings.Contains(none, "не записывала") {
		t.Errorf("empty reply = %q, ok = %v, want her side", none, ok)
	}
}

// Nothing said is an answer of its own. Falling through would hand the question
// to recall, which answers it with an old note.
func TestHistorySaysWhenThereIsNothing(t *testing.T) {
	now := time.Date(2026, 8, 4, 20, 0, 0, 0, time.UTC)
	h, _ := historyHandler(now)
	reply, ok := askHistory(h, "что я тебе говорил?")
	if !ok || !strings.Contains(reply, "ничего") {
		t.Fatalf("reply = %q, ok = %v", reply, ok)
	}
}

// Five is what fits in one spoken breath; the rest are on /history.
func TestHistoryStopsAtFive(t *testing.T) {
	now := time.Date(2026, 8, 4, 20, 0, 0, 0, time.UTC)
	var facts []ipc.Fact
	for i := 0; i < 12; i++ {
		facts = append(facts, ipc.Fact{Key: "k", Value: "v", Source: "tap:voice", Ts: now.Add(-time.Minute)})
	}
	h, _ := historyHandler(now, facts...)
	reply, _ := askHistory(h, "что ты записала?")
	if got := strings.Count(reply, ";"); got != historyReadOut-1 {
		t.Fatalf("reply = %q has %d separators, want %d", reply, got, historyReadOut-1)
	}
}