package phraser

import (
	"context"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
)

// A dead server must be distinguishable from bad phrasing. Both PhraseChat and
// PhraseQuery keep the turn alive with canned text — ChatFallback, "не знаю.",
// "вот что я нашла: …" — and every one of those is also a legitimate reply, so
// the text alone cannot say which happened. The error is the only signal, and
// before Vikunja #397 it was dropped: the talk scorer reported a full run with
// zero errors off a server that answered nothing.
func TestPhrasingReportsTheFailureWithTheFallback(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Error(w, "model not loaded", http.StatusServiceUnavailable)
	}))
	t.Cleanup(srv.Close)
	p := NewLLMPhraserAt(srv.URL, Config{})

	cases := []struct {
		name string
		call func() (string, error)
		want string
	}{
		{"chat", func() (string, error) {
			return p.PhraseChat(context.Background(), "как дела", nil)
		}, ChatFallback},
		{"knowledge", func() (string, error) {
			return p.PhraseQuery(context.Background(), "кто написал войну и мир", nil)
		}, "не знаю."},
		{"evidence", func() (string, error) {
			return p.PhraseQuery(context.Background(), "сколько воды я выпил", []string{"два литра"})
		}, "вот что я нашла: два литра"},
	}
	for _, c := range cases {
		t.Run(c.name, func(t *testing.T) {
			got, err := c.call()
			if err == nil {
				t.Fatalf("no error from a dead server; the scorer would count this as bad phrasing")
			}
			if got != c.want {
				t.Errorf("fallback text = %q, want %q — the daemon still has to say something", got, c.want)
			}
		})
	}
}

// An empty answer is a failure too: the server is up and produced no tokens,
// which is not an answer and must not score as one.
func TestEmptyKnowledgeAnswerIsAnError(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"choices":[{"message":{"content":""}}]}`))
	}))
	t.Cleanup(srv.Close)
	p := NewLLMPhraserAt(srv.URL, Config{})

	got, err := p.PhraseQuery(context.Background(), "кто написал войну и мир", nil)
	if err == nil {
		t.Fatal("an empty response scored as an answer")
	}
	if got != "не знаю." {
		t.Errorf("fallback text = %q, want \"не знаю.\"", got)
	}
	if !strings.Contains(err.Error(), "empty") {
		t.Errorf("error = %v; want it to name the empty response", err)
	}
}