package main

import (
	"context"
	"errors"
	"log"

	"github.com/kami/maven/internal/phraser"
)

// worldPhraser — the naming half of the degradation rule (docs/offload.md), as
// the query sources see it. Only *phraser.LLMPhraser implements it, so the
// Stub and every test double stay exactly as they are.
type worldPhraser interface {
	PhraseWorld(ctx context.Context, utterance string, sources []string) (string, error)
}

// worldGap — what he hears when the question is about the world, the workstation
// model is the one configured to answer it, and that machine is not answering.
//
// It says the true thing. The resident 1.7B is not a worse answer here, it is an
// invented one: "Война и мир" came back with Левитан as its author, and a
// question about his meeting came back as a swimming competition in Nottingham.
// Naming the gap is the rule CLAUDE.md already applies to a sibling service
// being down.
//
// The wording lives in fallbacks_ru_v1.json and is fixed there, not picked from
// variants: this sentence names one specific gap and must not drift into a
// general "I don't know".
func worldGap() string { return phraser.WorldGap() }

// phraseWorld asks the world model, or reports the gap.
//
// The three outcomes come straight from LLMPhraser.PhraseWorld: no workstation
// configured means the resident model answers as it always has, a workstation
// that is up answers, and a workstation that is down returns
// phraser.ErrNoWorldModel. A phraser that has no world seam at all — the Stub,
// and the doubles in the tests — is the first of those three.
func (h *reactiveHandler) phraseWorld(ctx context.Context, utterance string, sources []string) (string, error) {
	if h.phraser == nil {
		return "", phraser.ErrNoWorldModel
	}
	if w, ok := h.phraser.(worldPhraser); ok {
		return w.PhraseWorld(ctx, utterance, sources)
	}
	return h.phraser.PhraseQuery(ctx, utterance, sources)
}

// phraseSource asks the world model to answer from a passage someone already
// fetched — a live search result, a ZIM article, a page he named. It returns ""
// rather than the gap phrase, because these callers hold something better than a
// gap: the passage itself, which their own floor reads back to him. Nothing is
// invented either way, and a real quote beats "не могу сейчас".
func (h *reactiveHandler) phraseSource(ctx context.Context, name, utterance string, sources []string) string {
	reply, err := h.phraseWorld(ctx, utterance, sources)
	switch {
	case errors.Is(err, phraser.ErrNoWorldModel):
		log.Printf("voice: %s: no world model, reading the source back instead", name)
		return ""
	case err != nil:
		// The resident phraser answers this call with its fallback text and the
		// error together. Drop the text: these callers hold the passage itself
		// and read it back better than "вот что я нашла: <passage>" does.
		log.Printf("voice: %s: phrase: %v", name, err)
		return ""
	}
	return reply
}