package main

import (
	"context"
	"log"
	"strconv"

	"github.com/kami/maven/internal/ipc"
	"github.com/kami/maven/internal/memory"
	"github.com/kami/maven/internal/phraser"
	"github.com/kami/maven/internal/router"
	"github.com/kami/maven/internal/store"
)

// actionFact handles router.IntentFact: persist a tapped self-fact, index
// it for recall, and let pattern detection propose a routine.
func (h *reactiveHandler) actionFact(ctx context.Context, dec router.Decision) string {
	if !dec.Slots.HasKey {
		return phraser.Ack(phraser.FailFactUnparsed, nil)
	}
	// A question is never a fact about him (#470). "какая последняя версия
	// языка Go?" used to land here, and the value stored was whatever the
	// model invented for it, at confidence 1.00, indexed for recall under the
	// question's own text. Two such rows then claimed seven unrelated world
	// questions through recall and silently disabled world answering.
	//
	// The routing error itself is not fixed here — the answer is to answer.
	// Sending the turn down the query chain is what he asked for anyway, and
	// it costs a mis-routed capture nothing: an explicit "запиши ..." is not
	// question-shaped, so it never takes this branch.
	if router.IsQuestionShaped(dec.Utterance) {
		log.Printf("voice: fact write refused, utterance is a question: %q (key %q) — answering as a query",
			dec.Utterance, dec.Slots.Key)
		q := dec
		q.Intent = router.IntentQuery
		// The key the model extracted is its guess at what to store, not a
		// fact he has. Left in place, queryFactByKey would read it back and
		// claim the turn before any real source ran.
		q.Slots.Key, q.Slots.HasKey = "", false
		q.Slots.Value = ""
		return h.actionQuery(ctx, q)
	}
	// A complaint is not a fact either (#481). "сеть какая-то медленная" and
	// "интернет не работает" were stored as `self` rows at confidence 1.00, and
	// recall reads a self row back later as if it were still true — the same
	// class of row that outranked live search in #470. The sentence describes a
	// moment, so she answers it and stores nothing. An explicit "запомни ..."
	// and anything about him are both left alone by the test.
	if router.IsTransientComplaint(dec.Utterance) {
		log.Printf("voice: fact write refused, utterance is a passing complaint: %q (key %q) — answering as chat",
			dec.Utterance, dec.Slots.Key)
		c := dec
		c.Intent = router.IntentChat
		c.Slots.Key, c.Slots.HasKey = "", false
		c.Slots.Value = ""
		return h.actionChat(ctx, c)
	}
	now := h.now()
	req := ipc.WriteFactReq{
		Ts:     now,
		Kind:   "self",
		Key:    dec.Slots.Key,
		Value:  dec.Slots.Value,
		Source: "tap:voice",
		// Not 1.00 unconditionally any more (#470). A value he said is
		// evidence; a value the model supplied for words he never said is a
		// guess, and writing a guess at full confidence is the same mistake
		// the act path already refuses under "LLM output is not
		// authorization".
		Confidence: factConfidence(dec.Utterance, dec.Slots.Value),
		// Subject: the key doubles as the entity-resolution candidate —
		// a voice-tapped fact's key is usually the thing/person it's
		// about ("espresso_machine", "kate"), so queueing it for Nexus
		// resolution costs one async lookup and is a no-op (not_found)
		// for the abstract self-state keys (mood, water) that aren't
		// entities at all.
		Subject: dec.Slots.Key,
	}
	factID, err := h.api.WriteFact(ctx, req)
	if err != nil {
		log.Printf("voice: write fact: %v", err)
		return phraser.Ack(phraser.FailFact, nil)
	}
	// Index the fact in long-term memory (best-effort, must not fail the fact
	// write). Facts aren't in the notes table, so this is the only recall path
	// for them — "когда я пил воду?" reads back from here.
	//
	// The indexed text is the fact, not the utterance (#493). queryMemory
	// returns a fact's stored text verbatim, so what goes in here is what he
	// hears; storing the utterance meant recall answered with his own sentence
	// rather than the value. The utterance stays alongside as provenance —
	// readable on /trace, never the answer and never embedded.
	//
	// The vector id carries a timestamp, so a second tap of the same key adds a
	// row rather than replacing one, and recall then scores the superseded
	// value against the current one. CorrectValue and VoidLatestFact already
	// drop the key's vectors; an ordinary re-tap is the third way a value is
	// superseded and it did not (#493). Dropping first keeps exactly one vector
	// per key, which is what "recall answers with the current value" means.
	if h.recall.memStore != nil {
		pruneFactVectors(ctx, h.recall.memStore, dec.Slots.Key)
		text := store.FactRecallText(dec.Slots.Key, dec.Slots.Value)
		if vec, err := router.EmbedPassage(ctx, h.recall.embedder, text); err != nil {
			log.Printf("voice: embed fact for memory: %v", err)
		} else if err := h.recall.memStore.Insert(ctx, "fact:"+dec.Slots.Key+":"+strconv.FormatInt(now.Unix(), 10), vec, map[string]string{
			"source":    "voice",
			"type":      "fact",
			"text":      text,
			"utterance": dec.Utterance,
			"ts":        strconv.FormatInt(now.Unix(), 10),
		}); err != nil {
			log.Printf("voice: memory insert fact: %v", err)
		}
	}
	// Event extraction + pattern detection (best-effort, must not fail the
	// fact write). If the fact describes a recognizable action, it becomes a
	// normalized event; if ≥3 events for the same action+object show stable
	// intervals, a proposed routine is created and parked for confirmation.
	if h.dataStore != nil {
		if phrase := h.detectPattern(ctx, factID, dec.Slots.Key, dec.Slots.Value, now); phrase != "" {
			return phrase // "ты заправляешь ... напоминать?"
		}
	}
	return "" // replier phrases the success reply
}

// vectorPruner — the part of the vector index this file needs and memory.Store
// does not carry. store.MemoryStore implements it; the in-memory test double
// may not, and a double that cannot prune is not a reason to fail a fact write.
type vectorPruner interface {
	DeletePrefix(ctx context.Context, prefix string) (int64, error)
}

// pruneFactVectors drops every vector for one fact key, so the insert that
// follows is the only one left. Best-effort and silent on a store that cannot
// prune: the fact row is the truth, and a stale vector costs a wrong recall,
// not a lost fact.
func pruneFactVectors(ctx context.Context, ms memory.Store, key string) {
	p, ok := ms.(vectorPruner)
	if !ok {
		return
	}
	n, err := p.DeletePrefix(ctx, "fact:"+key+":")
	if err != nil {
		log.Printf("voice: prune memory vectors for %q: %v", key, err)
		return
	}
	if n > 0 {
		log.Printf("voice: %q superseded, dropped %d stale memory vector(s)", key, n)
	}
}