package router

import "strings"

// interrogatives — the question words that mark an utterance as asking rather
// than telling. Tokenized, never substring: "что" inside "чтобы" and "как"
// inside "какао" are not questions.
var interrogatives = []string{
	"что", "чего", "какой", "какая", "какое", "какие", "каких",
	"кто", "кого", "кому", "чей", "почему", "зачем", "отчего",
	"где", "куда", "откуда", "когда", "сколько", "как",
	"what", "who", "whom", "why", "when", "where", "which", "how",
}

// narrativeRequests — "tell me about X" asks for knowledge Maven does not
// hold about him. It carries no question mark and no interrogative, which is
// how "расскажи про битву при Ватерлоо" reached the fact store (#470).
var narrativeRequests = []string{
	"расскажи", "объясни", "опиши", "перечисли",
	"tell", "explain", "describe",
}

// captureVerbs — an explicit instruction to record something. These win over
// every test below, because "запиши что я пил воду" contains an interrogative
// and is still a capture: the word he said is "запиши".
var captureVerbs = []string{
	"запиши", "запомни", "отметь", "заметь", "добавь", "сохрани",
	"note", "remember", "log", "save",
}

// IsQuestionShaped reports whether text asks for something rather than
// records it. It is a deterministic offline test over tokens, so it costs
// nothing and never depends on the model that produced the routing decision.
//
// It exists because a mis-routed question used to be persisted as a fact
// about the owner, with the model's invented answer as the value (#470). The
// predicate is deliberately blunt: refusing to store a question is cheap and
// reversible, storing an invented fact about him is neither.
func IsQuestionShaped(text string) bool {
	t := strings.TrimSpace(text)
	if t == "" {
		return false
	}
	toks := planTokens(t)
	for _, v := range captureVerbs {
		if hasTok(toks, v) {
			return false
		}
	}
	if strings.HasSuffix(t, "?") {
		return true
	}
	for _, w := range interrogatives {
		if hasTok(toks, w) {
			return true
		}
	}
	for _, w := range narrativeRequests {
		if hasTok(toks, w) {
			return true
		}
	}
	return false
}