package router

import "strings"

// Money questions, matched deterministically (Vikunja #125).
//
// No new intent, for the same reason as tasks: the intent enum is a contract
// with the relabelling prompt. "сколько я потратил?" is a query; which figure
// it asks for is a lookup, not something to ask a 1.7B — and a model asked to
// invent a spending total will happily do it.

// MoneyWindow — which period a money question asks about.
type MoneyWindow int

const (
	MoneyNone MoneyWindow = iota
	MoneyToday
	MoneyMonth
	// MoneyUnsupported — a money question over a window nothing is stored for
	// ("вчера", "на прошлой неделе"). Claimed, not answered: the poller keeps
	// today and the month, and answering a question about yesterday with the
	// month-to-date total is worse than saying she does not keep it.
	MoneyUnsupported
)

// MoneyQuery — a parsed money question. Income is set when he asked what he
// EARNED rather than what he spent; the two read the same fact and differ only
// in which half of it leads the answer.
type MoneyQuery struct {
	Window MoneyWindow
	Income bool
}

// incomeNouns — the words that make a money question be about income.
var incomeNouns = []string{"заработал", "заработала", "получил", "доход", "доходы", "earned", "income"}

// moneyNouns — the words that make a question be about his money.
var moneyNouns = []string{
	"потратил", "потратила", "тратил", "траты", "трат", "расходы", "расходов",
	"заработал", "заработала", "доход", "доходы", "потрачено", "денег",
	"spend", "spent", "expenses", "earned", "income",
}

// ParseMoneyQuery reports whether an utterance asks about spending or income,
// and over which window. Defaults to the month: "сколько я потратил?" without a
// period is the month-to-date question, which is the one worth answering.
//
// Narrow on purpose. A money noun alone is not enough — "я потратил весь день
// на это" is him talking about his day, so an amount word or an explicit
// question word has to be there too. The two evidence halves are INDEPENDENT:
// "траты" and "расходы" used to sit in both lists, so either word alone
// satisfied the whole gate and "у меня в этом месяце большие траты", a
// statement, came back with a figure.
func ParseMoneyQuery(text string) (MoneyQuery, bool) {
	toks := planTokens(text)
	if len(toks) == 0 {
		return MoneyQuery{}, false
	}
	hasNoun := false
	for _, t := range toks {
		for _, n := range moneyNouns {
			if t == n {
				hasNoun = true
			}
		}
	}
	if !hasNoun {
		return MoneyQuery{}, false
	}
	// "весь день", "время", "силы" — spending that is not money.
	for _, t := range toks {
		switch t {
		case "день", "дня", "время", "времени", "силы", "сил", "нервы":
			return MoneyQuery{}, false
		}
	}
	asking := hasTok(toks, "сколько") || hasTok(toks, "какие") || hasTok(toks, "покажи") ||
		hasTok(toks, "how") || hasTok(toks, "much") || hasTok(toks, "my") ||
		hasTok(toks, "мои")
	if !asking {
		return MoneyQuery{}, false
	}
	income := false
	for _, t := range toks {
		for _, n := range incomeNouns {
			if t == n {
				income = true
			}
		}
	}
	lower := strings.ToLower(text)
	switch {
	// Windows nothing is stored for, named explicitly so they are refused
	// rather than silently answered with the month.
	case hasTok(toks, "вчера") || hasTok(toks, "позавчера") || strings.Contains(lower, "yesterday"),
		hasTok(toks, "неделю") || hasTok(toks, "неделе") || hasTok(toks, "неделя") ||
			strings.Contains(lower, "week"),
		hasTok(toks, "год") || hasTok(toks, "году") || strings.Contains(lower, "year"):
		return MoneyQuery{Window: MoneyUnsupported, Income: income}, true
	case hasTok(toks, "сегодня") || strings.Contains(lower, "today"):
		return MoneyQuery{Window: MoneyToday, Income: income}, true
	}
	return MoneyQuery{Window: MoneyMonth, Income: income}, true
}