package emotion

import "strings"

// Reaction is one turn's emotional reading of the user's message (design/01 §2:
// the persona config carries the emotion state-machine parameters and the
// affection curve; the machine itself only knows states and legal moves).
//
// design/01 fixes the model (states + transitions + decay + affection curve) but
// does not enumerate the trigger vocabulary, so the minimal reading implemented
// here is: a clearly angry turn, a clearly down turn, a strongly positive turn
// and a mildly positive turn, each moving the matching state and stepping the
// affection curve once. A turn with no cue carries no signal, which leaves the
// emotion to decay toward calm instead of jumping (see Observer.Observe).
type Reaction struct {
	// State is the emotion state this turn moves the machine toward. It is a
	// target, not a forced value: the machine walks its configured transition
	// table toward it (Machine.Move), so a persona's own table always wins.
	State EmotionState
	// AffectionDelta is the signed number of affection *steps* for this turn
	// (+1 warm, -1 cold, 0 neutral). The concrete magnitude is the persona's
	// configured affection curve step, applied by the caller.
	AffectionDelta int
	// Signal reports whether the turn carried any emotional cue at all.
	Signal bool
}

// React classifies one user turn into the persona's emotional response. Anger
// and negative cues win over positive ones, so a mixed message ("不开心" also
// contains "开心") never reads as positive.
func React(text string) Reaction {
	t := strings.ToLower(text)
	switch {
	case t == "":
		return Reaction{}
	case containsCue(t, angerCues()):
		return Reaction{State: Angry, AffectionDelta: affectionDown, Signal: true}
	case containsCue(t, negativeCues()):
		return Reaction{State: Sad, AffectionDelta: affectionDown, Signal: true}
	case containsCue(t, strongPositiveCues()):
		return Reaction{State: Excited, AffectionDelta: affectionUp, Signal: true}
	case containsCue(t, positiveCues()):
		return Reaction{State: Happy, AffectionDelta: affectionUp, Signal: true}
	default:
		return Reaction{}
	}
}

// Affection step signs. The magnitude comes from the persona's own curve.
const (
	affectionUp   = 1
	affectionDown = -1
)

// containsCue reports whether text contains any of the cues.
func containsCue(text string, cues []string) bool {
	for _, c := range cues {
		if strings.Contains(text, c) {
			return true
		}
	}
	return false
}

// angerCues are the protest/hostility cues that move the persona to angry. They
// are checked first so an angry turn is never read as merely sad or happy.
func angerCues() []string {
	return []string{
		"讨厌你", "烦你", "恨你", "别烦", "好烦", "烦死", "烦人", "生气", "气死", "气愤",
		"滚开", "走开", "闭嘴", "不理你", "分手", "凶我", "骂你",
		"angry", "annoying", "annoyed", "shut up", "hate you", "mad at",
	}
}

// negativeCues are the down/low cues that move the persona to sad — including
// tiredness, which in the five built-in states reads as the gentle/caring lane.
func negativeCues() []string {
	return []string{
		"不开心", "很难过", "难过", "伤心", "委屈", "失望", "沮丧", "郁闷", "崩溃", "心累",
		"累了", "好累", "疲惫", "困了", "想哭", "呜呜", "555", "糟糕", "焦虑", "孤独",
		"孤单", "寂寞", "失眠", "睡不着", "被冷落",
		"sad", "tired", "upset", "exhausted", "lonely", "depressed", "feel bad",
	}
}

// strongPositiveCues are the high-arousal warm cues that move the persona to
// excited (a stronger state than happy).
func strongPositiveCues() []string {
	return []string{
		"太开心", "好开心", "最喜欢", "太喜欢", "爱死", "太棒", "好耶", "好激动",
		"兴奋", "幸福死了", "amazing", "awesome", "so happy", "love you",
	}
}

// positiveCues are the everyday warm cues that move the persona to happy.
func positiveCues() []string {
	return []string{
		"开心", "高兴", "喜欢", "爱你", "想你", "抱抱", "么么", "亲亲", "摸摸", "谢谢",
		"辛苦", "哈哈", "嘿嘿", "嘻嘻", "真好", "厉害", "好棒", "期待", "满足", "幸福",
		"好呀", "好哒", "早安", "早上好", "中午好", "下午好", "晚上好", "晚安",
		"nice", "great", "thanks", "thank you", "haha", "hug", "miss you",
		"good morning", "good night", "good evening",
	}
}