import { regexTag, RULES } from './rules'
import type { Tag } from './tags'
import type { Pad } from './types'

export const clamp = (x: number, lo = -1, hi = 1) => Math.max(lo, Math.min(hi, x))

const HOUR = 3_600_000
const MOOD_HALF_LIFE_H = 8

// 高神經質的角色情緒消退較慢：50 為基準，0→0.5 倍，100→1.5 倍
export const halfLife = (neuroticism: number) => MOOD_HALF_LIFE_H * HOUR * (0.5 + neuroticism / 100)

// 讀檔時才計算：x = B + (x − B)·0.5^(Δ/τ)
export function decay(mood: Pad, baseline: Pad, elapsedMs: number, neuroticism: number): Pad {
  if (elapsedMs <= 0) return { p: mood.p, a: mood.a, d: mood.d }
  const k = Math.pow(0.5, elapsedMs / halfLife(neuroticism))
  return {
    p: baseline.p + (mood.p - baseline.p) * k,
    a: baseline.a + (mood.a - baseline.a) * k,
    d: baseline.d + (mood.d - baseline.d) * k,
  }
}

// 單軸每回合變化上限 ±0.3
export const TURN_CAP = 0.3

export function applyDelta(mood: Pad, delta: Pad): Pad {
  const step = (x: number, dx: number) => clamp(x + clamp(dx, -TURN_CAP, TURN_CAP))
  return { p: step(mood.p, delta.p), a: step(mood.a, delta.a), d: step(mood.d, delta.d) }
}

// 心情事件即評估標籤，增減量由 rules.ts 的規則表決定
export const MOOD_EVENTS = RULES
export type MoodEvent = Tag

// 八分區（Mehrabian 的 PAD 八分類）→ 情緒標籤與顏文字
const OCTANTS: Record<string, { label: string; kaomoji: string }> = {
  '+++': { label: '興奮', kaomoji: '(≧▽≦)' },
  '++-': { label: '撒嬌', kaomoji: '(๑>ᴗ<๑)' },
  '+-+': { label: '放鬆', kaomoji: '(´ᴗ`)' },
  '+--': { label: '溫順', kaomoji: '(︶ᴗ︶)' },
  '---': { label: '無聊', kaomoji: '(－_－)' },
  '--+': { label: '不屑', kaomoji: '(￢_￢)' },
  '-++': { label: '生氣', kaomoji: '(╬`益´)' },
  '-+-': { label: '焦慮', kaomoji: '(；´Д`)' },
}
const CALM = { label: '平靜', kaomoji: '(・ω・)' }
const CALM_RADIUS = 0.1

export function moodLabel(m: Pad): { label: string; kaomoji: string } {
  if (Math.abs(m.p) < CALM_RADIUS && Math.abs(m.a) < CALM_RADIUS && Math.abs(m.d) < CALM_RADIUS) return CALM
  const s = (x: number) => (x >= 0 ? '+' : '-')
  return OCTANTS[s(m.p) + s(m.a) + s(m.d)]!
}

/** 以使用者文字的關鍵字對應心情事件 */
export const keywordEvent = (text: string): MoodEvent | null => regexTag(text)