import { clamp } from './types.ts'
import type { Pad } from './types.ts'

export const TURN_CAP = 0.3

export const EVENTS = {
  praise: { p: 0.15, a: 0.05, d: 0.05 },
  scold: { p: -0.2, a: 0.15, d: -0.1 },
  success: { p: 0.08, a: 0.03, d: 0.05 },
  toolFailures: { p: -0.08, a: 0.1, d: -0.08 },
  returnAfterIdle: { p: 0.1, a: 0.08, d: 0 },
  lateNight: { p: -0.05, a: -0.1, d: 0 },
  likedTopic: { p: 0.12, a: 0.08, d: 0.03 },
  careIgnored: { p: -0.05, a: -0.03, d: -0.03 },
} as const satisfies Record<string, Pad>

export type MoodEvent = keyof typeof EVENTS

export const ZERO: Pad = { p: 0, a: 0, d: 0 }

/** 一回合內累計的變化量；單軸總變化不得超過 ±0.3 */
export function applyDelta(mood: Pad, turn: Pad, delta: Pad): { mood: Pad; turn: Pad } {
  const out = { mood: { ...mood }, turn: { ...turn } }
  for (const k of ['p', 'a', 'd'] as const) {
    const next = clamp(turn[k] + delta[k], -TURN_CAP, TURN_CAP)
    const step = next - turn[k]
    out.turn[k] = next
    out.mood[k] = clamp(mood[k] + step, -1, 1)
  }
  return out
}

/** 讀取時依經過時間往基線衰減：x = B + (x − B)·0.5^(Δ/τ) */
export function decay(mood: Pad, baseline: Pad, elapsedMs: number, halfLifeMs: number): Pad {
  const f = Math.pow(0.5, Math.max(0, elapsedMs) / halfLifeMs)
  return {
    p: baseline.p + (mood.p - baseline.p) * f,
    a: baseline.a + (mood.a - baseline.a) * f,
    d: baseline.d + (mood.d - baseline.d) * f,
  }
}

const MOODS: Record<string, { label: string; face: string }> = {
  '+++': { label: '開心', face: '(≧▽≦)' },
  '++-': { label: '安心', face: '(´▽`)' },
  '+-+': { label: '放鬆', face: '(´ω`)' },
  '+--': { label: '溫柔', face: '(｡･ω･｡)' },
  '-++': { label: '生氣', face: '(`Д´)' },
  '-+-': { label: '焦慮', face: '(；´Д`)' },
  '--+': { label: '無聊', face: '(¬_¬)' },
  '---': { label: '低落', face: '(´;ω;`)' },
}

/** 八分區對應情緒標籤與顏文字 */
export function moodLabel(m: Pad): { label: string; face: string } {
  const s = (x: number) => (x >= 0 ? '+' : '-')
  return MOODS[s(m.p) + s(m.a) + s(m.d)]!
}

// 心情標記：回覆末尾的隱藏標記，如 <!--mood p=0.1 a=-0.05 d=0-->
const TAG = /<!--\s*mood\b([^>]*?)-->\s*$/

export type ParsedReply = { text: string; delta: Pad | null }

export function parseMoodTag(reply: string): ParsedReply {
  const m = TAG.exec(reply)
  if (!m) return { text: stripStray(reply), delta: null }
  const text = stripStray(reply.slice(0, m.index).trimEnd())
  const vals: Partial<Pad> = {}
  for (const kv of (m[1] ?? '').trim().split(/\s+/)) {
    const mm = /^([pad])=(-?\d+(?:\.\d+)?)$/.exec(kv)
    if (mm) vals[mm[1] as keyof Pad] = Number(mm[2])
  }
  if (vals.p === undefined || vals.a === undefined || vals.d === undefined) return { text, delta: null }
  return { text, delta: { p: vals.p, a: vals.a, d: vals.d } }
}

// 格式錯誤的標記也不能露給使用者
function stripStray(s: string): string {
  return s.replace(/\s*<!--\s*mood\b[^>]*?(?:-->|$)/g, '').trimEnd()
}

const KEYWORDS: [MoodEvent, RegExp][] = [
  ['scold', /笨|白痴|廢物|爛|你很煩|閉嘴|stupid|useless|idiot/i],
  ['praise', /謝謝|感謝|太棒|好棒|厲害|讚|thanks?|thank you|great job|awesome/i],
  ['success', /成功|完成了|通過|搞定|passed|done|fixed/i],
]

/** 標記缺失或格式錯誤時的後備：用使用者文字的關鍵字對應事件 */
export function keywordEvent(text: string): MoodEvent | null {
  for (const [ev, re] of KEYWORDS) if (re.test(text)) return ev
  return null
}