// Deterministic parts — derived from hash(userId)export type CompanionBones = {
  rarity: Rarity
  species: Species
  eye: Eye
  hat: Hat
  shiny: boolean
  stats: Record<StatName, number>}// Model-generated soul — stored in config after first hatchexport type CompanionSoul = {
  name: string
  personality: string}export type Companion = CompanionBones &
  CompanionSoul & {
    hatchedAt: number}// What actually persists in config. Bones are regenerated from hash(userId)// on every read so species renames don't break stored companions and users// can't edit their way to a legendary.export type StoredCompanion = CompanionSoul & { hatchedAt: number }

export function getCompanion(): Companion | undefined {const stored = getGlobalConfig().companion
  if (!stored) return undefinedconst { bones } = roll(companionUserId())return { ...stored, ...bones }}

function mulberry32(seed: number): () => number {let a = seed >>> 0return function () {
    a |= 0
    a = (a + 0x6d2b79f5) | 0let t = Math.imul(a ^ (a >>> 15), 1 | a)
    t = (t + Math.imul(t ^ (t >>> 7), 61 | t)) ^ t
    return ((t ^ (t >>> 14)) >>> 0) / 4294967296}}

function rollFrom(rng: () => number): Roll {const rarity = rollRarity(rng)const bones: CompanionBones = {
    rarity,
    species: pick(rng, SPECIES),
    eye: pick(rng, EYES),
    hat: rarity === 'common' ? 'none' : pick(rng, HATS),
    shiny: rng() < 0.01,
    stats: rollStats(rng, rarity),}return { bones, inspirationSeed: Math.floor(rng() * 1e9) }}

const SALT = 'friend-2026-401'// Called from three hot paths (500ms sprite tick, per-keystroke PromptInput,// per-turn observer) with the same userId → cache the deterministic result.let rollCache: { key: string; value: Roll } | undefinedexport function roll(userId: string): Roll {const key = userId + SALTif (rollCache?.key === key) return rollCache.value
  const value = rollFrom(mulberry32(hashString(key)))
  rollCache = { key, value }return value
}

export function companionIntroText(name: string, species: string): string {return `# Companion
A small ${species} named ${name} sits beside the user's input box and occasionally comments in a speech bubble. You're not ${name} — it's a separate watcher.
When the user addresses ${name} directly (by name), its bubble will answer. Your job in that moment is to stay out of the way: respond in ONE line or less, or just answer any part of the message meant for you. Don't explain that you're not ${name} — they know. Don't narrate what ${name} might say — the bubble handles that.`}

export function getCompanionIntroAttachment(
  messages: Message[] | undefined,): Attachment[] {if (!feature('BUDDY')) return []const companion = getCompanion()if (!companion || getGlobalConfig().companionMuted) return []for (const msg of messages ?? []) {if (msg.type !== 'attachment') continueif (msg.attachment.type !== 'companion_intro') continueif (msg.attachment.name === companion.name) return []}return [{
      type: 'companion_intro',
      name: companion.name,
      species: companion.species,},]}

const TICK_MS = 500;const BUBBLE_SHOW = 20; // ticks → ~10s at 500msconst FADE_WINDOW = 6; // last ~3s the bubble dims so you know it's about to goconst PET_BURST_MS = 2500; // how long hearts float after /buddy petconst IDLE_SEQUENCE = [0, 0, 0, 0, 1, 0, 0, 0, -1, 0, 0, 2, 0, 0, 0];

if (reaction || petting) {
  spriteFrame = tick % frameCount;} else {const step = IDLE_SEQUENCE[tick % IDLE_SEQUENCE.length]!;if (step === -1) {
    spriteFrame = 0;
    blink = true;} else {
    spriteFrame = step % frameCount;}}const body = renderSprite(companion, spriteFrame).map(line =>
  blink ? line.replaceAll(companion.eye, '-') : line
)

export function companionReservedColumns(terminalColumns: number, speaking: boolean): number {if (!feature('BUDDY')) return 0;const companion = getCompanion();if (!companion || getGlobalConfig().companionMuted) return 0;if (terminalColumns < MIN_COLS_FOR_FULL_SPRITE) return 0;const nameWidth = stringWidth(companion.name);const bubble = speaking && !isFullscreenActive() ? BUBBLE_WIDTH : 0;return spriteColWidth(nameWidth) + SPRITE_PADDING_X + bubble;}

useBuddyNotification();const companionSpeaking = feature('BUDDY') ?useAppState(s => s.companionReaction !== undefined) : false;const { columns, rows } = useTerminalSize();const textInputColumns = columns - 3 - companionReservedColumns(columns, companionSpeaking);

if (columns < MIN_COLS_FOR_FULL_SPRITE) {const quip = reaction && reaction.length > NARROW_QUIP_CAP ? reaction.slice(0, NARROW_QUIP_CAP - 1) + '…' : reaction;const label = quip ? `"${quip}"` : focused ? ` ${companion.name} ` : companion.name;return <Box paddingX={1} alignSelf="flex-end"><Text>{petting && <Text color="autoAccept">{figures.heart} </Text>}<Text bold color={color}>{renderFace(companion)}</Text>{' '}<Text italic dimColor={!focused && !reaction} bold={focused} inverse={focused && !reaction} color={reaction ? fading ? 'inactive' : color : focused ? color : undefined}>{label}</Text></Text></Box>;}

addNotification({
  key: "buddy-teaser",
  jsx: <RainbowText text="/buddy" />,
  priority: "immediate",
  timeoutMs: 15000});

export function findBuddyTriggerPositions(text: string): Array<{ start: number; end: number }> {if (!feature('BUDDY')) return [];const triggers: Array<{ start: number; end: number }> = [];const re = /\/buddy\b/g;let m: RegExpExecArray | null;while ((m = re.exec(text)) !== null) {
    triggers.push({
      start: m.index,
      end: m.index + m[0].length
    });}return triggers;}

if (feature('BUDDY')) {void fireCompanionObserver(messagesRef.current, reaction => setAppState(prev => prev.companionReaction === reaction ? prev : {...prev,
    companionReaction: reaction
  }));}

companionReaction?: string
companionPetAt?: number