init claude-code

buddy/companion.ts

@@ -0,0 +1,133 @@
+import { getGlobalConfig } from '../utils/config.js'
+import {
+  type Companion,
+  type CompanionBones,
+  EYES,
+  HATS,
+  RARITIES,
+  RARITY_WEIGHTS,
+  type Rarity,
+  SPECIES,
+  STAT_NAMES,
+  type StatName,
+} from './types.js'
+
+// Mulberry32 — tiny seeded PRNG, good enough for picking ducks
+function mulberry32(seed: number): () => number {
+  let a = seed >>> 0
+  return function () {
+    a |= 0
+    a = (a + 0x6d2b79f5) | 0
+    let 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 hashString(s: string): number {
+  if (typeof Bun !== 'undefined') {
+    return Number(BigInt(Bun.hash(s)) & 0xffffffffn)
+  }
+  let h = 2166136261
+  for (let i = 0; i < s.length; i++) {
+    h ^= s.charCodeAt(i)
+    h = Math.imul(h, 16777619)
+  }
+  return h >>> 0
+}
+
+function pick<T>(rng: () => number, arr: readonly T[]): T {
+  return arr[Math.floor(rng() * arr.length)]!
+}
+
+function rollRarity(rng: () => number): Rarity {
+  const total = Object.values(RARITY_WEIGHTS).reduce((a, b) => a + b, 0)
+  let roll = rng() * total
+  for (const rarity of RARITIES) {
+    roll -= RARITY_WEIGHTS[rarity]
+    if (roll < 0) return rarity
+  }
+  return 'common'
+}
+
+const RARITY_FLOOR: Record<Rarity, number> = {
+  common: 5,
+  uncommon: 15,
+  rare: 25,
+  epic: 35,
+  legendary: 50,
+}
+
+// One peak stat, one dump stat, rest scattered. Rarity bumps the floor.
+function rollStats(
+  rng: () => number,
+  rarity: Rarity,
+): Record<StatName, number> {
+  const floor = RARITY_FLOOR[rarity]
+  const peak = pick(rng, STAT_NAMES)
+  let dump = pick(rng, STAT_NAMES)
+  while (dump === peak) dump = pick(rng, STAT_NAMES)
+
+  const stats = {} as Record<StatName, number>
+  for (const name of STAT_NAMES) {
+    if (name === peak) {
+      stats[name] = Math.min(100, floor + 50 + Math.floor(rng() * 30))
+    } else if (name === dump) {
+      stats[name] = Math.max(1, floor - 10 + Math.floor(rng() * 15))
+    } else {
+      stats[name] = floor + Math.floor(rng() * 40)
+    }
+  }
+  return stats
+}
+
+const SALT = 'friend-2026-401'
+
+export type Roll = {
+  bones: CompanionBones
+  inspirationSeed: number
+}
+
+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) }
+}
+
+// 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 } | undefined
+export function roll(userId: string): Roll {
+  const key = userId + SALT
+  if (rollCache?.key === key) return rollCache.value
+  const value = rollFrom(mulberry32(hashString(key)))
+  rollCache = { key, value }
+  return value
+}
+
+export function rollWithSeed(seed: string): Roll {
+  return rollFrom(mulberry32(hashString(seed)))
+}
+
+export function companionUserId(): string {
+  const config = getGlobalConfig()
+  return config.oauthAccount?.accountUuid ?? config.userID ?? 'anon'
+}
+
+// Regenerate bones from userId, merge with stored soul. Bones never persist
+// so species renames and SPECIES-array edits can't break stored companions,
+// and editing config.companion can't fake a rarity.
+export function getCompanion(): Companion | undefined {
+  const stored = getGlobalConfig().companion
+  if (!stored) return undefined
+  const { bones } = roll(companionUserId())
+  // bones last so stale bones fields in old-format configs get overridden
+  return { ...stored, ...bones }
+}