// Personal material for the companion, drawn from the growth journal.
//
// The kitten's cheers are warm but generic — they'd be the same words for
// anybody. The journal already knows things that are true of *this* writer and
// nobody else ("you're using 'make a decision' on your own now"), and that is a
// far better thing to hear after accepting an edit. §5a's own example.
//
// Three rules keep it from wearing out:
//   * A given line is served once per session. Personal praise repeated is
//     wallpaper, and wallpaper is worse than the generic cheer it replaced.
//   * The journal is fetched lazily, on the first accept, and never awaited —
//     the first cheer of a session is generic, and that's fine.
//   * Lines are built at call time from the pack, like every other companion
//     line, so a bubble composed after /api/me is in the right language.

import { api, type GrowthJournal } from '../../api/client'
import { pack, type Line } from '../../i18n'

let journal: GrowthJournal | null = null
let inFlight = false
let served = new Set<string>()

// warmPersonalCheers starts the one fetch this module ever needs. Safe to call
// often; a failure is silent and simply leaves the companion with its generic
// pool, which is exactly the pre-journal behaviour.
export function warmPersonalCheers(): void {
  if (journal || inFlight) return
  inFlight = true
  api
    .growth()
    .then((j) => {
      journal = j
    })
    .catch(() => {
      /* no journal, no personal cheer — never a visible failure */
    })
    .finally(() => {
      inFlight = false
    })
}

// personalCheer returns an unserved line about her own writing, or null when
// there is none — the caller falls back to the generic pool.
export function personalCheer(): Line | null {
  if (!journal) return null
  const t = pack()
  const candidates = [
    ...journal.stuck.map((s) => ({ key: `stuck:${s.phrase}`, line: () => t.journal.cheerStuck(s.phrase) })),
    ...journal.faded.map((f) => ({ key: `faded:${f.pattern}`, line: () => t.journal.cheerFaded(f.pattern) })),
  ].filter((c) => !served.has(c.key))
  if (candidates.length === 0) return null
  const chosen = candidates[Math.floor(Math.random() * candidates.length)]
  served.add(chosen.key)
  return chosen.line()
}

// Test seam, matching resetPackForTests: module state is per-session by design.
export function resetPersonalCheersForTests(): void {
  journal = null
  inFlight = false
  served = new Set()
}