import { mkdirSync, readFileSync, renameSync, writeFileSync } from 'node:fs'

export interface StarboardPost {
  channelID: string
  messageID: string
  signature: string
  deleted?: boolean
}

export interface ScanJob {
  kind: 'messages' | 'publicThreads' | 'privateThreads' | 'joinedThreads'
  channelID: string
  before?: string
}

export interface Candidate {
  channelID: string
}

export interface Backfill {
  phase: 'collecting' | 'posting'
  candidates: Record<string, Candidate>
  pending: Record<string, Candidate>
  processed: number
  startedAt: string
  completedAt?: string
  initialized: boolean
  jobs: ScanJob[]
  channels: string[]
  scanned: number
  skipped: string[]
  error?: string
}

export interface StarboardState {
  destinationID?: string
  posts: Record<string, StarboardPost>
  backfill?: Backfill
  archivedBoards?: Record<string, { posts: Record<string, StarboardPost>; backfill?: unknown }>
}

const FILE = new URL('../data/starboard.json', import.meta.url)

export function loadStarboard(): StarboardState {
  try {
    return JSON.parse(readFileSync(FILE, 'utf8')) as StarboardState
  } catch (error) {
    if ((error as NodeJS.ErrnoException).code === 'ENOENT') return { posts: {} }
    throw error
  }
}

export function saveStarboard(state: StarboardState): void {
  mkdirSync(new URL('.', FILE), { recursive: true })
  const temporary = new URL(`${FILE.href}.tmp`)
  writeFileSync(temporary, JSON.stringify(state, null, 2))
  renameSync(temporary, FILE)
}