export type PvpContentType = 'dungeon' | 'raid'
export type CpuDifficulty = 1 | 2 | 3 | 4 | 5

export type CpuPvpLeaderboardEntry = {
  characterName: string
  className: string
  contentType: PvpContentType
  encountersCleared: number
  cpuDifficulty: CpuDifficulty
  result: 'victory' | 'defeat'
  completedAt: string
}

const cpuLeaderboardKey = 'chronicle.pvpCpuLeaderboard.v1'
const checkpointKey = 'chronicle.pvpRoguelikeCheckpoint.v1'

export function randomCpuDifficulty(): CpuDifficulty {
  return (Math.floor(Math.random() * 5) + 1) as CpuDifficulty
}

export function loadCpuPvpLeaderboard(contentType?: PvpContentType): CpuPvpLeaderboardEntry[] {
  try {
    const raw = JSON.parse(localStorage.getItem(cpuLeaderboardKey) ?? '[]') as CpuPvpLeaderboardEntry[]
    return raw
      .filter((entry) => !contentType || entry.contentType === contentType)
      .sort((left, right) =>
        right.encountersCleared - left.encountersCleared
        || right.cpuDifficulty - left.cpuDifficulty
        || right.completedAt.localeCompare(left.completedAt),
      )
      .slice(0, 12)
  } catch {
    return []
  }
}

export function recordCpuPvpLeaderboard(entry: CpuPvpLeaderboardEntry) {
  const current = loadCpuPvpLeaderboard()
  const next = [...current, entry]
    .sort((left, right) =>
      right.encountersCleared - left.encountersCleared
      || right.cpuDifficulty - left.cpuDifficulty
      || right.completedAt.localeCompare(left.completedAt),
    )
    .slice(0, 30)
  localStorage.setItem(cpuLeaderboardKey, JSON.stringify(next))
}

function checkpointStorageKey(characterId: number, contentType: PvpContentType) {
  return `${checkpointKey}:${characterId}:${contentType}`
}

export function loadPvpRoguelikeCheckpoint(characterId: number, contentType: PvpContentType) {
  const value = Number(localStorage.getItem(checkpointStorageKey(characterId, contentType)) ?? 1)
  return Number.isInteger(value) && value >= 5 ? value : 1
}

export function recordPvpRoguelikeCheckpoint(
  characterId: number,
  contentType: PvpContentType,
  stage: number,
) {
  if (stage < 5 || stage % 5 !== 0) return loadPvpRoguelikeCheckpoint(characterId, contentType)
  const current = loadPvpRoguelikeCheckpoint(characterId, contentType)
  const next = Math.max(current, stage)
  localStorage.setItem(checkpointStorageKey(characterId, contentType), String(next))
  return next
}