/**
 * 会话交接：mailbox 工单识别、附件文件名、managed-session 清单。
 *
 * 与工单移交的 handoff.json 分开：那边有 issue/worktree/四种 sid，这边只有一个
 * claude 会话。混用解析会把会话包当工单包读崩。
 */

export const MAILBOX_TITLE = 'spx-session-mailbox'
export const MAILBOX_LABEL = 'spx-session-mailbox'
export const MAILBOX_MARKER = '<!-- spx:session-mailbox -->'
export const MAILBOX_BODY = `${MAILBOX_MARKER}
Superwork 会话交接邮箱。不要当任务处理，不要关闭。
`

const UUID_RE = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i
const LOGIN_RE = /^[\w.-]+$/
const FILENAME_RE = /^spx-handoff-session!([0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})!([\w.-]+)!([\w.-]+)!([^!]*)\.tgz$/i

export interface SessionHandoffManifest {
  version: 1
  kind: 'managed-session'
  from: string
  to: string
  createdAt: string
  workspacePath: string
  session: { id: string, name: string, profilePath?: string }
  claude: Array<{ id: string }>
}

export interface SessionHandoffAttachmentRef {
  sid: string
  from: string
  to: string
  name: string
}

export function isMailboxIssue(issue: {
  title?: string
  body?: string
  labels?: Array<{ name: string }> | null
}): boolean {
  if (issue.title === MAILBOX_TITLE)
    return true
  if ((issue.labels ?? []).some(l => l.name === MAILBOX_LABEL))
    return true
  if (typeof issue.body === 'string' && issue.body.includes(MAILBOX_MARKER))
    return true
  return false
}

export function slugSessionName(name: string): string {
  const trimmed = name.trim()
  if (!trimmed)
    return ''
  return trimmed.replace(/[^\p{L}\p{N}._-]+/gu, '_').slice(0, 40)
}

export function sessionHandoffAttachmentName(opts: {
  sid: string
  from: string
  to: string
  name: string
}): string {
  if (!UUID_RE.test(opts.sid))
    throw new Error(`会话 id 不是 UUID：${opts.sid}`)
  if (!LOGIN_RE.test(opts.from))
    throw new Error(`from 含非法字符：${opts.from}`)
  if (!LOGIN_RE.test(opts.to))
    throw new Error(`to 含非法字符：${opts.to}`)
  return `spx-handoff-session!${opts.sid}!${opts.from}!${opts.to}!${slugSessionName(opts.name)}.tgz`
}

export function parseSessionHandoffAttachmentName(filename: string): SessionHandoffAttachmentRef | undefined {
  const m = FILENAME_RE.exec(filename)
  if (!m)
    return undefined
  return { sid: m[1], from: m[2], to: m[3], name: m[4] ?? '' }
}

function optString(v: unknown): string | undefined {
  return typeof v === 'string' && v.length > 0 ? v : undefined
}

export function parseSessionHandoffManifest(json: string): SessionHandoffManifest {
  const raw = JSON.parse(json) as Record<string, unknown>
  if (!raw || typeof raw !== 'object')
    throw new Error('handoff.json 不是对象')
  if (raw.version !== 1)
    throw new Error(`handoff.json version 不支持：${String(raw.version)}`)
  if (raw.kind !== 'managed-session')
    throw new Error(`handoff.json kind 不是 managed-session：${String(raw.kind)}`)
  const from = optString(raw.from)
  const to = optString(raw.to)
  const createdAt = optString(raw.createdAt)
  const workspacePath = optString(raw.workspacePath)
  if (!from || !to || !createdAt || !workspacePath)
    throw new Error('handoff.json 缺少 from / to / createdAt / workspacePath')
  if (!LOGIN_RE.test(from) || !LOGIN_RE.test(to))
    throw new Error('handoff.json from/to 非法')
  const sessionRaw = (raw.session ?? {}) as Record<string, unknown>
  const id = optString(sessionRaw.id)
  const name = typeof sessionRaw.name === 'string' ? sessionRaw.name : ''
  if (!id || !UUID_RE.test(id))
    throw new Error(`handoff.json session.id 非法：${String(sessionRaw.id)}`)
  const claudeRaw = Array.isArray(raw.claude) ? raw.claude : []
  const claude = claudeRaw.map((e) => {
    const o = e as Record<string, unknown>
    const cid = optString(o.id)
    if (!cid || !UUID_RE.test(cid))
      throw new Error(`handoff.json claude 条目非法：${JSON.stringify(e)}`)
    return { id: cid }
  })
  if (claude.length === 0)
    throw new Error('handoff.json 没有 claude 会话文件')
  const profilePath = optString(sessionRaw.profilePath)
  return {
    version: 1,
    kind: 'managed-session',
    from,
    to,
    createdAt,
    workspacePath,
    session: { id, name, ...(profilePath ? { profilePath } : {}) },
    claude,
  }
}

export function buildSessionHandoffManifest(opts: {
  from: string
  to: string
  workspacePath: string
  session: { id: string, name: string, profilePath?: string }
  createdAt?: string
}): SessionHandoffManifest {
  if (!UUID_RE.test(opts.session.id))
    throw new Error(`会话 id 不是 UUID：${opts.session.id}`)
  if (!LOGIN_RE.test(opts.from) || !LOGIN_RE.test(opts.to))
    throw new Error('from/to 非法')
  return {
    version: 1,
    kind: 'managed-session',
    from: opts.from,
    to: opts.to,
    createdAt: opts.createdAt ?? new Date().toISOString(),
    workspacePath: opts.workspacePath,
    session: {
      id: opts.session.id,
      name: opts.session.name,
      ...(opts.session.profilePath ? { profilePath: opts.session.profilePath } : {}),
    },
    claude: [{ id: opts.session.id }],
  }
}