const BARE_P2P_SUITE_PREFIX = '[bare-p2p-v1]'
const BARE_P2P_SUITE_MAX_HISTORY = 2000

function bareP2pNowMs() {
  return Date.now()
}

function bareP2pId(prefix) {
  const rnd = Math.floor(Math.random() * 0x7fffffff)
  return prefix + '-' + bareP2pNowMs().toString(36) + '-' + rnd.toString(36)
}

function bareP2pCommonExamples(argv0, rows) {
  const out = []
  for (const r of rows || []) out.push('  ' + argv0 + ' ' + r)
  return out.join('\n')
}

function bareP2pHelpText(argv0, summary, usage, examples, seeAlso) {
  const lines = []
  lines.push('usage: ' + usage)
  lines.push(summary)
  lines.push('')
  lines.push('common options: --help --json --quiet --summary --timeout MS --no-color')
  if (examples && examples.length) {
    lines.push('')
    lines.push('examples:')
    lines.push(bareP2pCommonExamples(argv0, examples))
  }
  if (seeAlso && seeAlso.length) {
    lines.push('')
    lines.push('see also: ' + seeAlso.join(', '))
  }
  lines.push('')
  lines.push('troubleshooting: if peer data is empty, run `swarmtop` then `swarmdoctor`.')
  return lines.join('\n')
}

function bareP2pParseCommonFlags(args) {
  const rest = []
  const opt = {
    help: false,
    json: false,
    quiet: false,
    summary: false,
    timeoutMs: 4000,
    noColor: false,
    dryRun: false,
    yes: false
  }
  for (let i = 0; i < args.length; i++) {
    const a = String(args[i] || '')
    if (a === '-h' || a === '--help') opt.help = true
    else if (a === '--json') opt.json = true
    else if (a === '--quiet') opt.quiet = true
    else if (a === '--summary') opt.summary = true
    else if (a === '--dry-run') opt.dryRun = true
    else if (a === '--yes' || a === '-y') opt.yes = true
    else if (a === '--no-color') opt.noColor = true
    else if (a === '--timeout') {
      const n = parseInt(args[i + 1] || '4000', 10)
      if (Number.isFinite(n)) opt.timeoutMs = Math.max(250, Math.min(120000, n))
      i++
    } else rest.push(a)
  }
  return { opt, rest }
}

function bareP2pPrint(ctx, data, opt) {
  if (opt && opt.quiet) return
  if (opt && (opt.json || typeof data !== 'string')) {
    ctx.console.log(typeof data === 'string' ? JSON.stringify({ message: data }) : JSON.stringify(data, null, 2))
    return
  }
  ctx.console.log(String(data))
}

function bareP2pError(ctx, argv0, msg, next, opt) {
  if (opt && opt.quiet) {
    ctx.exitCode = 1
    return
  }
  ctx.console.error(argv0 + ': ' + msg + (next ? ' · try: ' + next : ''))
  ctx.exitCode = 1
}

function bareP2pSuggestSubcommand(sub, known) {
  const s = String(sub || '')
  if (!s) return ''
  let best = ''
  let bestScore = 1e9
  for (const k of known || []) {
    const kk = String(k || '')
    const d = Math.abs(kk.length - s.length) + (kk[0] === s[0] ? 0 : 2)
    if (d < bestScore) {
      bestScore = d
      best = kk
    }
  }
  return bestScore <= 4 ? best : ''
}

function bareP2pFirstRunHint(ctx, app, hint) {
  const env = ctx.env && typeof ctx.env === 'object' ? ctx.env : {}
  if (env.BARE_P2P_NO_HINTS === '1' || env.BARE_P2P_NO_HINTS === 'true') return
  const key = '__bare_p2p_hint_' + app
  if (ctx[key]) return
  ctx[key] = true
  try {
    ctx.console.log('hint: ' + hint)
  } catch {
    /* ignore */
  }
}

function bareP2pMaybeNext(ctx, opt, next) {
  if (opt && opt.quiet) return
  if (next) ctx.console.log('next: ' + next)
}

function bareP2pHome(ctx) {
  const env = ctx.env && typeof ctx.env === 'object' ? ctx.env : {}
  const home = typeof env.HOME === 'string' && env.HOME ? env.HOME : '/home/guest'
  return home
}

function bareP2pJoinPath(a, b) {
  if (!a.endsWith('/')) return a + '/' + b
  return a + b
}

function bareP2pDataDir(ctx) {
  return bareP2pJoinPath(bareP2pHome(ctx), '.bare/p2p-suite')
}

function bareP2pDataFile(ctx, app) {
  return bareP2pJoinPath(bareP2pDataDir(ctx), app + '.json')
}

async function bareP2pReadJson(ctx, path) {
  try {
    if (!ctx.vfs || typeof ctx.vfs.readFile !== 'function') return null
    const b = await ctx.vfs.readFile(path)
    if (!b) return null
    const t = ctx.b4a.toString(b).trim()
    if (!t) return null
    return JSON.parse(t)
  } catch {
    return null
  }
}

async function bareP2pWriteJson(ctx, path, obj) {
  if (!ctx.vfs || typeof ctx.vfs.writeFile !== 'function') return false
  const body = JSON.stringify(obj, null, 2) + '\n'
  const b4 = ctx.b4a
  const buf =
    b4 && typeof b4.from === 'function'
      ? b4.from(body)
      : new TextEncoder().encode(body)
  try {
    await ctx.vfs.writeFile(path, buf)
    return true
  } catch {
    return false
  }
}

function bareP2pDecodeEnvelope(line) {
  const s = String(line || '')
  if (!s.startsWith(BARE_P2P_SUITE_PREFIX)) return null
  const payload = s.slice(BARE_P2P_SUITE_PREFIX.length).trim()
  if (!payload) return null
  try {
    const obj = JSON.parse(payload)
    if (!obj || typeof obj !== 'object') return null
    return obj
  } catch {
    return null
  }
}

function bareP2pEncodeEnvelope(app, kind, payload) {
  return (
    BARE_P2P_SUITE_PREFIX +
    ' ' +
    JSON.stringify({
      schema: 1,
      suite: 'bare-p2p',
      version: '1',
      app,
      kind,
      tsMs: bareP2pNowMs(),
      payload: payload || {}
    })
  )
}

function bareP2pSend(ctx, app, kind, payload) {
  if (app === 'meshdrop' && typeof ctx.bareOsMeshdropSend === 'function') {
    return ctx.bareOsMeshdropSend({
      app,
      kind,
      payload: payload || {},
      tsMs: bareP2pNowMs()
    })
  }
  if (typeof ctx.bareOsChatSend !== 'function') {
    return { ok: false, reason: 'bareOsChatSend unavailable' }
  }
  return ctx.bareOsChatSend(bareP2pEncodeEnvelope(app, kind, payload))
}

function bareP2pCollectFromHistory(ctx, app, limit) {
  if (app === 'meshdrop' && typeof ctx.bareOsMeshdropHistory === 'function') {
    let hist = []
    try {
      hist = ctx.bareOsMeshdropHistory(
        Math.max(1, Math.min(BARE_P2P_SUITE_MAX_HISTORY, limit || 512))
      )
    } catch {
      hist = []
    }
    if (!Array.isArray(hist)) return []
    const out = []
    for (const ev of hist) {
      if (!ev || typeof ev !== 'object') continue
      if (ev.app !== app) continue
      out.push({
        fromPeerKey: typeof ev.fromPeerKey === 'string' ? ev.fromPeerKey : '',
        displayName: typeof ev.sender === 'string' ? ev.sender : '',
        local: Boolean(ev.local),
        receivedAtMs:
          typeof ev.receivedAtMs === 'number' ? ev.receivedAtMs : bareP2pNowMs(),
        packet: {
          app,
          kind: typeof ev.kind === 'string' ? ev.kind : 'unknown',
          payload: ev.payload && typeof ev.payload === 'object' ? ev.payload : {}
        }
      })
    }
    return out
  }
  if (typeof ctx.bareOsChatHistory !== 'function') return []
  let hist = []
  try {
    hist = ctx.bareOsChatHistory(
      Math.max(1, Math.min(BARE_P2P_SUITE_MAX_HISTORY, limit || 512))
    )
  } catch {
    hist = []
  }
  if (!Array.isArray(hist)) return []
  const out = []
  for (const ev of hist) {
    if (!ev || typeof ev !== 'object') continue
    const body = String(ev.body || '')
    const decoded = bareP2pDecodeEnvelope(body)
    if (!decoded || decoded.app !== app) continue
    out.push({
      fromPeerKey: typeof ev.fromPeerKey === 'string' ? ev.fromPeerKey : '',
      displayName: typeof ev.displayName === 'string' ? ev.displayName : '',
      local: Boolean(ev.local),
      receivedAtMs:
        typeof ev.receivedAtMs === 'number' ? ev.receivedAtMs : bareP2pNowMs(),
      packet: decoded
    })
  }
  return out
}

function bareP2pSubscribe(ctx, app, fn) {
  if (app === 'meshdrop' && typeof ctx.bareOsMeshdropSubscribe === 'function') {
    return ctx.bareOsMeshdropSubscribe((ev) => {
      if (!ev || typeof ev !== 'object' || ev.app !== app) return
      fn({
        fromPeerKey: typeof ev.fromPeerKey === 'string' ? ev.fromPeerKey : '',
        displayName: typeof ev.sender === 'string' ? ev.sender : '',
        local: Boolean(ev.local),
        receivedAtMs:
          typeof ev.receivedAtMs === 'number' ? ev.receivedAtMs : bareP2pNowMs(),
        packet: {
          app,
          kind: typeof ev.kind === 'string' ? ev.kind : 'unknown',
          payload: ev.payload && typeof ev.payload === 'object' ? ev.payload : {}
        }
      })
    })
  }
  if (typeof ctx.bareOsChatSubscribe !== 'function') return () => {}
  return ctx.bareOsChatSubscribe((ev) => {
    if (!ev || typeof ev !== 'object') return
    const body = String(ev.body || '')
    const decoded = bareP2pDecodeEnvelope(body)
    if (!decoded || decoded.app !== app) return
    fn({
      fromPeerKey: typeof ev.fromPeerKey === 'string' ? ev.fromPeerKey : '',
      displayName: typeof ev.displayName === 'string' ? ev.displayName : '',
      local: Boolean(ev.local),
      receivedAtMs:
        typeof ev.receivedAtMs === 'number' ? ev.receivedAtMs : bareP2pNowMs(),
      packet: decoded
    })
  })
}

async function bareP2pReadSwarmSnapshot(ctx) {
  const out = {
    atMs: bareP2pNowMs(),
    peerCount: null,
    topicCount: null,
    peers: []
  }
  const snap = await bareP2pReadJson(ctx, '/proc/bare_os/swarm')
  if (!snap || typeof snap !== 'object') return out
  if (typeof snap.peerCount === 'number') out.peerCount = snap.peerCount
  if (typeof snap.topicCount === 'number') out.topicCount = snap.topicCount
  const peers = Array.isArray(snap.peers) ? snap.peers : []
  const detailsRaw = await bareP2pReadJson(ctx, '/proc/bare_os/peer_details.json')
  const details =
    detailsRaw && typeof detailsRaw === 'object' && Array.isArray(detailsRaw.peers)
      ? detailsRaw.peers
      : []
  /** @type {Map<string, Record<string, unknown>>} */
  const byKey = new Map()
  for (const d of details) {
    if (!d || typeof d !== 'object') continue
    const rk = typeof d.remotePublicKey === 'string' ? d.remotePublicKey : ''
    const pid = typeof d.peerId === 'string' ? d.peerId : ''
    if (rk) byKey.set('k:' + rk, d)
    if (pid) byKey.set('p:' + pid, d)
  }
  const merged = []
  for (const p of peers) {
    if (!p || typeof p !== 'object') continue
    const rk = typeof p.remotePublicKey === 'string' ? p.remotePublicKey : ''
    const pid = typeof p.peerId === 'string' ? p.peerId : ''
    const d = (rk && byKey.get('k:' + rk)) || (pid && byKey.get('p:' + pid)) || null
    merged.push(d && typeof d === 'object' ? { ...p, ...d } : p)
  }
  out.peers = merged.slice(0, 128)
  return out
}

async function bareP2pReadProcJson(ctx, path) {
  const v = await bareP2pReadJson(ctx, path)
  return v && typeof v === 'object' ? v : {}
}