const pull = require("../server/node_modules/pull-stream")
const crypto = require("crypto")
const { getConfig } = require("../configs/config-manager.js")
const { buildValidatedTombstoneSet } = require('./tombstone_validator')
const { readTyped, memoIndex } = require('./typed_log')
const { collabContent, openInviteOf } = require('../backend/collab_content')
const calCollab = collabContent({ membersField: 'participants', undecField: 'encrypted', contentFields: ['title', 'deadline', 'status'], listFields: ['tags', 'invites'] })
const logLimit = getConfig().ssbLogStream?.limit || 1000
const INVITE_CODE_BYTES = 16

const safeText = (v) => String(v || "").trim()
const normalizeTags = (raw) => {
  if (!raw) return []
  if (Array.isArray(raw)) return raw.map(t => String(t || "").trim()).filter(Boolean)
  return String(raw).split(",").map(t => t.trim()).filter(Boolean)
}
const hasAnyInterval = (w, m, y) => !!(w || m || y)
const { expandRecurrence, truthy } = require('./recurrence')
const MAX_OCCURRENCES_PER_DATE = 520
const MAX_DATES_PER_VIEW = 5000

const ts = (v) => {
  const t = new Date(v).getTime()
  return Number.isFinite(t) ? t : null
}

const boundedOccurrences = (date, until, weekly, monthly, yearly) => {
  const start = ts(date)
  const end = ts(until)
  if (start === null || end === null) return expandRecurrence(date, until, weekly, monthly, yearly).slice(0, MAX_OCCURRENCES_PER_DATE)
  const limit = new Date(start)
  if (truthy(weekly)) limit.setUTCDate(limit.getUTCDate() + 7 * MAX_OCCURRENCES_PER_DATE)
  else if (truthy(monthly)) limit.setUTCMonth(limit.getUTCMonth() + MAX_OCCURRENCES_PER_DATE)
  else limit.setUTCFullYear(limit.getUTCFullYear() + MAX_OCCURRENCES_PER_DATE)
  const stop = Number.isFinite(limit.getTime()) ? Math.min(end, limit.getTime()) : end
  return expandRecurrence(date, new Date(stop).toISOString(), weekly, monthly, yearly).slice(0, MAX_OCCURRENCES_PER_DATE)
}

const assertCalendarDates = ({ deadline, date, until }) => {
  const now = Date.now()
  const dl = deadline ? ts(deadline) : null
  const dt = date ? ts(date) : null
  const un = until ? ts(until) : null
  if (deadline && dl === null) throw new Error("Deadline is not a valid date")
  if (date && dt === null) throw new Error("Date is not a valid date")
  if (until && un === null) throw new Error("The recurrence end is not a valid date")
  if (dl !== null && dl <= now) throw new Error("Deadline must be in the future")
  if (dt !== null && dt <= now) throw new Error("Date must be in the future")
  if (dt !== null && dl !== null && dt > dl) throw new Error("Date cannot be later than the deadline")
  if (un !== null && dt !== null && un < dt) throw new Error("The recurrence cannot end before it starts")
  if (un !== null && dl !== null && un > dl) throw new Error("The recurrence cannot end after the deadline")
}

module.exports = ({ cooler, pmModel, tribeCrypto, calendarCrypto, tribesModel }) => {
  let ssb
  const openSsb = async () => { if (!ssb) ssb = await cooler.open(); return ssb }

  const ownCrypto = calendarCrypto || tribeCrypto
  const lookupKey = (rid) => (ownCrypto && ownCrypto.getKey(rid)) || (tribeCrypto && tribeCrypto.getKey(rid)) || null
  const lookupKeys = (rid) => {
    const a = (ownCrypto && ownCrypto.getKeys(rid)) || []
    if (a.length) return a
    return (tribeCrypto && tribeCrypto.getKeys(rid)) || []
  }
  const lookupGen = (rid) => ((ownCrypto && ownCrypto.getGen(rid)) || (tribeCrypto && tribeCrypto.getGen(rid)) || 0)
  const keyProofFor = (keyHex, id) => { try { return crypto.createHmac("sha256", Buffer.from(keyHex, "hex")).update(String(id), "utf8").digest("hex") } catch (_) { return null } }

  const rotateCalendarKey = async (rootId, remainingMembers) => {
    if (!ownCrypto || !tribeCrypto || !rootId) return
    const existing = lookupKey(rootId)
    if (!existing) return
    const newKey = ownCrypto.generateTribeKey()
    const newGen = ownCrypto.addNewKey(rootId, newKey)
    const ssbClient = await openSsb()
    const ssbKeys = require("../server/node_modules/ssb-keys")
    const memberKeys = {}
    for (const m of new Set([ssbClient.id, ...(Array.isArray(remainingMembers) ? remainingMembers : [])])) {
      try { memberKeys[m] = tribeCrypto.boxKeyForMember(newKey, m, ssbKeys) } catch (_) {}
    }
    if (Object.keys(memberKeys).length) {
      await new Promise((resolve) => {
        ssbClient.publish({ type: "tribe-keys", tribeId: rootId, generation: newGen, memberKeys }, () => resolve())
      })
    }
  }

  const ingestOwnTribeKeys = async () => {
    if (!ownCrypto) return
    try {
      const ssbClient = await openSsb()
      const ssbKeys = require("../server/node_modules/ssb-keys")
      const config = require("../server/ssb_config")
      const msgs = await readAll(ssbClient)
      const authorOf = new Map()
      for (const m of msgs) if (m && m.key && m.value) authorOf.set(m.key, m.value.author)
      for (const m of msgs) {
        const c = m.value && m.value.content
        if (!c || c.type !== "tribe-keys") continue
        if (!c.tribeId || !authorOf.has(c.tribeId) || (m.value.author !== authorOf.get(c.tribeId) && m.value.author !== ssbClient.id)) continue
        const memberKeys = c.memberKeys
        if (!memberKeys || typeof memberKeys !== "object") continue
        const boxed = memberKeys[ssbClient.id]
        if (!boxed) continue
        try {
          const unboxed = ssbKeys.unbox(boxed, config.keys)
          const key = typeof unboxed === "string" ? unboxed : (unboxed && unboxed.toString ? unboxed.toString() : null)
          if (key && c.tribeId) ownCrypto.addNewKey(c.tribeId, key)
        } catch (_) {}
      }
    } catch (_) {}
  }

  const CALENDAR_TYPES = ["calendar", "calendarDate", "calendarNote", "calendarParticipant", "calendarReminderSent", "tribe-keys", "tombstone"]

  const readAll = async (ssbClient) => unwrapForIndex(await readTyped(ssbClient, CALENDAR_TYPES, { limit: logLimit, withWindow: true }))

  const ensureMemberKeys = async (ssbClient, messages, cals) => {
    if (!tribeCrypto || !ownCrypto) return
    const leavesByRoot = new Map()
    for (const m of messages) {
      const c = m.value && m.value.content
      if (!c || c.type !== "calendarParticipant" || c.on !== false || !c.target) continue
      if (!leavesByRoot.has(c.target)) leavesByRoot.set(c.target, [])
      leavesByRoot.get(c.target).push({ member: m.value.author, ts: Number(m.timestamp || m.value.timestamp || 0) })
    }
    const ssbKeys = require("../server/node_modules/ssb-keys")
    for (const cal of (Array.isArray(cals) ? cals : [])) {
      if (!cal || cal.tribeId || cal.encrypted || cal.author !== ssbClient.id) continue
      const rootId = cal.rootId
      if (!rootId || !lookupKey(rootId)) continue
      const members = Array.isArray(cal.participants) ? cal.participants : []
      const plan = ownCrypto.keyPlan({ rootId, ownerId: cal.author, gen: lookupGen(rootId), members, messages, leaves: leavesByRoot.get(rootId) || [] })
      if (plan.rotate) {
        await rotateCalendarKey(rootId, members)
        continue
      }
      if (!plan.missing.length) continue
      const key = lookupKey(rootId)
      const memberKeys = {}
      for (const m of plan.missing) {
        try { memberKeys[m] = tribeCrypto.boxKeyForMember(key, m, ssbKeys) } catch (_) {}
      }
      if (!Object.keys(memberKeys).length) continue
      await new Promise((resolve) => {
        ssbClient.publish({ type: "tribe-keys", tribeId: rootId, generation: lookupGen(rootId) || 1, memberKeys }, () => resolve())
      })
    }
  }

  const tribeHelpers = tribeCrypto ? tribeCrypto.createHelpers(tribesModel) : null
  const unwrapForIndex = (msgs) => tribeHelpers ? tribeHelpers.unwrapMessagesForKind(msgs, CALENDAR_TYPES) : msgs
  const encryptIfTribe = tribeHelpers ? tribeHelpers.encryptIfTribe : async (c) => c
  const decryptIfTribe = tribeHelpers ? tribeHelpers.decryptIfTribe : async (c) => c
  const assertReadable = tribeHelpers ? tribeHelpers.assertReadable : () => {}

  const encryptStandalone = (content, rootId) => {
    if (!tribeCrypto || !rootId) return content
    const key = lookupKey(rootId)
    if (!key) return content
    return tribeCrypto.encryptContent(content, [key], true)
  }

  const decryptScoped = async (content, rootId) => {
    if (!content) return content
    if (content.tribeId || (tribeCrypto && tribeCrypto.isTribeMsg(content))) return await decryptIfTribe(content)
    return decryptCalendarRoot(content, rootId)
  }

  const decryptCalendarRoot = (content, rootId) => {
    if (!content || !content.encryptedPayload) return content
    if (!tribeCrypto) return content
    const keys = lookupKeys(rootId)
    if (!keys || !keys.length) return { ...content, _undecryptable: true }
    return tribeCrypto.decryptContent(content, keys.map(k => [k]))
  }

  const tryDecryptPublicInviteKey = (invites) => {
    if (!tribeCrypto || !Array.isArray(invites)) return null
    for (const inv of invites) {
      if (!inv || typeof inv !== "object" || inv.public !== true) continue
      if (typeof inv.code !== "string") continue
      if (typeof inv.ek === "string") {
        try { const k = tribeCrypto.decryptFromInvite(inv.ek, inv.code, inv.salt); if (k) return k } catch (_) {}
      }
      if (typeof inv.ekChain === "string") {
        try { const chain = tribeCrypto.decryptChainFromInvite(inv.ekChain, inv.code, inv.salt); if (Array.isArray(chain) && chain.length && chain[0].key) return chain[0].key } catch (_) {}
      }
    }
    return null
  }

  const decryptIndexNodes = async (idx) => {
    if (!tribeCrypto) return
    for (const [k, n] of idx.nodes.entries()) {
      if (!n.c || !n.c.encryptedPayload) continue
      let root = k
      while (idx.parent.has(root)) root = idx.parent.get(root)
      let dec = null
      if (n.c.tribeId && tribesModel) {
        try {
          const r = await tribeCrypto.decryptFromTribe(n.c, tribesModel)
          if (r && !r._undecryptable) dec = r
        } catch (_) {}
      }
      if (!dec) {
        const r = decryptCalendarRoot(n.c, root)
        if (r && !r._undecryptable) dec = r
      }
      if (!dec) {
        const pubKey = tryDecryptPublicInviteKey(n.c.invites)
        if (pubKey) {
          try { const r = tribeCrypto.decryptContent(n.c, [[pubKey]]); if (r && !r._undecryptable) dec = r } catch (_) {}
        }
      }
      if (dec) {
        idx.nodes.set(k, { ...n, c: { ...dec, _decrypted: true } })
      } else {
        idx.nodes.set(k, { ...n, c: { ...n.c, _decrypted: false } })
      }
    }
  }

  const buildIndex = (messages) => {
    const tomb = new Set()
    const nodes = new Map()
    const parent = new Map()
    const child = new Map()
    const strictChild = new Map()
    const authorByKey = new Map()
    const tombRequests = []
    const participantMsgs = []

    for (const m of messages) {
      const k = m.key
      const v = m.value || {}
      const c = v.content
      if (!c) continue
      if (c.type === "tombstone" && c.target) { tombRequests.push({ target: c.target, author: v.author }); continue }
      if (c.type === "calendarParticipant" && c.target) { participantMsgs.push({ target: c.target, author: v.author, on: c.on !== false, keyProof: typeof c.keyProof === "string" ? c.keyProof : "", code: typeof c.code === "string" ? c.code : "", ts: v.timestamp || m.timestamp || 0 }); continue }
      if (c.type === "calendar") {
        nodes.set(k, { key: k, ts: v.timestamp || m.timestamp || 0, seq: v.sequence || 0, c, author: v.author })
        authorByKey.set(k, v.author)
        if (c.replaces) { parent.set(k, c.replaces); child.set(c.replaces, k) }
      }
    }

    for (const t of tombRequests) {
      const targetAuthor = authorByKey.get(t.target)
      if (targetAuthor && t.author === targetAuthor) tomb.add(t.target)
    }

    for (const [k, node] of nodes.entries()) {
      const t = node.c.replaces
      if (!t) continue
      const orig = nodes.get(t)
      if (orig && orig.author === node.author) strictChild.set(t, k)
    }

    const rootOf = (id) => { let cur = id; while (parent.has(cur)) cur = parent.get(cur); return cur }
    const tipOf = (id) => { let cur = id; while (child.has(cur)) cur = child.get(cur); return cur }
    const ownerTip = new Map()
    for (const [k, n] of nodes.entries()) {
      const r = rootOf(k)
      const rn = nodes.get(r)
      if (!rn || n.author !== rn.author || tomb.has(k)) continue
      const prev = ownerTip.has(r) ? nodes.get(ownerTip.get(r)) : null
      if (!prev || n.seq > prev.seq || (n.seq === prev.seq && n.ts >= prev.ts)) ownerTip.set(r, k)
    }
    const contentTipOf = (root) => ownerTip.get(root) || root

    const roots = new Set()
    for (const id of nodes.keys()) roots.add(rootOf(id))

    const joinAllowed = (root, pm) => {
      const rn = nodes.get(root)
      if (!rn) return false
      if (pm.author === rn.author || rn.c.tribeId) return true
      if (!rn.c.encryptedPayload && String(rn.c.status || "OPEN").toUpperCase() === "OPEN") return true
      return !!pm.keyProof && lookupKeys(root).some(k => keyProofFor(k, pm.author) === pm.keyProof)
    }
    const participantsByRoot = new Map()
    for (const pm of participantMsgs) {
      if (!nodes.has(pm.target)) continue
      const r = rootOf(pm.target)
      if (pm.on && !joinAllowed(r, pm)) continue
      if (!participantsByRoot.has(r)) participantsByRoot.set(r, new Map())
      const m2 = participantsByRoot.get(r)
      const prev = m2.get(pm.author)
      if (!prev || pm.ts >= prev.ts) m2.set(pm.author, { on: pm.on, ts: pm.ts })
    }

    const resolveParticipants = (root) => {
      const ownerNode = nodes.get(root)
      const oc = ownerNode ? ownerNode.c : {}
      const set = new Set(Array.isArray(oc.participants) ? oc.participants : [])
      for (const [au, st] of (participantsByRoot.get(root) || new Map())) {
        if (st.on) set.add(au); else set.delete(au)
      }
      return [...set]
    }

    const tipByRoot = new Map()
    for (const r of roots) tipByRoot.set(r, tipOf(r))
    const contentTipByRoot = new Map()
    for (const r of roots) contentTipByRoot.set(r, contentTipOf(r))

    return { tomb, nodes, parent, child, rootOf, tipOf, contentTipOf, tipByRoot, contentTipByRoot, resolveParticipants }
  }

  const buildCalendar = (node, rootId, participants) => {
    const c = node.c || {}
    if (c.type !== "calendar") return null
    const undec = c.encryptedPayload && c._decrypted === false
    return {
      key: node.key,
      rootId,
      title: undec ? "" : safeText(c.title),
      status: c.status || "OPEN",
      deadline: undec ? "" : (c.deadline || ""),
      tags: Array.isArray(c.tags) ? c.tags : [],
      mapUrl: typeof c.mapUrl === "string" ? c.mapUrl : "",
      author: node.author || c.author,
      participants: Array.isArray(participants) ? participants : (Array.isArray(c.participants) ? c.participants : []),
      invites: Array.isArray(c.invites) ? c.invites : [],
      createdAt: c.createdAt || new Date(node.ts).toISOString(),
      updatedAt: c.updatedAt || null,
      tribeId: c.tribeId || null,
      encrypted: !!undec,
      contentEncrypted: !!(c.encryptedPayload || c._decrypted === true)
    }
  }


  const calendarMembers = async (cal) => {
    const set = new Set([cal.author, ...(Array.isArray(cal.participants) ? cal.participants : [])].filter(Boolean))
    if (cal.tribeId && tribesModel) {
      try {
        const t = await tribesModel.getTribeById(cal.tribeId)
        for (const m of (t && Array.isArray(t.members) ? t.members : [])) set.add(m)
      } catch (_) {}
    }
    return set
  }

  const isClosed = (calendar) => {
    if (calendar.status === "CLOSED") return true
    if (!calendar.deadline) return false
    return new Date(calendar.deadline).getTime() <= Date.now()
  }

  const collectCalendars = async () => {
    const ssbClient = await openSsb()
    const messages = await readAll(ssbClient)
    const idx = buildIndex(messages)
    await decryptIndexNodes(idx)
    const items = []
    for (const rootId of idx.contentTipByRoot.keys()) {
      const contentTip = idx.contentTipByRoot.get(rootId) || rootId
      if (idx.tomb.has(contentTip)) continue
      const node = idx.nodes.get(contentTip)
      if (!node || node.c.type !== "calendar") continue
      const cal = buildCalendar(node, rootId, idx.resolveParticipants(rootId))
      if (!cal) continue
      cal.isClosed = isClosed(cal)
      items.push(cal)
    }
    return items
  }

  return {
    type: "calendar",

    async ingestKeys() { await ingestOwnTribeKeys() },

    async pruneOrphanKeys() {
      if (!ownCrypto || typeof ownCrypto.getAllRootIds !== "function") return 0
      try {
        const ssbClient = await openSsb()
        const messages = await readAll(ssbClient)
        const tomb = buildValidatedTombstoneSet(messages)
        const all = ownCrypto.getAllRootIds()
        let removed = 0
        for (const rid of all) {
          if (tomb.has(rid)) {
            try { ownCrypto.dropKey(rid); removed += 1 } catch (_) {}
          }
        }
        return removed
      } catch (_) { return 0 }
    },

    async resolveRootId(id) {
      const ssbClient = await openSsb()
      const messages = await readAll(ssbClient)
      const idx = buildIndex(messages)
      const root = idx.rootOf(id)
      if (idx.tomb.has(idx.contentTipOf(root))) throw new Error("Not found")
      return root
    },

    async resolveCurrentId(id) {
      const ssbClient = await openSsb()
      const messages = await readAll(ssbClient)
      const idx = buildIndex(messages)
      const tip = idx.contentTipOf(idx.rootOf(id))
      if (idx.tomb.has(tip)) throw new Error("Not found")
      return tip
    },

    async createCalendar({ title, status, deadline, tags, firstDate, firstDateLabel, firstNote, intervalWeekly, intervalMonthly, intervalYearly, intervalDeadline, mapUrl, tribeId }) {
      const ssbClient = await openSsb()
      const userId = ssbClient.id
      const now = new Date().toISOString()
      const validStatus = ["OPEN", "CLOSED"].includes(String(status).toUpperCase()) ? String(status).toUpperCase() : "OPEN"

      if (!firstDate) throw new Error("First date must be in the future")
      assertCalendarDates({
        deadline,
        date: firstDate,
        until: hasAnyInterval(intervalWeekly, intervalMonthly, intervalYearly) ? intervalDeadline : ""
      })

      let plainContent = {
        type: "calendar",
        title: safeText(title),
        status: validStatus,
        deadline: deadline || "",
        tags: normalizeTags(tags),
        mapUrl: safeText(mapUrl),
        author: userId,
        participants: [userId],
        invites: [],
        createdAt: now,
        updatedAt: now,
        ...(tribeId ? { tribeId } : {})
      }

      let calKey = null
      let content = plainContent
      if (tribeId) {
        content = await encryptIfTribe(plainContent)
      } else if (tribeCrypto) {
        calKey = ownCrypto.generateTribeKey()
        content = tribeCrypto.encryptContent(plainContent, [calKey], true)
      }

      const calMsg = await new Promise((resolve, reject) => {
        ssbClient.publish(content, (err, msg) => err ? reject(err) : resolve(msg))
      })

      const calendarId = calMsg.key

      if (calKey && tribeCrypto) {
        ownCrypto.setKey(calendarId, calKey, 1)
        try {
          const ssbKeys = require("../server/node_modules/ssb-keys")
          const boxedKey = tribeCrypto.boxKeyForMember(calKey, userId, ssbKeys)
          await new Promise((resolve) => {
            ssbClient.publish({ type: "tribe-keys", tribeId: calendarId, generation: 1, memberKeys: { [userId]: boxedKey } }, () => resolve())
          })
        } catch (_) {}
        if (validStatus === "OPEN") {
          try {
            const pubCode = crypto.randomBytes(INVITE_CODE_BYTES).toString("hex")
            const inviteSalt = tribeCrypto.generateInviteSalt()
            const ek = tribeCrypto.encryptForInvite(calKey, pubCode, inviteSalt)
            const tipId = await this.resolveCurrentId(calendarId)
            const item = await new Promise((resolve, reject) => ssbClient.get(tipId, (e, it) => e ? reject(e) : resolve(it)))
            const dec = decryptCalendarRoot(item.content, calendarId)
            let updated = {
              type: "calendar",
              title: dec.title || "",
              status: validStatus,
              deadline: dec.deadline || "",
              tags: Array.isArray(dec.tags) ? dec.tags : [],
              mapUrl: dec.mapUrl || "",
              author: userId,
              participants: [userId],
              invites: [{ code: pubCode, ek, salt: inviteSalt, gen: 1, public: true }],
              createdAt: dec.createdAt,
              updatedAt: new Date().toISOString(),
              replaces: tipId
            }
            updated = encryptStandalone(updated, calendarId)
            await new Promise((resolve, reject) => ssbClient.publish(updated, (e, res) => e ? reject(e) : resolve(res)))
            await new Promise((resolve, reject) => ssbClient.publish({ type: "tombstone", target: tipId, deletedAt: new Date().toISOString(), author: userId }, e => e ? reject(e) : resolve()))
          } catch (_) {}
        }
      }

      let dateContent = {
        type: "calendarDate",
        calendarId,
        date: new Date(firstDate).toISOString(),
        label: safeText(firstDateLabel),
        author: userId,
        createdAt: new Date().toISOString(),
        ...(intervalWeekly ? { intervalWeekly: true } : {}),
        ...(intervalMonthly ? { intervalMonthly: true } : {}),
        ...(intervalYearly ? { intervalYearly: true } : {}),
        ...(hasAnyInterval(intervalWeekly, intervalMonthly, intervalYearly) && (intervalDeadline || deadline) ? { intervalDeadline: intervalDeadline || deadline } : {}),
        ...(tribeId ? { tribeId } : {})
      }
      if (tribeId) dateContent = await encryptIfTribe(dateContent)
      else if (calKey) dateContent = tribeCrypto.encryptContent(dateContent, [calKey], true)
      const dateMsg = await new Promise((resolve, reject) => {
        ssbClient.publish(dateContent, (err, msg) => err ? reject(err) : resolve(msg))
      })

      if (firstNote && safeText(firstNote)) {
        let noteContent = {
          type: "calendarNote",
          calendarId,
          dateId: dateMsg.key,
          text: safeText(firstNote),
          author: userId,
          createdAt: new Date().toISOString(),
          ...(tribeId ? { tribeId } : {})
        }
        if (tribeId) noteContent = await encryptIfTribe(noteContent)
        else if (calKey) noteContent = tribeCrypto.encryptContent(noteContent, [calKey], true)
        await new Promise((resolve, reject) => {
          ssbClient.publish(noteContent, (err, msg) => err ? reject(err) : resolve(msg))
        })
      }

      return calMsg
    },

    async updateCalendarById(id, data) {
      const tipId = await this.resolveCurrentId(id)
      const rootId = await this.resolveRootId(id)
      const ssbClient = await openSsb()
      const userId = ssbClient.id
      const item = await new Promise((resolve, reject) => {
        ssbClient.get(tipId, (err, it) => err ? reject(err) : resolve(it))
      })
      if (!item || !item.content) throw new Error("Calendar not found")
      const oldDec = await decryptScoped(item.content, rootId)
      assertReadable(oldDec, "Calendar")
      if (item.author !== userId) throw new Error("Not the author")
      const nextDeadline = data.deadline !== undefined ? data.deadline : (oldDec.deadline || "")
      if (nextDeadline !== (oldDec.deadline || "")) assertCalendarDates({ deadline: nextDeadline })
      let updated = {
        type: "calendar",
        title: data.title !== undefined ? safeText(data.title) : (oldDec.title || ""),
        status: data.status !== undefined ? (["OPEN","CLOSED"].includes(String(data.status).toUpperCase()) ? String(data.status).toUpperCase() : oldDec.status) : (oldDec.status || "OPEN"),
        deadline: nextDeadline,
        tags: data.tags !== undefined ? normalizeTags(data.tags) : (Array.isArray(oldDec.tags) ? oldDec.tags : []),
        mapUrl: data.mapUrl !== undefined ? safeText(data.mapUrl) : (oldDec.mapUrl || ""),
        author: oldDec.author || userId,
        participants: oldDec.participants || [userId],
        invites: Array.isArray(oldDec.invites) ? oldDec.invites : [],
        ...(oldDec.tribeId ? { tribeId: oldDec.tribeId } : {}),
        createdAt: oldDec.createdAt,
        updatedAt: new Date().toISOString(),
        replaces: tipId
      }
      const closing = !oldDec.tribeId && String(oldDec.status || "OPEN").toUpperCase() === "OPEN" && updated.status === "CLOSED"
      if (closing) {
        updated.invites = updated.invites.filter(inv => !(inv && typeof inv === "object" && inv.public === true))
        try { await rotateCalendarKey(rootId, (updated.participants || []).filter(p => p !== userId)) } catch (_) {}
      }
      if (updated.tribeId) updated = await encryptIfTribe(updated)
      else updated = encryptStandalone(updated, rootId)
      const result = await new Promise((resolve, reject) => ssbClient.publish(updated, (e, res) => e ? reject(e) : resolve(res)))
      const tombstone = { type: "tombstone", target: tipId, deletedAt: new Date().toISOString(), author: userId }
      await new Promise((resolve, reject) => ssbClient.publish(tombstone, e => e ? reject(e) : resolve()))
      return result
    },

    async deleteCalendarById(id) {
      const tipId = await this.resolveCurrentId(id)
      const ssbClient = await openSsb()
      const userId = ssbClient.id
      const item = await new Promise((resolve, reject) => ssbClient.get(tipId, (e, it) => e ? reject(e) : resolve(it)))
      if (!item || !item.content) throw new Error("Calendar not found")
      const rootId = await this.resolveRootId(id)
      const dec = await decryptScoped(item.content, rootId)
      assertReadable(dec, "Calendar")
      if (item.author !== userId) throw new Error("Not the author")
      const tombstone = { type: "tombstone", target: tipId, deletedAt: new Date().toISOString(), author: userId }
      return new Promise((resolve, reject) => ssbClient.publish(tombstone, e => e ? reject(e) : resolve()))
    },

    async joinCalendar(calendarId) {
      const rootId = await this.resolveRootId(calendarId)
      const ssbClient = await openSsb()
      const userId = ssbClient.id
      const cal = await this.getCalendarById(rootId)
      if (!cal) throw new Error("Calendar not found")
      const participants = Array.isArray(cal.participants) ? cal.participants : []
      if (participants.includes(userId)) return
      if (tribeCrypto && Array.isArray(cal.invites)) {
        const pub = cal.invites.find(inv => typeof inv === "object" && inv.public === true && inv.code && (inv.ek || inv.ekChain))
        if (pub) return await this.joinByInvite(pub.code)
      }
      const content = { type: "calendarParticipant", target: rootId, on: true, createdAt: new Date().toISOString() }
      return new Promise((resolve, reject) => ssbClient.publish(content, (e, res) => e ? reject(e) : resolve(res)))
    },

    async leaveCalendar(calendarId) {
      const rootId = await this.resolveRootId(calendarId)
      const ssbClient = await openSsb()
      const userId = ssbClient.id
      const cal = await this.getCalendarById(rootId)
      if (!cal) throw new Error("Calendar not found")
      if (cal.author === userId) throw new Error("Author cannot leave")
      const participants = Array.isArray(cal.participants) ? cal.participants : []
      if (!participants.includes(userId)) return
      const content = { type: "calendarParticipant", target: rootId, on: false, createdAt: new Date().toISOString() }
      return new Promise((resolve, reject) => ssbClient.publish(content, (e, res) => e ? reject(e) : resolve(res)))
    },

    async findCalendarByLinkText(linkSubstring) {
      if (!linkSubstring) return null
      const ssbClient = await openSsb()
      const messages = await readAll(ssbClient)
      const idx = buildIndex(messages)
      await decryptIndexNodes(idx)
      for (const node of idx.nodes.values()) {
        const c = node && node.c
        if (!c || c.type !== "calendarNote") continue
        if (typeof c.text === "string" && c.text.includes(linkSubstring)) {
          return c.calendarId || null
        }
      }
      return null
    },

    async getCalendarById(id) {
      const ssbClient = await openSsb()
      const messages = await readAll(ssbClient)
      const idx = memoIndex('calendars', messages, buildIndex)
      await decryptIndexNodes(idx)
      let root = id
      while (idx.parent.has(root)) root = idx.parent.get(root)
      const contentTip = idx.contentTipOf(root)
      if (idx.tomb.has(contentTip)) return null
      const node = idx.nodes.get(contentTip)
      if (!node || node.c.type !== "calendar") return null
      const cal = buildCalendar(node, root, idx.resolveParticipants(root))
      if (!cal) return null
      cal.isClosed = isClosed(cal)
      return calCollab.fold(cal, await collectCalendars())
    },

    async listAll({ filter = "all", viewerId } = {}) {
      const ssbClient = await openSsb()
      const uid = viewerId || ssbClient.id
      let list = calCollab.visibleThenCollapsed(await collectCalendars(), uid)
      try { await ensureMemberKeys(ssbClient, await readAll(ssbClient), list) } catch (_) {}
      if (filter === "mine") list = list.filter(c => c.author === uid)
      else if (filter === "recent") {
        const now = Date.now()
        list = list.filter(c => new Date(c.createdAt).getTime() >= now - 86400000)
      }
      else if (filter === "open") list = list.filter(c => !c.isClosed)
      else if (filter === "closed") list = list.filter(c => c.isClosed)
      return list.slice().sort((a, b) => new Date(b.createdAt) - new Date(a.createdAt))
    },

    async addDate(calendarId, date, label, intervalWeekly, intervalMonthly, intervalYearly, intervalDeadline) {
      const ssbClient = await openSsb()
      const userId = ssbClient.id
      const rootId = await this.resolveRootId(calendarId)
      const cal = await this.getCalendarById(rootId)
      if (!cal) throw new Error("Calendar not found")
      if (cal.status === "CLOSED" && userId !== cal.author) throw new Error("Only the author can add dates to a CLOSED calendar")
      if (!date) throw new Error("Date must be in the future")
      const hasInterval = hasAnyInterval(intervalWeekly, intervalMonthly, intervalYearly)
      assertCalendarDates({
        deadline: cal.deadline || "",
        date,
        until: hasInterval ? intervalDeadline : ""
      })

      const ruleDeadline = hasInterval ? (intervalDeadline || cal.deadline || "") : ""
      if (!(await calendarMembers(cal)).has(userId)) {
        if (cal.tribeId || cal.status !== "OPEN") throw new Error("Only participants can add dates")
        await this.joinCalendar(rootId)
      }
      let dateContent = {
        type: "calendarDate",
        calendarId: rootId,
        date: new Date(date).toISOString(),
        label: safeText(label),
        author: userId,
        createdAt: new Date().toISOString(),
        ...(intervalWeekly ? { intervalWeekly: true } : {}),
        ...(intervalMonthly ? { intervalMonthly: true } : {}),
        ...(intervalYearly ? { intervalYearly: true } : {}),
        ...(ruleDeadline ? { intervalDeadline: ruleDeadline } : {}),
        ...(cal.tribeId ? { tribeId: cal.tribeId } : {})
      }
      if (cal.tribeId) dateContent = await encryptIfTribe(dateContent)
      else dateContent = encryptStandalone(dateContent, rootId)
      const msg = await new Promise((resolve, reject) => {
        ssbClient.publish(dateContent, (err, m) => err ? reject(err) : resolve(m))
      })
      return [msg]
    },

    async getDatesForCalendar(calendarId) {
      const rootId = await this.resolveRootId(calendarId)
      const cal = await this.getCalendarById(rootId)
      const calDeadline = cal && cal.deadline ? cal.deadline : ""
      const pubKey = cal ? tryDecryptPublicInviteKey(cal.invites) : null
      const members = cal ? await calendarMembers(cal) : new Set()
      const ssbClient = await openSsb()
      const messages = await readAll(ssbClient)
      const authorByKey = new Map()
      for (const m of messages) authorByKey.set(m.key, (m.value || {}).author)
      const tombstoned = new Set()
      for (const m of messages) {
        const c = (m.value || {}).content
        if (c && c.type === "tombstone" && c.target) {
          const targetAuthor = authorByKey.get(c.target)
          if (targetAuthor && (m.value || {}).author === targetAuthor) tombstoned.add(c.target)
        }
      }
      const dates = []
      for (const m of messages) {
        if (tombstoned.has(m.key)) continue
        const v = m.value || {}
        const c = v.content
        if (!c || c.type !== "calendarDate") continue
        if (c.calendarId !== rootId) continue
        if (!members.has(v.author)) continue
        let dec = c
        if (c.encryptedPayload && tribeCrypto) {
          if (c.tribeId && tribesModel) {
            const r = await tribeCrypto.decryptFromTribe(c, tribesModel)
            dec = r && !r._undecryptable ? r : c
            if (r && r._undecryptable) continue
          } else {
            const keys = [...(lookupKeys(c.calendarId) || []), ...(pubKey ? [pubKey] : [])]
            if (!keys.length) continue
            const r = tribeCrypto.decryptContent(c, keys.map(k => [k]))
            if (!r || r._undecryptable) continue
            dec = r
          }
        }
        const baseEntry = {
          key: m.key,
          calendarId: dec.calendarId || c.calendarId,
          label: dec.label || "",
          author: v.author || dec.author,
          createdAt: dec.createdAt || new Date(v.timestamp || 0).toISOString()
        }
        const hasInterval = !!(dec.intervalWeekly || dec.intervalMonthly || dec.intervalYearly)
        const ruleDeadline = dec.intervalDeadline || calDeadline
        if (hasInterval && ruleDeadline) {
          const occurrences = boundedOccurrences(dec.date, ruleDeadline, dec.intervalWeekly, dec.intervalMonthly, dec.intervalYearly)
          for (const occ of occurrences) {
            dates.push({ ...baseEntry, date: occ.toISOString() })
          }
        } else {
          dates.push({ ...baseEntry, date: dec.date })
        }
      }
      const owner = cal ? cal.author : null
      const kept = [...dates.filter(d => d.author === owner), ...dates.filter(d => d.author !== owner)].slice(0, MAX_DATES_PER_VIEW)
      kept.sort((a, b) => new Date(a.date) - new Date(b.date))
      return kept
    },

    async deleteDate(dateId, calendarId) {
      const ssbClient = await openSsb()
      const userId = ssbClient.id
      const rootId = await this.resolveRootId(calendarId)
      const cal = await this.getCalendarById(rootId)
      if (!cal) throw new Error("Calendar not found")
      const messages = await readAll(ssbClient)
      const authorByKey = new Map()
      for (const m of messages) authorByKey.set(m.key, (m.value || {}).author)
      const tombstoned = new Set()
      for (const m of messages) {
        const c = (m.value || {}).content
        if (c && c.type === "tombstone" && c.target) {
          const targetAuthor = authorByKey.get(c.target)
          if (targetAuthor && (m.value || {}).author === targetAuthor) tombstoned.add(c.target)
        }
      }
      let dateAuthor = null
      for (const m of messages) {
        if (m.key !== dateId) continue
        const c = (m.value || {}).content
        if (!c || c.type !== "calendarDate") continue
        if (tombstoned.has(m.key)) break
        let dec = c
        if (c.encryptedPayload && tribeCrypto && tribesModel) {
          const r = await tribeCrypto.decryptFromTribe(c, tribesModel)
          if (r && !r._undecryptable) dec = r
        }
        dateAuthor = dec.author || (m.value || {}).author
        break
      }
      if (!dateAuthor) throw new Error("Date not found")
      if (dateAuthor !== userId && cal.author !== userId) throw new Error("Not authorized")
      for (const m of messages) {
        const c = (m.value || {}).content
        if (!c || c.type !== "calendarNote") continue
        if (tombstoned.has(m.key)) continue
        if (c.dateId !== dateId) continue
        await new Promise((resolve, reject) => {
          ssbClient.publish({ type: "tombstone", target: m.key, deletedAt: new Date().toISOString(), author: userId }, (e) => e ? reject(e) : resolve())
        })
      }
      return new Promise((resolve, reject) => {
        ssbClient.publish({ type: "tombstone", target: dateId, deletedAt: new Date().toISOString(), author: userId }, (e) => e ? reject(e) : resolve())
      })
    },

    async addNote(calendarId, dateId, text) {
      const ssbClient = await openSsb()
      const userId = ssbClient.id
      const rootId = await this.resolveRootId(calendarId)
      const cal = await this.getCalendarById(rootId)
      if (!cal) throw new Error("Calendar not found")
      if (!cal.participants.includes(userId)) throw new Error("Only participants can add notes")
      let noteContent = {
        type: "calendarNote",
        calendarId: rootId,
        dateId,
        text: safeText(text),
        author: userId,
        createdAt: new Date().toISOString(),
        ...(cal.tribeId ? { tribeId: cal.tribeId } : {})
      }
      if (cal.tribeId) noteContent = await encryptIfTribe(noteContent)
      else noteContent = encryptStandalone(noteContent, rootId)
      return new Promise((resolve, reject) => {
        ssbClient.publish(noteContent, (err, msg) => err ? reject(err) : resolve(msg))
      })
    },

    async deleteNote(noteId) {
      const ssbClient = await openSsb()
      const userId = ssbClient.id
      const item = await new Promise((resolve, reject) => ssbClient.get(noteId, (e, it) => e ? reject(e) : resolve(it)))
      if (!item || !item.content) throw new Error("Note not found")
      if (item.author !== userId) throw new Error("Not the author")
      return new Promise((resolve, reject) => {
        ssbClient.publish({ type: "tombstone", target: noteId, deletedAt: new Date().toISOString(), author: userId }, (e, msg) => e ? reject(e) : resolve(msg))
      })
    },

    async getNotesForDate(calendarId, dateId) {
      const rootId = await this.resolveRootId(calendarId)
      const ssbClient = await openSsb()
      const messages = await readAll(ssbClient)
      const authorByKey = new Map()
      for (const m of messages) authorByKey.set(m.key, (m.value || {}).author)
      const tombstoned = new Set()
      for (const m of messages) {
        const c = (m.value || {}).content
        if (c && c.type === "tombstone" && c.target) {
          const targetAuthor = authorByKey.get(c.target)
          if (targetAuthor && (m.value || {}).author === targetAuthor) tombstoned.add(c.target)
        }
      }
      const notes = []
      let pubKey
      for (const m of messages) {
        const v = m.value || {}
        const c = v.content
        if (!c || c.type !== "calendarNote") continue
        if (tombstoned.has(m.key)) continue
        if (c.calendarId !== rootId || (dateId != null && c.dateId !== dateId)) continue
        let dec = c
        if (c.encryptedPayload) {
          let r = await decryptScoped(c, rootId)
          if ((!r || r._undecryptable) && !c.tribeId && tribeCrypto) {
            if (pubKey === undefined) {
              const cal = await this.getCalendarById(rootId).catch(() => null)
              pubKey = cal ? tryDecryptPublicInviteKey(cal.invites) : null
            }
            if (pubKey) r = tribeCrypto.decryptContent(c, [[pubKey]])
          }
          if (r && !r._undecryptable) dec = r
          else continue
        }
        notes.push({
          key: m.key,
          calendarId: dec.calendarId || c.calendarId,
          dateId: dec.dateId || c.dateId,
          text: dec.text || "",
          author: v.author || dec.author,
          createdAt: dec.createdAt || new Date(v.timestamp || 0).toISOString()
        })
      }
      notes.sort((a, b) => new Date(a.createdAt) - new Date(b.createdAt))
      return notes
    },

    async checkDueReminders() {
      if (!pmModel) return
      const ssbClient = await openSsb()
      const messages = await readAll(ssbClient)
      const now = Date.now()

      const sentMarkers = new Set()
      for (const m of messages) {
        const c = (m.value || {}).content
        if (!c || c.type !== "calendarReminderSent") continue
        const sig = c.occurrence ? `${c.calendarId}::${c.dateId}::${c.occurrence}` : `${c.calendarId}::${c.dateId}`
        sentMarkers.add(sig)
      }

      const authorByKey = new Map()
      for (const m of messages) authorByKey.set(m.key, (m.value || {}).author)
      const tombstoned = new Set()
      for (const m of messages) {
        const c = (m.value || {}).content
        if (c && c.type === "tombstone" && c.target) {
          const targetAuthor = authorByKey.get(c.target)
          if (targetAuthor && (m.value || {}).author === targetAuthor) tombstoned.add(c.target)
        }
      }

      const calendarInfo = new Map()
      const dueByCalendar = new Map()
      const dated = messages.filter(m => !tombstoned.has(m.key) && ((m.value || {}).content || {}).type === "calendarDate")
      const decoded = await Promise.all(dated.map(async (m) => {
        const c = m.value.content
        if (!(c.encryptedPayload && tribeCrypto && tribesModel)) return c
        const r = await tribeCrypto.decryptFromTribe(c, tribesModel)
        return !r || r._undecryptable ? null : r
      }))
      for (let i = 0; i < dated.length; i++) {
        const m = dated[i]
        const v = m.value || {}
        const c = v.content
        const dec = decoded[i]
        if (!dec || !dec.date) continue
        const calId = c.calendarId
        let info = calendarInfo.get(calId)
        if (info === undefined) {
          try {
            const cc = await this.getCalendarById(calId)
            info = cc ? { deadline: cc.deadline || "", members: await calendarMembers(cc) } : null
          } catch (_) { info = null }
          calendarInfo.set(calId, info)
        }
        if (!info || !info.members.has(v.author)) continue
        const calDeadline = info.deadline
        const hasInterval = !!(dec.intervalWeekly || dec.intervalMonthly || dec.intervalYearly)
        const ruleDeadline = dec.intervalDeadline || calDeadline
        const occurrences = (hasInterval && ruleDeadline)
          ? boundedOccurrences(dec.date, ruleDeadline, dec.intervalWeekly, dec.intervalMonthly, dec.intervalYearly)
          : [new Date(dec.date)]
        for (const occ of occurrences) {
          if (occ.getTime() > now) continue
          const occIso = occ.toISOString()
          const sig = hasInterval ? `${calId}::${m.key}::${occIso}` : `${calId}::${m.key}`
          if (sentMarkers.has(sig)) continue
          const entry = { key: m.key, calendarId: calId, date: occIso, label: dec.label || "", recurring: hasInterval }
          const list = dueByCalendar.get(calId) || []
          list.push(entry)
          dueByCalendar.set(calId, list)
        }
      }

      const publishMarker = (calendarId, dateId, occurrence) => new Promise((resolve, reject) => {
        const payload = {
          type: "calendarReminderSent",
          calendarId,
          dateId,
          sentAt: new Date().toISOString()
        }
        if (occurrence) payload.occurrence = occurrence
        ssbClient.publish(payload, (err) => err ? reject(err) : resolve())
      })

      for (const [calendarId, list] of dueByCalendar.entries()) {
        try {
          list.sort((a, b) => new Date(b.date) - new Date(a.date))
          const primary = list[0]
          const cal = await this.getCalendarById(calendarId)
          if (!cal) continue
          const participants = cal.participants.filter(p => typeof p === "string" && p.length > 0)
          if (participants.length > 0) {
            const notesForDay = await this.getNotesForDate(calendarId, primary.key)
            const notesBlock = notesForDay.length > 0
              ? notesForDay.map(n => `  - ${n.text}`).join("\n\n")
              : "  (no notes)"
            const subject = `Calendar Reminder: ${cal.title}`
            const text =
              `Reminder from: ${cal.author}\n` +
              `Title: ${cal.title}\n` +
              `Date: ${primary.label || primary.date}\n\n` +
              `Notes for this day:\n\n${notesBlock}\n\n` +
              `Visit Calendar: /calendars/${cal.rootId}`
            const chunkSize = 6
            for (let i = 0; i < participants.length; i += chunkSize) {
              await pmModel.sendMessage(participants.slice(i, i + chunkSize), subject, text)
            }
          }
          for (const dd of list) {
            try { await publishMarker(calendarId, dd.key, dd.recurring ? dd.date : null) } catch (_) {}
          }
        } catch (_) {}
      }
    },

    async generateInvite(calendarId, opts = {}) {
      const ssbClient = await openSsb()
      const userId = ssbClient.id
      const cal = await this.getCalendarById(calendarId)
      if (!cal) throw new Error("Calendar not found")
      if (cal.author !== userId) throw new Error("Only the author can generate invites")
      const code = crypto.randomBytes(INVITE_CODE_BYTES).toString("hex")
      let invite = code
      const calKey = !cal.tribeId ? lookupKey(cal.rootId) : null
      if (tribeCrypto && calKey) {
        const inviteSalt = tribeCrypto.generateInviteSalt()
        const ek = tribeCrypto.encryptForInvite(calKey, code, inviteSalt)
        invite = opts.public
          ? { code, ek, salt: inviteSalt, gen: lookupGen(cal.rootId), public: true }
          : { ch: tribeCrypto.hashInviteCode(code, inviteSalt), ek, salt: inviteSalt, gen: lookupGen(cal.rootId) }
      }
      if (opts.public && typeof invite !== "object") invite = { code, public: true }
      const tipId = await this.resolveCurrentId(calendarId)
      const item = await new Promise((resolve, reject) => ssbClient.get(tipId, (e, it) => e ? reject(e) : resolve(it)))
      const dec = await decryptScoped(item.content, cal.rootId)
      assertReadable(dec, "Calendar")
      const invites = [...(Array.isArray(dec.invites) ? dec.invites : []), invite]
      let updated = {
        type: "calendar",
        title: dec.title || "",
        status: dec.status || "OPEN",
        deadline: dec.deadline || "",
        tags: Array.isArray(dec.tags) ? dec.tags : [],
        mapUrl: dec.mapUrl || "",
        author: dec.author,
        participants: Array.isArray(dec.participants) ? dec.participants : [userId],
        invites,
        ...(dec.tribeId ? { tribeId: dec.tribeId } : {}),
        createdAt: dec.createdAt,
        updatedAt: new Date().toISOString(),
        replaces: tipId
      }
      if (updated.tribeId) updated = await encryptIfTribe(updated)
      else updated = encryptStandalone(updated, cal.rootId)
      await new Promise((resolve, reject) => ssbClient.publish(updated, (e, res) => e ? reject(e) : resolve(res)))
      const tombstone = { type: "tombstone", target: tipId, deletedAt: new Date().toISOString(), author: userId }
      await new Promise((resolve, reject) => ssbClient.publish(tombstone, e => e ? reject(e) : resolve()))
      return code
    },

    async getOpenInvite(calendarId) {
      return openInviteOf(await this.getCalendarById(calendarId).catch(() => null))
    },

    async generateOpenInvite(calendarId) {
      const cal = await this.getCalendarById(calendarId)
      if (!cal) throw new Error("Calendar not found")
      const existing = (Array.isArray(cal.invites) ? cal.invites : []).find(inv => typeof inv === "object" && inv.public === true)
      if (existing) throw new Error("An open invitation already exists")
      return this.generateInvite(calendarId, { public: true })
    },

    async removeOpenInvite(calendarId) {
      const ssbClient = await openSsb()
      const userId = ssbClient.id
      const cal = await this.getCalendarById(calendarId)
      if (!cal) throw new Error("Calendar not found")
      if (cal.author !== userId) throw new Error("Only the author can remove invites")
      const tipId = await this.resolveCurrentId(calendarId)
      const item = await new Promise((resolve, reject) => ssbClient.get(tipId, (e, it) => e ? reject(e) : resolve(it)))
      const dec = await decryptScoped(item.content, cal.rootId)
      assertReadable(dec, "Calendar")
      const invites = (Array.isArray(dec.invites) ? dec.invites : []).filter(inv => !(typeof inv === "object" && inv.public === true))
      let updated = {
        type: "calendar",
        title: dec.title || "",
        status: dec.status || "OPEN",
        deadline: dec.deadline || "",
        tags: Array.isArray(dec.tags) ? dec.tags : [],
        mapUrl: dec.mapUrl || "",
        author: dec.author,
        participants: Array.isArray(dec.participants) ? dec.participants : [userId],
        invites,
        ...(dec.tribeId ? { tribeId: dec.tribeId } : {}),
        createdAt: dec.createdAt,
        updatedAt: new Date().toISOString(),
        replaces: tipId
      }
      if (updated.tribeId) updated = await encryptIfTribe(updated)
      else updated = encryptStandalone(updated, cal.rootId)
      await new Promise((resolve, reject) => ssbClient.publish(updated, (e, res) => e ? reject(e) : resolve(res)))
      const tombstone = { type: "tombstone", target: tipId, deletedAt: new Date().toISOString(), author: userId }
      await new Promise((resolve, reject) => ssbClient.publish(tombstone, e => e ? reject(e) : resolve()))
      if (!dec.tribeId) await rotateCalendarKey(cal.rootId, Array.isArray(cal.participants) ? cal.participants : [])
    },

    async joinByInvite(code) {
      const ssbClient = await openSsb()
      const userId = ssbClient.id
      const calendars = await collectCalendars()
      let matched = null
      let matchedInvite = null
      for (const cal of calendars) {
        const invs = Array.isArray(cal.invites) ? cal.invites : []
        for (const inv of invs) {
          if (typeof inv === "string" && inv === code) { matched = cal; matchedInvite = inv; break }
          if (typeof inv === "object" && inv && (inv.code === code || (inv.ch && tribeCrypto && inv.ch === tribeCrypto.hashInviteCode(code, inv.salt)))) { matched = cal; matchedInvite = inv; break }
        }
        if (matched) break
      }
      if (!matched) throw new Error("Invalid or expired invite code")
      if (matched.participants.includes(userId)) throw new Error("Already a participant")
      if (typeof matchedInvite === "object" && matchedInvite.ch && tribeCrypto && matchedInvite.ek) {
        let probeKey = null
        try { probeKey = tribeCrypto.decryptFromInvite(matchedInvite.ek, code, matchedInvite.salt) } catch (_) {}
        const messages = await readAll(await openSsb())
        const spent = messages.some(m => {
          const c = m.value && m.value.content
          return c && c.type === "calendarParticipant" && c.on !== false && c.target === matched.rootId && c.code === matchedInvite.ch && m.value.author !== userId && (!probeKey || keyProofFor(probeKey, m.value.author) === c.keyProof)
        })
        if (spent) throw new Error("Invite already used")
      }
      let calKey = null
      if (tribeCrypto && typeof matchedInvite === "object") {
        if (matchedInvite.ekChain) {
          const chain = tribeCrypto.decryptChainFromInvite(matchedInvite.ekChain, code, matchedInvite.salt, 3)
          if (Array.isArray(chain) && chain.length) {
            for (const entry of chain) {
              if (Array.isArray(entry.keys) && entry.keys.length) {
                tribeCrypto.setKeys(entry.rootId, entry.keys, entry.gen || entry.keys.length)
              } else if (entry.key) {
                tribeCrypto.setKey(entry.rootId, entry.key, entry.gen || 1)
              }
            }
            calKey = chain[0].key
          }
        } else if (matchedInvite.ek) {
          calKey = tribeCrypto.decryptFromInvite(matchedInvite.ek, code, matchedInvite.salt)
          ownCrypto.setKey(matched.rootId, calKey, matchedInvite.gen || 1)
        }
      }
      const tipId = await this.resolveCurrentId(matched.rootId)
      const item = await new Promise((resolve, reject) => ssbClient.get(tipId, (e, it) => e ? reject(e) : resolve(it)))
      const dec = await decryptScoped(item.content, matched.rootId)
      assertReadable(dec, "Calendar")
      const isPublicInvite = typeof matchedInvite === "object" && matchedInvite.public === true
      const invites = isPublicInvite
        ? (Array.isArray(dec.invites) ? dec.invites : [])
        : (Array.isArray(dec.invites) ? dec.invites : []).filter(inv => {
            if (typeof inv === "string") return inv !== code
            return inv.code !== code
          })
      let updated = {
        type: "calendar",
        title: dec.title || "",
        status: dec.status || "OPEN",
        deadline: dec.deadline || "",
        tags: Array.isArray(dec.tags) ? dec.tags : [],
        mapUrl: dec.mapUrl || "",
        author: dec.author,
        participants: [...(Array.isArray(dec.participants) ? dec.participants : []), userId],
        invites,
        ...(dec.tribeId ? { tribeId: dec.tribeId } : {}),
        createdAt: dec.createdAt,
        updatedAt: new Date().toISOString(),
        replaces: tipId
      }
      if (updated.tribeId) updated = await encryptIfTribe(updated)
      else updated = encryptStandalone(updated, matched.rootId)
      await new Promise((resolve, reject) => ssbClient.publish(updated, (e, res) => e ? reject(e) : resolve(res)))
      const tombstone = { type: "tombstone", target: tipId, deletedAt: new Date().toISOString(), author: userId }
      await new Promise((resolve, reject) => ssbClient.publish(tombstone, e => e ? reject(e) : resolve()))
      if (tribeCrypto && calKey) {
        try {
          const ssbKeys = require("../server/node_modules/ssb-keys")
          const memberKeys = {}
          try { memberKeys[userId] = tribeCrypto.boxKeyForMember(calKey, userId, ssbKeys) } catch (_) {}
          if (matched.author && matched.author !== userId) {
            try { memberKeys[matched.author] = tribeCrypto.boxKeyForMember(calKey, matched.author, ssbKeys) } catch (_) {}
          }
          if (Object.keys(memberKeys).length) {
            await new Promise((resolve) => {
              ssbClient.publish({ type: "tribe-keys", tribeId: matched.rootId, generation: lookupGen(matched.rootId) || 1, memberKeys }, () => resolve())
            })
          }
        } catch (_) {}
      }
      await new Promise((resolve, reject) => ssbClient.publish({ type: "calendarParticipant", target: matched.rootId, on: true, ...(calKey ? { keyProof: keyProofFor(calKey, userId) } : {}), ...(matchedInvite && typeof matchedInvite === "object" && matchedInvite.ch ? { code: matchedInvite.ch } : {}), createdAt: new Date().toISOString() }, (e, res) => e ? reject(e) : resolve(res)))
      return matched.rootId
    }
  }
}