import { randomUUID } from 'node:crypto'

// ---------- Types ----------

export interface UserRecord {
  username: string
  createdAt: Date
}

export interface EnvironmentRecord {
  id: string
  secret: string
  machineName: string | null
  directory: string | null
  branch: string | null
  gitRepoUrl: string | null
  maxSessions: number
  workerType: string
  bridgeId: string | null
  capabilities: Record<string, unknown> | null
  status: string
  username: string | null
  lastPollAt: Date | null
  createdAt: Date
  updatedAt: Date
}

export interface SessionRecord {
  id: string
  environmentId: string | null
  title: string | null
  status: string
  source: string
  permissionMode: string | null
  workerEpoch: number
  username: string | null
  createdAt: Date
  updatedAt: Date
}

export interface WorkItemRecord {
  id: string
  environmentId: string
  sessionId: string
  state: string
  secret: string
  createdAt: Date
  updatedAt: Date
}

export interface SessionWorkerRecord {
  sessionId: string
  workerStatus: string | null
  externalMetadata: Record<string, unknown> | null
  requiresActionDetails: Record<string, unknown> | null
  lastHeartbeatAt: Date | null
  createdAt: Date
  updatedAt: Date
}

// ---------- Stores (in-memory Maps) ----------

const users = new Map<string, UserRecord>()
const tokenToUser = new Map<string, { username: string; createdAt: Date }>()
const environments = new Map<string, EnvironmentRecord>()
const sessions = new Map<string, SessionRecord>()
const workItems = new Map<string, WorkItemRecord>()
const sessionWorkers = new Map<string, SessionWorkerRecord>()

// UUID → session ownership: sessionId → Set of UUIDs
const sessionOwners = new Map<string, Set<string>>()

// ---------- User ----------

export function storeCreateUser(username: string): UserRecord {
  const existing = users.get(username)
  if (existing) return existing
  const record: UserRecord = { username, createdAt: new Date() }
  users.set(username, record)
  return record
}

export function storeGetUser(username: string): UserRecord | undefined {
  return users.get(username)
}

export function storeCreateToken(username: string, token: string): void {
  tokenToUser.set(token, { username, createdAt: new Date() })
}

export function storeGetUserByToken(
  token: string,
): { username: string; createdAt: Date } | undefined {
  return tokenToUser.get(token)
}

export function storeDeleteToken(token: string): boolean {
  return tokenToUser.delete(token)
}

// ---------- Environment ----------

export function storeCreateEnvironment(req: {
  secret: string
  machineName?: string
  directory?: string
  branch?: string
  gitRepoUrl?: string
  maxSessions?: number
  workerType?: string
  bridgeId?: string
  username?: string
  capabilities?: Record<string, unknown>
}): EnvironmentRecord {
  const id = `env_${randomUUID().replace(/-/g, '')}`
  const now = new Date()
  const record: EnvironmentRecord = {
    id,
    secret: req.secret,
    machineName: req.machineName ?? null,
    directory: req.directory ?? null,
    branch: req.branch ?? null,
    gitRepoUrl: req.gitRepoUrl ?? null,
    maxSessions: req.maxSessions ?? 1,
    workerType: req.workerType ?? 'claude_code',
    bridgeId: req.bridgeId ?? null,
    capabilities: req.capabilities ?? null,
    status: 'active',
    username: req.username ?? null,
    lastPollAt: now,
    createdAt: now,
    updatedAt: now,
  }
  environments.set(id, record)
  return record
}

export function storeGetEnvironment(id: string): EnvironmentRecord | undefined {
  return environments.get(id)
}

export function storeUpdateEnvironment(
  id: string,
  patch: Partial<
    Pick<
      EnvironmentRecord,
      | 'status'
      | 'lastPollAt'
      | 'updatedAt'
      | 'capabilities'
      | 'machineName'
      | 'maxSessions'
      | 'bridgeId'
    >
  >,
): boolean {
  const rec = environments.get(id)
  if (!rec) return false
  Object.assign(rec, patch, { updatedAt: new Date() })
  return true
}

export function storeListActiveEnvironments(): EnvironmentRecord[] {
  return [...environments.values()].filter(e => e.status === 'active')
}

export function storeListActiveEnvironmentsByUsername(
  username: string,
): EnvironmentRecord[] {
  return [...environments.values()].filter(
    e => e.status === 'active' && e.username === username,
  )
}

// ---------- Session ----------

export function storeCreateSession(req: {
  environmentId?: string | null
  title?: string | null
  source?: string
  permissionMode?: string | null
  idPrefix?: string
  username?: string | null
}): SessionRecord {
  const id = `${req.idPrefix || 'session_'}${randomUUID().replace(/-/g, '')}`
  const now = new Date()
  const record: SessionRecord = {
    id,
    environmentId: req.environmentId ?? null,
    title: req.title ?? null,
    status: 'idle',
    source: req.source ?? 'remote-control',
    permissionMode: req.permissionMode ?? null,
    workerEpoch: 0,
    username: req.username ?? null,
    createdAt: now,
    updatedAt: now,
  }
  sessions.set(id, record)
  return record
}

export function storeGetSession(id: string): SessionRecord | undefined {
  return sessions.get(id)
}

export function storeUpdateSession(
  id: string,
  patch: Partial<
    Pick<SessionRecord, 'title' | 'status' | 'workerEpoch' | 'updatedAt'>
  >,
): boolean {
  const rec = sessions.get(id)
  if (!rec) return false
  Object.assign(rec, patch, { updatedAt: new Date() })
  return true
}

export function storeListSessions(): SessionRecord[] {
  return [...sessions.values()]
}

export function storeListSessionsByUsername(username: string): SessionRecord[] {
  return [...sessions.values()].filter(s => s.username === username)
}

export function storeListSessionsByEnvironment(envId: string): SessionRecord[] {
  return [...sessions.values()].filter(s => s.environmentId === envId)
}

export function storeDeleteSession(id: string): boolean {
  sessionWorkers.delete(id)
  return sessions.delete(id)
}

// ---------- Session Worker ----------

export function storeGetSessionWorker(
  sessionId: string,
): SessionWorkerRecord | undefined {
  return sessionWorkers.get(sessionId)
}

export function storeUpsertSessionWorker(
  sessionId: string,
  patch: {
    workerStatus?: string | null
    externalMetadata?: Record<string, unknown> | null
    requiresActionDetails?: Record<string, unknown> | null
    lastHeartbeatAt?: Date | null
  },
): SessionWorkerRecord {
  const now = new Date()
  const existing = sessionWorkers.get(sessionId)
  const record: SessionWorkerRecord = existing ?? {
    sessionId,
    workerStatus: null,
    externalMetadata: null,
    requiresActionDetails: null,
    lastHeartbeatAt: null,
    createdAt: now,
    updatedAt: now,
  }

  if (patch.workerStatus !== undefined) {
    record.workerStatus = patch.workerStatus
  }
  if (patch.externalMetadata !== undefined) {
    if (patch.externalMetadata === null) {
      record.externalMetadata = null
    } else {
      record.externalMetadata = {
        ...(record.externalMetadata ?? {}),
        ...patch.externalMetadata,
      }
    }
  }
  if (patch.requiresActionDetails !== undefined) {
    record.requiresActionDetails = patch.requiresActionDetails
  }
  if (patch.lastHeartbeatAt !== undefined) {
    record.lastHeartbeatAt = patch.lastHeartbeatAt
  }
  record.updatedAt = now

  sessionWorkers.set(sessionId, record)
  return record
}

// ---------- Work Items ----------

// ---------- Session Ownership (UUID-based) ----------

export function storeBindSession(sessionId: string, uuid: string): void {
  let owners = sessionOwners.get(sessionId)
  if (!owners) {
    owners = new Set()
    sessionOwners.set(sessionId, owners)
  }
  owners.add(uuid)
}

export function storeIsSessionOwner(sessionId: string, uuid: string): boolean {
  const owners = sessionOwners.get(sessionId)
  return owners ? owners.has(uuid) : false
}

export function storeGetSessionOwners(
  sessionId: string,
): Set<string> | undefined {
  return sessionOwners.get(sessionId)
}

export function storeListSessionsByOwnerUuid(uuid: string): SessionRecord[] {
  const result: SessionRecord[] = []
  const resultIds = new Set<string>()

  // Collect sessions already owned by this UUID
  for (const [sessionId, owners] of sessionOwners) {
    if (owners.has(uuid)) {
      const session = sessions.get(sessionId)
      if (session) {
        result.push(session)
        resultIds.add(sessionId)
      }
    }
  }

  // Auto-bind orphaned sessions (no owner — typically ACP agent sessions created via REST registration)
  for (const [sessionId, session] of sessions) {
    if (resultIds.has(sessionId)) continue
    const owners = sessionOwners.get(sessionId)
    // No owners map entry at all, or empty owners set
    const isOrphaned = !owners || owners.size === 0
    if (isOrphaned) {
      storeBindSession(sessionId, uuid)
      result.push(session)
      resultIds.add(sessionId)
    }
  }

  return result
}

// ---------- Work Items (cont.) ----------

export function storeCreateWorkItem(req: {
  environmentId: string
  sessionId: string
  secret: string
}): WorkItemRecord {
  const id = `work_${randomUUID().replace(/-/g, '')}`
  const now = new Date()
  const record: WorkItemRecord = {
    id,
    environmentId: req.environmentId,
    sessionId: req.sessionId,
    state: 'pending',
    secret: req.secret,
    createdAt: now,
    updatedAt: now,
  }
  workItems.set(id, record)
  return record
}

export function storeGetWorkItem(id: string): WorkItemRecord | undefined {
  return workItems.get(id)
}

export function storeGetPendingWorkItem(
  environmentId: string,
): WorkItemRecord | undefined {
  for (const item of workItems.values()) {
    if (item.environmentId === environmentId && item.state === 'pending') {
      return item
    }
  }
  return undefined
}

export function storeUpdateWorkItem(
  id: string,
  patch: Partial<Pick<WorkItemRecord, 'state' | 'updatedAt'>>,
): boolean {
  const rec = workItems.get(id)
  if (!rec) return false
  Object.assign(rec, patch, { updatedAt: new Date() })
  return true
}

// ---------- ACP Agent (reuses EnvironmentRecord with workerType="acp") ----------

/** List all ACP agents (environments with workerType="acp") */
export function storeListAcpAgents(): EnvironmentRecord[] {
  return [...environments.values()].filter(e => e.workerType === 'acp')
}

/** List ACP agents by channel group (stored in bridgeId field) */
export function storeListAcpAgentsByChannelGroup(
  channelGroupId: string,
): EnvironmentRecord[] {
  return [...environments.values()].filter(
    e => e.workerType === 'acp' && e.bridgeId === channelGroupId,
  )
}

/** List online ACP agents */
export function storeListOnlineAcpAgents(): EnvironmentRecord[] {
  return [...environments.values()].filter(
    e => e.workerType === 'acp' && e.status === 'active',
  )
}

/** Mark an ACP agent as offline */
export function storeMarkAcpAgentOffline(id: string): boolean {
  const rec = environments.get(id)
  if (!rec || rec.workerType !== 'acp') return false
  Object.assign(rec, { status: 'offline', updatedAt: new Date() })
  return true
}

/** Mark an ACP agent as online (on reconnect) */
export function storeMarkAcpAgentOnline(id: string): boolean {
  const rec = environments.get(id)
  if (!rec || rec.workerType !== 'acp') return false
  Object.assign(rec, {
    status: 'active',
    lastPollAt: new Date(),
    updatedAt: new Date(),
  })
  return true
}

// ---------- Reset (for tests) ----------

export function storeReset() {
  users.clear()
  tokenToUser.clear()
  environments.clear()
  sessions.clear()
  workItems.clear()
  sessionWorkers.clear()
  sessionOwners.clear()
}