Function detectMultiClauding

src/commands/insights.ts:1062–1143

(
  sessions: Array<{
    session_id: string
    user_message_timestamps: string[]
  }>,
)

 * within a 30-minute window.
 */
export function detectMultiClauding(
  sessions: Array<{
    session_id: string
    user_message_timestamps: string[]
  }>,
): {
  overlap_events: number
  sessions_involved: number
  user_messages_during: number
} {
  const OVERLAP_WINDOW_MS = 30 * 60000
  const allSessionMessages: Array<{ ts: number; sessionId: string }> = []

  for (const session of sessions) {
    for (const timestamp of session.user_message_timestamps) {
      try {
        const ts = new Date(timestamp).getTime()
        allSessionMessages.push({ ts, sessionId: session.session_id })
      } catch {
        // Skip invalid timestamps
      }
    }
  }

  allSessionMessages.sort((a, b) => a.ts - b.ts)

  const multiClaudeSessionPairs = new Set<string>()
  const messagesDuringMulticlaude = new Set<string>()

  // Sliding window: sessionLastIndex tracks the most recent index for each session
  let windowStart = 0
  const sessionLastIndex = new Map<string, number>()

  for (let i = 0; i < allSessionMessages.length; i++) {
    const msg = allSessionMessages[i]!

    // Shrink window from the left
    while (
      windowStart < i &&
      msg.ts - allSessionMessages[windowStart]!.ts > OVERLAP_WINDOW_MS
    ) {
      const expiring = allSessionMessages[windowStart]!
      if (sessionLastIndex.get(expiring.sessionId) === windowStart) {
        sessionLastIndex.delete(expiring.sessionId)
      }
      windowStart++
    }

    // Check if this session appeared earlier in the window (pattern: s1 -> s2 -> s1)
    const prevIndex = sessionLastIndex.get(msg.sessionId)
    if (prevIndex !== undefined) {
      for (let j = prevIndex + 1; j < i; j++) {
        const between = allSessionMessages[j]!
        if (between.sessionId !== msg.sessionId) {
          const pair = [msg.sessionId, between.sessionId].sort().join(':')
          multiClaudeSessionPairs.add(pair)
          messagesDuringMulticlaude.add(
            `${allSessionMessages[prevIndex]!.ts}:${msg.sessionId}`,