Function buildThreadHistorySlice

shared/thread-history.ts:140–175

(
  pathEntries: SessionPathEntry[],
  revealedCompactions: number,
)

}

export function buildThreadHistorySlice(
  pathEntries: SessionPathEntry[],
  revealedCompactions: number,
) {
  const selectedCompactionIndex = getSelectedCompactionIndex(pathEntries, revealedCompactions)
  if (selectedCompactionIndex === -1) {
    return {
      sourceMessages: buildSourceMessagesFromPathEntries(pathEntries),
      previousMessageCount: 0,
    }
  }

  const selectedCompaction = pathEntries[selectedCompactionIndex]
  const firstKeptEntryId = selectedCompaction?.firstKeptEntryId
  const firstKeptIndex = firstKeptEntryId ? findEntryIndexById(pathEntries, firstKeptEntryId) : -1

  if (!selectedCompaction || firstKeptIndex === -1 || firstKeptIndex > selectedCompactionIndex) {
    return {
      sourceMessages: buildSourceMessagesFromPathEntries(pathEntries),
      previousMessageCount: 0,
    }
  }

  const sourceMessages: AgentMessage[] = []
  appendSourceMessagesFromEntryRange(
    sourceMessages,
    pathEntries,
    firstKeptIndex,
    pathEntries.length,
  )

  return {
    sourceMessages,
    previousMessageCount: countDisplayableEntriesInRange(pathEntries, 0, firstKeptIndex),
  }
}