// The status a page reads: the module flag, the search service's readiness (separate from the
// indexing indicator, which is the per-document rows), and the document counts by progress state.

import { type DocumentStatus, documents } from "../contract/index.js"
import { type KnowledgeDeps, type KnowledgeScope, knowledgeEnabled } from "./ports.js"

const PAGE = 200

export interface KnowledgeStatus {
  enabled: boolean
  service: { state: "registered" | "indexing" | "ready" | "degraded" | "disabled" | "unavailable"; reasons: string[] }
  documents: Record<DocumentStatus, number>
}

export async function knowledgeStatusOf(deps: KnowledgeDeps, scope: KnowledgeScope): Promise<KnowledgeStatus> {
  const counts: Record<DocumentStatus, number> = { queued: 0, indexing: 0, indexed: 0, failed: 0, cancelled: 0 }
  let cursor: string | undefined
  for (;;) {
    const page = await deps.data
      .forScope(scope)
      .of(documents)
      .list({ limit: PAGE, ...(cursor === undefined ? {} : { cursor }) })
    for (const row of page.items) counts[row.status as DocumentStatus] += 1
    if (!page.hasMore) break
    cursor = page.cursor
  }
  const enabled = await knowledgeEnabled(deps, scope)
  const readiness =
    deps.search === undefined
      ? { state: "unavailable" as const, reasons: ["the knowledge search service is not bound in this process"] }
      : await deps.search.readiness(scope).catch((error: unknown) => ({
          state: "unavailable" as const,
          reasons: [
            error instanceof Error
              ? (error.message.split("\n")[0] ?? error.message)
              : "the search service did not answer",
          ],
        }))
  return { enabled, service: readiness, documents: counts }
}