// A project's automatic PDF indexing (template lesson core-11): an administrator opts the project in,
// naming the collection its uploaded PDFs go into; no row is off. The administrator is recorded,
// because the indexing job runs for nobody and re-checks that person's permission before each file.

import { forbidden } from "@conusai-kit/core"
import { autoIndex } from "../contract/index.js"
import { requireCollection } from "./collections.js"
import { type KnowledgeDeps, type KnowledgeScope, knowledgeEnabled } from "./ports.js"

export interface AutoIndexView {
  /** The collection uploaded PDFs are indexed into, or null when automatic indexing is off. */
  collectionName: string | null
}

export async function getAutoIndex(deps: Pick<KnowledgeDeps, "data">, scope: KnowledgeScope): Promise<AutoIndexView> {
  const row = (await deps.data.forScope(scope).of(autoIndex).list({ limit: 1 })).items[0]
  return { collectionName: row?.collectionName ?? null }
}

/** Turns automatic indexing on into `collectionName` (which must exist), or off with `null`. */
export async function setAutoIndex(
  deps: KnowledgeDeps & { now?: () => number },
  scope: KnowledgeScope,
  collectionName: string | null,
): Promise<AutoIndexView> {
  if (collectionName !== null) {
    // The tenant-wall read first: another project's collection answers NotFound, never a policy refusal.
    await requireCollection(deps, scope, collectionName)
    if (!(await knowledgeEnabled(deps, scope))) throw forbidden("knowledge is switched off for this project")
  }
  await deps.data.unitOfWork.run(scope, async (tx) => {
    const row = (await tx.of(autoIndex).list({ limit: 1 })).items[0]
    if (collectionName === null) {
      if (row) await tx.of(autoIndex).delete(row.id)
      return
    }
    const patch = {
      collectionName,
      enabledBy: scope.actor.userId,
      enabledAt: new Date((deps.now ?? Date.now)()).toISOString(),
    }
    if (row) await tx.of(autoIndex).update(row.id, patch, row.version)
    else await tx.of(autoIndex).insert(patch)
  })
  return { collectionName }
}