import { test, expect, mock } from "bun:test";
import { readUnion } from "../src/read-model";
import { configure, configureStoreRegistry } from "../src/polyfill";

// A fake `ng` whose sparql_query answers the ANCHORED per-doc query (SELECT ?s ?p ?o
// WHERE { ?s ?p ?o }, anchor = the doc NURI) with ONLY that doc's triples. There is
// NO anchorless union scan: each doc is read independently by its own anchor. Each
// entity subject IRI IS its own document NURI (writeEntity convention), so the
// fixture keys triples by the doc NURI and returns them for the matching anchor.
function fakeNgWith(triplesByDoc: Record<string, Array<[string, string]>>) {
  return {
    doc_create: mock(async () => "did:ng:o:new"),
    sparql_update: mock(async () => undefined),
    sparql_query: mock(async (_sid: string, _query: string, _base: unknown, anchor: unknown) => {
      // Every read is ANCHORED to one doc NURI — never anchorless.
      if (anchor === undefined) {
        throw new Error("read-model must NEVER run an anchorless (union) query");
      }
      const doc = anchor as string;
      const triples = triplesByDoc[doc];
      if (!triples) return { results: { bindings: [] } };
      const bindings = triples.map(([p, o]) => ({
        s: { value: doc },
        p: { value: p },
        o: { value: o },
      }));
      return { results: { bindings } };
    }),
  };
}

function inject(triplesByDoc: Record<string, Array<[string, string]>>) {
  const ng = fakeNgWith(triplesByDoc);
  configure({ ng: ng as any, useShape: (() => {}) as any });
  configureStoreRegistry({
    getSession: async () => ({ sessionId: "sid-rm", privateStoreId: "priv" }),
    normalizeUser: (u: string) => u,
  });
  return ng;
}

const TYPE = "http://www.w3.org/1999/02/22-rdf-syntax-ns#type";
const FP = "http://festipod.org/";

test("readUnion reads each doc with its OWN anchored query (never anchorless)", async () => {
  const ng = inject({
    "did:ng:o:a": [[TYPE, `${FP}Event`], [`${FP}title`, "A"]],
    "did:ng:o:b": [[TYPE, `${FP}Event`], [`${FP}title`, "B"]],
  });
  const subjects = await readUnion(["did:ng:o:a", "did:ng:o:b"]);

  // One anchored query per doc = 2 sparql_query calls, each anchored (c[3] set).
  expect(ng.sparql_query).toHaveBeenCalledTimes(2);
  const anchored = ng.sparql_query.mock.calls.filter((c: unknown[]) => c[3] !== undefined);
  expect(anchored.length).toBe(2);
  // The anchors are exactly the requested doc NURIs.
  expect(new Set(anchored.map((c: unknown[]) => c[3]))).toEqual(
    new Set(["did:ng:o:a", "did:ng:o:b"]),
  );

  expect(subjects.length).toBe(2);
  const a = subjects.find((s) => s.subject === "did:ng:o:a")!;
  expect(a.props[`${FP}title`]).toEqual(["A"]);
  expect(a.graph).toBe("did:ng:o:a");
});

test("readUnion groups predicates per subject", async () => {
  inject({
    "did:ng:o:p": [
      [TYPE, `${FP}Participation`],
      [`${FP}event`, "did:ng:o:e"],
      [`${FP}user`, "urn:festipod:user:x"],
    ],
  });
  const s = (await readUnion(["did:ng:o:p"]))[0]!;
  expect(s.subject).toBe("did:ng:o:p");
  expect(s.props[`${FP}event`]).toEqual(["did:ng:o:e"]);
  expect(s.props[`${FP}user`]).toEqual(["urn:festipod:user:x"]);
});

test("readUnion returns [] for an empty doc set (no query)", async () => {
  const ng = inject({});
  const subjects = await readUnion([]);
  expect(subjects).toEqual([]);
  expect(ng.sparql_query).toHaveBeenCalledTimes(0);
});

test("a doc that fails to read is skipped, not aborting the batch", async () => {
  const ng = fakeNgWith({ "did:ng:o:ok": [[TYPE, `${FP}Event`], [`${FP}title`, "ok"]] });
  const orig = ng.sparql_query;
  // Make the anchored read throw for the bad doc only.
  ng.sparql_query = mock(async (sid: string, query: string, base: unknown, anchor: unknown) => {
    if (anchor === "did:ng:o:bad") throw new Error("RepoNotFound");
    return orig(sid, query, base, anchor);
  }) as any;
  configure({ ng: ng as any, useShape: (() => {}) as any });
  configureStoreRegistry({
    getSession: async () => ({ sessionId: "sid-rm", privateStoreId: "priv" }),
    normalizeUser: (u: string) => u,
  });

  const subjects = await readUnion(["did:ng:o:ok", "did:ng:o:bad"]);
  // The bad doc failed its read but the good one still lists.
  expect(subjects.map((s) => s.subject)).toEqual(["did:ng:o:ok"]);
});