import { expect, mock, test } from "bun:test";
import { indexing } from "../src/indexing";
import { curate } from "../src/curator";
import { entriesOf, entryValue } from "../src/index-document";
import { resolutionFromFailure, resolutionFromRead } from "../src/resolution";
import type { Nuri, UnionSubject } from "../src/port";
import { ENTRY_VALUE, INDEX_FIELD } from "../src/vocabulary";
import { FakeNextGraph, publishObject } from "./fake-nextgraph";

/**
 * The invariant this package is built around — an index only ever grows — and the
 * hole that was in it.
 *
 * `entriesOf` used to require EXACTLY ONE value per entry, so a subject carrying
 * two read as absent. An index could therefore SHRINK through nothing but
 * additions: no delete involved, the guarantee defeated by the one operation
 * meant to uphold it. These tests pin the fix at both levels.
 */

const FIELD = "http://schema.org/datePublished";

function subject(iri: string, values: string[]): UnionSubject {
  return { subject: iri, graph: "did:ng:o:index" as Nuri, props: { [ENTRY_VALUE]: values } };
}

test("an entry with several values still reads as one entry, deterministically", () => {
  const s = subject("did:ng:o:a", ["2026-02-02", "2026-01-01"]);
  expect(entryValue(s)).toBe("2026-01-01");
  // Order of arrival must not change the answer: two readers must agree.
  expect(entryValue(subject("did:ng:o:a", ["2026-01-01", "2026-02-02"]))).toBe("2026-01-01");
});

test("a subject with no value at all is not an entry", () => {
  expect(entryValue({ subject: "did:ng:o:a", graph: "did:ng:o:i" as Nuri, props: {} })).toBeUndefined();
  expect(entryValue(subject("did:ng:o:a", []))).toBeUndefined();
});

test("entriesOf keeps a multi-valued entry instead of dropping it", () => {
  const index = "did:ng:o:index" as Nuri;
  const entries = entriesOf([subject("did:ng:o:a", ["2026-02-02", "2026-01-01"])], index);
  expect(entries).toEqual([{ object: "did:ng:o:a" as Nuri, value: "2026-01-01" }]);
});

test("one stray non-NURI subject cannot make every real entry unreadable", () => {
  const index = "did:ng:o:index" as Nuri;
  // An index document is an ordinary document; its owner may put anything in it.
  // This used to THROW out of `entriesOf`, losing the whole index to one triple.
  const entries = entriesOf(
    [
      subject("http://example.org/not-a-nuri", ["2026-02-02"]),
      subject("did:ng:o:real", ["2026-01-01"]),
    ],
    index,
  );
  expect(entries).toEqual([{ object: "did:ng:o:real" as Nuri, value: "2026-01-01" }]);
});

test("an entry whose value is the empty string is still an entry", () => {
  const index = "did:ng:o:index" as Nuri;
  expect(entriesOf([subject("did:ng:o:a", [""])], index)).toEqual([
    { object: "did:ng:o:a" as Nuri, value: "" },
  ]);
});

test("adding a second value to an entry cannot make it disappear", async () => {
  const network = new FakeNextGraph();
  const ownerPort = network.portFor("alice");
  const owner = await indexing(ownerPort);
  const index = await owner.createIndex(FIELD);
  const article = await publishObject(network.portFor("bob"), FIELD, "2026-01-01");
  await (await indexing(network.portFor("bob"))).refer(index, article);
  await curate(ownerPort, index);

  // A pure ADD — the only write this package has. Before the fix this emptied
  // `read()` while both triples sat in the document.
  await ownerPort.addLiteralProperty(index, article, ENTRY_VALUE, "2026-02-02");

  expect(await owner.read(index)).toEqual([{ object: article, value: "2026-01-01" }]);
});

test("a raced double-add settles, and does not make every later run re-add", async () => {
  const network = new FakeNextGraph();
  const ownerPort = network.portFor("alice");
  const owner = await indexing(ownerPort);
  const index = await owner.createIndex(FIELD);
  const bobPort = network.portFor("bob");
  const article = await publishObject(bobPort, FIELD, "2026-01-01");
  await (await indexing(bobPort)).refer(index, article);
  await curate(ownerPort, index);

  // What two curation runs racing each other leave behind: the object's owner
  // edited it between their reads, so each added its own value.
  network.ownerReplacesValue(article, article, FIELD, "2026-02-02");
  await ownerPort.addLiteralProperty(index, article, ENTRY_VALUE, "2026-02-02");

  // The entry is still there, and the curator recognises it as already indexed —
  // before the fix it was invisible, so every run added yet another value.
  const report = await curate(ownerPort, index);
  expect(report.outcomes).toEqual([{ result: "unchanged", object: article }]);
  expect(await owner.read(index)).toEqual([{ object: article, value: "2026-01-01" }]);
});

// --- the descriptor follows the SAME rule, for the same reason ------------

test("a second declared field stops curation LOUDLY and costs no entry", async () => {
  const network = new FakeNextGraph();
  const ownerPort = network.portFor("alice");
  const owner = await indexing(ownerPort);
  const bobPort = network.portFor("bob");
  const index = await owner.createIndex(FIELD);
  for (const date of ["2026-01-01", "2026-02-02", "2026-03-03"]) {
    await (await indexing(bobPort)).refer(index, await publishObject(bobPort, FIELD, date));
  }
  await curate(ownerPort, index);
  expect(await owner.read(index)).toHaveLength(3);

  // One add-only write through the published surface — and the SMALLER string, the
  // direction in which "smallest wins" would have switched the index onto it.
  await ownerPort.addLiteralProperty(index, index, INDEX_FIELD, "http://schema.org/aaa");

  // Reading is untouched: an entry already written is a fact, and does not become
  // unreadable because the declaration above it turned ambiguous.
  expect(await owner.read(index)).toHaveLength(3);
  // Curating refuses, and says why instead of quietly picking one.
  await expect(curate(ownerPort, index)).rejects.toThrow(/declares 2 index fields/);
});

test("a mixed-field index is never produced: curation refuses before adding anything", async () => {
  const network = new FakeNextGraph();
  const ownerPort = network.portFor("alice");
  const owner = await indexing(ownerPort);
  const bobPort = network.portFor("bob");
  const NAME = "http://schema.org/name";

  const index = await owner.createIndex(NAME);
  const first = await publishObject(bobPort, NAME, "Anemone");
  await (await indexing(bobPort)).refer(index, first);
  await curate(ownerPort, index);

  // "…/datePublished" < "…/name", so under "smallest wins" the new field took over
  // while `first` kept its old value forever — one list ordered by two properties.
  await ownerPort.addLiteralProperty(index, index, INDEX_FIELD, FIELD);
  const second = await publishObject(bobPort, FIELD, "2026-02-02");
  await (await indexing(bobPort)).refer(index, second);

  await expect(curate(ownerPort, index)).rejects.toThrow(/refusing to curate rather than pick one/);
  expect(await owner.read(index)).toEqual([{ object: first, value: "Anemone" }]);
});

test("an index declaring no field at all is still refused", async () => {
  const network = new FakeNextGraph();
  const ownerPort = network.portFor("alice");
  const ordinary = await ownerPort.createPublicDocument();
  await expect((await indexing(ownerPort)).read(ordinary)).rejects.toThrow(/declares no index field/);
});

test("a field that could never match an object is refused at creation", async () => {
  const owner = await indexing(new FakeNextGraph().portFor("alice"));
  // It cannot be corrected later — nothing here deletes — so it is refused now.
  await expect(owner.createIndex("")).rejects.toThrow(/cannot be changed later/);
  await expect(owner.createIndex("   ")).rejects.toThrow(/cannot be changed later/);
});

// --- a field named like an Object.prototype member ------------------------

test("a field colliding with Object.prototype neither crashes nor is silently mis-read", async () => {
  const network = new FakeNextGraph();
  const ownerPort = network.portFor("alice");
  const owner = await indexing(ownerPort);
  const bobPort = network.portFor("bob");

  for (const field of ["constructor", "toString", "valueOf", "hasOwnProperty"]) {
    const index = await owner.createIndex(field);
    // An object that CARRIES such a predicate cannot be read at all: `readUnion`
    // fills `props` with `(props[p] ??= []).push(o)`, and `??=` does not assign
    // over the inherited member, so `.push` is undefined and the read throws.
    // Upstream's behaviour, mirrored by the double — so this comes back as a
    // failure to resolve, NOT as an entry.
    const carries = await publishObject(bobPort, field, "a value");
    // An object that merely LACKS it must still resolve cleanly: reading the field
    // off a plain object literal would otherwise hand back an inherited function.
    const lacks = await publishObject(bobPort, "http://schema.org/name", "unrelated");
    await (await indexing(bobPort)).refer(index, lacks);
    await (await indexing(bobPort)).refer(index, carries);

    const report = await curate(ownerPort, index);
    expect(report.outcomes[0]).toEqual({ result: "skipped", object: lacks, reason: "no-field" });
    expect(report.outcomes[1]?.result).toBe("unresolved");
    expect(await owner.read(index)).toEqual([]);
  }
});

// --- the resolution rule, which used to be unreachable in the adapter -----

test("an empty read resolves as unresolved — never as an object with no field", () => {
  const resolution = resolutionFromRead([]);
  expect(resolution.state).toBe("unresolved");
  // The distinction that matters: had this said `present`, the curator would have
  // filed a FAILED read as `skipped: "no-field"` — a fact about the object.
  expect(resolution.state === "unresolved" && resolution.reason).toContain("absent, unreadable");
});

test("a non-empty read resolves as present, carrying the subjects through", () => {
  const subjects = [subject("did:ng:o:a", ["v"])];
  expect(resolutionFromRead(subjects)).toEqual({ state: "present", subjects });
});

test("a read that threw resolves as unresolved, naming the error", () => {
  const resolution = resolutionFromFailure(new Error("broker unreachable"));
  expect(resolution).toEqual({ state: "unresolved", reason: "Error: broker unreachable" });
});

// --- a failure must SURFACE, not just be returned -------------------------

test("an unresolved reference is warned about, not only reported", async () => {
  const network = new FakeNextGraph();
  const ownerPort = network.portFor("alice");
  const owner = await indexing(ownerPort);
  const index = await owner.createIndex(FIELD);
  const article = await publishObject(network.portFor("bob"), FIELD, "2026-01-01");
  await (await indexing(network.portFor("bob"))).refer(index, article);
  network.breakReadsOf(article, "broker unreachable");

  const warn = mock((..._args: unknown[]) => {});
  const original = console.warn;
  console.warn = warn;
  try {
    await curate(ownerPort, index);
  } finally {
    console.warn = original;
  }

  expect(warn).toHaveBeenCalledTimes(1);
  expect(String(warn.mock.calls[0]?.[0])).toContain("broker unreachable");
});

test("a normal run warns about nothing", async () => {
  const network = new FakeNextGraph();
  const ownerPort = network.portFor("alice");
  const owner = await indexing(ownerPort);
  const index = await owner.createIndex(FIELD);
  const article = await publishObject(network.portFor("bob"), FIELD, "2026-01-01");
  await (await indexing(network.portFor("bob"))).refer(index, article);

  const warn = mock((..._args: unknown[]) => {});
  const original = console.warn;
  console.warn = warn;
  let report;
  try {
    report = await curate(ownerPort, index);
  } finally {
    console.warn = original;
  }
  // Assert the run actually DID something — otherwise this passes for a curation
  // that indexed nothing at all, which would warn about nothing either.
  expect(report.outcomes).toEqual([{ result: "indexed", object: article, value: "2026-01-01" }]);
  expect(warn).not.toHaveBeenCalled();
});

// --- an unreadable index must not be diagnosed as a malformed one ---------

test("an index that could not be read is refused, and says so without blaming the document", async () => {
  const network = new FakeNextGraph();
  const ownerPort = network.portFor("alice");
  const owner = await indexing(ownerPort);
  const index = await owner.createIndex(FIELD);
  network.breakReadsOf(index, "broker unreachable");

  // The real `readUnion` turns a failed read into `[]`, so the failure arrives
  // looking like a blank document. Whatever the shape, nothing may be written.
  await expect(curate(ownerPort, index)).rejects.toThrow();
  await expect(owner.read(index)).rejects.toThrow();

  network.healReadsOf(index);
  expect(await owner.read(index)).toEqual([]);
});