/**
 * anti-fork.test.ts — behavioral tests for the reconnection fix in the
 * polyfill-era shim (src/store-registry.ts), redesigned around the
 * pointer → doc-shim indirection. Two groups, one file:
 *
 *  (1) DETERMINISTIC RESOLUTION — a doc-shim whose account subject carries
 *      DUPLICATE scope-doc values (fork residue: several `shim:docPublic`) must
 *      resolve to the SAME canonical doc every time (lexicographically-smallest
 *      NURI), so the session that WROTE an entity and a fresh page that RESOLVES
 *      the doc never disagree. Robustness against PAST fork residue.
 *
 *  (2) BARRIER-AUTHORITATIVE RECONNECT (the core fix) — a fresh page over a
 *      persistent wallet resolves the SAME account through the doc-shim's
 *      first-`State` BARRIER, with NO account-level retry. The account records
 *      live in a subscribable doc-shim (`did:ng:o:...`) reached via a write-once
 *      POINTER triple in the store-root; opening the doc-shim makes a cold read
 *      authoritative, so a genuinely-present account is found on the first read
 *      and never re-provisioned (no fork). This replaced the deleted
 *      `resolveAccountReliably` / `provisionRetry` account retry.
 */

import { describe, it, expect, mock, beforeEach, afterAll } from "bun:test";
import {
  ensureAccount,
  resolveAccount,
  loadShim,
  resetRegistryCache,
} from "../src/store-registry";
import type { RegistrySession } from "../src/store-registry";
import {
  configure,
  configureStoreRegistry,
  resetStoreRegistry,
  resetConfig,
} from "../src/polyfill";
import { resetOpenedRepos } from "../src/open-repo";

afterAll(() => {
  resetConfig();
  resetStoreRegistry();
  resetRegistryCache();
  resetOpenedRepos();
});

const SESSION: RegistrySession = { sessionId: "sid-af", privateStoreId: "PRIV-AF" };
const ROOT = "did:ng:PRIV-AF";

// ---------------------------------------------------------------------------
// Fake ng — in-memory quad store modelling the pointer → doc-shim indirection.
//
//   - The POINTER (`<shim:root> <shim:shimDoc> <docShim>`) lives in the store-root
//     graph (keyed by GRAPH <ROOT>).
//   - AccountRecords live in the doc-shim (anchored default graph, keyed by the
//     anchor arg = the doc-shim NURI).
//   - doc_subscribe pushes an initial `State` so ensureRepoOpen resolves at once
//     (the barrier).
// ---------------------------------------------------------------------------

interface Quad { g: string; s: string; p: string; o: string }

function unescapeLiteral(s: string): string {
  let out = "";
  for (let i = 0; i < s.length; i++) {
    if (s[i] === "\\" && i + 1 < s.length) {
      const next = s[++i];
      out += next === "n" ? "\n" : next === "r" ? "\r" : next === "t" ? "\t" : next;
    } else {
      out += s[i];
    }
  }
  return out;
}

function makeSparqlUpdate(quads: Quad[]) {
  return mock(async (...a: unknown[]) => {
    const query = a[1] as string;
    const anchor = a[2] as string | undefined;
    const gm = query.match(/GRAPH <([^>]+)>\s*\{([\s\S]*)\}/);
    let g: string;
    let body: string;
    if (gm) {
      g = gm[1]!;
      body = gm[2]!;
    } else {
      if (!anchor) return undefined;
      g = anchor;
      body = query.replace(/^\s*INSERT DATA\s*\{/, "").replace(/\}\s*$/, "");
    }
    const sm = body.match(/<([^>]+)>/);
    if (!sm) return undefined;
    const s = sm[1]!;
    const pairRe = /(?:a|<([^>]+)>)\s+(?:"((?:[^"\\]|\\.)*)"|<([^>]+)>)/g;
    let m: RegExpExecArray | null;
    const after = body.slice(body.indexOf(sm[0]) + sm[0].length);
    while ((m = pairRe.exec(after)) !== null) {
      const p = m[1] ?? "urn:ng-eventually:shim:Account";
      const o = m[2] !== undefined ? unescapeLiteral(m[2]) : (m[3] ?? "");
      quads.push({ g, s, p, o });
    }
    return undefined;
  });
}

/** Build the account-SELECT bindings from the quads in ONE graph (the doc-shim),
 *  grouped per subject. A subject with DUPLICATE scope docs yields a cross-product
 *  of bindings — a corrupted shim. */
function accountBindings(quads: Quad[], anchor: string | undefined, onlySubject: string | null) {
  const bySubject = new Map<string, { id: string; pub: string[]; prot: string[]; priv: string[] }>();
  for (const q of quads) {
    if (q.g !== anchor) continue;
    if (onlySubject !== null && q.s !== onlySubject) continue;
    const rec = bySubject.get(q.s) ?? { id: "", pub: [], prot: [], priv: [] };
    if (q.p === "urn:ng-eventually:shim:id") rec.id = q.o;
    if (q.p === "urn:ng-eventually:shim:docPublic") rec.pub.push(q.o);
    if (q.p === "urn:ng-eventually:shim:docProtected") rec.prot.push(q.o);
    if (q.p === "urn:ng-eventually:shim:docPrivate") rec.priv.push(q.o);
    bySubject.set(q.s, rec);
  }
  const bindings: Array<Record<string, { value: string }>> = [];
  for (const rec of bySubject.values()) {
    if (!rec.id) continue;
    const pubs = rec.pub.length ? rec.pub : [""];
    const prots = rec.prot.length ? rec.prot : [""];
    const privs = rec.priv.length ? rec.priv : [""];
    for (const pub of pubs)
      for (const prot of prots)
        for (const priv of privs)
          bindings.push({
            id: { value: rec.id },
            docPublic: { value: pub },
            docProtected: { value: prot },
            docPrivate: { value: priv },
          });
  }
  return bindings;
}

/** Reactive fake ng modelling the pointer → doc-shim indirection. `doc_subscribe`
 *  pushes a first `State` so the doc-shim barrier resolves synchronously. */
function makeFakeNg() {
  const quads: Quad[] = [];
  let docCounter = 0;
  // Count account SELECTs per anchor graph. The AUTHORITATIVE account read is anchored
  // to the doc-shim (a did:ng:o: NURI). Counting per-anchor lets a test assert "exactly
  // one doc-shim account read" (no account RETRY).
  const accountReadsByAnchor = new Map<string, number>();
  const doc_create = mock(async (..._a: unknown[]) => `did:ng:o:doc${++docCounter}`);
  const sparql_update = makeSparqlUpdate(quads);
  const sparql_query = mock(async (...a: unknown[]) => {
    const query = a[1] as string;
    const anchor = a[3] as string | undefined;
    // Pointer SELECT (store-root).
    if (query.includes("<urn:ng-eventually:shim:shimDoc>")) {
      const bindings = quads
        .filter((q) => q.g === anchor && q.p === "urn:ng-eventually:shim:shimDoc")
        .map((q) => ({ shimDoc: { value: q.o } }));
      return { results: { bindings } };
    }
    // Account SELECT — anchored to the doc-shim (the authoritative read).
    if (query.includes("<urn:ng-eventually:shim:id>")) {
      accountReadsByAnchor.set(anchor ?? "", (accountReadsByAnchor.get(anchor ?? "") ?? 0) + 1);
      const subjM = query.match(/<([^>]+)>\s+a\s+<urn:ng-eventually:shim:Account>/);
      return { results: { bindings: accountBindings(quads, anchor, subjM ? subjM[1]! : null) } };
    }
    const bindings = quads
      .filter((q) => q.g === anchor && q.p === "urn:ng-eventually:shim:contains")
      .map((q) => ({ e: { value: q.o } }));
    return { results: { bindings } };
  });
  // Push a `State` on subscribe (the sync barrier) so ensureRepoOpen resolves at once.
  const doc_subscribe = mock(async (_repo: unknown, _sid: unknown, cb: Function) => {
    if (typeof cb === "function") cb({ V0: { State: {} } });
    return () => {};
  });
  return {
    doc_create, sparql_update, sparql_query, doc_subscribe,
    _quads: quads,
    // Total account reads across all anchors.
    getAccountQueryCount: () => [...accountReadsByAnchor.values()].reduce((a, b) => a + b, 0),
    // Account reads anchored to a did:ng:o: doc-shim.
    getDocShimAccountReads: () =>
      [...accountReadsByAnchor.entries()]
        .filter(([g]) => g.startsWith("did:ng:o:"))
        .reduce((a, [, n]) => a + n, 0),
  };
}

function inject(
  fakeNg: unknown,
  pointerGuard?: { attempts?: number; baseMs?: number; maxStepMs?: number },
) {
  configure({ ng: fakeNg as any, useShape: (() => {}) as any });
  configureStoreRegistry({
    getSession: async () => SESSION,
    normalizeId: (u) => u.trim().toLowerCase(),
    pointerGuard,
  });
  resetRegistryCache();
  resetOpenedRepos();
}

// ---------------------------------------------------------------------------
// (1) Deterministic resolution over fork residue (in the doc-shim)
// ---------------------------------------------------------------------------

describe("deterministic resolution over a doc-shim corrupted by fork residue", () => {
  beforeEach(() => { resetRegistryCache(); resetOpenedRepos(); });

  it("(1a) a subject with MULTIPLE docPublic values always resolves the SAME canonical (lexicographically-smallest)", async () => {
    const fakeNg = makeFakeNg();
    inject(fakeNg);
    const docShim = "did:ng:o:shimdoc";
    // Seed the pointer (store-root → doc-shim) and the corrupted record IN the doc-shim.
    fakeNg._quads.push({ g: ROOT, s: "urn:ng-eventually:shim:root", p: "urn:ng-eventually:shim:shimDoc", o: docShim });
    const subj = "urn:ng-eventually:shim:account:dupuser";
    const dupPublics = [
      "did:ng:o:pub-m", "did:ng:o:pub-a", "did:ng:o:pub-z", "did:ng:o:pub-c", "did:ng:o:pub-a",
    ];
    fakeNg._quads.push({ g: docShim, s: subj, p: "urn:ng-eventually:shim:id", o: "dupuser" });
    for (const p of dupPublics)
      fakeNg._quads.push({ g: docShim, s: subj, p: "urn:ng-eventually:shim:docPublic", o: p });
    fakeNg._quads.push({ g: docShim, s: subj, p: "urn:ng-eventually:shim:docProtected", o: "did:ng:o:prot-1" });
    fakeNg._quads.push({ g: docShim, s: subj, p: "urn:ng-eventually:shim:docPrivate", o: "did:ng:o:priv-1" });

    const r1 = await resolveAccount("dupuser");
    resetRegistryCache();
    const r2 = await resolveAccount("dupuser");
    const viaShim = (await loadShim()).get("dupuser");

    // Canonical = lexicographically smallest → "did:ng:o:pub-a".
    expect(r1?.docPublic).toBe("did:ng:o:pub-a");
    expect(r2?.docPublic).toBe(r1?.docPublic);
    expect(viaShim?.docPublic).toBe(r1?.docPublic);
    expect(viaShim?.docProtected).toBe("did:ng:o:prot-1");
    expect(viaShim?.docPrivate).toBe("did:ng:o:priv-1");
  });
});

// ---------------------------------------------------------------------------
// (2) Barrier-authoritative reconnect — the core fix (no account retry)
// ---------------------------------------------------------------------------

describe("reconnect resolves the SAME account through the doc-shim barrier (no fork, no account retry)", () => {
  beforeEach(() => { resetRegistryCache(); resetOpenedRepos(); });

  it("(2a) NO-FORK: account already in the doc-shim → reused, 0 new scope docs", async () => {
    const fakeNg = makeFakeNg();
    inject(fakeNg);
    // First login: provisions the account (1 doc-shim + 3 scope docs).
    const first = await ensureAccount("LauraBarrier");
    expect(fakeNg.doc_create).toHaveBeenCalledTimes(4);

    // Fresh page over the SAME persistent quads: reset all in-memory caches, keep the
    // quads. Reconnect must find the SAME account via the doc-shim barrier, NO new docs.
    resetRegistryCache();
    resetOpenedRepos();
    const second = await ensureAccount("LauraBarrier");

    expect(second.docPublic).toBe(first.docPublic);
    expect(second.docProtected).toBe(first.docProtected);
    expect(second.docPrivate).toBe(first.docPrivate);
    // Still 4 — no doc-shim re-created (pointer reused), no scope docs re-created.
    expect(fakeNg.doc_create).toHaveBeenCalledTimes(4);
  });

  it("(2b) barrier-authoritative: a fresh session finds the persisted account on the FIRST read — single doc-shim read, NO retry", async () => {
    // Seed session 1; capture the account NURIs + the persistent quads.
    const seed = makeFakeNg();
    inject(seed);
    const orig = await ensureAccount("BarrierUser");
    expect(seed.doc_create).toHaveBeenCalledTimes(4);

    // Fresh reactive session over the SAME persistent quads. The doc-shim pushes a
    // `State` on subscribe → resolveShimDoc opens the barrier → the account read is
    // authoritative on the FIRST attempt. Give a MULTI-attempt pointer guard to prove
    // it is NOT used for the account.
    const reconnect = makeFakeNg();
    reconnect._quads.push(...seed._quads);
    inject(reconnect, { attempts: 8, baseMs: 1, maxStepMs: 2 });

    const resolved = await ensureAccount("BarrierUser");

    expect(resolved.docPublic).toBe(orig.docPublic);
    expect(resolved.docProtected).toBe(orig.docProtected);
    expect(resolved.docPrivate).toBe(orig.docPrivate);
    expect(reconnect.doc_create).toHaveBeenCalledTimes(0); // no new docs → no fork
    // Barrier-authoritative: found on the FIRST doc-shim read.
    expect(reconnect.getDocShimAccountReads()).toBe(1);
  });

  it("(2c) GENUINELY NEW: a cold doc-shim reads 0 → provisioned exactly once, no retry", async () => {
    // Pointer + doc-shim exist but the doc-shim holds NO record for this account.
    const fakeNg = makeFakeNg();
    inject(fakeNg, { attempts: 5, baseMs: 1, maxStepMs: 2 });
    const docShim = "did:ng:o:preexisting-shim";
    fakeNg._quads.push({ g: ROOT, s: "urn:ng-eventually:shim:root", p: "urn:ng-eventually:shim:shimDoc", o: docShim });

    const rec = await ensureAccount("BrandNewUser");

    // Provisioned exactly ONE set of 3 scope docs (the doc-shim already existed).
    expect(fakeNg.doc_create).toHaveBeenCalledTimes(3);
    expect(rec.docPublic).toMatch(/^did:ng:o:doc/);
    expect(rec.docProtected).not.toBe(rec.docPublic);
    // Barrier-authoritative: exactly ONE doc-shim account read (the 0 is definitive).
    expect(fakeNg.getDocShimAccountReads()).toBe(1);
  });

  it("(2d) default budget (unset pointer guard): genuinely-new account → single doc-shim account read", async () => {
    const fakeNg = makeFakeNg();
    inject(fakeNg); // pointerGuard unset → attempts:1 (synchronous default)

    const rec = await ensureAccount("SyncUser");

    // 1 doc-shim + 3 scope docs.
    expect(fakeNg.doc_create).toHaveBeenCalledTimes(4);
    expect(fakeNg.getDocShimAccountReads()).toBe(1);
    expect(rec.docPublic).toMatch(/^did:ng:o:doc/);
  });

  it("(2e) idempotence within a session: ensureAccount twice never creates 2 sets", async () => {
    const fakeNg = makeFakeNg();
    inject(fakeNg);
    const a = await ensureAccount("SameUser");
    const b = await ensureAccount("SameUser");
    expect(b).toEqual(a);
    expect(fakeNg.doc_create).toHaveBeenCalledTimes(4); // 1 doc-shim + 3 scope docs
  });
});