/**
 * rigor/protocol-snapshot-lifecycle.test.js — snapshot lifecycle protocol
 * as a stateful rigor.object campaign with gated invariants
 * (before/after/between/when/unless).
 *
 * Lifecycle protocol (pinned from engine probes):
 *   - add/remove/setConfig: allowed while LIVE.
 *   - enable() (enableCondensedSnapshot): freezes RELATION writes
 *     (add/remove now THROW) but queries keep working; configs stay
 *     mutable; double-enable is idempotent.
 *   - restore(): serializes the condensed graph and rebuilds a fresh
 *     read-only arbiter; relation writes keep throwing; configs remain
 *     mutable and are NOT part of the snapshot; checks reflect the
 *     snapshot values (16-bit quantized).
 *   - between enable() and restore(): queries serve live values exactly.
 *   - after restore(): queries serve quantized snapshot values.
 *   - double-restore (snapshot-of-snapshot) is supported.
 *
 * The wrapper mirrors the protocol independently (flag + tuple mirror);
 * every method runs the REAL engine and rethrows engine errors, so the
 * invariants compare engine behavior against the mirror's prediction.
 */
import { describe, it } from 'node:test';
import assert from 'node:assert/strict';
import { rigor } from '@rigor/core';
import { Arbiter } from '../../src/index.js';
import { ArbiterSnapshot } from '../../src/core/arbiter/ArbiterSnapshot.js';
import { serializeArbiterSnapshot } from '../../src/core/SnapshotBinary.js';

const TOL = 0.5 / 65535 + 1e-9;
const NODES = 6;
const nodeKey = (id) => (id < 2 ? `u:${id}` : id === 2 ? 'g:0' : `doc:${id - 3}`);

function mirrorCheck(tuples, configs, src, rel, dst) {
  const srcKey = nodeKey(src);
  const dstKey = nodeKey(dst);
  const key = (s, r, d) => `${s}|${r}|${d}`;
  const p = (s, r, d) => tuples.get(key(s, r, d)) ?? 0;
  if (rel === 'can_read') {
    return p(srcKey, 'owner', dstKey);
  }
  if (rel === 'can_access') {
    let best = 0;
    for (let m = 0; m < NODES; m++) {
      best = Math.max(best, Math.min(p(srcKey, 'member_of', nodeKey(m)), p(nodeKey(m), 'reads', dstKey)));
    }
    return best;
  }
  return 0;
}

function makeWrapper() {
  const arbiter = new Arbiter();
  for (let i = 0; i < NODES; i++) arbiter.addNode(nodeKey(i), i < 2 ? 'user' : i === 2 ? 'group' : 'doc');
  arbiter.setRelationConfig('can_read', { type: 'direct', relation: 'owner' });
  arbiter.setRelationConfig('can_access', {
    type: 'chain',
    steps: [
      { relation: 'member_of', direction: 'out' },
      { relation: 'reads', direction: 'out' }
    ]
  });

  const tuples = new Map();
  const tupleKey = (src, rel, dst) => `${src}|${rel}|${dst}`;
  const ops = [];

  const wrapper = {
    flag: 'live',
    buffer: null,
    frozen: null,
    engine: arbiter,
    ops,
    add(src, rel, dst, p) {
      const key = nodeKey(src);
      const dstKey = nodeKey(dst);
      arbiter.addRelation(key, rel, dstKey, { possibility: p }); // throws when frozen
      tuples.set(tupleKey(key, rel, dstKey), p);
      return { ok: true };
    },
    remove(src, rel, dst) {
      arbiter.removeRelation(nodeKey(src), rel, nodeKey(dst)); // throws when frozen
      tuples.delete(tupleKey(nodeKey(src), rel, nodeKey(dst)));
      return { ok: true };
    },
    setConfig(which) {
      if (which === 'chain') {
        arbiter.setRelationConfig('can_access', {
          type: 'chain',
          steps: [
            { relation: 'member_of', direction: 'out' },
            { relation: 'reads', direction: 'out' }
          ]
        });
      } else {
        arbiter.setRelationConfig('can_read', { type: 'direct', relation: 'owner' });
      }
      return { ok: true };
    },
    enable() {
      if (wrapper.flag === 'restored') {
        throw new Error('enable after restore is out of contract');
      }
      arbiter.enableCondensedSnapshot();
      wrapper.flag = 'enabled';
      return { ok: true };
    },
    restore() {
      const buf = serializeArbiterSnapshot(arbiter); // throws when not enabled
      wrapper.frozen = new Map(tuples);
      wrapper.buffer = buf;
      const next = ArbiterSnapshot.fromSnapshotBinary(buf, {}, () => new Arbiter());
      wrapper.engine = next;
      wrapper.flag = 'restored';
      return { ok: true, bytes: buf.byteLength };
    },
    check(src, rel, dst) {
      const result = wrapper.engine.check(nodeKey(src), rel, nodeKey(dst));
      const expected = mirrorCheck(tuples, null, src, rel, dst);
      return { engine: result.possibility, expected, flag: wrapper.flag };
    },
    clone() {
      const fresh = makeWrapper();
      for (const op of ops) {
        const [name, ...args] = op;
        if (name === 'check') fresh.check(...args);
        else fresh[name](...args);
      }
      return fresh;
    }
  };

  const record = (name, fn) => {
    return (...args) => {
      const result = fn(...args);
      ops.push([name, ...args]);
      return result;
    };
  };

  wrapper.add = record('add', wrapper.add);
  wrapper.remove = record('remove', wrapper.remove);
  wrapper.setConfig = record('setConfig', wrapper.setConfig);
  wrapper.enable = record('enable', wrapper.enable);
  wrapper.restore = record('restore', wrapper.restore);
  wrapper.check = record('check', wrapper.check);
  return wrapper;
}

const nodeArg = rigor.gen.int(0, NODES - 1);
const relArg = rigor.gen.enum(['owner', 'member_of', 'reads']);
const checkRelArg = rigor.gen.enum(['can_read', 'can_access']);

const result = await rigor.campaign(
  [rigor.object('graph', makeWrapper, [
    rigor.method('add', function (src, rel, dst, p) { return this.add(src, rel, dst, p); },
      rigor.args(nodeArg, relArg, nodeArg, rigor.gen.oneOf([0.1, 0.3, 0.7, 0.9, 0.333]))),
    rigor.method('remove', function (src, rel, dst) { return this.remove(src, rel, dst); },
      rigor.args(nodeArg, relArg, nodeArg)),
    rigor.method('setConfig', function (which) { return this.setConfig(which); },
      rigor.args(rigor.gen.enum(['direct', 'chain']))),
    rigor.method('enable', function () { return this.enable(); }),
    rigor.method('restore', function () { return this.restore(); }),
    rigor.method('check', function (src, rel, dst) { return this.check(src, rel, dst); },
      rigor.args(rigor.gen.int(0, 1), checkRelArg, rigor.gen.oneOf([3, 4, 5])))
  ])],
  rigor.crucible([
    rigor.after('graph.enable', ({ objects }) => objects.graph.flag === 'enabled'),
    rigor.after('graph.restore', ({ objects }) => objects.graph.flag === 'restored' && objects.graph.frozen !== null),
    rigor.before('graph.enable', ({ objects }) => objects.graph.flag !== 'restored'),
    rigor.between('graph.enable', 'graph.restore', ({ action, objects, actual }) => {
      if (action !== 'graph.check') return true;
      return actual.engine === actual.expected && actual.flag === 'enabled';
    }),
    rigor.when(({ action, objects }) => action === 'graph.add' || action === 'graph.remove', ({ action, objects, error }) => {
      const frozen = objects.graph.flag !== 'live';
      const threw = error !== null;
      if (frozen) return threw === true;
      return threw === false;
    }),
    rigor.when(({ action }) => action === 'graph.check', ({ objects, actual }) => {
      if (actual.flag === 'restored') {
        return Math.abs(actual.engine - actual.expected) <= TOL;
      }
      return actual.engine === actual.expected;
    }),
    rigor.unless(({ action }) => action === 'graph.check', ({ action, objects, error }) => {
      if (action === 'graph.add' || action === 'graph.remove') return true;
      if (action === 'graph.restore') return objects.graph.flag !== 'live' || error !== null;
      return true;
    }),
    rigor.after('graph.setConfig', ({ objects, error }) => error === null || objects.graph.flag === 'restored' ? true : false),
    rigor.beforeStep(0, ({ objects, calls }) => {
      const g = objects.graph;
      return g.tuples.size === 0 && g.flag === 'live' && calls.length === 0;
    }),
    rigor.afterStep(2, ({ objects, calls }) => {
      const g = objects.graph;
      if (g.flag === 'restored') return true;
      const engineKeys = new Set();
      for (const r of g.engine.relations) {
        const srcKey = g.engine.keyByNodeId.get(r.src);
        const dstKey = g.engine.keyByNodeId.get(r.dst);
        if (srcKey !== undefined && dstKey !== undefined) {
          engineKeys.add(`${srcKey}|${r.rel}|${dstKey}`);
        }
      }
      for (const k of g.tuples.keys()) {
        if (!engineKeys.has(k)) return false;
      }
      return g.tuples.size === engineKeys.size;
    }),
    rigor.beforeStep(4, ({ objects, calls }) => {
      const g = objects.graph;
      if (g.flag === 'live' || g.flag === 'enabled') {
        return g.tuples.size === g.engine.relations.length;
      }
      return true;
    })
  ])
).run({ effort: 400, seed: 'snapshot-lifecycle-protocol', maxTraceLength: 24 });

describe('Snapshot lifecycle protocol (rigor gated invariants)', () => {
  it('every random lifecycle sequence honors the protocol', () => {
    const inv = result.crucibleVerdict;
    assert.equal(inv.passed, true, [
      `protocol violated in ${inv.failureCount} cases:`,
      ...result.failures.slice(0, 5).map((f) =>
        `  [${f.invariant}] action=${f.action} args=${JSON.stringify(f.args)} actual=${JSON.stringify(f.actual)} error=${f.error}`
      )
    ].join('\n'));
  });
});