#!/usr/bin/env node
/**
 * Unit tests for consensus-resolver.js
 */

const assert = require('assert');
const {
  parseClaimValue,
  resolveDomainConsensus,
  applyTieBreaker,
  LEGACY_CLAIM_TIMESTAMP
} = require('../includes/core/consensus-resolver');

const DEFAULT_CONFIG = {
  CONSENSUS_QUORUM_THRESHOLD: 0.5,
  CONSENSUS_MIN_VOTES: 2,
  CONSENSUS_TIE_BREAKER: 'timestamp',
  CONSENSUS_VOTE_VALIDATION: true
};

const LOCAL = 'local-peer-key';
const REMOTE_A = 'remote-a-key';
const REMOTE_B = 'remote-b-key';

function resolve(domain, claims, voterVotes, overrides = {}) {
  return resolveDomainConsensus({
    domain,
    claims,
    voterVotes,
    config: { ...DEFAULT_CONFIG, ...overrides.config },
    localWriter: overrides.localWriter ?? LOCAL,
    activePeers: overrides.activePeers ?? 4
  });
}

function testLegacyClaimTimestamp() {
  const parsed = parseClaimValue('hs://legacy-hash');
  assert.strictEqual(parsed.timestamp, LEGACY_CLAIM_TIMESTAMP);
  assert.strictEqual(parsed.legacy, true);
}

function testNoClaims() {
  const state = resolve('example.test', {}, {});
  assert.strictEqual(state.status, 'no_claims');
  assert.strictEqual(state.hash, null);
}

function testSingleLocalClaim() {
  const state = resolve(
    'solo.test',
    { [LOCAL]: { hash: 'hs://solo', timestamp: 1000 } },
    {}
  );
  assert.strictEqual(state.status, 'resolved');
  assert.strictEqual(state.resolvedClaimant, LOCAL);
  assert.strictEqual(state.hash, 'hs://solo');
}

function testInsufficientQuorum() {
  const state = resolve(
    'quorum.test',
    {
      [LOCAL]: { hash: 'hs://local', timestamp: 1000 },
      [REMOTE_A]: { hash: 'hs://remote', timestamp: 2000 }
    },
    { [LOCAL]: LOCAL },
    { activePeers: 10 }
  );
  assert.strictEqual(state.status, 'insufficient_quorum');
  assert.strictEqual(state.quorumMet, false);
}

function testQuorumResolved() {
  const claims = {
    [LOCAL]: { hash: 'hs://local', timestamp: 1000 },
    [REMOTE_A]: { hash: 'hs://remote', timestamp: 2000 }
  };
  const votes = {
    voter1: LOCAL,
    voter2: LOCAL,
    voter3: LOCAL
  };
  const state = resolve('winner.test', claims, votes, { activePeers: 4 });
  assert.strictEqual(state.status, 'resolved');
  assert.strictEqual(state.resolvedClaimant, LOCAL);
}

function testVoteValidationDisabled() {
  const state = resolve(
    'noval.test',
    { [LOCAL]: { hash: 'hs://local', timestamp: 1 } },
    { voter1: REMOTE_A, voter2: REMOTE_A, voter3: REMOTE_A },
    { config: { CONSENSUS_VOTE_VALIDATION: false }, activePeers: 4 }
  );
  assert.strictEqual(state.status, 'resolved');
  assert.strictEqual(state.resolvedClaimant, REMOTE_A);
}

function testVoteValidationEnabled() {
  const state = resolve(
    'val.test',
    {
      [LOCAL]: { hash: 'hs://local', timestamp: 1 },
      [REMOTE_A]: { hash: 'hs://remote', timestamp: 2 }
    },
    { voter1: REMOTE_B, voter2: REMOTE_B, voter3: REMOTE_B },
    { activePeers: 4 }
  );
  assert.strictEqual(state.status, 'insufficient_quorum');
}

function testTieTimestamp() {
  const claims = {
    [REMOTE_A]: { hash: 'hs://a', timestamp: 5000 },
    [REMOTE_B]: { hash: 'hs://b', timestamp: 1000 }
  };
  const votes = { v1: REMOTE_A, v2: REMOTE_B, v3: REMOTE_A, v4: REMOTE_B };
  const state = resolve('tie.test', claims, votes, {
    activePeers: 4,
    localWriter: 'other-peer'
  });
  assert.strictEqual(state.status, 'tie');
  assert.strictEqual(state.resolvedClaimant, REMOTE_B);
}

function testTieBreakerLexicographicPrefersLocal() {
  const winner = applyTieBreaker([REMOTE_B, LOCAL], {}, LOCAL, 'lexicographic');
  assert.strictEqual(winner, LOCAL);
}

function testDuplicateVoteLastWinsViaOrderedReplay() {
  const { createEmptyViewState, applyEventToView } = require('../includes/core/consensus-apply');
  const { EVENT_TYPES } = require('../includes/core/consensus-events');
  const view = createEmptyViewState();
  const domain = 'dup.test';

  applyEventToView(view, {
    type: EVENT_TYPES.CLAIM_UPSERT,
    domain,
    claimant: REMOTE_A,
    hash: 'hs://a',
    timestamp: 1,
    ssl: false,
    clients: []
  });
  applyEventToView(view, {
    type: EVENT_TYPES.CLAIM_UPSERT,
    domain,
    claimant: REMOTE_B,
    hash: 'hs://b',
    timestamp: 2,
    ssl: false,
    clients: []
  });
  applyEventToView(view, { type: EVENT_TYPES.VOTE_UPSERT, domain, claimant: REMOTE_A, voter: 'voter1' });
  applyEventToView(view, { type: EVENT_TYPES.VOTE_UPSERT, domain, claimant: REMOTE_B, voter: 'voter1' });
  applyEventToView(view, { type: EVENT_TYPES.VOTE_UPSERT, domain, claimant: REMOTE_A, voter: 'voter2' });
  applyEventToView(view, { type: EVENT_TYPES.VOTE_UPSERT, domain, claimant: REMOTE_A, voter: 'voter3' });

  const domainState = view.domains.get(domain);
  assert.strictEqual(domainState.voterVotes.get('voter1'), REMOTE_B);

  const { buildDomainSnapshotFromView } = require('../includes/core/consensus-resolver');
  const snapshot = buildDomainSnapshotFromView(view, domain);
  const state = resolve(domain, snapshot.claims, snapshot.voterVotes, { activePeers: 4, localWriter: 'x' });
  assert.strictEqual(state.resolvedClaimant, REMOTE_A);
}

function run() {
  testLegacyClaimTimestamp();
  testNoClaims();
  testSingleLocalClaim();
  testInsufficientQuorum();
  testQuorumResolved();
  testVoteValidationDisabled();
  testVoteValidationEnabled();
  testTieTimestamp();
  testTieBreakerLexicographicPrefersLocal();
  testDuplicateVoteLastWinsViaOrderedReplay();
  console.log('consensus-resolver.test.js: all passed');
}

run();