import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
import Database from 'better-sqlite3';
import { drizzle } from 'drizzle-orm/better-sqlite3';
import fs from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';
import * as schema from '../db/schema.js';
import { eq } from 'drizzle-orm';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
type TestDb = ReturnType<typeof drizzle<typeof schema>>;
let sqlite: Database.Database;
let testDb: TestDb;

vi.mock('../db/index.js', () => ({
  getDb: () => testDb,
  schema,
}));

vi.mock('../ws/handler.js', () => ({
  connectionManager: {
    sendToAdmins: vi.fn(),
    getAllOnlineUserIds: () => [],
    sendToUser: vi.fn(),
    sendToDmMembers: vi.fn(),
    evictFederatedCallsForHost: vi.fn().mockReturnValue(0),
    getAllFederatedCalls: vi.fn(() => new Map()),
  },
}));

vi.mock('../utils/federationAuth.js', () => ({
  getOurOrigin: () => 'https://test.example',
  buildFederationHeaders: () => ({ 'Content-Type': 'application/json' }),
  generateHmacSecret: () => 'secret',
  ROTATION_GRACE_PERIOD_MS: 15 * 60 * 1000,
}));

vi.mock('../utils/federationOutbox.js', () => ({
  isFederationRelayEnabled: () => true,
  queueOutboxEvent: vi.fn(),
  appendMutationLog: vi.fn(),
}));

vi.mock('../utils/federationPeerActivation.js', () => ({
  onPeerActivated: vi.fn(),
  onPeerDeactivated: vi.fn().mockResolvedValue(undefined),
  startupBootstrapSync: vi.fn(),
}));

vi.mock('../utils/storageJanitor.js', () => ({
  runFederationJanitor: vi.fn(),
}));

vi.mock('../utils/thumbnail.js', () => ({
  generateThumbnail: vi.fn(),
}));

vi.mock('../routes/dm.js', () => ({
  getDmMessageWithUser: vi.fn(),
}));

vi.mock('../utils/federationAuthFailure.js', () => ({
  evaluateAuthFailure: vi.fn().mockReturnValue({ kind: 'increment', newAuthFailures: 1 }),
  AUTH_FAILURE_THRESHOLD: 5,
}));

const invokeRollbackMock = vi.fn();
vi.mock('./federationRollback.js', () => ({
  invokePermanentFailureCallback: invokeRollbackMock,
  registerPermanentFailureCallback: vi.fn(),
  _resetCallbacks: vi.fn(),
}));

function applyMigrations(db: Database.Database): void {
  const migrationsDir = path.resolve(__dirname, '../../drizzle');
  const files = fs.readdirSync(migrationsDir).filter(f => f.endsWith('.sql')).sort();
  for (const f of files) {
    const sql = fs.readFileSync(path.join(migrationsDir, f), 'utf8');
    const statements = sql.split(/-->\s*statement-breakpoint/);
    for (const stmt of statements) {
      const clean = stmt.trim();
      if (clean) db.exec(clean);
    }
  }
}

function seedPeer(id: string): void {
  testDb.insert(schema.federationPeers).values({
    id, origin: 'https://peer.example', hmacSecret: 'secret',
    status: 'active', lastSyncedAt: Date.now(), createdAt: Date.now(),
  }).run();
}

function seedOutboxEntry(id: string, peerId: string, entityId: string, eventType = 'create'): void {
  testDb.insert(schema.federationOutbox).values({
    id, peerId, contextId: 'ch-1', entityId,
    contextType: 'dm', eventType, payload: JSON.stringify({
      message: { userId: 'u', homeUserId: 'u', homeInstance: 'test.example', content: 'hi', replyToId: null, editedAt: null, createdAt: Date.now() },
    }),
    encryptionVersion: 0, attempts: 0, nextRetryAt: Date.now() - 1000,
    expiresAt: Date.now() + 30 * 86_400_000,
    createdAt: Date.now(),
  }).run();
}

describe('outbox worker — duplicate rejection is terminal', () => {
  beforeEach(() => {
    sqlite = new Database(':memory:');
    testDb = drizzle(sqlite, { schema });
    applyMigrations(sqlite);
    vi.restoreAllMocks();
    // Re-apply the static mocks that vi.restoreAllMocks() would undo.
    // isFederationRelayEnabled is mocked at module level via vi.mock (hoisted),
    // so it survives restoreAllMocks — spies created with vi.spyOn are the ones
    // that get restored. The fetch spy is re-created per test via mockImplementation.
  });

  it('deletes the outbox entry when the peer responds with duplicate rejection', async () => {
    seedPeer('peer-dup');
    seedOutboxEntry('entry-dup', 'peer-dup', 'msg-already-there');

    // Mock the fetch to return a relay response with duplicate rejection
    vi.spyOn(globalThis, 'fetch').mockImplementation(async () =>
      new Response(JSON.stringify({
        accepted: [],
        rejected: [{ messageId: 'msg-already-there', reason: 'duplicate' }],
      }), { status: 200, headers: { 'Content-Type': 'application/json' } }),
    );

    const workerModule = await import('./federationWorker.js');
    const processOutboxTick = (workerModule as { processOutboxTick?: () => Promise<void> }).processOutboxTick;
    if (!processOutboxTick) {
      throw new Error('processOutboxTick must be exported for this test. If not yet exported, export it.');
    }
    await processOutboxTick();

    // Verify the outbox entry was deleted (terminal treatment)
    const remaining = testDb.select().from(schema.federationOutbox)
      .where(eq(schema.federationOutbox.id, 'entry-dup')).get();
    expect(remaining).toBeUndefined();
  });

  it('retains outbox entries for non-duplicate rejection reasons (e.g., processing_error)', async () => {
    seedPeer('peer-transient');
    seedOutboxEntry('entry-transient', 'peer-transient', 'msg-transient');

    vi.spyOn(globalThis, 'fetch').mockImplementation(async () =>
      new Response(JSON.stringify({
        accepted: [],
        rejected: [{ messageId: 'msg-transient', reason: 'processing_error' }],
      }), { status: 200, headers: { 'Content-Type': 'application/json' } }),
    );

    const workerModule = await import('./federationWorker.js');
    const processOutboxTick = (workerModule as { processOutboxTick?: () => Promise<void> }).processOutboxTick;
    if (!processOutboxTick) {
      throw new Error('processOutboxTick must be exported for this test.');
    }
    await processOutboxTick();

    const remaining = testDb.select().from(schema.federationOutbox)
      .where(eq(schema.federationOutbox.id, 'entry-transient')).get();
    // The entry must be retained — a 200 OK with a transient rejection reason
    // does not delete the outbox entry. (Backoff is only applied on non-OK HTTP
    // responses; a 200 with a rejection means the peer processed the batch but
    // declined this particular message — the entry stays for the next tick.)
    expect(remaining).toBeDefined();
  });
});

// ─── Sentinel test helpers ───────────────────────────────────────────────────

function seedSentinelPeer(
  id: string,
  origin: string,
  status: string,
  instanceName?: string,
): void {
  testDb.insert(schema.federationPeers).values({
    id,
    origin,
    hmacSecret: 'secret',
    status,
    instanceName: instanceName ?? null,
    lastSyncedAt: 0,
    createdAt: Date.now(),
  }).run();
}

type FedCallEntry = import('../ws/handler.js').FederatedCallEntry;

function makeFedCall(partial: Partial<FedCallEntry>): FedCallEntry {
  return {
    dmChannelId: null,
    federatedId: `fed-${Math.random().toString(36).slice(2, 8)}`,
    callerId: 'caller',
    callerHomeUserId: 'caller-home',
    federatedCallHost: 'https://hostA.example',
    livekitUrl: 'wss://lk.example',
    tokens: new Map(),
    ringedUserIds: [],
    state: 'active',
    startedAt: Date.now(),
    ...partial,
  };
}

// ─── Sentinel describe block ─────────────────────────────────────────────────

describe('federatedCallSentinel', () => {
  beforeEach(() => {
    sqlite = new Database(':memory:');
    testDb = drizzle(sqlite, { schema });
    applyMigrations(sqlite);
  });

  afterEach(() => {
    sqlite.close();
  });

  it('early-exits when there are no federated calls (no DB work, no eviction calls)', async () => {
    const { connectionManager } = await import('../ws/handler.js');
    vi.mocked(connectionManager.getAllFederatedCalls).mockReturnValue(new Map());
    vi.mocked(connectionManager.evictFederatedCallsForHost).mockClear();

    const { runFederatedCallSentinelTick } = await import('./federationWorker.js');
    await runFederatedCallSentinelTick();

    expect(connectionManager.evictFederatedCallsForHost).not.toHaveBeenCalled();
  });

  it('evicts entries whose host peer is non-active', async () => {
    seedSentinelPeer('p-A', 'https://hostA.example', 'unreachable', 'HostA');
    seedSentinelPeer('p-B', 'https://hostB.example', 'active', 'HostB');

    const calls = new Map<string, FedCallEntry>([
      ['fed-1', makeFedCall({ federatedId: 'fed-1', federatedCallHost: 'https://hostA.example' })],
      ['fed-2', makeFedCall({ federatedId: 'fed-2', federatedCallHost: 'https://hostB.example' })],
    ]);

    const { connectionManager } = await import('../ws/handler.js');
    vi.mocked(connectionManager.getAllFederatedCalls).mockReturnValue(calls);
    vi.mocked(connectionManager.evictFederatedCallsForHost).mockClear();

    const { runFederatedCallSentinelTick } = await import('./federationWorker.js');
    await runFederatedCallSentinelTick();

    expect(connectionManager.evictFederatedCallsForHost).toHaveBeenCalledTimes(1);
    expect(connectionManager.evictFederatedCallsForHost).toHaveBeenCalledWith(
      'https://hostA.example',
      { reason: 'peer_transient_failure', peerLabel: 'HostA' },
    );
  });

  it('maps rejected/revoked to peer_rejected', async () => {
    seedSentinelPeer('p-rej', 'https://hostRej.example', 'rejected', 'Rej');
    seedSentinelPeer('p-rev', 'https://hostRev.example', 'revoked', 'Rev');

    const calls = new Map<string, FedCallEntry>([
      ['fed-rej', makeFedCall({ federatedId: 'fed-rej', federatedCallHost: 'https://hostRej.example' })],
      ['fed-rev', makeFedCall({ federatedId: 'fed-rev', federatedCallHost: 'https://hostRev.example' })],
    ]);

    const { connectionManager } = await import('../ws/handler.js');
    vi.mocked(connectionManager.getAllFederatedCalls).mockReturnValue(calls);
    vi.mocked(connectionManager.evictFederatedCallsForHost).mockClear();

    const { runFederatedCallSentinelTick } = await import('./federationWorker.js');
    await runFederatedCallSentinelTick();

    expect(connectionManager.evictFederatedCallsForHost).toHaveBeenCalledWith(
      'https://hostRej.example',
      { reason: 'peer_rejected', peerLabel: 'Rej' },
    );
    expect(connectionManager.evictFederatedCallsForHost).toHaveBeenCalledWith(
      'https://hostRev.example',
      { reason: 'peer_rejected', peerLabel: 'Rev' },
    );
  });

  it('treats a missing peer row as transient failure', async () => {
    const calls = new Map<string, FedCallEntry>([
      ['fed-missing', makeFedCall({ federatedId: 'fed-missing', federatedCallHost: 'https://ghost.example' })],
    ]);
    const { connectionManager } = await import('../ws/handler.js');
    vi.mocked(connectionManager.getAllFederatedCalls).mockReturnValue(calls);
    vi.mocked(connectionManager.evictFederatedCallsForHost).mockClear();

    const { runFederatedCallSentinelTick } = await import('./federationWorker.js');
    await runFederatedCallSentinelTick();

    expect(connectionManager.evictFederatedCallsForHost).toHaveBeenCalledWith(
      'https://ghost.example',
      { reason: 'peer_transient_failure', peerLabel: undefined },
    );
  });
});

// ─── Terminal rejection reasons + rollback invocation ────────────────────────

describe('outbox worker — terminal rejection reasons + rollback invocation', () => {
  beforeEach(() => {
    sqlite = new Database(':memory:');
    testDb = drizzle(sqlite, { schema });
    applyMigrations(sqlite);
    vi.restoreAllMocks();
    invokeRollbackMock.mockReset();
  });

  afterEach(() => {
    sqlite.close();
  });

  it('recipient_not_found for friend_request_create is terminal AND invokes rollback', async () => {
    seedPeer('peer-r1');
    seedOutboxEntry('entry-r1', 'peer-r1', 'msg-1', 'friend_request_create');

    vi.spyOn(globalThis, 'fetch').mockImplementation(async () =>
      new Response(JSON.stringify({
        accepted: [],
        rejected: [{ messageId: 'msg-1', reason: 'recipient_not_found' }],
      }), { status: 200, headers: { 'Content-Type': 'application/json' } }),
    );

    const workerModule = await import('./federationWorker.js');
    const processOutboxTick = (workerModule as { processOutboxTick?: () => Promise<void> }).processOutboxTick!;
    await processOutboxTick();

    const remaining = testDb.select().from(schema.federationOutbox)
      .where(eq(schema.federationOutbox.id, 'entry-r1')).get();
    expect(remaining).toBeUndefined();

    expect(invokeRollbackMock).toHaveBeenCalledTimes(1);
    expect(invokeRollbackMock).toHaveBeenCalledWith('friend_request_create', 'msg-1', 'recipient_not_found');
  });

  it('recipient_not_found for dm_message_create: row deleted, rollback still invoked (no-op inside registry)', async () => {
    seedPeer('peer-r2');
    seedOutboxEntry('entry-r2', 'peer-r2', 'msg-2', 'dm_message_create');

    vi.spyOn(globalThis, 'fetch').mockImplementation(async () =>
      new Response(JSON.stringify({
        accepted: [],
        rejected: [{ messageId: 'msg-2', reason: 'recipient_not_found' }],
      }), { status: 200, headers: { 'Content-Type': 'application/json' } }),
    );

    const workerModule = await import('./federationWorker.js');
    const processOutboxTick = (workerModule as { processOutboxTick?: () => Promise<void> }).processOutboxTick!;
    await processOutboxTick();

    const remaining = testDb.select().from(schema.federationOutbox)
      .where(eq(schema.federationOutbox.id, 'entry-r2')).get();
    expect(remaining).toBeUndefined();

    // Worker always calls invoke; whether a callback is registered is the registry's concern
    expect(invokeRollbackMock).toHaveBeenCalledTimes(1);
    expect(invokeRollbackMock).toHaveBeenCalledWith('dm_message_create', 'msg-2', 'recipient_not_found');
  });

  it('duplicate rejection is terminal but does NOT invoke rollback callback', async () => {
    seedPeer('peer-r3');
    seedOutboxEntry('entry-r3', 'peer-r3', 'msg-3', 'friend_request_create');

    vi.spyOn(globalThis, 'fetch').mockImplementation(async () =>
      new Response(JSON.stringify({
        accepted: [],
        rejected: [{ messageId: 'msg-3', reason: 'duplicate' }],
      }), { status: 200, headers: { 'Content-Type': 'application/json' } }),
    );

    const workerModule = await import('./federationWorker.js');
    const processOutboxTick = (workerModule as { processOutboxTick?: () => Promise<void> }).processOutboxTick!;
    await processOutboxTick();

    const remaining = testDb.select().from(schema.federationOutbox)
      .where(eq(schema.federationOutbox.id, 'entry-r3')).get();
    expect(remaining).toBeUndefined();

    expect(invokeRollbackMock).not.toHaveBeenCalled();
  });

  it('attribution_mismatch is terminal AND invokes rollback', async () => {
    seedPeer('peer-r4');
    seedOutboxEntry('entry-r4', 'peer-r4', 'msg-4', 'friend_request_create');

    vi.spyOn(globalThis, 'fetch').mockImplementation(async () =>
      new Response(JSON.stringify({
        accepted: [],
        rejected: [{ messageId: 'msg-4', reason: 'attribution_mismatch' }],
      }), { status: 200, headers: { 'Content-Type': 'application/json' } }),
    );

    const workerModule = await import('./federationWorker.js');
    const processOutboxTick = (workerModule as { processOutboxTick?: () => Promise<void> }).processOutboxTick!;
    await processOutboxTick();

    const remaining = testDb.select().from(schema.federationOutbox)
      .where(eq(schema.federationOutbox.id, 'entry-r4')).get();
    expect(remaining).toBeUndefined();

    expect(invokeRollbackMock).toHaveBeenCalledTimes(1);
    expect(invokeRollbackMock).toHaveBeenCalledWith('friend_request_create', 'msg-4', 'attribution_mismatch');
  });

  it('non-terminal rejection (processing_error) does NOT invoke rollback and retains the outbox row', async () => {
    seedPeer('peer-r5');
    seedOutboxEntry('entry-r5', 'peer-r5', 'msg-5', 'friend_request_create');

    vi.spyOn(globalThis, 'fetch').mockImplementation(async () =>
      new Response(JSON.stringify({
        accepted: [],
        rejected: [{ messageId: 'msg-5', reason: 'processing_error' }],
      }), { status: 200, headers: { 'Content-Type': 'application/json' } }),
    );

    const workerModule = await import('./federationWorker.js');
    const processOutboxTick = (workerModule as { processOutboxTick?: () => Promise<void> }).processOutboxTick!;
    await processOutboxTick();

    const remaining = testDb.select().from(schema.federationOutbox)
      .where(eq(schema.federationOutbox.id, 'entry-r5')).get();
    expect(remaining).toBeDefined();

    expect(invokeRollbackMock).not.toHaveBeenCalled();
  });
});

describe('unreachable transition resets probe pacing', () => {
  beforeEach(() => {
    sqlite = new Database(':memory:');
    testDb = drizzle(sqlite, { schema });
    applyMigrations(sqlite);
    vi.restoreAllMocks();
  });

  it('crossing the threshold sets status=unreachable and resets pacing', async () => {
    testDb.insert(schema.federationPeers).values({
      id: 'peer-thr', origin: 'https://peer.example', hmacSecret: 'secret',
      status: 'active', consecutiveFailures: 9, probeAttempts: 4, lastProbeAt: 123,
      lastSyncedAt: Date.now(), createdAt: Date.now(),
    }).run();
    seedOutboxEntry('e-thr', 'peer-thr', 'm-thr');
    vi.spyOn(globalThis, 'fetch').mockRejectedValue(new Error('down'));

    const { processOutboxTick } = await import('./federationWorker.js');
    await processOutboxTick();

    const row = testDb.select().from(schema.federationPeers)
      .where(eq(schema.federationPeers.id, 'peer-thr')).get()!;
    expect(row.status).toBe('unreachable');
    expect(row.consecutiveFailures).toBe(10);
    expect(row.probeAttempts).toBe(0);
    expect(row.lastProbeAt).toBeNull();
  });
});

describe('processRecoveryTick — demand-driven recovery', () => {
  beforeEach(() => {
    sqlite = new Database(':memory:');
    testDb = drizzle(sqlite, { schema });
    applyMigrations(sqlite);
    vi.restoreAllMocks();
  });

  function seedUnreachable(id: string, attempts = 0, lastProbeAt: number | null = null): void {
    testDb.insert(schema.federationPeers).values({
      id, origin: 'https://peer.example', hmacSecret: 'secret',
      status: 'unreachable', consecutiveFailures: 10,
      probeAttempts: attempts, lastProbeAt,
      lastSyncedAt: Date.now(), createdAt: Date.now(),
    }).run();
  }

  it('recovers a peer with queued mail when the probe succeeds', async () => {
    seedUnreachable('peer-a');                 // lastProbeAt=null → immediately due
    seedOutboxEntry('e-a', 'peer-a', 'm-a');   // has pending mail
    const spy = vi.spyOn(globalThis, 'fetch').mockResolvedValue(new Response('{}', { status: 200 }));

    const { processRecoveryTick } = await import('./federationWorker.js');
    await processRecoveryTick();

    expect(spy).toHaveBeenCalledWith('https://peer.example/api/instance/info', expect.anything());
    const row = testDb.select().from(schema.federationPeers)
      .where(eq(schema.federationPeers.id, 'peer-a')).get()!;
    expect(row.status).toBe('active');
  });

  it('advances backoff when the probe fails', async () => {
    seedUnreachable('peer-b');
    seedOutboxEntry('e-b', 'peer-b', 'm-b');
    vi.spyOn(globalThis, 'fetch').mockResolvedValue(new Response('', { status: 502 }));

    const { processRecoveryTick } = await import('./federationWorker.js');
    await processRecoveryTick();

    const row = testDb.select().from(schema.federationPeers)
      .where(eq(schema.federationPeers.id, 'peer-b')).get()!;
    expect(row.status).toBe('unreachable');
    expect(row.probeAttempts).toBe(1);
    expect(row.lastProbeAt).toBeGreaterThan(0);
  });

  it('does NOT probe a silent peer before the 15-min backstop is due', async () => {
    seedUnreachable('peer-c', 1, Date.now() - 60_000); // no outbox entry, probed 1m ago
    const spy = vi.spyOn(globalThis, 'fetch').mockResolvedValue(new Response('{}', { status: 200 }));

    const { processRecoveryTick } = await import('./federationWorker.js');
    await processRecoveryTick();

    expect(spy).not.toHaveBeenCalled();
  });

  it('does NOT probe a pending peer before its backoff interval elapses', async () => {
    seedUnreachable('peer-d', 0, Date.now() - 5_000); // BACKOFF[0]=30s, probed 5s ago
    seedOutboxEntry('e-d', 'peer-d', 'm-d');
    const spy = vi.spyOn(globalThis, 'fetch').mockResolvedValue(new Response('{}', { status: 200 }));

    const { processRecoveryTick } = await import('./federationWorker.js');
    await processRecoveryTick();

    expect(spy).not.toHaveBeenCalled();
  });
});