import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
import request from 'supertest';
import { createHmac } from 'node:crypto';
import express, { type NextFunction, type Request, type Response } from 'express';
import { configureQueue, drain } from '../lib/queue.js';

vi.mock('../db/ingest_events.dao.js', () => ({
  recordDelivery: vi.fn(),
  markProcessing: vi.fn(),
  markDone: vi.fn(),
  markFailed: vi.fn(),
  resetStaleProcessing: vi.fn(),
}));

vi.mock('../db/notes.dao.js', () => ({
  createNotes: vi.fn(),
  getAllNotes: vi.fn(),
  streamAllNotes: vi.fn(),
}));

import {
  recordDelivery,
  markDone,
  markFailed,
  markProcessing,
} from '../db/ingest_events.dao.js';
import { createNotes } from '../db/notes.dao.js';
import slackRouter from '../routes/slack.routes.js';

const mockRecordDelivery = vi.mocked(recordDelivery);
const mockCreateNotes = vi.mocked(createNotes);
const mockMarkDone = vi.mocked(markDone);
const mockMarkFailed = vi.mocked(markFailed);
const mockMarkProcessing = vi.mocked(markProcessing);

const SECRET = 'slack-test-secret';

// Mirrors app.ts: the raw parser must claim the body so the bytes Slack signed
// survive to verifySignature.
const app = express();
app.use('/v1/slack', express.raw({ type: '*/*', limit: '2mb' }), slackRouter);
app.use((err: Error, _req: Request, res: Response, _next: NextFunction) => {
  console.error(`Unhandled error: ${err.message}`);
  if (res.headersSent) return;
  res.status(500).json({ error: 'Internal server error' });
});

const FIELDS: Record<string, string> = {
  command: '/sticky',
  text: 'Deploys are scary',
  user_id: 'U123',
  user_name: 'jane',
  team_id: 'T999',
  channel_id: 'C555',
  channel_name: 'retro',
  trigger_id: 'trg_1',
};

const encode = (fields: Record<string, string>): string =>
  new URLSearchParams(fields).toString();

const sign = (body: string, timestamp: string, secret = SECRET): string =>
  `v0=${createHmac('sha256', secret).update(`v0:${timestamp}:${body}`).digest('hex')}`;

const now = (): string => Math.floor(Date.now() / 1000).toString();

const postRaw = (body: string, signature: string, timestamp: string) =>
  request(app)
    .post('/v1/slack/commands')
    .set('Content-Type', 'application/x-www-form-urlencoded')
    .set('x-slack-request-timestamp', timestamp)
    .set('x-slack-signature', signature)
    .send(body);

/** Signs whatever it sends, so the happy path is the default. */
const postCommand = (overrides: Record<string, string | undefined> = {}) => {
  const fields: Record<string, string> = { ...FIELDS };
  for (const [key, value] of Object.entries(overrides)) {
    if (value === undefined) {
      delete fields[key];
    } else {
      fields[key] = value;
    }
  }
  const body = encode(fields);
  const timestamp = now();
  return postRaw(body, sign(body, timestamp), timestamp);
};

describe('POST /v1/slack/commands', () => {
  const originalSecret = process.env.SLACK_SIGNING_SECRET;

  beforeEach(() => {
    vi.clearAllMocks();
    process.env.SLACK_SIGNING_SECRET = SECRET;
    configureQueue({ baseDelayMs: 0, maxAttempts: 2 });
    mockRecordDelivery.mockResolvedValue(42);
    mockCreateNotes.mockResolvedValue([]);
  });

  afterEach(async () => {
    await drain();
    if (originalSecret === undefined) {
      delete process.env.SLACK_SIGNING_SECRET;
    } else {
      process.env.SLACK_SIGNING_SECRET = originalSecret;
    }
  });

  it('should confirm a valid command with ephemeral text', async () => {
    const res = await postCommand();

    expect(res.status).toBe(200);
    expect(res.body).toEqual({
      response_type: 'ephemeral',
      text: 'Added to Kongruity: "Deploys are scary"',
    });
  });

  it('should create the note behind the ack', async () => {
    await postCommand();
    await drain();

    expect(mockCreateNotes).toHaveBeenCalledOnce();
    const [notes] = mockCreateNotes.mock.calls[0];
    expect(notes).toHaveLength(1);
    expect(notes[0].id).toBe('slack_trg_1');
    expect(notes[0].text).toBe('Deploys are scary');
    expect(notes[0].author).toBe('jane');
  });

  it('should record provenance from the slash command fields', async () => {
    await postCommand();
    await drain();

    const [notes] = mockCreateNotes.mock.calls[0];
    expect(notes[0].sourceMeta).toMatchObject({
      provider: 'slack',
      externalId: 'trg_1',
      channelId: 'C555',
      channelName: 'retro',
      authorHandle: 'jane',
      authorUserId: 'U123',
      teamId: 'T999',
      via: 'slash-command',
    });
    expect(typeof notes[0].sourceMeta?.receivedAt).toBe('string');
  });

  it('should omit provenance keys whose source field is absent', async () => {
    await postCommand({ channel_name: undefined, team_id: undefined });
    await drain();

    const [notes] = mockCreateNotes.mock.calls[0];
    const meta = notes[0].sourceMeta ?? {};
    expect('channelName' in meta).toBe(false);
    expect('teamId' in meta).toBe(false);
  });

  it('should respond before the insert finishes', async () => {
    let finishInsert: () => void = () => {};
    mockCreateNotes.mockImplementation(
      () => new Promise((resolve) => {
        finishInsert = () => resolve([]);
      })
    );

    const res = await postCommand();

    expect(res.status).toBe(200);
    expect(mockMarkDone).not.toHaveBeenCalled();

    finishInsert();
    await drain();

    expect(mockMarkDone).toHaveBeenCalledWith(42);
  });

  it('should mark the delivery done once the insert succeeds', async () => {
    await postCommand();
    await drain();

    expect(mockMarkProcessing).toHaveBeenCalledWith(42);
    expect(mockMarkDone).toHaveBeenCalledWith(42);
    expect(mockMarkFailed).not.toHaveBeenCalled();
  });

  it('should mark the delivery failed when the insert keeps failing', async () => {
    mockCreateNotes.mockRejectedValue(new Error('connection refused'));

    await postCommand();
    await drain();

    expect(mockMarkFailed).toHaveBeenCalledWith(42, 'connection refused');
    expect(mockMarkDone).not.toHaveBeenCalled();
  });

  it('should apply cleanSlackText to the stored note', async () => {
    await postCommand({
      text: 'Ping <@U9|dan> in <#C1|ops> about <https://ex.com|the doc> &amp; ship',
    });
    await drain();

    const [notes] = mockCreateNotes.mock.calls[0];
    expect(notes[0].text).toBe('Ping @dan in #ops about the doc & ship');
  });

  it('should echo the cleaned text rather than the raw mrkdwn', async () => {
    const res = await postCommand({ text: 'read <https://ex.com|the doc>' });

    expect(res.body.text).toBe('Added to Kongruity: "read the doc"');
  });

  it('should truncate a long echo so it does not flood the channel', async () => {
    const long = 'a'.repeat(400);

    const res = await postCommand({ text: long });

    expect(res.status).toBe(200);
    expect(res.body.text).toContain('…');
    expect(res.body.text.length).toBeLessThan(160);
  });

  it('should store the whole note even when the echo is truncated', async () => {
    const long = 'a'.repeat(400);

    await postCommand({ text: long });
    await drain();

    const [notes] = mockCreateNotes.mock.calls[0];
    expect(notes[0].text).toBe(long);
  });

  it('should fall back to a synthetic external id when trigger_id is absent', async () => {
    await postCommand({ trigger_id: undefined });

    expect(mockRecordDelivery).toHaveBeenCalledOnce();
    const [input] = mockRecordDelivery.mock.calls[0];
    expect(input.provider).toBe('slack');
    expect(input.externalId).toMatch(/^T999:U123:\d+$/);
  });

  it('should truncate the note id to the 64 character column width', async () => {
    await postCommand({ trigger_id: 'trg_'.padEnd(120, 'x') });
    await drain();

    const [notes] = mockCreateNotes.mock.calls[0];
    expect(notes[0].id).toHaveLength(64);
    expect(notes[0].id.startsWith('slack_trg_x')).toBe(true);
  });

  it('should drop a duplicate trigger_id without enqueueing work', async () => {
    mockRecordDelivery.mockResolvedValue(null);

    const res = await postCommand();
    await drain();

    expect(res.status).toBe(200);
    expect(res.body).toEqual({ response_type: 'ephemeral', text: 'Already captured.' });
    expect(mockCreateNotes).not.toHaveBeenCalled();
    expect(mockMarkProcessing).not.toHaveBeenCalled();
  });

  it('should return usage when the text is empty', async () => {
    const res = await postCommand({ text: '' });

    expect(res.status).toBe(200);
    expect(res.body).toEqual({
      response_type: 'ephemeral',
      text: 'Usage: /sticky <your note>',
    });
    expect(mockRecordDelivery).not.toHaveBeenCalled();
  });

  it('should return usage when the text is only whitespace', async () => {
    const res = await postCommand({ text: '   ' });

    expect(res.status).toBe(200);
    expect(res.body.text).toBe('Usage: /sticky <your note>');
    expect(mockRecordDelivery).not.toHaveBeenCalled();
  });

  /**
   * Markup can be non-empty before cleaning and empty after it. Recording the
   * delivery first would consume the trigger_id that dedups a Slack retry.
   */
  it('should return usage without recording a delivery when the text cleans away to nothing', async () => {
    const res = await postCommand({ text: '<>' });

    expect(res.status).toBe(200);
    expect(res.body.text).toBe('Usage: /sticky <your note>');
    expect(mockRecordDelivery).not.toHaveBeenCalled();
    expect(mockCreateNotes).not.toHaveBeenCalled();
  });

  it('should reject an unrecognized command name', async () => {
    const res = await postCommand({ command: '/todo' });

    expect(res.status).toBe(200);
    expect(res.body).toEqual({
      response_type: 'ephemeral',
      text: 'Unknown command /todo.',
    });
    expect(mockRecordDelivery).not.toHaveBeenCalled();
  });

  it('should fall back to the user id when no user_name is sent', async () => {
    await postCommand({ user_name: undefined });
    await drain();

    const [notes] = mockCreateNotes.mock.calls[0];
    expect(notes[0].author).toBe('U123');
  });

  it('should fall back to "unknown" when the sender is unidentified', async () => {
    await postCommand({ user_name: undefined, user_id: undefined });
    await drain();

    const [notes] = mockCreateNotes.mock.calls[0];
    expect(notes[0].author).toBe('unknown');
  });

  it('should reject a signature computed with the wrong secret', async () => {
    const body = encode(FIELDS);
    const timestamp = now();

    const res = await postRaw(body, sign(body, timestamp, 'wrong-secret'), timestamp);

    expect(res.status).toBe(401);
    expect(res.body).toEqual({ error: 'Invalid signature' });
    expect(mockRecordDelivery).not.toHaveBeenCalled();
  });

  it('should reject a body altered after signing', async () => {
    const body = encode(FIELDS);
    const timestamp = now();
    const signature = sign(body, timestamp);
    const tampered = body.replace('scary', 'great');

    const res = await postRaw(tampered, signature, timestamp);

    expect(res.status).toBe(401);
    expect(mockRecordDelivery).not.toHaveBeenCalled();
  });

  it('should reject a request with no signature header', async () => {
    const body = encode(FIELDS);

    const res = await request(app)
      .post('/v1/slack/commands')
      .set('Content-Type', 'application/x-www-form-urlencoded')
      .set('x-slack-request-timestamp', now())
      .send(body);

    expect(res.status).toBe(401);
    expect(mockRecordDelivery).not.toHaveBeenCalled();
  });

  it('should reject a replayed request whose timestamp is outside the tolerance', async () => {
    const body = encode(FIELDS);
    const stale = (Math.floor(Date.now() / 1000) - 3600).toString();

    const res = await postRaw(body, sign(body, stale), stale);

    expect(res.status).toBe(401);
    expect(mockRecordDelivery).not.toHaveBeenCalled();
  });

  it('should return 500 when no signing secret is configured', async () => {
    delete process.env.SLACK_SIGNING_SECRET;

    const res = await postCommand();

    expect(res.status).toBe(500);
    expect(res.body).toEqual({ error: 'Slack is not configured' });
    expect(mockRecordDelivery).not.toHaveBeenCalled();
  });

  it('should return 500 when recording the delivery fails', async () => {
    mockRecordDelivery.mockRejectedValue(new Error('connection refused'));

    const res = await postCommand();

    expect(res.status).toBe(500);
    expect(mockCreateNotes).not.toHaveBeenCalled();
  });

  it('should answer every user-facing outcome with ephemeral JSON', async () => {
    const responses = await Promise.all([
      postCommand(),
      postCommand({ text: '' }),
      postCommand({ command: '/todo' }),
    ]);

    for (const res of responses) {
      expect(res.status).toBe(200);
      expect(res.headers['content-type']).toMatch(/application\/json/);
      expect(res.body.response_type).toBe('ephemeral');
      expect(typeof res.body.text).toBe('string');
    }
  });
});