import { mkdtempSync, rmSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { join } from 'node:path';
import { DatabaseSync } from 'node:sqlite';
import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
import type { LlmService } from '../llm/llm.service.js';
import { RssStore } from './rss.store.js';
import { fitOneLine, parseSummaryItems, RssService } from './rss.service.js';

const FEED_A = `<rss version="2.0"><channel>
  <item><title>Alpha headline</title></item>
  <item><title>Beta headline</title></item>
</channel></rss>`;
const FEED_B = `<rss version="2.0"><channel>
  <item><title>Gamma headline</title></item>
</channel></rss>`;

function feedResponse(xml: string): Response {
  return { ok: true, status: 200, text: async () => xml } as Response;
}

describe('RssService.handle', () => {
  let dir: string;
  let dbFile: string;
  let llm: { chat: ReturnType<typeof vi.fn> };
  let svc: RssService;
  let fetchMock: ReturnType<typeof vi.fn>;

  beforeEach(() => {
    dir = mkdtempSync(join(tmpdir(), 'mesh-bot-rss-svc-'));
    dbFile = join(dir, 'test.db');
    llm = { chat: vi.fn() };
    svc = new RssService(
      llm as unknown as LlmService,
      new DatabaseSync(dbFile),
    );
    fetchMock = vi.fn();
    vi.stubGlobal('fetch', fetchMock);
  });

  afterEach(() => {
    vi.unstubAllGlobals();
    rmSync(dir, { recursive: true, force: true });
  });

  const ctx = (text: string) => ({ text });
  // second connection — the same shape production uses for a separate table in one file
  const stored = () => new RssStore(new DatabaseSync(dbFile));

  it('replies with usage on bare #rss and on unknown subcommands', async () => {
    const help = await svc.handle(ctx('#rss'));
    expect(help).toContain('#rss add <url> <name>');
    expect(help).toContain('#rss get <name|#tag>');
    expect(await svc.handle(ctx('#rss frobnicate'))).toBe(help);
  });

  it('add: validates the feed, stores source with LLM tags, replies added (tags: ...)', async () => {
    fetchMock.mockResolvedValueOnce(feedResponse(FEED_A));
    llm.chat.mockResolvedValueOnce('#AI, News');

    const reply = await svc.handle(
      ctx('#rss add https://a.example/rss my feed'),
    );

    expect(reply).toBe('added my feed (tags: ai, news)');
    expect(stored().get('my feed')).toMatchObject({
      url: 'https://a.example/rss',
      tags: ['ai', 'news'],
    });
    const [messages, opts] = llm.chat.mock.calls[0];
    expect(opts).toEqual({ maxTokens: 50 });
    expect(messages[0].content).toContain('Alpha headline');
  });

  it('add: LLM failure still stores the source with empty tags and says so', async () => {
    fetchMock.mockResolvedValueOnce(feedResponse(FEED_A));
    llm.chat.mockRejectedValueOnce(new Error('llm down'));

    const reply = await svc.handle(
      ctx('#rss add https://a.example/rss myfeed'),
    );

    expect(reply).toBe('added myfeed (tag generation failed - no tags)');
    expect(stored().get('myfeed')?.tags).toEqual([]);
  });

  it('add: rejects invalid urls without fetching or storing', async () => {
    expect(await svc.handle(ctx('#rss add not a url x'))).toBe('invalid url');
    expect(await svc.handle(ctx('#rss add ftp://a.example/rss x'))).toBe(
      'invalid url',
    );
    expect(fetchMock).not.toHaveBeenCalled();
    expect(stored().list()).toEqual([]);
  });

  it('add: rejects duplicate names case-insensitively without fetching', async () => {
    stored().add({ name: 'MyFeed', url: 'https://old.example/rss', tags: [] });

    const reply = await svc.handle(
      ctx('#rss add https://a.example/rss myfeed'),
    );

    expect(reply).toBe('myfeed already exists - remove it first');
    expect(fetchMock).not.toHaveBeenCalled();
    expect(stored().get('myfeed')?.url).toBe('https://old.example/rss'); // untouched
  });

  it('add: reports non-2xx and unparseable feeds, stores nothing', async () => {
    fetchMock.mockResolvedValueOnce({ ok: false, status: 404 } as Response);
    expect(await svc.handle(ctx('#rss add https://a.example/rss x'))).toBe(
      'feed fetch failed (HTTP 404)',
    );

    fetchMock.mockResolvedValueOnce(feedResponse('this is not xml'));
    expect(await svc.handle(ctx('#rss add https://b.example/rss y'))).toBe(
      'not a valid feed (no items)',
    );
    expect(stored().list()).toEqual([]);
  });

  it('remove: deletes case-insensitively, reports missing names', async () => {
    stored().add({ name: 'Gone', url: 'https://g.example/rss', tags: [] });
    expect(await svc.handle(ctx('#rss remove gone'))).toBe('removed gone');
    expect(stored().list()).toEqual([]);
    expect(await svc.handle(ctx('#rss remove nope'))).toBe(
      'no source named nope',
    );
  });

  it('tags: no tags yet when empty, distinct sorted list otherwise', async () => {
    expect(await svc.handle(ctx('#rss tags'))).toBe('no tags yet');
    stored().add({
      name: 'A',
      url: 'https://a.example/rss',
      tags: ['zeta', 'alpha'],
    });
    stored().add({
      name: 'B',
      url: 'https://b.example/rss',
      tags: ['beta', 'alpha'],
    });
    expect(await svc.handle(ctx('#rss tags'))).toBe('alpha, beta, zeta');
  });

  it('sources: no sources yet when empty, names otherwise', async () => {
    expect(await svc.handle(ctx('#rss sources'))).toBe('no sources yet');
    stored().add({ name: 'Bee', url: 'https://b.example/rss', tags: [] });
    stored().add({ name: 'Aye', url: 'https://a.example/rss', tags: [] });
    expect(await svc.handle(ctx('#rss sources'))).toBe('Aye, Bee');
  });

  it('get <name>: summarizes via chat with a bounded maxTokens and replies with headered lines', async () => {
    stored().add({ name: 'myfeed', url: 'https://a.example/rss', tags: [] });
    fetchMock.mockResolvedValueOnce(feedResponse(FEED_A));
    llm.chat.mockResolvedValueOnce(
      'Chips: EU funds foundries.\nPark: Riverfront expansion approved.',
    );

    const reply = await svc.handle(ctx('#rss get myfeed'));

    expect(reply).toEqual([
      'Chips: EU funds foundries.',
      'Park: Riverfront expansion approved.',
    ]);
    const [messages, opts] = llm.chat.mock.calls[0];
    // headroom for the server's reasoning tokens (they count against max_tokens) — see rss.service.ts
    expect(opts).toEqual({ maxTokens: 2500 });
    const prompt = messages[0].content;
    expect(prompt).toContain('exactly 3-5 lines');
    expect(prompt).toContain('<short header>: <one or two short sentences>');
    expect(prompt).toContain('at most 20 characters');
    expect(prompt).toContain('No intro, no outro, no numbering');
    expect(prompt).toContain('Alpha headline');
    expect(prompt).toContain('Beta headline');
  });

  it('get <name>: caps items at 5', async () => {
    stored().add({ name: 'myfeed', url: 'https://a.example/rss', tags: [] });
    fetchMock.mockResolvedValueOnce(feedResponse(FEED_A));
    const seven = ['a', 'b', 'c', 'd', 'e', 'f', 'g']
      .map((c) => `${c}: item ${c}`)
      .join('\n');
    llm.chat.mockResolvedValueOnce(seven);

    const reply = await svc.handle(ctx('#rss get myfeed'));

    expect(reply).toEqual([
      'a: item a',
      'b: item b',
      'c: item c',
      'd: item d',
      'e: item e',
    ]);
  });

  it('get <name>: drops empty and separator-less lines, sends what remains when fewer than 3 are valid', async () => {
    stored().add({ name: 'myfeed', url: 'https://a.example/rss', tags: [] });
    fetchMock.mockResolvedValueOnce(feedResponse(FEED_A));
    llm.chat.mockResolvedValueOnce(
      'Chips: EU funds foundries.\n\nJust a sentence without a header\n   \nPark: expansion approved.',
    );

    const reply = await svc.handle(ctx('#rss get myfeed'));

    expect(reply).toEqual([
      'Chips: EU funds foundries.',
      'Park: expansion approved.',
    ]);
  });

  it('get <name>: hard-cuts an over-length line at a word boundary so each item fits one packet', async () => {
    stored().add({ name: 'myfeed', url: 'https://a.example/rss', tags: [] });
    fetchMock.mockResolvedValueOnce(feedResponse(FEED_A));
    const longLine = `Chips: ${'word '.repeat(40)}`; // 207 chars — over the per-line cap
    llm.chat.mockResolvedValueOnce(`${longLine}\nPark: short line.`);

    const reply = await svc.handle(ctx('#rss get myfeed'));

    expect(Array.isArray(reply)).toBe(true);
    const [cut, ok] = reply as string[];
    expect(cut.length).toBeLessThanOrEqual(180);
    expect(longLine.startsWith(cut)).toBe(true); // prefix — cut at a word boundary, not mid-word
    expect(cut.endsWith(' ')).toBe(false);
    expect(ok).toBe('Park: short line.'); // other lines untouched
  });

  it('get #tag: collects items across all sources with the tag; one dead feed does not sink it', async () => {
    stored().add({ name: 'A', url: 'https://a.example/rss', tags: ['tech'] });
    stored().add({ name: 'B', url: 'https://b.example/rss', tags: ['tech'] });
    stored().add({ name: 'C', url: 'https://c.example/rss', tags: ['other'] }); // not matched by #tech
    fetchMock
      .mockResolvedValueOnce(feedResponse(FEED_A)) // A answers (Alpha, Beta)
      .mockRejectedValueOnce(new Error('down')); // B is dead

    llm.chat.mockResolvedValueOnce('Chips: only alpha survived.');
    const reply = await svc.handle(ctx('#rss get #tech'));

    // B's fetch rejected, yet the summary still went out from A's titles alone
    expect(reply).toEqual(['Chips: only alpha survived.']);
    expect(llm.chat).toHaveBeenCalledTimes(1);
    const content = llm.chat.mock.calls[0][0][0].content;
    expect(content).toContain('Alpha headline');
  });

  it('get #tag: merges titles from every source carrying the tag', async () => {
    stored().add({ name: 'A', url: 'https://a.example/rss', tags: ['tech'] });
    stored().add({ name: 'B', url: 'https://b.example/rss', tags: ['tech'] });
    fetchMock
      .mockResolvedValueOnce(feedResponse(FEED_A)) // A → Alpha, Beta
      .mockResolvedValueOnce(feedResponse(FEED_B)); // B → Gamma

    llm.chat.mockResolvedValueOnce(
      'Alpha: first headline.\nGamma: second headline.',
    );
    const reply = await svc.handle(ctx('#rss get #tech'));

    expect(reply).toEqual([
      'Alpha: first headline.',
      'Gamma: second headline.',
    ]);
    const content = llm.chat.mock.calls[0][0][0].content;
    expect(content).toContain('Alpha headline');
    expect(content).toContain('Gamma headline'); // proves B's feed was collected too
  });

  it('get: unknown name and tag get distinct error replies', async () => {
    expect(await svc.handle(ctx('#rss get nope'))).toBe('no source named nope');
    stored().add({ name: 'A', url: 'https://a.example/rss', tags: ['tech'] });
    expect(await svc.handle(ctx('#rss get #nothing'))).toBe(
      'no sources with tag nothing',
    );
  });
});

describe('parseSummaryItems (per-line items for multi-message summaries)', () => {
  it('keeps lines with a header separator, drops empty and separator-less ones', () => {
    expect(
      parseSummaryItems(
        'Chips: EU funds foundries.\n\nNo header here\n   \nPark: expansion approved.',
      ),
    ).toEqual(['Chips: EU funds foundries.', 'Park: expansion approved.']);
  });

  it('caps at 5 items', () => {
    const seven = ['a', 'b', 'c', 'd', 'e', 'f', 'g']
      .map((c) => `${c}: item`)
      .join('\n');
    expect(parseSummaryItems(seven)).toHaveLength(5);
    expect(parseSummaryItems(seven)[4]).toBe('e: item');
  });

  it('returns [] when nothing is valid', () => {
    expect(parseSummaryItems('no headers at all\n')).toEqual([]);
  });
});

describe('fitOneLine (one mesh packet per line)', () => {
  it('passes through lines that already fit, including exactly 185 chars', () => {
    const short = 'Chips: EU funds foundries.';
    expect(fitOneLine(short)).toBe(short);
    const exact = 'x'.repeat(185);
    expect(fitOneLine(exact)).toBe(exact);
  });

  it('cuts over-long lines at a word boundary near 180', () => {
    const long = `Chips: ${'word '.repeat(40)}`; // 207 chars
    const cut = fitOneLine(long);
    expect(cut.length).toBeLessThanOrEqual(180);
    expect(long.startsWith(cut)).toBe(true); // prefix — not mid-word
    expect(cut.endsWith(' ')).toBe(false);
  });

  it('hard-cuts at 180 when there is no word boundary in reach', () => {
    const long = 'w'.repeat(250);
    expect(fitOneLine(long)).toBe('w'.repeat(180));
  });
});