import { describe, test } from 'node:test';
import assert from 'node:assert/strict';
import { generateIcal, generateIcalFromQueue } from '../ical-generator.mjs';

const SAMPLE_EVENT = {
  id: 'post-2026-04-14-ai-strategy',
  title: 'LinkedIn: AI strategy in public sector',
  description: 'Pillar: AI Strategy | Format: Standard | Draft: assets/drafts/week-W16/monday.md',
  date: '2026-04-14',
  time: '08:30',
  duration: 30,
};

const SAMPLE_QUEUE_ENTRY = {
  id: 'post-2026-04-14-ai-strategy',
  draft_path: 'assets/drafts/week-W16/monday.md',
  scheduled_date: '2026-04-14',
  scheduled_time: '08:30',
  pillar: 'AI Strategy',
  format: 'Standard',
  hook_preview: 'AI strategy in public sector',
  character_count: 1450,
  status: 'scheduled',
  created_at: '2026-04-10',
};

describe('generateIcal', () => {
  test('returns valid empty VCALENDAR for empty events array', () => {
    const ical = generateIcal([]);
    assert.match(ical, /^BEGIN:VCALENDAR\r\n/);
    assert.match(ical, /\r\nEND:VCALENDAR\r\n$/);
    assert.match(ical, /PRODID:-\/\/linkedin-studio\/\/EN/);
    assert.match(ical, /VERSION:2\.0/);
    assert.ok(!ical.includes('BEGIN:VEVENT'), 'should not contain VEVENT');
  });

  test('generates VEVENT with correct DTSTART, SUMMARY, UID', () => {
    const ical = generateIcal([SAMPLE_EVENT]);
    assert.match(ical, /BEGIN:VEVENT/);
    assert.match(ical, /DTSTART;TZID=Europe\/Oslo:20260414T083000/);
    assert.match(ical, /SUMMARY:LinkedIn: AI strategy in public sector/);
    assert.match(ical, /UID:post-2026-04-14-ai-strategy@linkedin-studio/);
    assert.match(ical, /END:VEVENT/);
  });

  test('generates correct DTEND from duration', () => {
    const ical = generateIcal([SAMPLE_EVENT]);
    assert.match(ical, /DTEND;TZID=Europe\/Oslo:20260414T090000/);
  });

  test('defaults duration to 30 minutes when not specified', () => {
    const event = { ...SAMPLE_EVENT, duration: undefined };
    const ical = generateIcal([event]);
    assert.match(ical, /DTEND;TZID=Europe\/Oslo:20260414T090000/);
  });

  test('has CRLF line endings throughout', () => {
    const ical = generateIcal([SAMPLE_EVENT]);
    const lines = ical.split('\r\n');
    assert.ok(lines.length > 5, 'should have multiple lines');
    const bareLF = ical.replace(/\r\n/g, '').includes('\n');
    assert.ok(!bareLF, 'should not contain bare LF without CR');
  });

  test('includes VALARM with 15-minute trigger', () => {
    const ical = generateIcal([SAMPLE_EVENT]);
    assert.match(ical, /BEGIN:VALARM/);
    assert.match(ical, /TRIGGER:-PT15M/);
    assert.match(ical, /ACTION:DISPLAY/);
    assert.match(ical, /END:VALARM/);
  });

  test('includes DTSTAMP in UTC format', () => {
    const ical = generateIcal([SAMPLE_EVENT]);
    assert.match(ical, /DTSTAMP:\d{8}T\d{6}Z/);
  });

  test('folds lines longer than 75 octets', () => {
    const longDescription = 'A'.repeat(200);
    const event = { ...SAMPLE_EVENT, description: longDescription };
    const ical = generateIcal([event]);
    const lines = ical.split('\r\n');
    for (const line of lines) {
      const octets = Buffer.byteLength(line, 'utf-8');
      assert.ok(octets <= 75, `Line exceeds 75 octets (${octets}): "${line.slice(0, 40)}..."`);
    }
  });

  test('escapes special characters in SUMMARY and DESCRIPTION', () => {
    const event = {
      ...SAMPLE_EVENT,
      title: 'Test: commas, semicolons; and\\backslashes',
      description: 'Line1\nLine2, with; special\\chars',
    };
    const ical = generateIcal([event]);
    assert.match(ical, /SUMMARY:Test: commas\\, semicolons\; and\\\\backslashes/);
    assert.match(ical, /DESCRIPTION:Line1\\nLine2\\, with\; special\\\\chars/);
  });

  test('handles multiple events', () => {
    const event2 = {
      ...SAMPLE_EVENT,
      id: 'post-2026-04-16-leadership',
      title: 'LinkedIn: Leadership lessons',
      date: '2026-04-16',
      time: '12:00',
    };
    const ical = generateIcal([SAMPLE_EVENT, event2]);
    const veventCount = (ical.match(/BEGIN:VEVENT/g) || []).length;
    assert.equal(veventCount, 2);
  });

  test('includes VTIMEZONE for Europe/Oslo', () => {
    const ical = generateIcal([SAMPLE_EVENT]);
    assert.match(ical, /BEGIN:VTIMEZONE/);
    assert.match(ical, /TZID:Europe\/Oslo/);
    assert.match(ical, /END:VTIMEZONE/);
  });

  test('supports custom timezone parameter', () => {
    const ical = generateIcal([SAMPLE_EVENT], { timezone: 'America/New_York' });
    assert.match(ical, /TZID:America\/New_York/);
    assert.match(ical, /DTSTART;TZID=America\/New_York/);
  });
});

describe('generateIcalFromQueue', () => {
  test('transforms queue entry format to event format', () => {
    const events = generateIcalFromQueue([SAMPLE_QUEUE_ENTRY]);
    assert.equal(events.length, 1);
    const e = events[0];
    assert.equal(e.id, 'post-2026-04-14-ai-strategy');
    assert.equal(e.date, '2026-04-14');
    assert.equal(e.time, '08:30');
    assert.ok(e.title.includes('AI strategy in public sector'));
    assert.ok(e.description.includes('AI Strategy'));
    assert.ok(e.description.includes('Standard'));
  });

  test('handles missing scheduled_time gracefully', () => {
    const entry = { ...SAMPLE_QUEUE_ENTRY, scheduled_time: undefined };
    const events = generateIcalFromQueue([entry]);
    assert.equal(events[0].time, '09:00');
  });

  test('handles empty array', () => {
    const events = generateIcalFromQueue([]);
    assert.deepEqual(events, []);
  });

  test('generates valid iCal when piped through generateIcal', () => {
    const events = generateIcalFromQueue([SAMPLE_QUEUE_ENTRY]);
    const ical = generateIcal(events);
    assert.match(ical, /BEGIN:VCALENDAR/);
    assert.match(ical, /BEGIN:VEVENT/);
    assert.match(ical, /END:VCALENDAR/);
  });
});