import { describe, expect, test } from 'bun:test';
import { patchContact, patchEvent, setProperty, setPropertyList } from './patch';
import { parseContacts, parseEvents } from './ical';

// What these protect: an edit must change what was asked and NOTHING else. Every failure mode here is
// silent — the write succeeds, the list still looks right, and something the UI cannot show is gone.

const EVENT = [
  'BEGIN:VCALENDAR',
  'VERSION:2.0',
  'BEGIN:VEVENT',
  'UID:abc',
  'DTSTAMP:20260827T100000Z',
  'DTSTART;TZID=Europe/Lisbon:20260828T130000',
  'DTEND;TZID=Europe/Lisbon:20260828T140000',
  'SUMMARY:Before',
  'RRULE:FREQ=WEEKLY',
  'ATTENDEE;CN=Someone:mailto:someone@example.com',
  'X-APPLE-TRAVEL-ADVISORY-BEHAVIOR:AUTOMATIC',
  'BEGIN:VALARM',
  'ACTION:DISPLAY',
  'TRIGGER:-PT15M',
  'END:VALARM',
  'END:VEVENT',
  'END:VCALENDAR',
].join('\r\n');

const ALL_DAY = [
  'BEGIN:VCALENDAR',
  'VERSION:2.0',
  'BEGIN:VEVENT',
  'UID:def',
  'DTSTAMP:20260827T100000Z',
  'DTSTART;VALUE=DATE:20260829',
  'DTEND;VALUE=DATE:20260830',
  'SUMMARY:Holiday',
  'END:VEVENT',
  'END:VCALENDAR',
].join('\r\n');

const CARD = [
  'BEGIN:VCARD',
  'VERSION:3.0',
  'UID:ghi',
  'FN:Peter Griffin',
  'N:Griffin;Peter;;;',
  'EMAIL;TYPE=INTERNET:peter@quahog.example',
  'EMAIL;TYPE=WORK:peter@brewery.example',
  'TEL;TYPE=CELL:+351912345678',
  'X-SOMETHING-ELSE:kept',
  'END:VCARD',
].join('\r\n');

describe('setProperty', () => {
  test('changes only the line it owns, and keeps what it does not understand', () => {
    const out = setProperty(EVENT, 'SUMMARY', 'After');
    expect(out).toContain('SUMMARY:After');
    for (const kept of ['RRULE:FREQ=WEEKLY', 'ATTENDEE;CN=Someone', 'X-APPLE-TRAVEL', 'BEGIN:VALARM'])
      expect(out).toContain(kept);
  });

  test('preserves parameters by default, and replaces them when told', () => {
    expect(setProperty(EVENT, 'DTSTART', '20260901T090000')).toContain('DTSTART;TZID=Europe/Lisbon:20260901T090000');
    expect(setProperty(EVENT, 'DTSTART', '20260901T090000Z', '')).toContain('DTSTART:20260901T090000Z');
  });

  test('appends after UID when absent, so it lands in the right component', () => {
    const lines = setProperty(EVENT, 'LOCATION', 'Ramiro').split('\r\n');
    expect(lines[lines.indexOf('UID:abc') + 1]).toBe('LOCATION:Ramiro');
  });

  test('null removes it', () => {
    expect(setProperty(EVENT, 'RRULE', null)).not.toContain('RRULE');
  });

  // The regression that shipped once: replacing only the first line of a FOLDED value left the rest
  // behind, and each edit inherited the tail of the last.
  test('replaces the whole of a folded value', () => {
    const folded = EVENT.replace('SUMMARY:Before', 'SUMMARY:Before and a great deal more text\r\n  folded onto line two');
    const out = setProperty(folded, 'SUMMARY', 'After');
    expect(parseEvents(out)[0]!.summary).toBe('After');
    expect(out).not.toContain('folded onto line two');
  });

  test('a long value is folded to 75 octets and reads back whole', () => {
    const long = 'y'.repeat(300);
    const out = setProperty(EVENT, 'SUMMARY', long);
    expect(out.split('\r\n').every((l) => Buffer.byteLength(l, 'utf8') <= 75)).toBe(true);
    expect(parseEvents(out)[0]!.summary).toBe(long);
  });

  test('repeated edits do not accumulate', () => {
    let out = EVENT;
    for (const v of ['one'.repeat(40), 'two'.repeat(40), 'three']) out = setProperty(out, 'SUMMARY', v);
    expect(parseEvents(out)[0]!.summary).toBe('three');
  });
});

describe('setPropertyList', () => {
  test('replaces the whole list and carries parameters over by position', () => {
    const out = setPropertyList(CARD, 'EMAIL', ['new@example.com'], ';TYPE=INTERNET');
    expect(out).toContain('EMAIL;TYPE=INTERNET:new@example.com');
    expect(out).not.toContain('brewery');
    expect(parseContacts(out)[0]!.emails).toEqual(['new@example.com']);
  });

  test('extra values get the default parameters', () => {
    const out = setPropertyList(CARD, 'TEL', ['+351911111111', '+351922222222'], ';TYPE=CELL');
    expect(out).toContain('TEL;TYPE=CELL:+351911111111');
    expect(out).toContain('TEL;TYPE=CELL:+351922222222');
  });

  test('an empty list removes them all, and leaves the rest of the card', () => {
    const out = setPropertyList(CARD, 'EMAIL', [], ';TYPE=INTERNET');
    expect(out).not.toContain('EMAIL');
    expect(out).toContain('X-SOMETHING-ELSE:kept');
    expect(out).toContain('TEL;TYPE=CELL:+351912345678');
  });
});

describe('patchEvent', () => {
  test('a text-only patch does not touch the times', () => {
    const out = patchEvent(EVENT, { summary: 'After' });
    expect(out).toContain('DTSTART;TZID=Europe/Lisbon:20260828T130000');
    expect(out).not.toContain('SEQUENCE');
  });

  test('moving a timed event writes UTC and DROPS the stale TZID', () => {
    const out = patchEvent(EVENT, { start: '2026-09-01T08:00:00Z', end: '2026-09-01T09:00:00Z' });
    expect(out).toContain('DTSTART:20260901T080000Z');
    expect(out).toContain('DTEND:20260901T090000Z');
    expect(out).not.toContain('TZID');
  });

  test('moving bumps SEQUENCE, so a phone reads an update rather than a duplicate', () => {
    const once = patchEvent(EVENT, { start: '2026-09-01T08:00:00Z' });
    expect(once).toContain('SEQUENCE:1');
    expect(patchEvent(once, { start: '2026-09-02T08:00:00Z' })).toContain('SEQUENCE:2');
  });

  test('changing only the end leaves the start exactly as it was', () => {
    const out = patchEvent(ALL_DAY, { end: '2026-08-31' });
    expect(out).toContain('DTSTART;VALUE=DATE:20260829');
    expect(out).toContain('DTEND;VALUE=DATE:20260901'); // inclusive in, exclusive out
  });

  // The one that would silently move a holiday: the file's DTEND is exclusive, so editing anything else
  // about the event must not re-add a day to it.
  test('editing an all-day event does not drift its end', () => {
    const out = patchEvent(patchEvent(ALL_DAY, { summary: 'A' }), { start: '2026-08-29' });
    expect(out).toContain('DTEND;VALUE=DATE:20260830');
  });

  test('timed becomes all-day, both ends rewritten', () => {
    const out = patchEvent(EVENT, { allDay: true, start: '2026-08-28' });
    expect(out).toContain('DTSTART;VALUE=DATE:20260828');
    expect(out).toContain('DTEND;VALUE=DATE:20260829');
    expect(parseEvents(out)[0]!.allDay).toBe(true);
  });

  test('null removes a field, an empty string does not', () => {
    const withPlace = patchEvent(EVENT, { location: 'Ramiro' });
    expect(patchEvent(withPlace, { location: null })).not.toContain('LOCATION');
    expect(patchEvent(withPlace, { location: '' })).toContain('LOCATION:');
  });

  test('separators are escaped and survive the round trip', () => {
    const out = patchEvent(EVENT, { summary: 'a, b; c' });
    expect(parseEvents(out)[0]!.summary).toBe('a, b; c');
  });
});

describe('patchContact', () => {
  test('renaming updates N as well as FN', () => {
    const out = patchContact(CARD, { fullName: 'Lois Griffin' });
    expect(out).toContain('FN:Lois Griffin');
    expect(out).toContain('N:Griffin;Lois;;;');
  });

  test('a patch that names no list leaves both lists alone', () => {
    const out = patchContact(CARD, { org: 'Pawtucket' });
    expect(parseContacts(out)[0]!.emails).toEqual(['peter@quahog.example', 'peter@brewery.example']);
    expect(out).toContain('ORG:Pawtucket');
  });

  test('everything unknown survives', () => {
    expect(patchContact(CARD, { fullName: 'Peter L. Griffin' })).toContain('X-SOMETHING-ELSE:kept');
  });

  test('REV moves, because some clients break a tie with it', () => {
    expect(patchContact(CARD, { title: 'Safety Inspector' })).toContain('REV:');
  });
});

// The bug that live testing caught, and the reason `within` exists. Radicale stores a VTIMEZONE beside
// any event carrying a TZID, and that block has DTSTART lines of its own — the summer-time rule. Taking
// the first DTSTART in the file rewrote the timezone and left the event where it was.
const WITH_VTIMEZONE = [
  'BEGIN:VCALENDAR',
  'VERSION:2.0',
  'BEGIN:VTIMEZONE',
  'TZID:Europe/Lisbon',
  'BEGIN:DAYLIGHT',
  'DTSTART:20000326T010000',
  'TZOFFSETFROM:+0000',
  'RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3',
  'END:DAYLIGHT',
  'END:VTIMEZONE',
  'BEGIN:VEVENT',
  'UID:jkl',
  'DTSTAMP:20260827T100000Z',
  'DTSTART;TZID=Europe/Lisbon:20260828T130000',
  'DTEND;TZID=Europe/Lisbon:20260828T140000',
  'SUMMARY:Probe',
  'END:VEVENT',
  'END:VCALENDAR',
].join('\r\n');

describe('a file with a VTIMEZONE', () => {
  test('moving the event does not touch the timezone rule', () => {
    const out = patchEvent(WITH_VTIMEZONE, { start: '2026-09-01T08:00:00Z', end: '2026-09-01T09:00:00Z' });
    expect(out).toContain('DTSTART:20000326T010000'); // the summer-time rule, untouched
    expect(out).toContain('DTSTART:20260901T080000Z'); // the event, moved
    expect(out).not.toContain('DTSTART;TZID=Europe/Lisbon:20260828T130000');
    expect(parseEvents(out)[0]!.start).toBe('2026-09-01T08:00:00Z');
  });

  test('the VTIMEZONE block survives intact', () => {
    const out = patchEvent(WITH_VTIMEZONE, { summary: 'Renamed' });
    for (const kept of ['BEGIN:VTIMEZONE', 'TZID:Europe/Lisbon', 'BEGIN:DAYLIGHT', 'TZOFFSETFROM:+0000'])
      expect(out).toContain(kept);
    expect(parseEvents(out)[0]!.summary).toBe('Renamed');
  });

  test('a summary is not appended into the wrong component', () => {
    const out = patchEvent(WITH_VTIMEZONE, { location: 'Ramiro' });
    const lines = out.split('\r\n');
    expect(lines.indexOf('LOCATION:Ramiro')).toBeGreaterThan(lines.indexOf('BEGIN:VEVENT'));
  });
});