import { describe, expect, it } from 'vitest';

import type { ScheduleContext, Slot } from '@/lib/schedule/types';

import { MESSAGE_MAX_CHARS, SCREEN_SCHEMA_VERSION } from './contract';
import { buildScreenPayload, selectActiveMessage, type MessageCandidate } from './viewmodel';

const ZURICH = 'Europe/Zurich';
const FULL_DAY: Slot[] = [{ open: '10:00', close: '18:30' }];
const SPLIT_DAY: Slot[] = [
  { open: '10:00', close: '13:00' },
  { open: '14:00', close: '18:30' },
];

function context(overrides: Partial<ScheduleContext> = {}): ScheduleContext {
  return {
    timezone: ZURICH,
    weekly: [
      { dayOfWeek: 0, isClosed: true, slots: [] },
      { dayOfWeek: 1, isClosed: true, slots: [] },
      { dayOfWeek: 2, isClosed: false, slots: FULL_DAY },
      { dayOfWeek: 3, isClosed: false, slots: SPLIT_DAY },
      { dayOfWeek: 4, isClosed: false, slots: FULL_DAY },
      { dayOfWeek: 5, isClosed: false, slots: FULL_DAY },
      { dayOfWeek: 6, isClosed: false, slots: FULL_DAY },
    ],
    exceptions: [],
    vacations: [],
    holidays: [],
    ...overrides,
  };
}

function input(overrides: Partial<Parameters<typeof buildScreenPayload>[0]> = {}) {
  return {
    // Tuesday 2026-09-22, 12:00 in Zurich: the shop is open.
    now: new Date('2026-09-22T10:00:00Z'),
    ctx: context(),
    shopName: 'ITA ITO',
    logoUrl: 'https://trmnl.loxi.ch/brand/logo-eink.png',
    messages: [] as MessageCandidate[],
    ...overrides,
  };
}

describe('selectActiveMessage', () => {
  const now = new Date('2026-09-22T10:00:00Z');

  const base: MessageCandidate = {
    textFr: 'Bonjour',
    textEn: 'Hello',
    startsAt: null,
    endsAt: null,
    priority: 0,
    isActive: true,
  };

  it('returns nothing when there is nothing to say', () => {
    expect(selectActiveMessage([], now)).toBeNull();
  });

  it('returns a permanent active message', () => {
    expect(selectActiveMessage([base], now)?.textFr).toBe('Bonjour');
  });

  it('ignores a deactivated message', () => {
    expect(selectActiveMessage([{ ...base, isActive: false }], now)).toBeNull();
  });

  it('ignores a message whose window has not opened', () => {
    const future = { ...base, startsAt: new Date('2026-09-23T00:00:00Z') };
    expect(selectActiveMessage([future], now)).toBeNull();
  });

  it('ignores a message whose window has closed', () => {
    const past = { ...base, endsAt: new Date('2026-09-21T00:00:00Z') };
    expect(selectActiveMessage([past], now)).toBeNull();
  });

  it('keeps a message inside its window', () => {
    const current = {
      ...base,
      startsAt: new Date('2026-09-21T00:00:00Z'),
      endsAt: new Date('2026-09-23T00:00:00Z'),
    };
    expect(selectActiveMessage([current], now)?.textFr).toBe('Bonjour');
  });

  it('prefers the highest priority', () => {
    const chosen = selectActiveMessage(
      [
        { ...base, textFr: 'Normale', priority: 1 },
        { ...base, textFr: 'Urgente', priority: 9 },
      ],
      now,
    );
    expect(chosen?.textFr).toBe('Urgente');
  });
});

describe('buildScreenPayload', () => {
  it('stamps the schema version and the generation time with the shop offset', () => {
    const payload = buildScreenPayload(input());
    expect(payload.schema).toBe(SCREEN_SCHEMA_VERSION);
    expect(payload.generated_at).toBe('2026-09-22T12:00:00+02:00');
  });

  it('describes an open day', () => {
    const payload = buildScreenPayload(input());
    expect(payload.today).toMatchObject({
      date_fr: 'Mardi 22 septembre',
      date_en: 'Tuesday 22 September',
      status: 'OPEN',
      status_fr: 'OUVERT',
      status_en: 'OPEN',
      hours_text: '10:00 – 18:30',
      next_change_fr: 'Ferme à 18:30',
      next_change_en: 'Closes at 6:30 pm',
      is_exception: false,
    });
  });

  it('still says OUVERT when closing is imminent', () => {
    // 18:05 local: the big word must stay OUVERT, the detail line carries the warning.
    const payload = buildScreenPayload(input({ now: new Date('2026-09-22T16:05:00Z') }));
    expect(payload.today.status).toBe('CLOSING_SOON');
    expect(payload.today.status_fr).toBe('OUVERT');
    expect(payload.today.next_change_fr).toBe('Ferme à 18:30');
  });

  it('describes a closed day and points at the next opening', () => {
    // Monday 2026-09-21, 12:00 local.
    const payload = buildScreenPayload(input({ now: new Date('2026-09-21T10:00:00Z') }));
    expect(payload.today.status).toBe('CLOSED');
    expect(payload.today.status_fr).toBe('FERMÉ');
    expect(payload.today.status_en).toBe('CLOSED');
    expect(payload.today.hours_text).toBe('');
    expect(payload.today.next_change_fr).toBe('Ouvre demain à 10:00');
    expect(payload.today.next_change_en).toBe('Opens tomorrow at 10:00 am');
  });

  it('says nothing about the future when the shop never reopens', () => {
    const payload = buildScreenPayload(
      input({
        ctx: context({
          weekly: [0, 1, 2, 3, 4, 5, 6].map((dayOfWeek) => ({
            dayOfWeek,
            isClosed: true,
            slots: [],
          })),
        }),
      }),
    );
    expect(payload.today.next_change_fr).toBe('');
    expect(payload.today.next_change_en).toBe('');
  });

  it('lays the week out Monday to Sunday and marks today', () => {
    const payload = buildScreenPayload(input());
    expect(payload.week).toHaveLength(7);
    expect(payload.week.map((day) => day.label_fr)).toEqual([
      'Lun',
      'Mar',
      'Mer',
      'Jeu',
      'Ven',
      'Sam',
      'Dim',
    ]);
    expect(payload.week.map((day) => day.label_en)).toEqual([
      'Mon',
      'Tue',
      'Wed',
      'Thu',
      'Fri',
      'Sat',
      'Sun',
    ]);
    // Tuesday is index 1 of a Monday-first week.
    expect(payload.week.map((day) => day.is_today)).toEqual([
      false,
      true,
      false,
      false,
      false,
      false,
      false,
    ]);
    expect(payload.week[0]?.is_closed).toBe(true);
    expect(payload.week[2]?.hours_text).toBe('10:00 – 13:00 · 14:00 – 18:30');
  });

  it('marks exceptional days in the week strip', () => {
    const payload = buildScreenPayload(
      input({
        ctx: context({
          exceptions: [
            {
              date: '2026-09-24',
              isClosed: true,
              slots: null,
              reason: 'TEMPORARY',
              noteFr: 'Fermé',
              noteEn: 'Closed',
              source: 'MANUAL',
            },
          ],
        }),
      }),
    );
    expect(payload.week[3]?.is_exception).toBe(true);
    expect(payload.week[3]?.is_closed).toBe(true);
  });

  it('carries no banner when the shop has nothing to say', () => {
    expect(buildScreenPayload(input()).banner).toBeNull();
  });

  it('raises the automatic banner when only today departs from the reference week', () => {
    const payload = buildScreenPayload(
      input({
        ctx: context({
          exceptions: [
            {
              date: '2026-09-22',
              isClosed: false,
              slots: [{ open: '14:00', close: '18:30' }],
              reason: 'TEMPORARY',
              noteFr: 'Ouverture retardée',
              noteEn: 'Late opening',
              source: 'MANUAL',
            },
          ],
        }),
      }),
    );
    expect(payload.banner).toEqual({
      kind: 'SCHEDULE_TODAY',
      text_fr: "Changement d'horaire aujourd'hui",
      text_en: 'Opening hours changed today',
    });
  });

  it('raises the weekly banner when a later day departs', () => {
    const payload = buildScreenPayload(
      input({
        ctx: context({
          exceptions: [
            {
              date: '2026-09-24',
              isClosed: true,
              slots: null,
              reason: 'TEMPORARY',
              noteFr: null,
              noteEn: null,
              source: 'MANUAL',
            },
          ],
        }),
      }),
    );
    expect(payload.banner?.kind).toBe('SCHEDULE_WEEK');
  });

  it('lets a free-text message win over the automatic banner', () => {
    const payload = buildScreenPayload(
      input({
        ctx: context({
          exceptions: [
            {
              date: '2026-09-24',
              isClosed: true,
              slots: null,
              reason: 'TEMPORARY',
              noteFr: null,
              noteEn: null,
              source: 'MANUAL',
            },
          ],
        }),
        messages: [
          {
            textFr: 'Nouvelle collection en boutique',
            textEn: 'New collection in store',
            startsAt: null,
            endsAt: null,
            priority: 0,
            isActive: true,
          },
        ],
      }),
    );
    expect(payload.banner).toEqual({
      kind: 'MESSAGE',
      text_fr: 'Nouvelle collection en boutique',
      text_en: 'New collection in store',
    });
  });

  it('shows the French line alone when the translation is missing', () => {
    const payload = buildScreenPayload(
      input({
        messages: [
          {
            textFr: 'Fermeture exceptionnelle',
            textEn: null,
            startsAt: null,
            endsAt: null,
            priority: 0,
            isActive: true,
          },
        ],
      }),
    );
    expect(payload.banner?.text_fr).toBe('Fermeture exceptionnelle');
    expect(payload.banner?.text_en).toBe('');
  });

  it('truncates a message that would overflow the banner', () => {
    const tooLong = 'a'.repeat(MESSAGE_MAX_CHARS + 40);
    const payload = buildScreenPayload(
      input({
        messages: [
          {
            textFr: tooLong,
            textEn: tooLong,
            startsAt: null,
            endsAt: null,
            priority: 0,
            isActive: true,
          },
        ],
      }),
    );
    expect(payload.banner?.text_fr.length).toBeLessThanOrEqual(MESSAGE_MAX_CHARS);
    expect(payload.banner?.text_fr.endsWith('…')).toBe(true);
  });

  it('matches the frozen payload contract', () => {
    // This snapshot is the regression guard for the whole display pipeline:
    // any change to the shape or to a computed string has to be acknowledged
    // here before it can reach the panel.
    expect(
      buildScreenPayload(
        input({
          ctx: context({
            exceptions: [
              {
                date: '2026-09-24',
                isClosed: false,
                slots: [{ open: '14:00', close: '18:30' }],
                reason: 'TEMPORARY',
                noteFr: 'Ouverture retardée',
                noteEn: 'Late opening',
                source: 'MANUAL',
              },
            ],
            holidays: [
              {
                date: '2026-09-25',
                nameFr: 'Jeûne genevois',
                nameEn: 'Geneva Fast',
                isAutoClosed: true,
              },
            ],
          }),
          messages: [
            {
              textFr: 'Fermeture exceptionnelle jeudi après-midi',
              textEn: 'Exceptionally closed on Thursday afternoon',
              startsAt: null,
              endsAt: null,
              priority: 0,
              isActive: true,
            },
          ],
        }),
      ),
    ).toMatchSnapshot();
  });
});