import { describe, it, expect, beforeAll, beforeEach } from 'bun:test';
import { Database } from 'bun:sqlite';
import { initializeDatabase } from '../../../src/db';
import { TaskService } from '../../../src/tasks/service';
import { CommandService } from '../../../src/services/command';

function ymdInTZ(d: Date, tz: string = 'Europe/Madrid'): string {
  const parts = new Intl.DateTimeFormat('en-GB', {
    timeZone: tz,
    year: 'numeric',
    month: '2-digit',
    day: '2-digit',
  }).formatToParts(d);
  const get = (t: string) => parts.find(p => p.type === t)?.value || '';
  return `${get('year')}-${get('month')}-${get('day')}`;
}

function addDaysToYMD(ymd: string, days: number, tz: string = 'Europe/Madrid'): string {
  const [Y, M, D] = ymd.split('-').map(n => parseInt(n, 10));
  const base = new Date(Date.UTC(Y, (M || 1) - 1, D || 1));
  base.setUTCDate(base.getUTCDate() + days);
  return ymdInTZ(base, tz);
}

describe('CommandService - parser de fechas (hoy/mañana y formatos YYYY/YY-MM-DD)', () => {
  let memdb: Database;

  beforeAll(() => {
    memdb = new Database(':memory:');
    initializeDatabase(memdb);
    TaskService.dbInstance = memdb;
    CommandService.dbInstance = memdb;
  });

  beforeEach(() => {
    process.env.NODE_ENV = 'test';
    process.env.TZ = 'Europe/Madrid';
    memdb.exec('DELETE FROM task_assignments; DELETE FROM tasks;');
  });

  it('interpreta "hoy" como due_date de hoy en la TZ configurada', async () => {
    const sender = '600111222';
    const ctx = {
      sender,
      groupId: `${sender}@s.whatsapp.net`, // DM
      message: '/t n prueba hoy',
      mentions: [] as string[],
    };
    await CommandService.handle(ctx);

    const row = memdb.prepare(`SELECT id, due_date FROM tasks ORDER BY id DESC LIMIT 1`).get() as any;
    const todayYMD = ymdInTZ(new Date(), process.env.TZ);
    expect(row).toBeTruthy();
    expect(String(row.due_date)).toBe(todayYMD);
  });

  it('interpreta "mañana" (con o sin acento) como due_date de mañana', async () => {
    const sender = '600111222';
    const ctx = {
      sender,
      groupId: `${sender}@s.whatsapp.net`, // DM
      message: '/t n prueba mañana',
      mentions: [] as string[],
    };
    await CommandService.handle(ctx);

    const row = memdb.prepare(`SELECT id, due_date FROM tasks ORDER BY id DESC LIMIT 1`).get() as any;
    const todayYMD = ymdInTZ(new Date(), process.env.TZ);
    const tomorrowYMD = addDaysToYMD(todayYMD, 1, process.env.TZ);
    expect(row).toBeTruthy();
    expect(String(row.due_date)).toBe(tomorrowYMD);
  });

  it('elige la última fecha futura cuando hay varias (mezcla YYYY-MM-DD y tokens)', async () => {
    const sender = '600111222';
    const ctx = {
      sender,
      groupId: `${sender}@s.whatsapp.net`, // DM
      // contiene pasado (2020-01-01), hoy (futuro válido) y una futura explícita, y termina con "mañana"
      message: '/t n mezcla 2020-01-01 hoy 2099-01-01 mañana',
      mentions: [] as string[],
    };
    await CommandService.handle(ctx);

    const row = memdb.prepare(`SELECT id, due_date FROM tasks ORDER BY id DESC LIMIT 1`).get() as any;
    const todayYMD = ymdInTZ(new Date(), process.env.TZ);
    const tomorrowYMD = addDaysToYMD(todayYMD, 1, process.env.TZ);
    expect(row).toBeTruthy();
    expect(String(row.due_date)).toBe(tomorrowYMD);
  });

  it('acepta formato YY-MM-DD y normaliza a YYYY-MM-DD (pivot en 2000s)', async () => {
    const sender = '600111222';
    const ctx = {
      sender,
      groupId: `${sender}@s.whatsapp.net`,
      message: '/t n con corto 25-12-19',
      mentions: [] as string[],
    };
    await CommandService.handle(ctx);

    const row = memdb.prepare(`SELECT id, due_date FROM tasks ORDER BY id DESC LIMIT 1`).get() as any;
    expect(row).toBeTruthy();
    expect(String(row.due_date)).toBe('2025-12-19');
  });

  it('acepta formato YY-MM-DD con ceros y futuro lejano seguro (30-01-05 → 2030-01-05)', async () => {
    const sender = '600111222';
    const ctx = {
      sender,
      groupId: `${sender}@s.whatsapp.net`,
      message: '/t n con corto 30-01-05',
      mentions: [] as string[],
    };
    await CommandService.handle(ctx);

    const row = memdb.prepare(`SELECT id, due_date FROM tasks ORDER BY id DESC LIMIT 1`).get() as any;
    expect(row).toBeTruthy();
    expect(String(row.due_date)).toBe('2030-01-05');
  });

  it('rechaza formatos no permitidos y no establece due_date', async () => {
    const sender = '600111222';
    const invalids = [
      '/t n invalida 25/12/30',  // separador no permitido
      '/t n invalida 2025/12/01', // separador no permitido
      '/t n invalida 2025-2-01',  // mes 1 dígito
      '/t n invalida 2025-02-3',  // día 1 dígito
      '/t n invalida 2025-13-01', // mes inválido
      '/t n invalida 2025-00-10', // mes inválido
      '/t n invalida 2025-02-30', // día inválido calendario
      '/t n invalida 25-12',      // dos partes no permitido
      '/t n invalida 12-25',      // dos partes no permitido
      '/t n invalida 2025-1-1',   // sin padding
    ];

    for (const msg of invalids) {
      memdb.exec('DELETE FROM task_assignments; DELETE FROM tasks;');

      await CommandService.handle({
        sender,
        groupId: `${sender}@s.whatsapp.net`,
        message: msg,
        mentions: [] as string[],
      });

      const row = memdb.prepare(`SELECT id, due_date FROM tasks ORDER BY id DESC LIMIT 1`).get() as any;
      expect(row).toBeTruthy();
      expect(row.due_date).toBeNull();
    }
  });
});