import { describe, expect, it } from 'vitest';
import { selectIssuerEmail } from '../helpers/email-ingestion-issuer.helper.js';

describe('selectIssuerEmail', () => {
  it('returns null for missing evidence', () => {
    expect(selectIssuerEmail(undefined)).toBeNull();
    expect(selectIssuerEmail(null)).toBeNull();
    expect(selectIssuerEmail({})).toBeNull();
  });

  it('prefers a non-provider body candidate over headers', () => {
    expect(
      selectIssuerEmail({
        from: 'forwarder@gmail.com',
        replyTo: 'reply@x.com',
        issuerCandidates: ['vendor@acme.com'],
      }),
    ).toBe('vendor@acme.com');
  });

  it('skips a provider body candidate when a Reply-To exists', () => {
    expect(
      selectIssuerEmail({
        from: 'vendor@acme.com',
        replyTo: 'reply@x.com',
        issuerCandidates: ['notify@morning.co'],
      }),
    ).toBe('vendor@acme.com');
  });

  it('keeps a provider body candidate when there is no Reply-To', () => {
    expect(
      selectIssuerEmail({
        from: 'forwarder@gmail.com',
        issuerCandidates: ['notify@morning.co'],
      }),
    ).toBe('notify@morning.co');
  });

  it('returns the first non-provider candidate, scanning in order', () => {
    expect(
      selectIssuerEmail({
        replyTo: 'reply@x.com',
        issuerCandidates: ['c@sumit.co.il', 'real-issuer@vendor.com'],
      }),
    ).toBe('real-issuer@vendor.com');
  });

  it('falls back to originalFrom before from', () => {
    expect(
      selectIssuerEmail({
        from: 'forwarder@gmail.com',
        originalFrom: 'vendor@acme.com',
      }),
    ).toBe('vendor@acme.com');
  });

  it('falls back to Reply-To when from is a known provider', () => {
    expect(
      selectIssuerEmail({
        from: 'notify@morning.co',
        replyTo: 'reply@x.com',
      }),
    ).toBe('reply@x.com');
  });

  it('falls back to from when nothing else is usable', () => {
    expect(selectIssuerEmail({ from: 'notify@morning.co' })).toBe('notify@morning.co');
  });

  it('extracts the bare address from a "Name <addr>" form', () => {
    expect(selectIssuerEmail({ from: 'Acme Billing <billing@acme.com>' })).toBe('billing@acme.com');
  });

  it('ignores empty/null candidates', () => {
    expect(
      selectIssuerEmail({
        from: 'vendor@acme.com',
        issuerCandidates: [null, '', '   '],
      }),
    ).toBe('vendor@acme.com');
  });
});