From 86008934963bb4e01e023fab67da608e52d01dec Mon Sep 17 00:00:00 2001
From: Gustavo <gustavk.saj11@gmail.com>
Date: Sat, 1 Aug 2026 10:29:19 -0300
Subject: [PATCH] Add deterministic variant selection and message rendering

---
 src/outreach/campaign-messages.mjs | 14 ++++++++++++++
 tests/campaign-messages.test.mjs   | 27 +++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)
 create mode 100644 src/outreach/campaign-messages.mjs
 create mode 100644 tests/campaign-messages.test.mjs

diff --git a/src/outreach/campaign-messages.mjs b/src/outreach/campaign-messages.mjs
new file mode 100644
index 0000000..a77c5b0
--- /dev/null
+++ b/src/outreach/campaign-messages.mjs
@@ -0,0 +1,14 @@
+import { renderTemplate } from './templates.mjs';
+
+// Distribuicao deterministica por lead_id % variantes.length: o mesmo lead
+// sempre cai na mesma variante mesmo que a fila seja regenerada depois, sem
+// precisar guardar nenhum estado extra so pra isso.
+export function variantForLead(variants, leadId) {
+  if (!variants.length) throw new Error('campanha sem variantes ativas');
+  const index = Number(leadId) % variants.length;
+  return variants[index];
+}
+
+export function renderCampaignMessage(variant, lead) {
+  return renderTemplate(variant.mensagem, lead);
+}
diff --git a/tests/campaign-messages.test.mjs b/tests/campaign-messages.test.mjs
new file mode 100644
index 0000000..fad8e65
--- /dev/null
+++ b/tests/campaign-messages.test.mjs
@@ -0,0 +1,27 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { variantForLead, renderCampaignMessage } from '../src/outreach/campaign-messages.mjs';
+
+const variants = [{ id: 1, code: 'A', mensagem: 'Ola A' }, { id: 2, code: 'B', mensagem: 'Ola B' }, { id: 3, code: 'C', mensagem: 'Ola C' }];
+
+test('variantForLead e deterministico (mesmo lead sempre cai na mesma variante)', () => {
+  const primeira = variantForLead(variants, 42);
+  const segunda = variantForLead(variants, 42);
+  assert.equal(primeira.code, segunda.code);
+});
+
+test('variantForLead distribui entre variantes diferentes conforme o id', () => {
+  assert.equal(variantForLead(variants, 0).code, 'A');
+  assert.equal(variantForLead(variants, 1).code, 'B');
+  assert.equal(variantForLead(variants, 2).code, 'C');
+  assert.equal(variantForLead(variants, 3).code, 'A');
+});
+
+test('variantForLead lanca erro sem variantes ativas', () => {
+  assert.throws(() => variantForLead([], 1), /sem variantes/);
+});
+
+test('renderCampaignMessage substitui variaveis do lead', () => {
+  const texto = renderCampaignMessage({ mensagem: 'Ola {empresa}, sobre {produto}' }, { empresa: 'Oficina do Ze', produto: 'ERP' });
+  assert.equal(texto, 'Ola Oficina do Ze, sobre ERP');
+});