Add RFM segmentation analytics

backend/test/analyticsService.test.js

@@ -1,7 +1,13 @@
 const assert = require('node:assert/strict');
 const test = require('node:test');
 
-const { buildDateFilter, normalizeDateParam } = require('../services/analyticsService');
+const {
+    buildRfmSegments,
+    buildDateFilter,
+    getRfmSegment,
+    normalizeDateParam,
+    scoreTertile
+} = require('../services/analyticsService');
 
 test('normalizeDateParam accepts strict ISO dates', () => {
     assert.equal(normalizeDateParam('2026-05-28'), '2026-05-28');
@@ -32,3 +38,42 @@ test('buildDateFilter ignores invalid bounds', () => {
         'WHERE data_pedido_date IS NOT NULL AND data_pedido_date <= $1::date'
     );
 });
+
+test('scoreTertile scores higher values higher by default', () => {
+    const values = [10, 20, 30, 40, 50];
+
+    assert.equal(scoreTertile(10, values), 1);
+    assert.equal(scoreTertile(30, values), 2);
+    assert.equal(scoreTertile(50, values), 3);
+});
+
+test('scoreTertile can score lower values higher for recency', () => {
+    const recencyDays = [2, 10, 20, 40, 80];
+
+    assert.equal(scoreTertile(2, recencyDays, false), 3);
+    assert.equal(scoreTertile(20, recencyDays, false), 2);
+    assert.equal(scoreTertile(80, recencyDays, false), 1);
+});
+
+test('getRfmSegment maps the 3x3 RFM matrix', () => {
+    assert.deepEqual(getRfmSegment(3, 3), { key: 'champions', label: 'Champions' });
+    assert.deepEqual(getRfmSegment(2, 2), { key: 'need_attention', label: 'Precisam de Atenção' });
+    assert.deepEqual(getRfmSegment(1, 1), { key: 'lost', label: 'Perdidos' });
+});
+
+test('buildRfmSegments summarizes segment count and revenue', () => {
+    const segments = buildRfmSegments([
+        { segmentKey: 'champions', monetary: 100 },
+        { segmentKey: 'champions', monetary: 50 },
+        { segmentKey: 'lost', monetary: 25 }
+    ]);
+
+    const champions = segments.find(segment => segment.key === 'champions');
+    const lost = segments.find(segment => segment.key === 'lost');
+
+    assert.equal(champions.count, 2);
+    assert.equal(champions.totalRevenue, 150);
+    assert.equal(champions.averageRevenue, 75);
+    assert.equal(lost.count, 1);
+    assert.equal(lost.totalRevenue, 25);
+});