From 043a07bd0dabaa50d3931bc4c1f368bbd8074387 Mon Sep 17 00:00:00 2001
From: Sam Lown <sam.lown@invopop.com>
Date: Mon, 4 Dec 2023 09:30:12 +0000
Subject: [PATCH] Fixing support for simplified documents

---
 items.go                          |  18 +++--
 parties.go                        |   5 +-
 test/data/invoice-simplified.json | 123 ++++++++++++++++++++++++++++++
 test/examples_test.go             |  11 +++
 4 files changed, 149 insertions(+), 8 deletions(-)
 create mode 100644 test/data/invoice-simplified.json
 create mode 100644 test/examples_test.go

diff --git a/items.go b/items.go
index 277b9f4..6b19138 100644
--- a/items.go
+++ b/items.go
@@ -47,18 +47,23 @@ func generateLineDetails(inv *bill.Invoice) []*dettaglioLinee {
 	var dl []*dettaglioLinee
 
 	for _, line := range inv.Lines {
-		vatTax := line.Taxes.Get(tax.CategoryVAT)
-
-		dl = append(dl, &dettaglioLinee{
+		d := &dettaglioLinee{
 			NumeroLinea:         strconv.Itoa(line.Index),
 			Descrizione:         line.Item.Name,
 			Quantita:            formatAmount(&line.Quantity),
 			PrezzoUnitario:      formatAmount(&line.Item.Price),
 			PrezzoTotale:        formatAmount(&line.Sum),
-			AliquotaIVA:         formatPercentage(vatTax.Percent),
-			Natura:              vatTax.Ext[it.ExtKeySDINature].String(),
 			ScontoMaggiorazione: extractLinePriceAdjustments(line),
-		})
+		}
+		if len(line.Taxes) > 0 {
+			vatTax := line.Taxes.Get(tax.CategoryVAT)
+			if vatTax != nil {
+				d.AliquotaIVA = formatPercentage(vatTax.Percent)
+				d.Natura = vatTax.Ext[it.ExtKeySDINature].String()
+			}
+		}
+
+		dl = append(dl, d)
 	}
 
 	return dl
@@ -114,7 +119,6 @@ func findRiferimentoNormativo(rateTotal *tax.RateTotal) string {
 	def := regime.ExtensionDef(it.ExtKeySDINature)
 
 	nature := rateTotal.Ext[it.ExtKeySDINature]
-
 	for _, c := range def.Codes {
 		if c.Code == nature {
 			return c.Name[i18n.IT]
diff --git a/parties.go b/parties.go
index e504c37..0a51c8e 100644
--- a/parties.go
+++ b/parties.go
@@ -95,8 +95,11 @@ func newCedentePrestatore(s *org.Party) *supplier {
 }
 
 func newCessionarioCommittente(c *org.Party) *customer {
-	nc := new(customer)
+	if c == nil {
+		return nil
+	}
 
+	nc := new(customer)
 	if len(c.Addresses) > 0 {
 		nc.Sede = newAddress(c.Addresses[0])
 	}
diff --git a/test/data/invoice-simplified.json b/test/data/invoice-simplified.json
new file mode 100644
index 0000000..926b00a
--- /dev/null
+++ b/test/data/invoice-simplified.json
@@ -0,0 +1,123 @@
+{
+	"$schema": "https://gobl.org/draft-0/envelope",
+	"head": {
+		"uuid": "679a2f25-7483-11ec-9722-7ea2cb436ff6",
+		"dig": {
+			"alg": "sha256",
+			"val": "427155d9bff1a6df157e956f0850ee880a44c8aa2adc8864e3cd48a758805193"
+		}
+	},
+	"doc": {
+		"$schema": "https://gobl.org/draft-0/bill/invoice",
+		"type": "standard",
+		"series": "SAMPLE",
+		"code": "055",
+		"issue_date": "2023-12-04",
+		"currency": "EUR",
+		"tax": {
+			"tags": [
+				"simplified"
+			]
+		},
+		"supplier": {
+			"name": "MªF. Services",
+			"tax_id": {
+				"country": "IT",
+				"code": "12345678903"
+			},
+			"people": [
+				{
+					"name": {
+						"given": "GIANCARLO",
+						"surname": "ROSSI"
+					}
+				}
+			],
+			"addresses": [
+				{
+					"num": "1",
+					"street": "VIALE DELLA LIBERTÀ",
+					"locality": "ROMA",
+					"region": "RM",
+					"code": "00100",
+					"country": "IT"
+				}
+			],
+			"emails": [
+				{
+					"addr": "billing@example.com"
+				}
+			],
+			"telephones": [
+				{
+					"num": "999999999"
+				}
+			],
+			"registration": {
+				"capital": "50000.00",
+				"currency": "EUR",
+				"office": "RM",
+				"entry": "123456"
+			},
+			"ext": {
+				"it-sdi-fiscal-regime": "RF01"
+			}
+		},
+		"lines": [
+			{
+				"i": 1,
+				"quantity": "20",
+				"item": {
+					"name": "Random products",
+					"price": "90.00",
+					"unit": "h"
+				},
+				"sum": "1800.00",
+				"discounts": [
+					{
+						"percent": "10%",
+						"amount": "180.00",
+						"reason": "Special discount"
+					}
+				],
+				"taxes": [
+					{
+						"cat": "VAT",
+						"rate": "standard",
+						"percent": "22.0%"
+					}
+				],
+				"total": "1620.00"
+			}
+		],
+		"payment": {
+			"instructions": {
+				"key": "card"
+			}
+		},
+		"totals": {
+			"sum": "1620.00",
+			"total": "1620.00",
+			"taxes": {
+				"categories": [
+					{
+						"code": "VAT",
+						"rates": [
+							{
+								"key": "standard",
+								"base": "1620.00",
+								"percent": "22.0%",
+								"amount": "356.40"
+							}
+						],
+						"amount": "356.40"
+					}
+				],
+				"sum": "356.40"
+			},
+			"tax": "356.40",
+			"total_with_tax": "1976.40",
+			"payable": "1976.40"
+		}
+	}
+}
diff --git a/test/examples_test.go b/test/examples_test.go
new file mode 100644
index 0000000..17e17d5
--- /dev/null
+++ b/test/examples_test.go
@@ -0,0 +1,11 @@
+package test_test
+
+import (
+	"testing"
+
+	"github.com/invopop/gobl.fatturapa/test"
+)
+
+func TestExamples(t *testing.T) {
+	test.TestConversion()
+}