From 5b31c05c539671298c8c967a34d09f5573764e97 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Paulo=20Sima=CC=83o?= <paulo@digitalcircle.com.br>
Date: Wed, 29 Sep 2021 22:04:43 -0300
Subject: [PATCH] cnpj on the way

---
 cnpj/lib.go      | 65 ++++++++++++++++++++++++++++++++++++++++++++++++
 cnpj/lib_test.go | 20 +++++++++++++++
 2 files changed, 85 insertions(+)
 create mode 100644 cnpj/lib.go
 create mode 100644 cnpj/lib_test.go

diff --git a/cnpj/lib.go b/cnpj/lib.go
new file mode 100644
index 0000000..0339b94
--- /dev/null
+++ b/cnpj/lib.go
@@ -0,0 +1,65 @@
+package cnpj
+
+import (
+	"strconv"
+	"unicode"
+)
+
+//Gets a string and formats is as CPF
+func Format(s string) string {
+	raw := Strip(s)
+	ret := raw[0:2] + "." + raw[2:5] + "." + raw[5:8] + "/" + raw[8:12] + "-" + raw[12:14]
+	return ret
+
+}
+
+//Removes all non-digit symbols
+func Strip(s string) string {
+	ret := ""
+	for _, v := range s {
+		if unicode.IsDigit(v) {
+			ret = ret + string(v)
+		}
+	}
+	return ret
+}
+
+//Checks if verification digit are respected
+func Check(s string) bool {
+	raw := Strip(s)
+	nums := make([]int, 0)
+	for _, v := range raw {
+		i, _ := strconv.Atoi(string(v))
+		nums = append(nums, i)
+	}
+
+	d1 := 0
+	mul := 5
+	for _, v := range nums[0 : len(nums)-2] {
+		d1 = d1 + (v * mul)
+		mul--
+		if mul == 2 {
+			mul = 9
+		}
+	}
+	mod1 := 11 - ((d1) % 11)
+	if mod1 > 10 {
+		mod1 = 0
+	}
+
+	d2 := 0
+	mul = 6
+	for _, v := range nums[0 : len(nums)-2] {
+		d2 = d2 + (v * mul)
+		mul--
+		if mul == 2 {
+			mul = 9
+		}
+	}
+	d2 = d2 + (mod1 * mul)
+	mod2 := 11 - ((d2) % 11)
+	if mod2 > 10 {
+		mod2 = 0
+	}
+	return mod1 == nums[len(nums)-2] && mod2 == nums[len(nums)-1]
+}
diff --git a/cnpj/lib_test.go b/cnpj/lib_test.go
new file mode 100644
index 0000000..41992b2
--- /dev/null
+++ b/cnpj/lib_test.go
@@ -0,0 +1,20 @@
+package cnpj
+
+import (
+	"log"
+	"testing"
+)
+
+func TestFormat(t *testing.T) {
+	log.Printf(Format("03794020685"))
+}
+
+func TestCheck(t *testing.T) {
+	for _, v := range []string{
+		"60.119.200/0001-90",
+	} {
+		ret := Check(v)
+		log.Printf("%s=>%v", v, ret)
+	}
+
+}