From c54d17ee30a6d189899128e386ef9031a9d81357 Mon Sep 17 00:00:00 2001
From: surdeus <surdeus@gmail.com>
Date: Wed, 27 Mar 2024 12:51:48 +0500
Subject: [PATCH] Init.

---
 go.mod            |   3 +
 inns/errors.go    |  11 +++
 inns/inns_test.go |  80 +++++++++++++++++++
 inns/main.go      | 193 ++++++++++++++++++++++++++++++++++++++++++++++
 main.go           |   7 ++
 5 files changed, 294 insertions(+)
 create mode 100644 go.mod
 create mode 100644 inns/errors.go
 create mode 100644 inns/inns_test.go
 create mode 100644 inns/main.go
 create mode 100644 main.go

diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..badb8e6
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module vultras.su/core/biz
+
+go 1.21.8
diff --git a/inns/errors.go b/inns/errors.go
new file mode 100644
index 0000000..05d5871
--- /dev/null
+++ b/inns/errors.go
@@ -0,0 +1,11 @@
+package inns
+
+import (
+	"errors"
+)
+
+var (
+	IncorrectFormatErr = errors.New("incorrect INN format")
+	IncorrectLenErr = errors.New("incorrect INN length")
+	SumsNotMatchErr = errors.New("control sums do not match")
+)
diff --git a/inns/inns_test.go b/inns/inns_test.go
new file mode 100644
index 0000000..0f8d048
--- /dev/null
+++ b/inns/inns_test.go
@@ -0,0 +1,80 @@
+package inns
+
+import (
+	"testing"
+)
+
+var (
+	testStrInns = []string{
+		"663802 397223",
+		"8252 47222169",
+		"8712530 92145",
+		"0873 820 72512",
+		"227 62 3382327",
+		"886 62 2222010",
+		"464 350 209157",
+		"758956582077",
+		"212551260755",
+		"0432444 61455",
+		"428880301819",
+		"61309 59 33498",
+		"667344101205",
+		"6189115998",
+		"426 1455105",
+		"562 5340715",
+		"6588135629",
+		"253 7102466",
+		"8195196 357",
+		"23838 17246",
+		"812 5976843",
+		"4710 107563",
+		"3732 71726",
+		"2170 439945",
+		"2193865 820",
+		"8122 281402",
+	}
+	testStrInnsErr = []string{
+		"66380a2397223",
+		"825247222eu169",
+		"8712530921457553",
+		"087753382072512",
+		"22762hetu3382327",
+		"886ao622222010",
+		"4643he50209157",
+		"75895 te 6582077",
+		"2asn12551260755",
+		"043abc244461455",
+		"428880err301819",
+		"0x613095933498",
+		"667344101205h",
+		"618911xerr5998",
+		"426x1455105",
+		"562x5340715",
+		"658813moreerr5629",
+		"253x7102466",
+		"8195196x357",
+		"23check838 17246",
+		"8check12x5976843",
+		"4710x107563",
+		"03732x71726",
+		"2170x439945",
+		"2193865x820",
+		"81shit2 281402",
+	}
+)
+
+func TestInnFromStr(t *testing.T) {
+	for _, rawInn := range testStrInns {
+		_, err := NewFromStr(rawInn)
+		if err != nil {
+			t.Fatalf("InnFromStr(%q), err == %q", rawInn, err)
+		}
+	}
+	for _, rawInn := range testStrInnsErr {
+		_, err := NewFromStr(rawInn)
+		if err == nil {
+			t.Fatalf("InnFromStr(%q), err == %v, must be though", rawInn, err)
+		}
+	}
+}
+
diff --git a/inns/main.go b/inns/main.go
new file mode 100644
index 0000000..850638c
--- /dev/null
+++ b/inns/main.go
@@ -0,0 +1,193 @@
+package inns
+
+// The package implements the basic
+// Russian Federation INN format
+// storing it in int64 to keep
+// searching and storing as
+// quick as possible.
+
+import (
+	"strings"
+	"unicode"
+	"strconv"
+	"fmt"
+	"slices"
+)
+
+type InnType uint8
+const (
+	IncorrectInnType InnType = iota
+	LegalInnType
+	IndividualInnType
+)
+
+func removeSpaces(s string) string {
+	return strings.Map(func(r rune) rune{
+		if unicode.IsSpace(r) {
+			return -1
+		}
+		return r
+	}, s)
+}
+
+type Inn int64
+
+func NewFromInt64(innRaw int64) (Inn, error) {
+	inn := Inn(innRaw)
+	if !inn.isCorrectLen() {
+		return -1, IncorrectLenErr
+	}
+
+	if !inn.isSumCorrect() {
+		return -1, SumsNotMatchErr
+	}
+
+	return inn, nil
+
+}
+// Convert string with spaces into the INN
+// and return error if anything is wrong with it.
+func NewFromStr(str string) (Inn, error) {
+	str = removeSpaces(str)
+	innRaw, err := strconv.ParseInt(str, 10, 64)
+	if err != nil {
+		return -1, IncorrectFormatErr
+	}
+	return NewFromInt64(innRaw)
+}
+
+
+func (inn Inn) Type() InnType {
+	ln := inn.length()
+	switch ln {
+	case 9, 10:
+		return LegalInnType
+	case 11, 12:
+		return IndividualInnType
+	}
+	return IncorrectInnType
+}
+
+func (inn Inn) length() int {
+	ln := 0
+	for {
+		if inn == 0 {
+			break
+		}
+		inn /= 10
+		ln++
+	}
+	if ln == 9 || ln == 11 {
+		ln++
+	}
+	return ln
+}
+
+func (inn Inn) isCorrectLen() bool {
+	ln := inn.length()
+	if ln == 9 || ln == 11 {
+		ln++
+	}
+	return ln == 10 || ln == 12
+}
+
+var (
+	// Koefs for the control sum.
+	innSum10 = [9]int64{
+		2, 4, 10, 3, 5, 9, 4, 6, 8,
+	}
+	innSum11 = [10]int64{
+		7, 2, 4, 10, 3, 5, 9, 4, 6, 8,
+	}
+	innSum12 = [11]int64{
+		3, 7, 2, 4, 10, 3, 5, 9, 4, 6, 8,
+	}
+)
+
+// Get the integer representation of digits in string INN.
+func (inn Inn) digits() []int64 {
+	ln := inn.length()
+	v := int64(inn)
+	ret := make([]int64, ln)
+	for i := 0 ; i<ln ; i++{
+		ret[i] = v % 10
+		v /= 10
+	}
+	slices.Reverse(ret)
+	return ret
+}
+
+// 
+func (inn Inn) specifiedSum() int64 {
+	ln := inn.length()
+	v := int64(inn)
+	switch ln {
+	case 10:
+		return v%10
+	case 12:
+		return v%100
+	default:
+		return -1
+	}
+}
+
+// Returns the supposed control sum rune. (the last number)
+func (inn Inn) sum() int64 {
+	d := inn.digits()
+	ln := inn.length()
+	switch ln {
+	case 10 :
+		var n10 int64
+		for i, ni := range d[:9] {
+			n10 += innSum10[i] * ni
+		}
+		n10 = (n10 % 11) % 10
+		return n10
+	case 12 :
+		var n11 int64
+		for i, ni := range d[:10] {
+			n11 += innSum11[i] * ni
+		}
+		n11 = (n11 % 11) % 10
+
+		var n12 int64
+		for i, ni := range d[:10] {
+			n12 += innSum12[i] * ni
+		}
+		n12 += innSum12[10] * n11
+		n12 = (n12 % 11) % 10
+
+		return n11*10 + n12
+	}
+	return -1
+}
+
+func (inn Inn) isSumCorrect() bool {
+	return inn.specifiedSum() == inn.sum()
+}
+
+func (inn Inn) String() string {
+	return fmt.Sprintf("%d", inn)
+}
+
+// Fancy way to print INN with space delimiters.
+func (inn Inn) Fancy() string {
+	ln := inn.length()
+	str := fmt.Sprintf("%d", inn)
+
+	// Adding zero depending on length.
+	if len(str) == 9 || len(str) == 11 {
+		str = "0"+str
+	}
+
+	switch ln {
+	case 10 :
+		return fmt.Sprintf("%s %s %s", str[:4], str[4:9], str[9:])
+	case 12 :
+		return fmt.Sprintf("%s %s %s", str[:4], str[4:10], str[10:])
+	}
+
+	// Reaching the point if the length is incorrect.
+	return "<"+IncorrectLenErr.Error()+">"
+}
+
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..cce8563
--- /dev/null
+++ b/main.go
@@ -0,0 +1,7 @@
+package main
+
+// The package contains
+// business related types and functions
+// that are used across related applications
+// and packages.
+