feat: Basic Fraction Entity Added (#2)

* feat: fraction entity added

* resolve dependency cycle

change router/router -> router/core

* fix

* delete router/main.go

* Apply suggestions from code review

Co-authored-by: Lee ByeongJun <[email protected]>

---------

Co-authored-by: tolelom <[email protected]>
Co-authored-by: Lee ByeongJun <[email protected]>

router/alpha-router-params.go → core/alpha-router-params.go

@@ -1,4 +1,4 @@
-package router
+package core
 
 type AlphaRouterParams struct {
 }

core/alpha-router.go

@@ -0,0 +1,64 @@
+package core
+
+import (
+	"router/core/entities"
+	"router/core/entities/fractions"
+)
+
+type AlphaRouter struct {
+	portionProvider IPortionProvider
+}
+
+func NewAlphaRouter(params AlphaRouterParams) *AlphaRouter {
+	return &AlphaRouter{}
+}
+
+// TODO: 원본 코드에서는 async 함수
+// 라우트 한 결과는 SwapRoute
+func (a AlphaRouter) route(
+	amount fractions.CurrencyAmount,
+	quoteCurrency entities.Currency,
+	tradeType TradeType,
+	swapConfig SwapOptions,
+) SwapRoute {
+	//originalAmount := amount
+	//
+	//currencyIn, currencyOut := a.determineCurrencyInOutFromTradeType(tradeType, amount, quoteCurrency)
+	//
+	//// currencyIn, currencyOut은 Currency 타입이고
+	//// Currency 타입은 NativeCurrency(GNOT)이거나 Token 타입이다.
+	//// 아래에서 Token 타입이길 원하는 듯하다.
+	//tokenIn := currencyIn.Wrapped()
+	//tokenOut := currencyOut.Wrapped()
+	//
+	//// core 패키지를 TradeType 패키지로 변경하면 가독성이 더 좋아질 듯 하다.
+	//if tradeType == EXACT_OUTPUT {
+	//	// TODO: GetPortionAmount에서 반환 값인 CurrencyAmount을 반환하지 못할 경우가 있을 수도 있다.(높은 확률로)
+	//	portionAmount := a.portionProvider.GetPortionAmount(
+	//		amount,
+	//		tradeType,
+	//		swapConfig,
+	//	)
+	//
+	//	//result := portionAmount.GreaterThan(0)
+	//	//if result {
+	//	//	amount = amount.add(portionAmount)
+	//	//}
+	//}
+	//
+	//swapRoute := SwapRoute{}
+	//return swapRoute
+	return SwapRoute{}
+}
+
+func (a AlphaRouter) determineCurrencyInOutFromTradeType(
+	tradeType TradeType,
+	amount fractions.CurrencyAmount,
+	quoteCurrency entities.Currency,
+) (entities.Currency, entities.Currency) {
+	if tradeType == EXACT_INPUT {
+		return amount.Currency, quoteCurrency
+	} else {
+		return quoteCurrency, amount.Currency
+	}
+}

core/entities/baseCurrency.go

@@ -0,0 +1,29 @@
+package entities
+
+type BaseCurrency struct {
+	isNative bool
+	isToken  bool
+
+	chainId  int
+	decimals int
+
+	symbol  string
+	name    string
+	address string
+}
+
+func NewBaseCurrency(chainId int, decimals int, symbol string, name string) *BaseCurrency {
+	return &BaseCurrency{
+		// 아래 코드는 원문
+		//invariant(Number.isSafeInteger(chainId), 'CHAIN_ID');
+		//invariant(
+		//	decimals >= 0 && decimals < 255 && Number.isInteger(decimals),
+		//	'DECIMALS',
+		//);
+
+		chainId:  chainId,
+		decimals: decimals,
+		symbol:   symbol,
+		name:     name,
+	}
+}

router/core/entities/currency.go → core/entities/currency.go

@@ -4,5 +4,5 @@ package entities
 // Token과 NativeCurrency 모두 BaseCurrency를 상속받는다.
 // 하지만 여기서의 Currency는 NativeCurrency와 Token에 포함된다.
 type Currency interface {
-	wrapped() Token
+	Wrapped() Token
 }

core/entities/fractions/currencyAmount.go

@@ -0,0 +1,16 @@
+package fractions
+
+import (
+	"router/core/entities"
+)
+
+type CurrencyAmount struct {
+	Fraction
+	Currency entities.Currency
+}
+
+//func (c CurrencyAmount) add(other CurrencyAmount) CurrencyAmount {
+//	added := c.Fraction.add(other)
+//
+//	return CurrencyAmount.fromFractionAmount()
+//}

core/entities/fractions/fraction.go

@@ -0,0 +1,119 @@
+package fractions
+
+import (
+	"errors"
+	"math/big"
+)
+
+type Fraction struct {
+	Numerator   *big.Int
+	Denominator *big.Int
+}
+
+func NewFraction(numerator int64, denominator int64) *Fraction {
+	return &Fraction{
+		Numerator:   big.NewInt(numerator),
+		Denominator: big.NewInt(denominator),
+	}
+}
+
+func tryParseFraction(value interface{}) (Fraction, error) {
+	switch v := value.(type) {
+	case Fraction:
+		return v, nil
+	case *big.Int:
+		return Fraction{Numerator: v, Denominator: big.NewInt(1)}, nil
+	case big.Int:
+		return Fraction{Numerator: &v, Denominator: big.NewInt(1)}, nil
+	// TODO: int64 등 추가 바람
+	default:
+		return Fraction{}, errors.New("not a fraction")
+	}
+}
+
+// ---------------------------
+// TODO: 형을 자유롭게 받은 다음 tryParseFraction으로 한 번 거르고 사용하도록 하기
+// 덧셈
+func (f Fraction) Add(other *Fraction) *Fraction {
+	numerator1 := new(big.Int).Mul(f.Numerator, other.Denominator)
+	numerator2 := new(big.Int).Mul(other.Numerator, f.Denominator)
+	denominator := new(big.Int).Mul(f.Denominator, other.Denominator)
+	resultNumerator := new(big.Int).Add(numerator1, numerator2)
+
+	// TODO: 약분
+	//g := utils.Gcd(resultNumerator, denominator)
+
+	return &Fraction{
+		Numerator:   resultNumerator,
+		Denominator: denominator,
+	}
+}
+
+// 뺄셈
+// TODO: 덧셈 활용해서 코드 단순화 할 수도 있을지도...
+func (f Fraction) Sub(other *Fraction) *Fraction {
+	numerator1 := new(big.Int).Mul(f.Numerator, other.Denominator)
+	numerator2 := new(big.Int).Mul(other.Numerator, f.Denominator)
+	denominator := new(big.Int).Mul(f.Denominator, other.Denominator)
+	resultNumerator := new(big.Int).Sub(numerator1, numerator2)
+
+	// TODO: 약분
+	//g := utils.Gcd(resultNumerator, denominator)
+
+	return &Fraction{
+		Numerator:   resultNumerator,
+		Denominator: denominator,
+	}
+}
+
+func (f Fraction) LessThan(other *Fraction) bool {
+	leftValue := new(big.Int).Mul(f.Numerator, other.Denominator)
+	rightValue := new(big.Int).Mul(other.Numerator, f.Denominator)
+	return leftValue.Cmp(rightValue) < 0
+}
+
+func (f Fraction) GreaterThan(other *Fraction) bool {
+	leftValue := new(big.Int).Mul(f.Numerator, other.Denominator)
+	rightValue := new(big.Int).Mul(other.Numerator, f.Denominator)
+	return leftValue.Cmp(rightValue) > 0
+}
+
+// 약분이 완료되었다는 가정
+// WARN: 약분이 안되었다는 가정이라면 약분하는 로직 추가해야 함
+func (f Fraction) Equals(other *Fraction) bool {
+	return f.Numerator.Cmp(other.Numerator) == 0 &&
+		f.Denominator.Cmp(other.Denominator) == 0
+}
+
+// 몫
+func (f Fraction) Quotient() *big.Int {
+	return new(big.Int).Quo(f.Numerator, f.Denominator)
+}
+
+// NOTE: 단순 나머지가 아니라 분수 형태로 표시한다
+// 좋은 형태의 함수는 아니라 생각
+func (f Fraction) Remainder() Fraction {
+	return Fraction{
+		Numerator:   new(big.Int).Rem(f.Numerator, f.Denominator),
+		Denominator: f.Denominator,
+	}
+}
+
+// 역
+func (f Fraction) Invert() Fraction {
+	return Fraction{
+		Numerator:   f.Denominator,
+		Denominator: f.Numerator,
+	}
+}
+
+//func (f Fraction) GreaterThan(other interface{}) (bool, error) {
+//	otherParsed, err := tryParseFraction(other)
+//	if err != nil {
+//		return false, err
+//	}
+//left := f.Numerator * otherParsed.Denominator
+//right := otherParsed.Denominator * f.Numerator
+//
+//	return left > right, nil
+//}

core/entities/fractions/fraction_test.go

@@ -0,0 +1,39 @@
+package fractions
+
+import (
+	"testing"
+)
+
+func TestFraction_Add(t *testing.T) {
+	fraction1 := NewFraction(1, 2)
+	fraction2 := NewFraction(1, 3)
+
+	result := fraction1.Add(fraction2)
+
+	expected := NewFraction(5, 6)
+
+	if result.Numerator.Cmp(expected.Numerator) != 0 || result.Denominator.Cmp(expected.Denominator) != 0 {
+		t.Fatalf("Add: expected %v, got %v", expected, result)
+	}
+}
+
+func TestFraction_Sub(t *testing.T) {
+	fraction1 := NewFraction(1, 2)
+	fraction2 := NewFraction(1, 3)
+	result := fraction1.Sub(fraction2)
+	expected := NewFraction(1, 6)
+	if result.Numerator.Cmp(expected.Numerator) != 0 || result.Denominator.Cmp(expected.Denominator) != 0 {
+		t.Fatalf("Sub: expected %v, got %v", expected, result)
+	}
+}
+
+func TestFraction_LessThan(t *testing.T) {
+	fraction1 := NewFraction(1, 2)
+	fraction2 := NewFraction(1, 3)
+	result := fraction1.LessThan(fraction2)
+	expected := false
+
+	if result != expected {
+		t.Fatalf("LessThan: expected %v, got %v", expected, result)
+	}
+}

core/entities/gnot.go

@@ -0,0 +1,21 @@
+package entities
+
+type Gnot struct {
+	NativeCurrency
+}
+
+func NewGnot(chainId int) *Gnot {
+	return &Gnot{
+		NativeCurrency: NativeCurrency{
+			BaseCurrency: BaseCurrency{
+				chainId: chainId,
+			},
+		},
+	}
+}
+
+func (g Gnot) Wrapped() Token {
+	wgnot := WGNOT[g.chainId]
+	// invariant(!!wgnot, 'WRAPPED')
+	return wgnot
+}

core/entities/nativeCurrency.go

@@ -0,0 +1,6 @@
+package entities
+
+// Gnot이 NativeCurrency를 상속한다.
+type NativeCurrency struct {
+	BaseCurrency
+}

core/entities/token.go

@@ -0,0 +1,13 @@
+package entities
+
+type Token struct {
+	BaseCurrency
+}
+
+func NewToken() *Token {
+	return &Token{}
+}
+
+func (t Token) Wrapped() Token {
+	return t
+}

core/entities/utils/math.go

@@ -0,0 +1,8 @@
+package utils
+
+import "math/big"
+
+func Gcd(a, b *big.Int) *big.Int {
+
+	return a
+}

core/entities/wgnot.go

@@ -0,0 +1,10 @@
+package entities
+
+var WGNOT = map[int]Token{
+	//1:  NewToken(),
+	//2:  NewToken(),
+	//3:  NewToken(),
+	//4:  NewToken(),
+	//5:  NewToken(),
+	//99: NewToken(),
+}

core/router.go

@@ -0,0 +1,14 @@
+package core
+
+type SwapRoute struct {
+}
+
+type IRouter interface {
+}
+
+// TODO: 원문: type SwapOptions = SwapOptionsUniversalRouter | SwapOptionsSwapRouter02
+type SwapOptions struct {
+}
+
+type SwapOptionsUniversalRouter struct {
+}

core/types.go

@@ -0,0 +1,13 @@
+package core
+
+import (
+	"router/core/entities/fractions"
+)
+
+// interface는 I 접두사를 붙이는 것이 관행인가?
+type IPortionProvider interface {
+	GetPortionAmount(tokenOutAmount fractions.CurrencyAmount, tradeType TradeType, swapConfig SwapOptions) fractions.CurrencyAmount
+}
+
+type PortionProvider struct {
+}