feat: Added contract_function_selector

contract_function_selector.go

@@ -0,0 +1,276 @@
+package hedera
+
+import (
+	"golang.org/x/crypto/sha3"
+)
+
+type ContractFunctionSelector struct {
+	function   *string
+	params     string
+	paramTypes []solidity
+}
+
+type solidity struct {
+	ty    argument
+	array bool
+}
+
+type argument string
+
+const (
+	aBool     argument = "bool"
+	aString   argument = "string"
+	aInt8     argument = "int8"
+	aInt32    argument = "int32"
+	aInt64    argument = "int64"
+	aInt256   argument = "int256"
+	aUint8    argument = "uint8"
+	aUint32   argument = "uint32"
+	aUint64   argument = "uint64"
+	aUint256  argument = "uint256"
+	aBytes    argument = "bytes"
+	aBytes32  argument = "bytes32"
+	aFunction argument = "function"
+	aAddress  argument = "address"
+)
+
+func NewContractFunctionSelector(name string) ContractFunctionSelector {
+	var function *string
+
+	if name == "" {
+		function = nil
+	} else {
+		function = &name
+	}
+
+	return ContractFunctionSelector{
+		function:   function,
+		params:     "",
+		paramTypes: []solidity{},
+	}
+}
+
+func (selector *ContractFunctionSelector) addParam(ty solidity) *ContractFunctionSelector {
+	if len(selector.paramTypes) > 0 {
+		selector.params += ","
+	}
+
+	selector.params += string(ty.ty)
+	if ty.array {
+		selector.params += "[]"
+	}
+
+	selector.paramTypes = append(selector.paramTypes, ty)
+	return selector
+}
+
+func (selector *ContractFunctionSelector) AddFunction() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aFunction,
+		array: false,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddAddress() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aAddress,
+		array: false,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddBool() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aBool,
+		array: false,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddString() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aString,
+		array: false,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddInt8() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aInt8,
+		array: false,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddInt32() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aInt32,
+		array: false,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddInt64() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aInt64,
+		array: false,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddInt256() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aInt256,
+		array: false,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddUint8() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aUint8,
+		array: false,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddUint32() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aUint32,
+		array: false,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddUint64() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aUint64,
+		array: false,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddUint256() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aUint256,
+		array: false,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddBytes() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aBytes,
+		array: false,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddBytes32() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aBytes32,
+		array: false,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddAddressArray() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aAddress,
+		array: true,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddBoolArray() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aBool,
+		array: true,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddStringArray() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aString,
+		array: true,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddInt8Array() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aInt8,
+		array: true,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddInt32Array() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aInt32,
+		array: true,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddInt64Array() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aInt64,
+		array: true,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddInt256Array() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aInt256,
+		array: true,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddUint8Array() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aUint8,
+		array: true,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddUint32Array() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aUint32,
+		array: true,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddUint64Array() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aUint64,
+		array: true,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddUint256Array() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aUint256,
+		array: true,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddBytesArray() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aBytes,
+		array: true,
+	})
+}
+
+func (selector *ContractFunctionSelector) AddBytes32Array() *ContractFunctionSelector {
+	return selector.addParam(solidity{
+		ty:    aBytes32,
+		array: true,
+	})
+}
+
+func (selector *ContractFunctionSelector) String() string {
+	function := ""
+	if selector.function != nil {
+		function = *selector.function
+	}
+
+	return function + "(" + selector.params + ")"
+}
+
+func (selector *ContractFunctionSelector) build(function *string) []byte {
+	if function != nil {
+		selector.function = function
+	} else if selector.function == nil {
+		panic("unreacahble: function name must be non-nil at this point")
+	}
+
+	hash := sha3.NewLegacyKeccak256()
+	hash.Write([]byte(selector.String()))
+
+	return hash.Sum(nil)[0:4]
+}