// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package common

import (
	"bytes"
	"encoding/hex"
	"fmt"
	"math/big"
	"math/rand"
	"reflect"

	"github.com/XinFinOrg/XDPoSChain/common/hexutil"
	"github.com/XinFinOrg/XDPoSChain/crypto/sha3"
)

const (
	HashLength                       = 32
	AddressLength                    = 20
	BlockSigners                     = "xdc0000000000000000000000000000000000000089"
	MasternodeVotingSMC              = "xdc0000000000000000000000000000000000000088"
	RandomizeSMC                     = "xdc0000000000000000000000000000000000000090"
	FoudationAddr                    = "xdc0000000000000000000000000000000000000068"
	TeamAddr                         = "xdc0000000000000000000000000000000000000099"
	XDCXAddr                         = "xdc0000000000000000000000000000000000000091"
	TradingStateAddr                 = "xdc0000000000000000000000000000000000000092"
	XDCXLendingAddress               = "xdc0000000000000000000000000000000000000093"
	XDCXLendingFinalizedTradeAddress = "xdc0000000000000000000000000000000000000094"
	XDCNativeAddress                 = "xdc0000000000000000000000000000000000000001"
	LendingLockAddress               = "xdc0000000000000000000000000000000000000011"
	VoteMethod                       = "0x6dd7d8ea"
	UnvoteMethod                     = "0x02aa9be2"
	ProposeMethod                    = "0x01267951"
	ResignMethod                     = "0xae6e43f5"
	SignMethod                       = "0xe341eaa4"
	XDCXApplyMethod                  = "0xc6b32f34"
	XDCZApplyMethod                  = "0xc6b32f34"
)

var (
	BlockSignersBinary                     = Address{19: 0x89} // xdc0000000000000000000000000000000000000089
	MasternodeVotingSMCBinary              = Address{19: 0x88} // xdc0000000000000000000000000000000000000088
	RandomizeSMCBinary                     = Address{19: 0x90} // xdc0000000000000000000000000000000000000090
	FoudationAddrBinary                    = Address{19: 0x68} // xdc0000000000000000000000000000000000000068
	TeamAddrBinary                         = Address{19: 0x99} // xdc0000000000000000000000000000000000000099
	XDCXAddrBinary                         = Address{19: 0x91} // xdc0000000000000000000000000000000000000091
	TradingStateAddrBinary                 = Address{19: 0x92} // xdc0000000000000000000000000000000000000092
	XDCXLendingAddressBinary               = Address{19: 0x93} // xdc0000000000000000000000000000000000000093
	XDCXLendingFinalizedTradeAddressBinary = Address{19: 0x94} // xdc0000000000000000000000000000000000000094
	XDCNativeAddressBinary                 = Address{19: 0x01} // xdc0000000000000000000000000000000000000001
	LendingLockAddressBinary               = Address{19: 0x11} // xdc0000000000000000000000000000000000000011
)

var (
	hashT    = reflect.TypeOf(Hash{})
	addressT = reflect.TypeOf(Address{})
)

// Hash represents the 32 byte Keccak256 hash of arbitrary data.
type Hash [HashLength]byte

type Vote struct {
	Masternode Address
	Voter      Address
}

// BytesToHash sets b to hash.
// If b is larger than len(h), b will be cropped from the left.
func BytesToHash(b []byte) Hash {
	var h Hash
	h.SetBytes(b)
	return h
}

func StringToHash(s string) Hash { return BytesToHash([]byte(s)) }

// BigToHash sets byte representation of b to hash.
// If b is larger than len(h), b will be cropped from the left.
func BigToHash(b *big.Int) Hash { return BytesToHash(b.Bytes()) }

func Uint64ToHash(b uint64) Hash { return BytesToHash(new(big.Int).SetUint64(b).Bytes()) }

// HexToHash sets byte representation of s to hash.
// If b is larger than len(h), b will be cropped from the left.
func HexToHash(s string) Hash { return BytesToHash(FromHex(s)) }

// Cmp compares two hashes.
func (h Hash) Cmp(other Hash) int {
	return bytes.Compare(h[:], other[:])
}

// IsZero returns if a Hash is empty
func (h Hash) IsZero() bool { return h == Hash{} }

// Get the string representation of the underlying hash
func (h Hash) Str() string   { return string(h[:]) }

// Bytes gets the byte representation of the underlying hash.
func (h Hash) Bytes() []byte { return h[:] }

// Big converts a hash to a big integer.
func (h Hash) Big() *big.Int { return new(big.Int).SetBytes(h[:]) }

// Hex converts a hash to a hex string.
func (h Hash) Hex() string   { return hexutil.Encode(h[:]) }

// TerminalString implements log.TerminalStringer, formatting a string for console
// output during logging.
func (h Hash) TerminalString() string {
	return fmt.Sprintf("%x…%x", h[:3], h[29:])
}

// String implements the stringer interface and is used also by the logger when
// doing full logging into a file.
func (h Hash) String() string {
	return h.Hex()
}

// Format implements fmt.Formatter, forcing the byte slice to be formatted as is,
// without going through the stringer interface used for logging.
func (h Hash) Format(s fmt.State, c rune) {
	fmt.Fprintf(s, "%"+string(c), h[:])
}

// UnmarshalText parses a hash in hex syntax.
func (h *Hash) UnmarshalText(input []byte) error {
	return hexutil.UnmarshalFixedText("Hash", input, h[:])
}

// UnmarshalJSON parses a hash in hex syntax.
func (h *Hash) UnmarshalJSON(input []byte) error {
	return hexutil.UnmarshalFixedJSON(hashT, input, h[:])
}

// MarshalText returns the hex representation of h.
func (h Hash) MarshalText() ([]byte, error) {
	return hexutil.Bytes(h[:]).MarshalText()
}

// SetBytes sets the hash to the value of b.
// If b is larger than len(h), b will be cropped from the left.
func (h *Hash) SetBytes(b []byte) {
	if len(b) > len(h) {
		b = b[len(b)-HashLength:]
	}

	copy(h[HashLength-len(b):], b)
}

// Set string `s` to h. If s is larger than len(h) s will be cropped (from left) to fit.
func (h *Hash) SetString(s string) { h.SetBytes([]byte(s)) }

// Sets h to other
func (h *Hash) Set(other Hash) {
	copy(h[:], other[:])
}

// Generate implements testing/quick.Generator.
func (h Hash) Generate(rand *rand.Rand, size int) reflect.Value {
	m := rand.Intn(len(h))
	for i := len(h) - 1; i > m; i-- {
		h[i] = byte(rand.Uint32())
	}
	return reflect.ValueOf(h)
}

func EmptyHash(h Hash) bool {
	return h == Hash{}
}

// UnprefixedHash allows marshaling a Hash without 0x prefix.
type UnprefixedHash Hash

// UnmarshalText decodes the hash from hex. The 0x prefix is optional.
func (h *UnprefixedHash) UnmarshalText(input []byte) error {
	return hexutil.UnmarshalFixedUnprefixedText("UnprefixedHash", input, h[:])
}

// MarshalText encodes the hash as hex.
func (h UnprefixedHash) MarshalText() ([]byte, error) {
	return []byte(hex.EncodeToString(h[:])), nil
}

/////////// Address

// Address represents the 20 byte address of an Ethereum account.
type Address [AddressLength]byte

func BytesToAddress(b []byte) Address {
	var a Address
	a.SetBytes(b)
	return a
}

func StringToAddress(s string) Address { return BytesToAddress([]byte(s)) }

// BigToAddress returns Address with byte values of b.
// If b is larger than len(h), b will be cropped from the left.
func BigToAddress(b *big.Int) Address { return BytesToAddress(b.Bytes()) }

// HexToAddress returns Address with byte values of s.
// If s is larger than len(h), s will be cropped from the left.
func HexToAddress(s string) Address { return BytesToAddress(FromHex(s)) }

// IsHexAddress verifies whether a string can represent a valid hex-encoded
// Ethereum address or not.
func IsHexAddress(s string) bool {
	if hasXDCPrefix(s) {
		s = s[3:]
	}
	if hasHexPrefix(s) {
		s = s[2:]
	}
	return len(s) == 2*AddressLength && isHex(s)
}

// IsZero returns if a address is empty
func (a Address) IsZero() bool { return a == Address{} }

// Get the string representation of the underlying address
func (a Address) Str() string   { return string(a[:]) }
func (a Address) Bytes() []byte { return a[:] }
func (a Address) Big() *big.Int { return new(big.Int).SetBytes(a[:]) }
func (a Address) Hash() Hash    { return BytesToHash(a[:]) }

// Hex returns an EIP55-compliant hex string representation of the address.
func (a Address) Hex() string {
	unchecksummed := hex.EncodeToString(a[:])
	sha := sha3.NewKeccak256()
	sha.Write([]byte(unchecksummed))
	hash := sha.Sum(nil)

	result := []byte(unchecksummed)
	for i := 0; i < len(result); i++ {
		hashByte := hash[i/2]
		if i%2 == 0 {
			hashByte = hashByte >> 4
		} else {
			hashByte &= 0xf
		}
		if result[i] > '9' && hashByte > 7 {
			result[i] -= 32
		}
	}
	return "xdc" + string(result)
}

// String implements the stringer interface and is used also by the logger.
func (a Address) String() string {
	return a.Hex()
}

// Format implements fmt.Formatter, forcing the byte slice to be formatted as is,
// without going through the stringer interface used for logging.
func (a Address) Format(s fmt.State, c rune) {
	fmt.Fprintf(s, "%"+string(c), a[:])
}

// Sets the address to the value of b. If b is larger than len(a) it will panic
func (a *Address) SetBytes(b []byte) {
	if len(b) > len(a) {
		b = b[len(b)-AddressLength:]
	}
	copy(a[AddressLength-len(b):], b)
}

// Set string `s` to a. If s is larger than len(a) it will panic
func (a *Address) SetString(s string) { a.SetBytes([]byte(s)) }

// Sets a to other
func (a *Address) Set(other Address) {
	copy(a[:], other[:])
}

// MarshalText returns the hex representation of a.
func (a Address) MarshalText() ([]byte, error) {
	// Handle '0x' or 'xdc' prefix here.
	if Enable0xPrefix {
		return hexutil.Bytes(a[:]).MarshalText()
	} else {
		return hexutil.Bytes(a[:]).MarshalXDCText()
	}
}

// UnmarshalText parses a hash in hex syntax.
func (a *Address) UnmarshalText(input []byte) error {
	return hexutil.UnmarshalFixedText("Address", input, a[:])
}

// UnmarshalJSON parses a hash in hex syntax.
func (a *Address) UnmarshalJSON(input []byte) error {
	return hexutil.UnmarshalFixedJSON(addressT, input, a[:])
}

// UnprefixedHash allows marshaling an Address without 0x prefix.
type UnprefixedAddress Address

// UnmarshalText decodes the address from hex. The 0x prefix is optional.
func (a *UnprefixedAddress) UnmarshalText(input []byte) error {
	return hexutil.UnmarshalFixedUnprefixedText("UnprefixedAddress", input, a[:])
}

// MarshalText encodes the address as hex.
func (a UnprefixedAddress) MarshalText() ([]byte, error) {
	return []byte(hex.EncodeToString(a[:])), nil
}

// Extract validators from byte array.
func RemoveItemFromArray(array []Address, items []Address) []Address {
	// Create newArray to stop append change array value
	newArray := make([]Address, len(array))
	copy(newArray, array)

	if len(items) == 0 {
		return newArray
	}

	for _, item := range items {
		for i := len(newArray) - 1; i >= 0; i-- {
			if newArray[i] == item {
				newArray = append(newArray[:i], newArray[i+1:]...)
			}
		}
	}

	return newArray
}

// Extract validators from byte array.
func ExtractAddressToBytes(penalties []Address) []byte {
	data := []byte{}
	for _, signer := range penalties {
		data = append(data, signer[:]...)
	}
	return data
}

func ExtractAddressFromBytes(bytePenalties []byte) []Address {
	if bytePenalties != nil && len(bytePenalties) < AddressLength {
		return []Address{}
	}
	penalties := make([]Address, len(bytePenalties)/AddressLength)
	for i := 0; i < len(penalties); i++ {
		copy(penalties[i][:], bytePenalties[i*AddressLength:])
	}
	return penalties
}