package wallet

import (
	"math/bits"

	"github.com/phamminh0811/private-grpc/crypto"
	"github.com/phamminh0811/private-grpc/nockchain"
)

var InitialBits = []bool{true, false, false, true, true, false, true, false, false, false, false, false, false, false, true, true, true, true, false, false, false, false, false, true, true, true, false, true, true, false, true, false, true, true, false, false, false, false, true, false, true, true, true, false}

func NumBitsUint64(v uint64) int {
	if v == 0 {
		return 0
	}
	return 64 - bits.LeadingZeros64(v)
}

func Uint64ToBitsLSB0(x uint64) []bool {
	bits := make([]bool, 64)
	for i := 0; i < 64; i++ {
		bits[i] = ((x >> i) & 1) == 1
	}
	return bits
}

func BoolsToBytesLSB0(bits []bool) []byte {
	if len(bits) == 0 {
		return nil
	}
	n := (len(bits) + 7) / 8 // ceil division
	bytes := make([]byte, n)
	for i, bit := range bits {
		if bit {
			byteIdx := i / 8
			bitIdx := i % 8
			bytes[byteIdx] |= 1 << bitIdx // LSB0: least-significant bit first
		}
	}
	return bytes
}

func EncodeNoteData(noteData *nockchain.NockchainLock) []byte {
	bits := InitialBits

	numPubkeys := noteData.KeysRequired
	numPubkeysSz := NumBitsUint64(uint64(numPubkeys))
	numPubkeysSzSz := NumBitsUint64(uint64(numPubkeysSz))

	bits = append(bits, false)
	for i := 0; i < numPubkeysSzSz; i++ {
		bits = append(bits, false)
	}
	bits = append(bits, true)

	if numPubkeysSzSz > 1 {
		numPubkeysSzBits := Uint64ToBitsLSB0(uint64(numPubkeysSz))
		bits = append(bits, numPubkeysSzBits[0:numPubkeysSzSz-1]...)
	}

	numPubkeysBits := Uint64ToBitsLSB0(uint64(numPubkeys))
	bits = append(bits, numPubkeysBits[0:numPubkeysSz]...)
	bits = append(bits, []bool{true, false}...)
	for _, pkStr := range noteData.Pubkeys {
		pkHash := crypto.Base58ToTip5Hash(pkStr)
		for i, hash := range pkHash {
			if i != 4 {
				bits = append(bits, []bool{true, false}...)
			}
			hashSz := NumBitsUint64(hash)
			hashSzSz := NumBitsUint64(uint64(hashSz))

			bits = append(bits, false)
			for i := 0; i < hashSzSz; i++ {
				bits = append(bits, false)
			}
			bits = append(bits, true)

			if hashSzSz > 1 {
				hashSzBits := Uint64ToBitsLSB0(uint64(hashSz))
				bits = append(bits, hashSzBits[0:hashSzSz-1]...)
			}

			hashBits := Uint64ToBitsLSB0(hash)
			bits = append(bits, hashBits[0:hashSz]...)
		}
	}

	bits = append(bits, []bool{true, false, false, true, false, true, false, true}...)
	return BoolsToBytesLSB0(bits)
}