package types

import (
	"bytes"
	"encoding/hex"
	"encoding/json"
	"errors"
	"fmt"
	"strings"

	"github.com/tendermint/tendermint/crypto"
	yaml "gopkg.in/yaml.v2"

	tmamino "github.com/cosmos/cosmos-sdk/crypto/codec"
	"github.com/cosmos/cosmos-sdk/types/bech32"
)

const (
	// Constants defined here are the defaults value for address.
	// You can use the specific values for your project.
	// Add the follow lines to the `main()` of your server.
	//
	//	config := sdk.GetConfig()
	//	config.SetBech32PrefixForAccount(yourBech32PrefixAccAddr, yourBech32PrefixAccPub)
	//	config.SetBech32PrefixForValidator(yourBech32PrefixValAddr, yourBech32PrefixValPub)
	//	config.SetBech32PrefixForConsensusNode(yourBech32PrefixConsAddr, yourBech32PrefixConsPub)
	//	config.SetCoinType(yourCoinType)
	//	config.SetFullFundraiserPath(yourFullFundraiserPath)
	//	config.Seal()

	// AddrLen defines a valid address length
	AddrLen = 20
	// Bech32PrefixAccAddr defines the Bech32 prefix of an account's address
	Bech32MainPrefix = "cosmos"

	// Atom in https://github.com/satoshilabs/slips/blob/master/slip-0044.md
	CoinType = 118

	// BIP44Prefix is the parts of the BIP44 HD path that are fixed by
	// what we used during the fundraiser.
	FullFundraiserPath = "44'/118'/0'/0/0"

	// PrefixAccount is the prefix for account keys
	PrefixAccount = "acc"
	// PrefixValidator is the prefix for validator keys
	PrefixValidator = "val"
	// PrefixConsensus is the prefix for consensus keys
	PrefixConsensus = "cons"
	// PrefixPublic is the prefix for public keys
	PrefixPublic = "pub"
	// PrefixOperator is the prefix for operator keys
	PrefixOperator = "oper"

	// PrefixAddress is the prefix for addresses
	PrefixAddress = "addr"

	// Bech32PrefixAccAddr defines the Bech32 prefix of an account's address
	Bech32PrefixAccAddr = Bech32MainPrefix
	// Bech32PrefixAccPub defines the Bech32 prefix of an account's public key
	Bech32PrefixAccPub = Bech32MainPrefix + PrefixPublic
	// Bech32PrefixValAddr defines the Bech32 prefix of a validator's operator address
	Bech32PrefixValAddr = Bech32MainPrefix + PrefixValidator + PrefixOperator
	// Bech32PrefixValPub defines the Bech32 prefix of a validator's operator public key
	Bech32PrefixValPub = Bech32MainPrefix + PrefixValidator + PrefixOperator + PrefixPublic
	// Bech32PrefixConsAddr defines the Bech32 prefix of a consensus node address
	Bech32PrefixConsAddr = Bech32MainPrefix + PrefixValidator + PrefixConsensus
	// Bech32PrefixConsPub defines the Bech32 prefix of a consensus node public key
	Bech32PrefixConsPub = Bech32MainPrefix + PrefixValidator + PrefixConsensus + PrefixPublic
)

// Address is a common interface for different types of addresses used by the SDK
type Address interface {
	Equals(Address) bool
	Empty() bool
	Marshal() ([]byte, error)
	MarshalJSON() ([]byte, error)
	Bytes() []byte
	String() string
	Format(s fmt.State, verb rune)
}

// Ensure that different address types implement the interface
var _ Address = AccAddress{}
var _ Address = ValAddress{}
var _ Address = ConsAddress{}

var _ yaml.Marshaler = AccAddress{}
var _ yaml.Marshaler = ValAddress{}
var _ yaml.Marshaler = ConsAddress{}

// ----------------------------------------------------------------------------
// account
// ----------------------------------------------------------------------------

// AccAddress a wrapper around bytes meant to represent an account address.
// When marshaled to a string or JSON, it uses Bech32.
type AccAddress []byte

// AccAddressFromHex creates an AccAddress from a hex string.
func AccAddressFromHex(address string) (addr AccAddress, err error) {
	bz, err := addressBytesFromHexString(address)
	return AccAddress(bz), err
}

// VerifyAddressFormat verifies that the provided bytes form a valid address
// according to the default address rules or a custom address verifier set by
// GetConfig().SetAddressVerifier()
func VerifyAddressFormat(bz []byte) error {
	verifier := GetConfig().GetAddressVerifier()
	if verifier != nil {
		return verifier(bz)
	}
	if len(bz) != AddrLen {
		return errors.New("incorrect address length")
	}
	return nil
}

// AccAddressFromBech32 creates an AccAddress from a Bech32 string.
func AccAddressFromBech32(address string) (addr AccAddress, err error) {
	if len(strings.TrimSpace(address)) == 0 {
		return AccAddress{}, nil
	}

	bech32PrefixAccAddr := GetConfig().GetBech32AccountAddrPrefix()

	bz, err := GetFromBech32(address, bech32PrefixAccAddr)
	if err != nil {
		return nil, err
	}

	err = VerifyAddressFormat(bz)
	if err != nil {
		return nil, err
	}

	return AccAddress(bz), nil
}

// Returns boolean for whether two AccAddresses are Equal
func (aa AccAddress) Equals(aa2 Address) bool {
	if aa.Empty() && aa2.Empty() {
		return true
	}

	return bytes.Equal(aa.Bytes(), aa2.Bytes())
}

// Returns boolean for whether an AccAddress is empty
func (aa AccAddress) Empty() bool {
	if aa == nil {
		return true
	}

	aa2 := AccAddress{}
	return bytes.Equal(aa.Bytes(), aa2.Bytes())
}

// Marshal returns the raw address bytes. It is needed for protobuf
// compatibility.
func (aa AccAddress) Marshal() ([]byte, error) {
	return aa, nil
}

// Unmarshal sets the address to the given data. It is needed for protobuf
// compatibility.
func (aa *AccAddress) Unmarshal(data []byte) error {
	*aa = data
	return nil
}

// MarshalJSON marshals to JSON using Bech32.
func (aa AccAddress) MarshalJSON() ([]byte, error) {
	return json.Marshal(aa.String())
}

// MarshalYAML marshals to YAML using Bech32.
func (aa AccAddress) MarshalYAML() (interface{}, error) {
	return aa.String(), nil
}

// UnmarshalJSON unmarshals from JSON assuming Bech32 encoding.
func (aa *AccAddress) UnmarshalJSON(data []byte) error {
	var s string
	err := json.Unmarshal(data, &s)
	if err != nil {
		return err
	}

	aa2, err := AccAddressFromBech32(s)
	if err != nil {
		return err
	}

	*aa = aa2
	return nil
}

// UnmarshalYAML unmarshals from JSON assuming Bech32 encoding.
func (aa *AccAddress) UnmarshalYAML(data []byte) error {
	var s string
	err := yaml.Unmarshal(data, &s)
	if err != nil {
		return err
	}

	aa2, err := AccAddressFromBech32(s)
	if err != nil {
		return err
	}

	*aa = aa2
	return nil
}

// Bytes returns the raw address bytes.
func (aa AccAddress) Bytes() []byte {
	return aa
}

// String implements the Stringer interface.
func (aa AccAddress) String() string {
	if aa.Empty() {
		return ""
	}

	bech32PrefixAccAddr := GetConfig().GetBech32AccountAddrPrefix()

	bech32Addr, err := bech32.ConvertAndEncode(bech32PrefixAccAddr, aa.Bytes())
	if err != nil {
		panic(err)
	}

	return bech32Addr
}

// Format implements the fmt.Formatter interface.
// nolint: errcheck
func (aa AccAddress) Format(s fmt.State, verb rune) {
	switch verb {
	case 's':
		s.Write([]byte(aa.String()))
	case 'p':
		s.Write([]byte(fmt.Sprintf("%p", aa)))
	default:
		s.Write([]byte(fmt.Sprintf("%X", []byte(aa))))
	}
}

// ----------------------------------------------------------------------------
// validator operator
// ----------------------------------------------------------------------------

// ValAddress defines a wrapper around bytes meant to present a validator's
// operator. When marshaled to a string or JSON, it uses Bech32.
type ValAddress []byte

// ValAddressFromHex creates a ValAddress from a hex string.
func ValAddressFromHex(address string) (addr ValAddress, err error) {
	bz, err := addressBytesFromHexString(address)
	return ValAddress(bz), err
}

// ValAddressFromBech32 creates a ValAddress from a Bech32 string.
func ValAddressFromBech32(address string) (addr ValAddress, err error) {
	if len(strings.TrimSpace(address)) == 0 {
		return ValAddress{}, nil
	}

	bech32PrefixValAddr := GetConfig().GetBech32ValidatorAddrPrefix()

	bz, err := GetFromBech32(address, bech32PrefixValAddr)
	if err != nil {
		return nil, err
	}

	err = VerifyAddressFormat(bz)
	if err != nil {
		return nil, err
	}

	return ValAddress(bz), nil
}

// Returns boolean for whether two ValAddresses are Equal
func (va ValAddress) Equals(va2 Address) bool {
	if va.Empty() && va2.Empty() {
		return true
	}

	return bytes.Equal(va.Bytes(), va2.Bytes())
}

// Returns boolean for whether an AccAddress is empty
func (va ValAddress) Empty() bool {
	if va == nil {
		return true
	}

	va2 := ValAddress{}
	return bytes.Equal(va.Bytes(), va2.Bytes())
}

// Marshal returns the raw address bytes. It is needed for protobuf
// compatibility.
func (va ValAddress) Marshal() ([]byte, error) {
	return va, nil
}

// Unmarshal sets the address to the given data. It is needed for protobuf
// compatibility.
func (va *ValAddress) Unmarshal(data []byte) error {
	*va = data
	return nil
}

// MarshalJSON marshals to JSON using Bech32.
func (va ValAddress) MarshalJSON() ([]byte, error) {
	return json.Marshal(va.String())
}

// MarshalYAML marshals to YAML using Bech32.
func (va ValAddress) MarshalYAML() (interface{}, error) {
	return va.String(), nil
}

// UnmarshalJSON unmarshals from JSON assuming Bech32 encoding.
func (va *ValAddress) UnmarshalJSON(data []byte) error {
	var s string

	err := json.Unmarshal(data, &s)
	if err != nil {
		return err
	}

	va2, err := ValAddressFromBech32(s)
	if err != nil {
		return err
	}

	*va = va2
	return nil
}

// UnmarshalYAML unmarshals from YAML assuming Bech32 encoding.
func (va *ValAddress) UnmarshalYAML(data []byte) error {
	var s string

	err := yaml.Unmarshal(data, &s)
	if err != nil {
		return err
	}

	va2, err := ValAddressFromBech32(s)
	if err != nil {
		return err
	}

	*va = va2
	return nil
}

// Bytes returns the raw address bytes.
func (va ValAddress) Bytes() []byte {
	return va
}

// String implements the Stringer interface.
func (va ValAddress) String() string {
	if va.Empty() {
		return ""
	}

	bech32PrefixValAddr := GetConfig().GetBech32ValidatorAddrPrefix()

	bech32Addr, err := bech32.ConvertAndEncode(bech32PrefixValAddr, va.Bytes())
	if err != nil {
		panic(err)
	}

	return bech32Addr
}

// Format implements the fmt.Formatter interface.
// nolint: errcheck
func (va ValAddress) Format(s fmt.State, verb rune) {
	switch verb {
	case 's':
		s.Write([]byte(va.String()))
	case 'p':
		s.Write([]byte(fmt.Sprintf("%p", va)))
	default:
		s.Write([]byte(fmt.Sprintf("%X", []byte(va))))
	}
}

// ----------------------------------------------------------------------------
// consensus node
// ----------------------------------------------------------------------------

// ConsAddress defines a wrapper around bytes meant to present a consensus node.
// When marshaled to a string or JSON, it uses Bech32.
type ConsAddress []byte

// ConsAddressFromHex creates a ConsAddress from a hex string.
func ConsAddressFromHex(address string) (addr ConsAddress, err error) {
	bz, err := addressBytesFromHexString(address)
	return ConsAddress(bz), err
}

// ConsAddressFromBech32 creates a ConsAddress from a Bech32 string.
func ConsAddressFromBech32(address string) (addr ConsAddress, err error) {
	if len(strings.TrimSpace(address)) == 0 {
		return ConsAddress{}, nil
	}

	bech32PrefixConsAddr := GetConfig().GetBech32ConsensusAddrPrefix()

	bz, err := GetFromBech32(address, bech32PrefixConsAddr)
	if err != nil {
		return nil, err
	}

	err = VerifyAddressFormat(bz)
	if err != nil {
		return nil, err
	}

	return ConsAddress(bz), nil
}

// get ConsAddress from pubkey
func GetConsAddress(pubkey crypto.PubKey) ConsAddress {
	return ConsAddress(pubkey.Address())
}

// Returns boolean for whether two ConsAddress are Equal
func (ca ConsAddress) Equals(ca2 Address) bool {
	if ca.Empty() && ca2.Empty() {
		return true
	}

	return bytes.Equal(ca.Bytes(), ca2.Bytes())
}

// Returns boolean for whether an ConsAddress is empty
func (ca ConsAddress) Empty() bool {
	if ca == nil {
		return true
	}

	ca2 := ConsAddress{}
	return bytes.Equal(ca.Bytes(), ca2.Bytes())
}

// Marshal returns the raw address bytes. It is needed for protobuf
// compatibility.
func (ca ConsAddress) Marshal() ([]byte, error) {
	return ca, nil
}

// Unmarshal sets the address to the given data. It is needed for protobuf
// compatibility.
func (ca *ConsAddress) Unmarshal(data []byte) error {
	*ca = data
	return nil
}

// MarshalJSON marshals to JSON using Bech32.
func (ca ConsAddress) MarshalJSON() ([]byte, error) {
	return json.Marshal(ca.String())
}

// MarshalYAML marshals to YAML using Bech32.
func (ca ConsAddress) MarshalYAML() (interface{}, error) {
	return ca.String(), nil
}

// UnmarshalJSON unmarshals from JSON assuming Bech32 encoding.
func (ca *ConsAddress) UnmarshalJSON(data []byte) error {
	var s string

	err := json.Unmarshal(data, &s)
	if err != nil {
		return err
	}

	ca2, err := ConsAddressFromBech32(s)
	if err != nil {
		return err
	}

	*ca = ca2
	return nil
}

// UnmarshalYAML unmarshals from YAML assuming Bech32 encoding.
func (ca *ConsAddress) UnmarshalYAML(data []byte) error {
	var s string

	err := yaml.Unmarshal(data, &s)
	if err != nil {
		return err
	}

	ca2, err := ConsAddressFromBech32(s)
	if err != nil {
		return err
	}

	*ca = ca2
	return nil
}

// Bytes returns the raw address bytes.
func (ca ConsAddress) Bytes() []byte {
	return ca
}

// String implements the Stringer interface.
func (ca ConsAddress) String() string {
	if ca.Empty() {
		return ""
	}

	bech32PrefixConsAddr := GetConfig().GetBech32ConsensusAddrPrefix()

	bech32Addr, err := bech32.ConvertAndEncode(bech32PrefixConsAddr, ca.Bytes())
	if err != nil {
		panic(err)
	}

	return bech32Addr
}

// Bech32ifyAddressBytes returns a bech32 representation of address bytes.
// Returns an empty sting if the byte slice is 0-length. Returns an error if the bech32 conversion
// fails or the prefix is empty.
func Bech32ifyAddressBytes(prefix string, bs []byte) (string, error) {
	if len(bs) == 0 {
		return "", nil
	}
	if len(prefix) == 0 {
		return "", errors.New("prefix cannot be empty")
	}
	return bech32.ConvertAndEncode(prefix, bs)
}

// MustBech32ifyAddressBytes returns a bech32 representation of address bytes.
// Returns an empty sting if the byte slice is 0-length. It panics if the bech32 conversion
// fails or the prefix is empty.
func MustBech32ifyAddressBytes(prefix string, bs []byte) string {
	s, err := Bech32ifyAddressBytes(prefix, bs)
	if err != nil {
		panic(err)
	}
	return s
}

// Format implements the fmt.Formatter interface.
// nolint: errcheck
func (ca ConsAddress) Format(s fmt.State, verb rune) {
	switch verb {
	case 's':
		s.Write([]byte(ca.String()))
	case 'p':
		s.Write([]byte(fmt.Sprintf("%p", ca)))
	default:
		s.Write([]byte(fmt.Sprintf("%X", []byte(ca))))
	}
}

// ----------------------------------------------------------------------------
// auxiliary
// ----------------------------------------------------------------------------

// Bech32PubKeyType defines a string type alias for a Bech32 public key type.
type Bech32PubKeyType string

// Bech32 conversion constants
const (
	Bech32PubKeyTypeAccPub  Bech32PubKeyType = "accpub"
	Bech32PubKeyTypeValPub  Bech32PubKeyType = "valpub"
	Bech32PubKeyTypeConsPub Bech32PubKeyType = "conspub"
)

// Bech32ifyPubKey returns a Bech32 encoded string containing the appropriate
// prefix based on the key type provided for a given PublicKey.
func Bech32ifyPubKey(pkt Bech32PubKeyType, pubkey crypto.PubKey) (string, error) {
	var bech32Prefix string

	switch pkt {
	case Bech32PubKeyTypeAccPub:
		bech32Prefix = GetConfig().GetBech32AccountPubPrefix()

	case Bech32PubKeyTypeValPub:
		bech32Prefix = GetConfig().GetBech32ValidatorPubPrefix()

	case Bech32PubKeyTypeConsPub:
		bech32Prefix = GetConfig().GetBech32ConsensusPubPrefix()

	}

	return bech32.ConvertAndEncode(bech32Prefix, pubkey.Bytes())
}

// MustBech32ifyPubKey calls Bech32ifyPubKey except it panics on error.
func MustBech32ifyPubKey(pkt Bech32PubKeyType, pubkey crypto.PubKey) string {
	res, err := Bech32ifyPubKey(pkt, pubkey)
	if err != nil {
		panic(err)
	}

	return res
}

// GetPubKeyFromBech32 returns a PublicKey from a bech32-encoded PublicKey with
// a given key type.
func GetPubKeyFromBech32(pkt Bech32PubKeyType, pubkeyStr string) (crypto.PubKey, error) {
	var bech32Prefix string

	switch pkt {
	case Bech32PubKeyTypeAccPub:
		bech32Prefix = GetConfig().GetBech32AccountPubPrefix()

	case Bech32PubKeyTypeValPub:
		bech32Prefix = GetConfig().GetBech32ValidatorPubPrefix()

	case Bech32PubKeyTypeConsPub:
		bech32Prefix = GetConfig().GetBech32ConsensusPubPrefix()

	}

	bz, err := GetFromBech32(pubkeyStr, bech32Prefix)
	if err != nil {
		return nil, err
	}

	pk, err := tmamino.PubKeyFromBytes(bz)
	if err != nil {
		return nil, err
	}

	return pk, nil
}

// MustGetPubKeyFromBech32 calls GetPubKeyFromBech32 except it panics on error.
func MustGetPubKeyFromBech32(pkt Bech32PubKeyType, pubkeyStr string) crypto.PubKey {
	res, err := GetPubKeyFromBech32(pkt, pubkeyStr)
	if err != nil {
		panic(err)
	}

	return res
}

// GetFromBech32 decodes a bytestring from a Bech32 encoded string.
func GetFromBech32(bech32str, prefix string) ([]byte, error) {
	if len(bech32str) == 0 {
		return nil, errors.New("decoding Bech32 address failed: must provide an address")
	}

	hrp, bz, err := bech32.DecodeAndConvert(bech32str)
	if err != nil {
		return nil, err
	}

	if hrp != prefix {
		return nil, fmt.Errorf("invalid Bech32 prefix; expected %s, got %s", prefix, hrp)
	}

	return bz, nil
}

func addressBytesFromHexString(address string) ([]byte, error) {
	if len(address) == 0 {
		return nil, errors.New("decoding Bech32 address failed: must provide an address")
	}

	return hex.DecodeString(address)
}