package tron

import (
  "encoding/hex"
  "strings"

  "code.luxferre.top/luxferre/kisstron/base58"
)

// ToBase58CheckAddress converts an address given in any accepted format
// (base58check, 41-prefixed hex, or 0x-prefixed hex) to its base58check
// representation, verifying the checksum. The argument may be a string or a
// byte slice.
func ToBase58CheckAddress(raw any) (string, error) {
  switch v := raw.(type) {
  case string:
    return strToBase58Check(v)
  case []byte:
    return bytesToBase58Check(v)
  }
  return "", ErrBadAddress
}

func strToBase58Check(s string) (string, error) {
  if len(s) == 0 {
    return "", ErrBadAddress
  }
  if s[0] == 'T' && len(s) == 34 {
    if !base58.IsValid(s) {
      return "", ErrBadAddress
    }
    return s, nil
  }
  if len(s) == 42 {
    if strings.HasPrefix(s, "0x") {
      b, err := hex.DecodeString(s[2:])
      if err != nil || len(b) != 20 {
        return "", ErrBadAddress
      }
      return base58.CheckEncode(append([]byte{0x41}, b...)), nil
    }
    b, err := hex.DecodeString(s)
    if err != nil || len(b) != 21 {
      return "", ErrBadAddress
    }
    return base58.CheckEncode(b), nil
  }
  if strings.HasPrefix(s, "0x") && len(s) == 44 {
    b, err := hex.DecodeString(s[2:])
    if err != nil || len(b) != 21 {
      return "", ErrBadAddress
    }
    return base58.CheckEncode(b), nil
  }
  return "", ErrBadAddress
}

func bytesToBase58Check(b []byte) (string, error) {
  switch {
  case len(b) == 21 && b[0] == 0x41:
    return base58.CheckEncode(b), nil
  case len(b) == 20:
    return base58.CheckEncode(append([]byte{0x41}, b...)), nil
  default:
    return strToBase58Check(string(b))
  }
}

// ToHexAddress converts an address to its 41-prefixed hex representation.
func ToHexAddress(raw any) (string, error) {
  addr, err := ToBase58CheckAddress(raw)
  if err != nil {
    return "", err
  }
  b, err := base58.CheckDecode(addr)
  if err != nil {
    return "", ErrBadAddress
  }
  return hex.EncodeToString(b), nil
}

// ToRawAddress returns the 21-byte raw form of an address.
func ToRawAddress(raw any) ([]byte, error) {
  addr, err := ToBase58CheckAddress(raw)
  if err != nil {
    return nil, err
  }
  return base58.CheckDecode(addr)
}

// ToTvmAddress returns the 20-byte TVM (Ethereum-style) form of an address.
func ToTvmAddress(raw any) ([]byte, error) {
  b, err := ToRawAddress(raw)
  if err != nil {
    return nil, err
  }
  return b[1:], nil
}

// IsBase58CheckAddress reports whether value is a valid base58check address.
func IsBase58CheckAddress(value string) bool {
  if len(value) == 0 || value[0] != 'T' {
    return false
  }
  b, err := base58.CheckDecode(value)
  return err == nil && len(b) == 21
}

// IsHexAddress reports whether value is a valid 41-prefixed hex address.
func IsHexAddress(value string) bool {
  if !strings.HasPrefix(value, "41") {
    return false
  }
  b, err := hex.DecodeString(value)
  return err == nil && len(b) == 21
}

// IsAddress reports whether value is any accepted TRON address format.
func IsAddress(value string) bool {
  return IsBase58CheckAddress(value) || IsHexAddress(value)
}