encode.go

/*
 * Cadence - The resource-oriented smart contract programming language
 *
 * Copyright 2019-2022 Dapper Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package json

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"math/big"
	goRuntime "runtime"
	"strconv"
	"strings"

	"github.com/onflow/cadence"
	"github.com/onflow/cadence/runtime/sema"
)

// An Encoder converts Cadence values into JSON-encoded bytes.
type Encoder struct {
	enc *json.Encoder
}

// Encode returns the JSON-encoded representation of the given value.
//
// This function returns an error if the Cadence value cannot be represented as JSON.
func Encode(value cadence.Value) ([]byte, error) {
	var w bytes.Buffer
	enc := NewEncoder(&w)

	err := enc.Encode(value)
	if err != nil {
		return nil, err
	}

	return w.Bytes(), nil
}

// MustEncode returns the JSON-encoded representation of the given value, or panics
// if the value cannot be represented as JSON.
func MustEncode(value cadence.Value) []byte {
	b, err := Encode(value)
	if err != nil {
		panic(err)
	}
	return b
}

// NewEncoder initializes an Encoder that will write JSON-encoded bytes to the
// given io.Writer.
func NewEncoder(w io.Writer) *Encoder {
	return &Encoder{enc: json.NewEncoder(w)}
}

// Encode writes the JSON-encoded representation of the given value to this
// encoder's io.Writer.
//
// This function returns an error if the given value's type is not supported
// by this encoder.
func (e *Encoder) Encode(value cadence.Value) (err error) {
	// capture panics that occur during struct preparation
	defer func() {
		if r := recover(); r != nil {
			// don't recover Go errors
			goErr, ok := r.(goRuntime.Error)
			if ok {
				panic(goErr)
			}

			panicErr, isError := r.(error)
			if !isError {
				panic(r)
			}

			err = fmt.Errorf("failed to encode value: %w", panicErr)
		}
	}()

	preparedValue := Prepare(value)

	return e.enc.Encode(&preparedValue)
}

// JSON struct definitions

type jsonValue interface{}

type jsonValueObject struct {
	Type  string    `json:"type"`
	Value jsonValue `json:"value"`
}

type jsonEmptyValueObject struct {
	Type string `json:"type"`
}

type jsonDictionaryItem struct {
	Key   jsonValue `json:"key"`
	Value jsonValue `json:"value"`
}

type jsonCompositeValue struct {
	ID     string               `json:"id"`
	Fields []jsonCompositeField `json:"fields"`
}

type jsonCompositeField struct {
	Name  string    `json:"name"`
	Value jsonValue `json:"value"`
}

type jsonLinkValue struct {
	TargetPath jsonValue `json:"targetPath"`
	BorrowType string    `json:"borrowType"`
}

type jsonPathValue struct {
	Domain     string `json:"domain"`
	Identifier string `json:"identifier"`
}

type jsonFieldType struct {
	Id   string    `json:"id"`
	Type jsonValue `json:"type"`
}

type jsonNominalType struct {
	Kind         string                `json:"kind"`
	TypeID       string                `json:"typeID"`
	Fields       []jsonFieldType       `json:"fields"`
	Initializers [][]jsonParameterType `json:"initializers"`
	Type         jsonValue             `json:"type"`
}

type jsonSimpleType struct {
	Kind string `json:"kind"`
}

type jsonUnaryType struct {
	Kind string    `json:"kind"`
	Type jsonValue `json:"type"`
}

type jsonConstantSizedArrayType struct {
	Kind string    `json:"kind"`
	Type jsonValue `json:"type"`
	Size uint      `json:"size"`
}

type jsonDictionaryType struct {
	Kind      string    `json:"kind"`
	KeyType   jsonValue `json:"key"`
	ValueType jsonValue `json:"value"`
}

type jsonReferenceType struct {
	Kind       string    `json:"kind"`
	Type       jsonValue `json:"type"`
	Authorized bool      `json:"authorized"`
}

type jsonRestrictedType struct {
	Kind         string      `json:"kind"`
	TypeID       string      `json:"typeID"`
	Type         jsonValue   `json:"type"`
	Restrictions []jsonValue `json:"restrictions"`
}

type jsonParameterType struct {
	Label string    `json:"label"`
	Id    string    `json:"id"`
	Type  jsonValue `json:"type"`
}

type jsonFunctionType struct {
	Kind       string              `json:"kind"`
	TypeID     string              `json:"typeID"`
	Parameters []jsonParameterType `json:"parameters"`
	Return     jsonValue           `json:"return"`
}

type jsonTypeValue struct {
	StaticType jsonValue `json:"staticType"`
}

type jsonCapabilityValue struct {
	Path       jsonValue `json:"path"`
	Address    string    `json:"address"`
	BorrowType jsonValue `json:"borrowType"`
}

const (
	voidTypeStr       = "Void"
	optionalTypeStr   = "Optional"
	boolTypeStr       = "Bool"
	characterTypeStr  = "Character"
	stringTypeStr     = "String"
	addressTypeStr    = "Address"
	intTypeStr        = "Int"
	int8TypeStr       = "Int8"
	int16TypeStr      = "Int16"
	int32TypeStr      = "Int32"
	int64TypeStr      = "Int64"
	int128TypeStr     = "Int128"
	int256TypeStr     = "Int256"
	uintTypeStr       = "UInt"
	uint8TypeStr      = "UInt8"
	uint16TypeStr     = "UInt16"
	uint32TypeStr     = "UInt32"
	uint64TypeStr     = "UInt64"
	uint128TypeStr    = "UInt128"
	uint256TypeStr    = "UInt256"
	word8TypeStr      = "Word8"
	word16TypeStr     = "Word16"
	word32TypeStr     = "Word32"
	word64TypeStr     = "Word64"
	fix64TypeStr      = "Fix64"
	ufix64TypeStr     = "UFix64"
	arrayTypeStr      = "Array"
	dictionaryTypeStr = "Dictionary"
	structTypeStr     = "Struct"
	resourceTypeStr   = "Resource"
	eventTypeStr      = "Event"
	contractTypeStr   = "Contract"
	linkTypeStr       = "Link"
	pathTypeStr       = "Path"
	typeTypeStr       = "Type"
	capabilityTypeStr = "Capability"
	enumTypeStr       = "Enum"
)

// Prepare traverses the object graph of the provided value and constructs
// a struct representation that can be marshalled to JSON.
func Prepare(v cadence.Value) jsonValue {
	switch x := v.(type) {
	case cadence.Void:
		return prepareVoid()
	case cadence.Optional:
		return prepareOptional(x)
	case cadence.Bool:
		return prepareBool(x)
	case cadence.Character:
		return prepareCharacter(x)
	case cadence.String:
		return prepareString(x)
	case cadence.Address:
		return prepareAddress(x)
	case cadence.Int:
		return prepareInt(x)
	case cadence.Int8:
		return prepareInt8(x)
	case cadence.Int16:
		return prepareInt16(x)
	case cadence.Int32:
		return prepareInt32(x)
	case cadence.Int64:
		return prepareInt64(x)
	case cadence.Int128:
		return prepareInt128(x)
	case cadence.Int256:
		return prepareInt256(x)
	case cadence.UInt:
		return prepareUInt(x)
	case cadence.UInt8:
		return prepareUInt8(x)
	case cadence.UInt16:
		return prepareUInt16(x)
	case cadence.UInt32:
		return prepareUInt32(x)
	case cadence.UInt64:
		return prepareUInt64(x)
	case cadence.UInt128:
		return prepareUInt128(x)
	case cadence.UInt256:
		return prepareUInt256(x)
	case cadence.Word8:
		return prepareWord8(x)
	case cadence.Word16:
		return prepareWord16(x)
	case cadence.Word32:
		return prepareWord32(x)
	case cadence.Word64:
		return prepareWord64(x)
	case cadence.Fix64:
		return prepareFix64(x)
	case cadence.UFix64:
		return prepareUFix64(x)
	case cadence.Array:
		return prepareArray(x)
	case cadence.Dictionary:
		return prepareDictionary(x)
	case cadence.Struct:
		return prepareStruct(x)
	case cadence.Resource:
		return prepareResource(x)
	case cadence.Event:
		return prepareEvent(x)
	case cadence.Contract:
		return prepareContract(x)
	case cadence.Link:
		return prepareLink(x)
	case cadence.Path:
		return preparePath(x)
	case cadence.TypeValue:
		return prepareTypeValue(x)
	case cadence.Capability:
		return prepareCapability(x)
	case cadence.Enum:
		return prepareEnum(x)
	default:
		panic(fmt.Errorf("unsupported value: %T, %v", v, v))
	}
}

func prepareVoid() jsonValue {
	return jsonEmptyValueObject{Type: voidTypeStr}
}

func prepareOptional(v cadence.Optional) jsonValue {
	var value interface{}

	if v.Value != nil {
		value = Prepare(v.Value)
	}

	return jsonValueObject{
		Type:  optionalTypeStr,
		Value: value,
	}
}

func prepareBool(v cadence.Bool) jsonValue {
	return jsonValueObject{
		Type:  boolTypeStr,
		Value: v,
	}
}

func prepareCharacter(v cadence.Character) jsonValue {
	return jsonValueObject{
		Type:  characterTypeStr,
		Value: v,
	}
}

func prepareString(v cadence.String) jsonValue {
	return jsonValueObject{
		Type:  stringTypeStr,
		Value: v,
	}
}

func prepareAddress(v cadence.Address) jsonValue {
	return jsonValueObject{
		Type:  addressTypeStr,
		Value: encodeBytes(v.Bytes()),
	}
}

func prepareInt(v cadence.Int) jsonValue {
	return jsonValueObject{
		Type:  intTypeStr,
		Value: encodeBig(v.Big()),
	}
}

func prepareInt8(v cadence.Int8) jsonValue {
	return jsonValueObject{
		Type:  int8TypeStr,
		Value: encodeInt(int64(v)),
	}
}

func prepareInt16(v cadence.Int16) jsonValue {
	return jsonValueObject{
		Type:  int16TypeStr,
		Value: encodeInt(int64(v)),
	}
}

func prepareInt32(v cadence.Int32) jsonValue {
	return jsonValueObject{
		Type:  int32TypeStr,
		Value: encodeInt(int64(v)),
	}
}

func prepareInt64(v cadence.Int64) jsonValue {
	return jsonValueObject{
		Type:  int64TypeStr,
		Value: encodeInt(int64(v)),
	}
}

func prepareInt128(v cadence.Int128) jsonValue {
	return jsonValueObject{
		Type:  int128TypeStr,
		Value: encodeBig(v.Big()),
	}
}

func prepareInt256(v cadence.Int256) jsonValue {
	return jsonValueObject{
		Type:  int256TypeStr,
		Value: encodeBig(v.Big()),
	}
}

func prepareUInt(v cadence.UInt) jsonValue {
	return jsonValueObject{
		Type:  uintTypeStr,
		Value: encodeBig(v.Big()),
	}
}

func prepareUInt8(v cadence.UInt8) jsonValue {
	return jsonValueObject{
		Type:  uint8TypeStr,
		Value: encodeUInt(uint64(v)),
	}
}

func prepareUInt16(v cadence.UInt16) jsonValue {
	return jsonValueObject{
		Type:  uint16TypeStr,
		Value: encodeUInt(uint64(v)),
	}
}

func prepareUInt32(v cadence.UInt32) jsonValue {
	return jsonValueObject{
		Type:  uint32TypeStr,
		Value: encodeUInt(uint64(v)),
	}
}

func prepareUInt64(v cadence.UInt64) jsonValue {
	return jsonValueObject{
		Type:  uint64TypeStr,
		Value: encodeUInt(uint64(v)),
	}
}

func prepareUInt128(v cadence.UInt128) jsonValue {
	return jsonValueObject{
		Type:  uint128TypeStr,
		Value: encodeBig(v.Big()),
	}
}

func prepareUInt256(v cadence.UInt256) jsonValue {
	return jsonValueObject{
		Type:  uint256TypeStr,
		Value: encodeBig(v.Big()),
	}
}

func prepareWord8(v cadence.Word8) jsonValue {
	return jsonValueObject{
		Type:  word8TypeStr,
		Value: encodeUInt(uint64(v)),
	}
}

func prepareWord16(v cadence.Word16) jsonValue {
	return jsonValueObject{
		Type:  word16TypeStr,
		Value: encodeUInt(uint64(v)),
	}
}

func prepareWord32(v cadence.Word32) jsonValue {
	return jsonValueObject{
		Type:  word32TypeStr,
		Value: encodeUInt(uint64(v)),
	}
}

func prepareWord64(v cadence.Word64) jsonValue {
	return jsonValueObject{
		Type:  word64TypeStr,
		Value: encodeUInt(uint64(v)),
	}
}

func prepareFix64(v cadence.Fix64) jsonValue {
	return jsonValueObject{
		Type:  fix64TypeStr,
		Value: encodeFix64(int64(v)),
	}
}

func prepareUFix64(v cadence.UFix64) jsonValue {
	return jsonValueObject{
		Type:  ufix64TypeStr,
		Value: encodeUFix64(uint64(v)),
	}
}

func prepareArray(v cadence.Array) jsonValue {
	values := make([]jsonValue, len(v.Values))

	for i, value := range v.Values {
		values[i] = Prepare(value)
	}

	return jsonValueObject{
		Type:  arrayTypeStr,
		Value: values,
	}
}

func prepareDictionary(v cadence.Dictionary) jsonValue {
	items := make([]jsonDictionaryItem, len(v.Pairs))

	for i, pair := range v.Pairs {
		items[i] = jsonDictionaryItem{
			Key:   Prepare(pair.Key),
			Value: Prepare(pair.Value),
		}
	}

	return jsonValueObject{
		Type:  dictionaryTypeStr,
		Value: items,
	}
}

func prepareStruct(v cadence.Struct) jsonValue {
	return prepareComposite(structTypeStr, v.StructType.ID(), v.StructType.Fields, v.Fields)
}

func prepareResource(v cadence.Resource) jsonValue {
	return prepareComposite(resourceTypeStr, v.ResourceType.ID(), v.ResourceType.Fields, v.Fields)
}

func prepareEvent(v cadence.Event) jsonValue {
	return prepareComposite(eventTypeStr, v.EventType.ID(), v.EventType.Fields, v.Fields)
}

func prepareContract(v cadence.Contract) jsonValue {
	return prepareComposite(contractTypeStr, v.ContractType.ID(), v.ContractType.Fields, v.Fields)
}

func prepareEnum(v cadence.Enum) jsonValue {
	return prepareComposite(enumTypeStr, v.EnumType.ID(), v.EnumType.Fields, v.Fields)
}

func prepareComposite(kind, id string, fieldTypes []cadence.Field, fields []cadence.Value) jsonValue {
	nonFunctionFieldTypes := make([]cadence.Field, 0)

	for _, field := range fieldTypes {
		if _, ok := field.Type.(*cadence.FunctionType); !ok {
			nonFunctionFieldTypes = append(nonFunctionFieldTypes, field)
		}
	}

	if len(nonFunctionFieldTypes) != len(fields) {
		panic(fmt.Errorf(
			"%s field count (%d) does not match declared type (%d)",
			kind,
			len(fields),
			len(nonFunctionFieldTypes),
		))
	}

	compositeFields := make([]jsonCompositeField, len(fields))

	for i, value := range fields {
		fieldType := nonFunctionFieldTypes[i]

		compositeFields[i] = jsonCompositeField{
			Name:  fieldType.Identifier,
			Value: Prepare(value),
		}
	}

	return jsonValueObject{
		Type: kind,
		Value: jsonCompositeValue{
			ID:     id,
			Fields: compositeFields,
		},
	}
}

func prepareLink(x cadence.Link) jsonValue {
	return jsonValueObject{
		Type: linkTypeStr,
		Value: jsonLinkValue{
			TargetPath: preparePath(x.TargetPath),
			BorrowType: x.BorrowType,
		},
	}
}

func preparePath(x cadence.Path) jsonValue {
	return jsonValueObject{
		Type: pathTypeStr,
		Value: jsonPathValue{
			Domain:     x.Domain,
			Identifier: x.Identifier,
		},
	}
}

func prepareParameterType(parameterType cadence.Parameter, results typeResults) jsonParameterType {
	return jsonParameterType{
		Label: parameterType.Label,
		Id:    parameterType.Identifier,
		Type:  prepareType(parameterType.Type, results),
	}
}

func prepareFieldType(fieldType cadence.Field, results typeResults) jsonFieldType {
	return jsonFieldType{
		Id:   fieldType.Identifier,
		Type: prepareType(fieldType.Type, results),
	}
}

func prepareFields(fieldTypes []cadence.Field, results typeResults) []jsonFieldType {
	fields := make([]jsonFieldType, 0)
	for _, field := range fieldTypes {
		fields = append(fields, prepareFieldType(field, results))
	}
	return fields
}

func prepareParameters(parameterTypes []cadence.Parameter, results typeResults) []jsonParameterType {
	parameters := make([]jsonParameterType, 0)
	for _, param := range parameterTypes {
		parameters = append(parameters, prepareParameterType(param, results))
	}
	return parameters
}

func prepareInitializers(initializerTypes [][]cadence.Parameter, results typeResults) [][]jsonParameterType {
	initializers := make([][]jsonParameterType, 0)
	for _, params := range initializerTypes {
		initializers = append(initializers, prepareParameters(params, results))
	}
	return initializers
}

func prepareType(typ cadence.Type, results typeResults) jsonValue {

	var supportedRecursiveType bool
	switch typ.(type) {
	case cadence.CompositeType, cadence.InterfaceType:
		supportedRecursiveType = true
	}

	if _, ok := results[typ]; ok {
		if !supportedRecursiveType {
			panic(fmt.Errorf("failed to prepare type: unsupported recursive type: %T", typ))
		}

		return typ.ID()
	}

	if supportedRecursiveType {
		results[typ] = struct{}{}
	}

	switch typ := typ.(type) {
	case cadence.AnyType,
		cadence.AnyStructType,
		cadence.AnyResourceType,
		cadence.AddressType,
		cadence.MetaType,
		cadence.VoidType,
		cadence.NeverType,
		cadence.BoolType,
		cadence.StringType,
		cadence.CharacterType,
		cadence.BytesType,
		cadence.NumberType,
		cadence.SignedNumberType,
		cadence.IntegerType,
		cadence.SignedIntegerType,
		cadence.FixedPointType,
		cadence.SignedFixedPointType,
		cadence.IntType,
		cadence.Int8Type,
		cadence.Int16Type,
		cadence.Int32Type,
		cadence.Int64Type,
		cadence.Int128Type,
		cadence.Int256Type,
		cadence.UIntType,
		cadence.UInt8Type,
		cadence.UInt16Type,
		cadence.UInt32Type,
		cadence.UInt64Type,
		cadence.UInt128Type,
		cadence.UInt256Type,
		cadence.Word8Type,
		cadence.Word16Type,
		cadence.Word32Type,
		cadence.Word64Type,
		cadence.Fix64Type,
		cadence.UFix64Type,
		cadence.BlockType,
		cadence.PathType,
		cadence.CapabilityPathType,
		cadence.StoragePathType,
		cadence.PublicPathType,
		cadence.PrivatePathType,
		cadence.AccountKeyType,
		cadence.AuthAccountContractsType,
		cadence.AuthAccountKeysType,
		cadence.AuthAccountType,
		cadence.PublicAccountContractsType,
		cadence.PublicAccountKeysType,
		cadence.PublicAccountType,
		cadence.DeployedContractType:
		return jsonSimpleType{
			Kind: typ.ID(),
		}
	case cadence.OptionalType:
		return jsonUnaryType{
			Kind: "Optional",
			Type: prepareType(typ.Type, results),
		}
	case cadence.VariableSizedArrayType:
		return jsonUnaryType{
			Kind: "VariableSizedArray",
			Type: prepareType(typ.ElementType, results),
		}
	case cadence.ConstantSizedArrayType:
		return jsonConstantSizedArrayType{
			Kind: "ConstantSizedArray",
			Type: prepareType(typ.ElementType, results),
			Size: typ.Size,
		}
	case cadence.DictionaryType:
		return jsonDictionaryType{
			Kind:      "Dictionary",
			KeyType:   prepareType(typ.KeyType, results),
			ValueType: prepareType(typ.ElementType, results),
		}
	case *cadence.StructType:
		return jsonNominalType{
			Kind:         "Struct",
			Type:         "",
			TypeID:       string(typ.Location.TypeID(nil, typ.QualifiedIdentifier)),
			Fields:       prepareFields(typ.Fields, results),
			Initializers: prepareInitializers(typ.Initializers, results),
		}
	case *cadence.ResourceType:
		return jsonNominalType{
			Kind:         "Resource",
			Type:         "",
			TypeID:       string(typ.Location.TypeID(nil, typ.QualifiedIdentifier)),
			Fields:       prepareFields(typ.Fields, results),
			Initializers: prepareInitializers(typ.Initializers, results),
		}
	case *cadence.EventType:
		return jsonNominalType{
			Kind:         "Event",
			Type:         "",
			TypeID:       string(typ.Location.TypeID(nil, typ.QualifiedIdentifier)),
			Fields:       prepareFields(typ.Fields, results),
			Initializers: [][]jsonParameterType{prepareParameters(typ.Initializer, results)},
		}
	case *cadence.ContractType:
		return jsonNominalType{
			Kind:         "Contract",
			Type:         "",
			TypeID:       string(typ.Location.TypeID(nil, typ.QualifiedIdentifier)),
			Fields:       prepareFields(typ.Fields, results),
			Initializers: prepareInitializers(typ.Initializers, results),
		}
	case *cadence.StructInterfaceType:
		return jsonNominalType{
			Kind:         "StructInterface",
			Type:         "",
			TypeID:       string(typ.Location.TypeID(nil, typ.QualifiedIdentifier)),
			Fields:       prepareFields(typ.Fields, results),
			Initializers: prepareInitializers(typ.Initializers, results),
		}
	case *cadence.ResourceInterfaceType:
		return jsonNominalType{
			Kind:         "ResourceInterface",
			Type:         "",
			TypeID:       string(typ.Location.TypeID(nil, typ.QualifiedIdentifier)),
			Fields:       prepareFields(typ.Fields, results),
			Initializers: prepareInitializers(typ.Initializers, results),
		}
	case *cadence.ContractInterfaceType:
		return jsonNominalType{
			Kind:         "ContractInterface",
			Type:         "",
			TypeID:       string(typ.Location.TypeID(nil, typ.QualifiedIdentifier)),
			Fields:       prepareFields(typ.Fields, results),
			Initializers: prepareInitializers(typ.Initializers, results),
		}
	case *cadence.FunctionType:
		return jsonFunctionType{
			Kind:       "Function",
			TypeID:     typ.ID(),
			Return:     prepareType(typ.ReturnType, results),
			Parameters: prepareParameters(typ.Parameters, results),
		}
	case cadence.ReferenceType:
		return jsonReferenceType{
			Kind:       "Reference",
			Authorized: typ.Authorized,
			Type:       prepareType(typ.Type, results),
		}
	case *cadence.RestrictedType:
		restrictions := make([]jsonValue, 0)
		for _, restriction := range typ.Restrictions {
			restrictions = append(restrictions, prepareType(restriction, results))
		}
		return jsonRestrictedType{
			Kind:         "Restriction",
			TypeID:       typ.ID(),
			Type:         prepareType(typ.Type, results),
			Restrictions: restrictions,
		}
	case cadence.CapabilityType:
		return jsonUnaryType{
			Kind: "Capability",
			Type: prepareType(typ.BorrowType, results),
		}
	case *cadence.EnumType:
		return jsonNominalType{
			Kind:         "Enum",
			TypeID:       string(typ.Location.TypeID(nil, typ.QualifiedIdentifier)),
			Fields:       prepareFields(typ.Fields, results),
			Initializers: prepareInitializers(typ.Initializers, results),
			Type:         prepareType(typ.RawType, results),
		}
	case nil:
		return ""
	default:
		panic(fmt.Errorf("unsupported type: %T, %v", typ, typ))
	}
}

type typeResults map[cadence.Type]struct{}

func prepareTypeValue(typeValue cadence.TypeValue) jsonValue {
	return jsonValueObject{
		Type: typeTypeStr,
		Value: jsonTypeValue{
			StaticType: prepareType(typeValue.StaticType, typeResults{}),
		},
	}
}

func prepareCapability(capability cadence.Capability) jsonValue {
	return jsonValueObject{
		Type: capabilityTypeStr,
		Value: jsonCapabilityValue{
			Path:       preparePath(capability.Path),
			Address:    encodeBytes(capability.Address.Bytes()),
			BorrowType: prepareType(capability.BorrowType, typeResults{}),
		},
	}
}

func encodeBytes(v []byte) string {
	return fmt.Sprintf("0x%x", v)
}

func encodeBig(v *big.Int) string {
	return v.String()
}

func encodeInt(v int64) string {
	return strconv.FormatInt(v, 10)
}

func encodeUInt(v uint64) string {
	return strconv.FormatUint(v, 10)
}

func encodeFix64(v int64) string {
	integer := v / sema.Fix64Factor
	fraction := v % sema.Fix64Factor

	negative := fraction < 0

	var builder strings.Builder

	if negative {
		fraction = -fraction
		if integer == 0 {
			builder.WriteRune('-')
		}
	}

	builder.WriteString(fmt.Sprintf(
		"%d.%08d",
		integer,
		fraction,
	))

	return builder.String()
}

func encodeUFix64(v uint64) string {
	integer := v / sema.Fix64Factor
	fraction := v % sema.Fix64Factor

	return fmt.Sprintf(
		"%d.%08d",
		integer,
		fraction,
	)
}