import { DataItem } from 'ethereum-types';
import * as ethUtil from 'ethereumjs-util';
import * as _ from 'lodash';
import { BigNumber } from '../configured_bignumber';
import * as Constants from './constants';
import {
Calldata,
CalldataBlock,
DependentCalldataBlock,
MemberCalldataBlock,
PayloadCalldataBlock,
RawCalldata,
} from './calldata';
import { DecodingRules, EncodingRules } from './utils/rules';
export interface DataTypeFactory {
create: (dataItem: DataItem, parentDataType?: DataType) => DataType;
mapDataItemToDataType: (dataItem: DataItem) => DataType;
}
export interface DataTypeStaticInterface {
matchType: (type: string) => boolean;
encodeValue: (value: any) => Buffer;
decodeValue: (rawCalldata: RawCalldata) => any;
}
export abstract class DataType {
private static readonly _DEFAULT_ENCODING_RULES: EncodingRules = { optimize: false, annotate: false };
private static readonly _DEFAULT_DECODING_RULES: DecodingRules = { structsAsObjects: false };
private readonly _dataItem: DataItem;
private readonly _factory: DataTypeFactory;
constructor(dataItem: DataItem, factory: DataTypeFactory) {
this._dataItem = dataItem;
this._factory = factory;
}
public getDataItem(): DataItem {
return this._dataItem;
}
public getFactory(): DataTypeFactory {
return this._factory;
}
public encode(value: any, rules?: EncodingRules, selector?: string): string {
const rules_ = rules ? rules : DataType._DEFAULT_ENCODING_RULES;
const calldata = new Calldata(rules_);
if (selector) {
calldata.setSelector(selector);
}
const block = this.generateCalldataBlock(value);
calldata.setRoot(block); // @TODO CHANGE
const calldataHex = calldata.toHexString();
return calldataHex;
}
public decode(calldata: string, rules?: DecodingRules, hasSelector: boolean = false): any {
const rawCalldata = new RawCalldata(calldata, hasSelector);
const rules_ = rules ? rules : DataType._DEFAULT_DECODING_RULES;
const value = this.generateValue(rawCalldata, rules_);
return value;
}
public abstract generateCalldataBlock(value: any, parentBlock?: CalldataBlock): CalldataBlock;
public abstract generateValue(calldata: RawCalldata, rules: DecodingRules): any;
public abstract getSignature(): string;
public abstract isStatic(): boolean;
}
export abstract class PayloadDataType extends DataType {
protected _hasConstantSize: boolean;
public constructor(dataItem: DataItem, factory: DataTypeFactory, hasConstantSize: boolean) {
super(dataItem, factory);
this._hasConstantSize = hasConstantSize;
}
public generateCalldataBlock(value: any, parentBlock?: CalldataBlock): PayloadCalldataBlock {
const encodedValue = this.encodeValue(value);
const name = this.getDataItem().name;
const signature = this.getSignature();
const parentName = parentBlock === undefined ? '' : parentBlock.getName();
const block = new PayloadCalldataBlock(name, signature, parentName, encodedValue);
return block;
}
public generateValue(calldata: RawCalldata, rules: DecodingRules): any {
const value = this.decodeValue(calldata);
return value;
}
public isStatic(): boolean {
return this._hasConstantSize;
}
public abstract encodeValue(value: any): Buffer;
public abstract decodeValue(calldata: RawCalldata): any;
}
export abstract class DependentDataType extends DataType {
protected _dependency: DataType;
protected _parent: DataType;
private readonly _isStatic: boolean;
public constructor(dataItem: DataItem, factory: DataTypeFactory, dependency: DataType, parent: DataType) {
super(dataItem, factory);
this._dependency = dependency;
this._parent = parent;
this._isStatic = true;
}
public generateCalldataBlock(value: any, parentBlock?: CalldataBlock): DependentCalldataBlock {
if (parentBlock === undefined) {
throw new Error(`DependentDataType requires a parent block to generate its block`);
}
const dependencyBlock = this._dependency.generateCalldataBlock(value, parentBlock);
const name = this.getDataItem().name;
const signature = this.getSignature();
const parentName = parentBlock === undefined ? '' : parentBlock.getName();
const block = new DependentCalldataBlock(name, signature, parentName, dependencyBlock, parentBlock);
return block;
}
public generateValue(calldata: RawCalldata, rules: DecodingRules): any {
const destinationOffsetBuf = calldata.popWord();
const currentOffset = calldata.getOffset();
const destinationOffsetRelative = parseInt(ethUtil.bufferToHex(destinationOffsetBuf), Constants.HEX_BASE);
const destinationOffsetAbsolute = calldata.toAbsoluteOffset(destinationOffsetRelative);
calldata.setOffset(destinationOffsetAbsolute);
const value = this._dependency.generateValue(calldata, rules);
calldata.setOffset(currentOffset);
return value;
}
public isStatic(): boolean {
return this._isStatic;
}
}
export interface MemberMap {
[key: string]: number;
}
export abstract class MemberDataType extends DataType {
protected readonly _arrayLength: number | undefined;
protected readonly _arrayElementType: string | undefined;
private readonly _memberMap: MemberMap;
private readonly _members: DataType[];
private readonly _isArray: boolean;
public constructor(
dataItem: DataItem,
factory: DataTypeFactory,
isArray: boolean = false,
arrayLength?: number,
arrayElementType?: string,
) {
super(dataItem, factory);
this._memberMap = {};
this._members = [];
this._isArray = isArray;
this._arrayLength = arrayLength;
this._arrayElementType = arrayElementType;
if (isArray && arrayLength !== undefined) {
[this._members, this._memberMap] = this._createMembersWithLength(dataItem, arrayLength);
} else if (!isArray) {
[this._members, this._memberMap] = this._createMembersWithKeys(dataItem);
}
}
public generateCalldataBlock(value: any[] | object, parentBlock?: CalldataBlock): MemberCalldataBlock {
const block =
value instanceof Array
? this._generateCalldataBlockFromArray(value, parentBlock)
: this._generateCalldataBlockFromObject(value, parentBlock);
return block;
}
public generateValue(calldata: RawCalldata, rules: DecodingRules): any[] | object {
let members = this._members;
if (this._isArray && this._arrayLength === undefined) {
const arrayLengthBuf = calldata.popWord();
const arrayLengthHex = ethUtil.bufferToHex(arrayLengthBuf);
const hexBase = 16;
const arrayLength = new BigNumber(arrayLengthHex, hexBase);
[members] = this._createMembersWithLength(this.getDataItem(), arrayLength.toNumber());
}
calldata.startScope();
let value: any[] | object;
if (rules.structsAsObjects && !this._isArray) {
value = {};
_.each(this._memberMap, (idx: number, key: string) => {
const member = this._members[idx];
const memberValue = member.generateValue(calldata, rules);
(value as { [key: string]: any })[key] = memberValue;
});
} else {
value = [];
_.each(members, (member: DataType, idx: number) => {
const memberValue = member.generateValue(calldata, rules);
(value as any[]).push(memberValue);
});
}
calldata.endScope();
return value;
}
public isStatic(): boolean {
/* For Tuple:
const isStaticTuple = this.children.length === 0;
return isStaticTuple; // @TODO: True in every case or only when dynamic data?
For Array:
if isLengthDefined = false then this is false
Otherwise if the first element is a Pointer then false
*/
if (this._isArray && this._arrayLength === undefined) {
return false;
}
// Search for dependent members
const dependentMember = _.find(this._members, (member: DataType) => {
return member instanceof DependentDataType;
});
const isStatic = dependentMember === undefined; // static if we couldn't find a dependent member
return isStatic;
}
protected _generateCalldataBlockFromArray(value: any[], parentBlock?: CalldataBlock): MemberCalldataBlock {
// Sanity check length
if (this._arrayLength !== undefined && value.length !== this._arrayLength) {
throw new Error(
`Expected array of ${JSON.stringify(
this._arrayLength,
)} elements, but got array of length ${JSON.stringify(value.length)}`,
);
}
const parentName = parentBlock === undefined ? '' : parentBlock.getName();
const methodBlock: MemberCalldataBlock = new MemberCalldataBlock(
this.getDataItem().name,
this.getSignature(),
parentName,
);
let members = this._members;
if (this._isArray && this._arrayLength === undefined) {
[members] = this._createMembersWithLength(this.getDataItem(), value.length);
const lenBuf = ethUtil.setLengthLeft(
ethUtil.toBuffer(`0x${value.length.toString(Constants.HEX_BASE)}`),
Constants.EVM_WORD_WIDTH_IN_BYTES,
);
methodBlock.setHeader(lenBuf);
}
const memberBlocks: CalldataBlock[] = [];
_.each(members, (member: DataType, idx: number) => {
const block = member.generateCalldataBlock(value[idx], methodBlock);
memberBlocks.push(block);
});
methodBlock.setMembers(memberBlocks);
return methodBlock;
}
protected _generateCalldataBlockFromObject(obj: object, parentBlock?: CalldataBlock): MemberCalldataBlock {
const parentName = parentBlock === undefined ? '' : parentBlock.getName();
const methodBlock: MemberCalldataBlock = new MemberCalldataBlock(
this.getDataItem().name,
this.getSignature(),
parentName,
);
const memberBlocks: CalldataBlock[] = [];
const childMap = _.cloneDeep(this._memberMap);
_.forOwn(obj, (value: any, key: string) => {
if (!(key in childMap)) {
throw new Error(
`Could not assign tuple to object: unrecognized key '${key}' in object ${this.getDataItem().name}`,
);
}
const block = this._members[this._memberMap[key]].generateCalldataBlock(value, methodBlock);
memberBlocks.push(block);
delete childMap[key];
});
if (Object.keys(childMap).length !== 0) {
throw new Error(`Could not assign tuple to object: missing keys ${Object.keys(childMap)}`);
}
methodBlock.setMembers(memberBlocks);
return methodBlock;
}
protected _computeSignatureOfMembers(): string {
// Compute signature of members
let signature = `(`;
_.each(this._members, (member: DataType, i: number) => {
signature += member.getSignature();
if (i < this._members.length - 1) {
signature += ',';
}
});
signature += ')';
return signature;
}
private _createMembersWithKeys(dataItem: DataItem): [DataType[], MemberMap] {
// Sanity check
if (dataItem.components === undefined) {
throw new Error(`Expected components`);
}
const members: DataType[] = [];
const memberMap: MemberMap = {};
_.each(dataItem.components, (memberItem: DataItem) => {
const childDataItem: DataItem = {
type: memberItem.type,
name: `${dataItem.name}.${memberItem.name}`,
};
const components = memberItem.components;
if (components !== undefined) {
childDataItem.components = components;
}
const child = this.getFactory().create(childDataItem, this);
memberMap[memberItem.name] = members.length;
members.push(child);
});
return [members, memberMap];
}
private _createMembersWithLength(dataItem: DataItem, length: number): [DataType[], MemberMap] {
const members: DataType[] = [];
const memberMap: MemberMap = {};
const range = _.range(length);
_.each(range, (idx: number) => {
const childDataItem: DataItem = {
type: this._arrayElementType ? this._arrayElementType : '',
name: `${dataItem.name}[${idx.toString(Constants.DEC_BASE)}]`,
};
const components = dataItem.components;
if (components !== undefined) {
childDataItem.components = components;
}
const child = this.getFactory().create(childDataItem, this);
memberMap[idx.toString(Constants.DEC_BASE)] = members.length;
members.push(child);
});
return [members, memberMap];
}
}