import { assert } from '@0xproject/assert';
import {
    ContractWrappers,
    EtherTokenWrapper,
    ExchangeWrapper,
    TokenRegistryWrapper,
    TokenTransferProxyWrapper,
    TokenWrapper,
    ZeroExContractConfig,
} from '@0xproject/contract-wrappers';
import {
    generatePseudoRandomSalt,
    getOrderHashHex,
    isValidOrderHash,
    isValidSignature,
    signOrderHashAsync,
} from '@0xproject/order-utils';
import { OrderWatcher, OrderWatcherConfig } from '@0xproject/order-watcher';
import { ECSignature, Order, Provider, SignedOrder, TransactionReceiptWithDecodedLogs } from '@0xproject/types';
import { BigNumber } from '@0xproject/utils';
import { Web3Wrapper } from '@0xproject/web3-wrapper';
import * as _ from 'lodash';

import { constants } from './utils/constants';

/**
 * The ZeroEx class is the single entry-point into the 0x.js library. It contains all of the library's functionality
 * and all calls to the library should be made through a ZeroEx instance.
 */
export class ZeroEx {
    /**
     * When creating an order without a specified taker or feeRecipient you must supply the Solidity
     * address null type (as opposed to Javascripts `null`, `undefined` or empty string). We expose
     * this constant for your convenience.
     */
    public static NULL_ADDRESS = constants.NULL_ADDRESS;
    /**
     * An instance of the ExchangeWrapper class containing methods for interacting with the 0x Exchange smart contract.
     */
    public exchange: ExchangeWrapper;
    /**
     * An instance of the TokenRegistryWrapper class containing methods for interacting with the 0x
     * TokenRegistry smart contract.
     */
    public tokenRegistry: TokenRegistryWrapper;
    /**
     * An instance of the TokenWrapper class containing methods for interacting with any ERC20 token smart contract.
     */
    public token: TokenWrapper;
    /**
     * An instance of the EtherTokenWrapper class containing methods for interacting with the
     * wrapped ETH ERC20 token smart contract.
     */
    public etherToken: EtherTokenWrapper;
    /**
     * An instance of the TokenTransferProxyWrapper class containing methods for interacting with the
     * tokenTransferProxy smart contract.
     */
    public proxy: TokenTransferProxyWrapper;
    private _contractWrappers: ContractWrappers;
    /**
     * Generates a pseudo-random 256-bit salt.
     * The salt can be included in a 0x order, ensuring that the order generates a unique orderHash
     * and will not collide with other outstanding orders that are identical in all other parameters.
     * @return  A pseudo-random 256-bit number that can be used as a salt.
     */
    public static generatePseudoRandomSalt(): BigNumber {
        return generatePseudoRandomSalt();
    }
    /**
     * Verifies that the elliptic curve signature `signature` was generated
     * by signing `data` with the private key corresponding to the `signerAddress` address.
     * @param   data          The hex encoded data signed by the supplied signature.
     * @param   signature     An object containing the elliptic curve signature parameters.
     * @param   signerAddress The hex encoded address that signed the data, producing the supplied signature.
     * @return  Whether the signature is valid for the supplied signerAddress and data.
     */
    public static isValidSignature(data: string, signature: ECSignature, signerAddress: string): boolean {
        return isValidSignature(data, signature, signerAddress);
    }
    /**
     * Computes the orderHash for a supplied order.
     * @param   order   An object that conforms to the Order or SignedOrder interface definitions.
     * @return  The resulting orderHash from hashing the supplied order.
     */
    public static getOrderHashHex(order: Order | SignedOrder): string {
        return getOrderHashHex(order);
    }
    /**
     * Checks if the supplied hex encoded order hash is valid.
     * Note: Valid means it has the expected format, not that an order with the orderHash exists.
     * Use this method when processing orderHashes submitted as user input.
     * @param   orderHash    Hex encoded orderHash.
     * @return  Whether the supplied orderHash has the expected format.
     */
    public static isValidOrderHash(orderHash: string): boolean {
        return isValidOrderHash(orderHash);
    }
    /**
     * A unit amount is defined as the amount of a token above the specified decimal places (integer part).
     * E.g: If a currency has 18 decimal places, 1e18 or one quintillion of the currency is equivalent
     * to 1 unit.
     * @param   amount      The amount in baseUnits that you would like converted to units.
     * @param   decimals    The number of decimal places the unit amount has.
     * @return  The amount in units.
     */
    public static toUnitAmount(amount: BigNumber, decimals: number): BigNumber {
        assert.isValidBaseUnitAmount('amount', amount);
        assert.isNumber('decimals', decimals);
        const unitAmount = Web3Wrapper.toUnitAmount(amount, decimals);
        return unitAmount;
    }
    /**
     * A baseUnit is defined as the smallest denomination of a token. An amount expressed in baseUnits
     * is the amount expressed in the smallest denomination.
     * E.g: 1 unit of a token with 18 decimal places is expressed in baseUnits as 1000000000000000000
     * @param   amount      The amount of units that you would like converted to baseUnits.
     * @param   decimals    The number of decimal places the unit amount has.
     * @return  The amount in baseUnits.
     */
    public static toBaseUnitAmount(amount: BigNumber, decimals: number): BigNumber {
        assert.isBigNumber('amount', amount);
        assert.isNumber('decimals', decimals);
        const baseUnitAmount = Web3Wrapper.toBaseUnitAmount(amount, decimals);
        return baseUnitAmount;
    }
    /**
     * Instantiates a new ZeroEx instance that provides the public interface to the 0x.js library.
     * @param   provider    The Provider instance you would like the 0x.js library to use for interacting with
     *                      the Ethereum network.
     * @param   config      The configuration object. Look up the type for the description.
     * @return  An instance of the 0x.js ZeroEx class.
     */
    constructor(provider: Provider, config: ZeroExContractConfig) {
        assert.isWeb3Provider('provider', provider);
        this._contractWrappers = new ContractWrappers(provider, config);

        this.proxy = this._contractWrappers.proxy;
        this.token = this._contractWrappers.token;
        this.exchange = this._contractWrappers.exchange;
        this.tokenRegistry = this._contractWrappers.tokenRegistry;
        this.etherToken = this._contractWrappers.etherToken;
    }
    /**
     * Sets a new web3 provider for 0x.js. Updating the provider will stop all
     * subscriptions so you will need to re-subscribe to all events relevant to your app after this call.
     * @param   provider    The Web3Provider you would like the 0x.js library to use from now on.
     * @param   networkId   The id of the network your provider is connected to
     */
    public setProvider(provider: Provider, networkId: number): void {
        this._contractWrappers.setProvider(provider, networkId);
    }
    /**
     * Get the provider instance currently used by 0x.js
     * @return  Web3 provider instance
     */
    public getProvider(): Provider {
        return this._contractWrappers.getProvider();
    }
    /**
     * Get user Ethereum addresses available through the supplied web3 provider available for sending transactions.
     * @return  An array of available user Ethereum addresses.
     */
    public async getAvailableAddressesAsync(): Promise<string[]> {
        // Hack: Get Web3Wrapper from ZeroExContract
        const web3Wrapper: Web3Wrapper = (this._contractWrappers as any)._web3Wrapper;
        const availableAddresses = await web3Wrapper.getAvailableAddressesAsync();
        return availableAddresses;
    }
    /**
     * Signs an orderHash and returns it's elliptic curve signature.
     * This method currently supports TestRPC, Geth and Parity above and below V1.6.6
     * @param   orderHash       Hex encoded orderHash to sign.
     * @param   signerAddress   The hex encoded Ethereum address you wish to sign it with. This address
     *          must be available via the Provider supplied to 0x.js.
     * @param   shouldAddPersonalMessagePrefix  Some signers add the personal message prefix `\x19Ethereum Signed Message`
     *          themselves (e.g Parity Signer, Ledger, TestRPC) and others expect it to already be done by the client
     *          (e.g Metamask). Depending on which signer this request is going to, decide on whether to add the prefix
     *          before sending the request.
     * @return  An object containing the Elliptic curve signature parameters generated by signing the orderHash.
     */
    public async signOrderHashAsync(
        orderHash: string,
        signerAddress: string,
        shouldAddPersonalMessagePrefix: boolean,
    ): Promise<ECSignature> {
        return signOrderHashAsync(
            this._contractWrappers.getProvider(),
            orderHash,
            signerAddress,
            shouldAddPersonalMessagePrefix,
        );
    }
    /**
     * Waits for a transaction to be mined and returns the transaction receipt.
     * @param   txHash            Transaction hash
     * @param   pollingIntervalMs How often (in ms) should we check if the transaction is mined.
     * @param   timeoutMs         How long (in ms) to poll for transaction mined until aborting.
     * @return  Transaction receipt with decoded log args.
     */
    public async awaitTransactionMinedAsync(
        txHash: string,
        pollingIntervalMs = 1000,
        timeoutMs?: number,
    ): Promise<TransactionReceiptWithDecodedLogs> {
        // Hack: Get Web3Wrapper from ZeroExContract
        const web3Wrapper: Web3Wrapper = (this._contractWrappers as any)._web3Wrapper;
        const transactionReceiptWithDecodedLogs = await web3Wrapper.awaitTransactionMinedAsync(
            txHash,
            pollingIntervalMs,
            timeoutMs,
        );
        return transactionReceiptWithDecodedLogs;
    }
    /**
     * Instantiates and returns a new OrderWatcher instance.
     * Defaults to watching the pending state.
     * @param   config      The configuration object. Look up the type for the description.
     * @return  An instance of the 0x.js OrderWatcher class.
     */
    public async createOrderWatcherAsync(config?: OrderWatcherConfig): Promise<OrderWatcher> {
        // Hack: Get Web3Wrapper from ZeroExContract
        const web3Wrapper: Web3Wrapper = (this._contractWrappers as any)._web3Wrapper;
        const networkId = await web3Wrapper.getNetworkIdAsync();
        const provider = this._contractWrappers.getProvider();
        const orderWatcher = new OrderWatcher(provider, networkId, config);
        return orderWatcher;
    }
}