library TxHistoryLib {
    //
    // Structures
    // -----------------------------------------------------------------------------------------------------------------
    struct AssetEntry {
        int256 amount;
        uint256 blockNumber;
        address currencyCt;      //0 for ethers
        uint256 currencyId;
    }

    struct TxHistory {
        AssetEntry[] deposits;
        mapping(address => mapping(uint256 => AssetEntry[])) currencyDeposits;

        AssetEntry[] withdrawals;
        mapping(address => mapping(uint256 => AssetEntry[])) currencyWithdrawals;
    }

    //
    // Functions
    // -----------------------------------------------------------------------------------------------------------------
    function addDeposit(TxHistory storage self, int256 amount, address currencyCt, uint256 currencyId)
    internal
    {
        AssetEntry memory deposit = AssetEntry(amount, block.number, currencyCt, currencyId);
        self.deposits.push(deposit);
        self.currencyDeposits[currencyCt][currencyId].push(deposit);
    }

    function addWithdrawal(TxHistory storage self, int256 amount, address currencyCt, uint256 currencyId)
    internal
    {
        AssetEntry memory withdrawal = AssetEntry(amount, block.number, currencyCt, currencyId);
        self.withdrawals.push(withdrawal);
        self.currencyWithdrawals[currencyCt][currencyId].push(withdrawal);
    }

    //----

    function deposit(TxHistory storage self, uint index)
    internal
    view
    returns (int256 amount, uint256 blockNumber, address currencyCt, uint256 currencyId)
    {
        require(index < self.deposits.length);

        amount = self.deposits[index].amount;
        blockNumber = self.deposits[index].blockNumber;
        currencyCt = self.deposits[index].currencyCt;
        currencyId = self.deposits[index].currencyId;
    }

    function depositsCount(TxHistory storage self)
    internal
    view
    returns (uint256)
    {
        return self.deposits.length;
    }

    function currencyDeposit(TxHistory storage self, address currencyCt, uint256 currencyId, uint index)
    internal
    view
    returns (int256 amount, uint256 blockNumber)
    {
        require(index < self.currencyDeposits[currencyCt][currencyId].length);

        amount = self.currencyDeposits[currencyCt][currencyId][index].amount;
        blockNumber = self.currencyDeposits[currencyCt][currencyId][index].blockNumber;
    }

    function currencyDepositsCount(TxHistory storage self, address currencyCt, uint256 currencyId)
    internal
    view
    returns (uint256)
    {
        return self.currencyDeposits[currencyCt][currencyId].length;
    }

    //----

    function withdrawal(TxHistory storage self, uint index)
    internal
    view
    returns (int256 amount, uint256 blockNumber, address currencyCt, uint256 currencyId)
    {
        require(index < self.withdrawals.length);

        amount = self.withdrawals[index].amount;
        blockNumber = self.withdrawals[index].blockNumber;
        currencyCt = self.withdrawals[index].currencyCt;
        currencyId = self.withdrawals[index].currencyId;
    }

    function withdrawalsCount(TxHistory storage self)
    internal
    view
    returns (uint256)
    {
        return self.withdrawals.length;
    }

    function currencyWithdrawal(TxHistory storage self, address currencyCt, uint256 currencyId, uint index)
    internal
    view
    returns (int256 amount, uint256 blockNumber)
    {
        require(index < self.currencyWithdrawals[currencyCt][currencyId].length);

        amount = self.currencyWithdrawals[currencyCt][currencyId][index].amount;
        blockNumber = self.currencyWithdrawals[currencyCt][currencyId][index].blockNumber;
    }

    function currencyWithdrawalsCount(TxHistory storage self, address currencyCt, uint256 currencyId)
    internal
    view
    returns (uint256)
    {
        return self.currencyWithdrawals[currencyCt][currencyId].length;
    }
}
/*
 * Hubii Nahmii
 *
 * Compliant with the Hubii Nahmii specification v0.12.
 *
 * Copyright (C) 2017-2018 Hubii AS
 */
function deposit(TxHistory storage self, uint index)
internal
view
returns (int256 amount, uint256 blockNumber, address currencyCt, uint256 currencyId)
{
    require(index < self.deposits.length);

    amount = self.deposits[index].amount;
    blockNumber = self.deposits[index].blockNumber;
    currencyCt = self.deposits[index].currencyCt;
    currencyId = self.deposits[index].currencyId;
}

//----