// SPDX-License-Identifier: GPL-3.0-only
pragma solidity >0.7.0;
pragma experimental ABIEncoderV2;

/// @notice Different types of internal tokens
///  - UnderlyingToken: underlying asset for a cToken (except for Ether)
///  - cToken: Compound interest bearing token
///  - cETH: Special handling for cETH tokens
///  - Ether: the one and only
///  - NonMintable: tokens that do not have an underlying (therefore not cTokens)
enum TokenType {UnderlyingToken, cToken, cETH, Ether, NonMintable}

/// @notice Specifies the different trade action types in the system. Each trade action type is
/// encoded in a tightly packed bytes32 object. Trade action type is the first big endian byte of the
/// 32 byte trade action object. The schemas for each trade action type are defined below.
enum TradeActionType {
    // (uint8 TradeActionType, uint8 MarketIndex, uint88 fCashAmount, uint32 minImpliedRate, uint120 unused)
    Lend,
    // (uint8 TradeActionType, uint8 MarketIndex, uint88 fCashAmount, uint32 maxImpliedRate, uint128 unused)
    Borrow,
    // (uint8 TradeActionType, uint8 MarketIndex, uint88 assetCashAmount, uint32 minImpliedRate, uint32 maxImpliedRate, uint88 unused)
    AddLiquidity,
    // (uint8 TradeActionType, uint8 MarketIndex, uint88 assetCashAmount, uint32 minImpliedRate, uint32 maxImpliedRate, uint88 unused)
    RemoveLiquidity,
    // (uint8 TradeActionType, uint32 Maturity, int88 fCashResidualAmount, uint128 unused)
    PurchaseNTokenResidual,
    // (uint8 TradeActionType, address CounterpartyAddress, int88 fCashAmountToSettle)
    SettleCashDebt
}

/// @notice Specifies different deposit actions that can occur during BalanceAction or BalanceActionWithTrades
enum DepositActionType {
    // No deposit action
    None,
    // Deposit asset cash, depositActionAmount is specified in asset cash external precision
    DepositAsset,
    // Deposit underlying tokens that are mintable to asset cash, depositActionAmount is specified in underlying token
    // external precision
    DepositUnderlying,
    // Deposits specified asset cash external precision amount into an nToken and mints the corresponding amount of
    // nTokens into the account
    DepositAssetAndMintNToken,
    // Deposits specified underlying in external precision, mints asset cash, and uses that asset cash to mint nTokens
    DepositUnderlyingAndMintNToken,
    // Redeems an nToken balance to asset cash. depositActionAmount is specified in nToken precision. Considered a deposit action
    // because it deposits asset cash into an account. If there are fCash residuals that cannot be sold off, will revert.
    RedeemNToken,
    // Converts specified amount of asset cash balance already in Notional to nTokens. depositActionAmount is specified in
    // Notional internal 8 decimal precision.
    ConvertCashToNToken
}

/// @notice Used internally for PortfolioHandler state
enum AssetStorageState {NoChange, Update, Delete}

/****** Calldata objects ******/

/// @notice Defines a balance action for batchAction
struct BalanceAction {
    // Deposit action to take (if any)
    DepositActionType actionType;
    uint16 currencyId;
    // Deposit action amount must correspond to the depositActionType, see documentation above.
    uint256 depositActionAmount;
    // Withdraw an amount of asset cash specified in Notional internal 8 decimal precision
    uint256 withdrawAmountInternalPrecision;
    // If set to true, will withdraw entire cash balance. Useful if there may be an unknown amount of asset cash
    // residual left from trading.
    bool withdrawEntireCashBalance;
    // If set to true, will redeem asset cash to the underlying token on withdraw.
    bool redeemToUnderlying;
}

/// @notice Defines a balance action with a set of trades to do as well
struct BalanceActionWithTrades {
    DepositActionType actionType;
    uint16 currencyId;
    uint256 depositActionAmount;
    uint256 withdrawAmountInternalPrecision;
    bool withdrawEntireCashBalance;
    bool redeemToUnderlying;
    // Array of tightly packed 32 byte objects that represent trades. See TradeActionType documentation
    bytes32[] trades;
}

/****** In memory objects ******/
/// @notice Internal object that represents settled cash balances
struct SettleAmount {
    uint256 currencyId;
    int256 netCashChange;
}

/// @notice Internal object that represents a token
struct Token {
    address tokenAddress;
    bool hasTransferFee;
    int256 decimals;
    TokenType tokenType;
}

/// @notice Internal object that represents an nToken portfolio
struct nTokenPortfolio {
    CashGroupParameters cashGroup;
    PortfolioState portfolioState;
    int256 totalSupply;
    int256 cashBalance;
    uint256 lastInitializedTime;
    bytes6 parameters;
    address tokenAddress;
}

/// @notice Internal object used during liquidation
struct LiquidationFactors {
    address account;
    // Aggregate free collateral of the account denominated in ETH underlying, 8 decimal precision
    int256 netETHValue;
    // Amount of net local currency asset cash before haircuts and buffers available
    int256 localAssetAvailable;
    // Amount of net collateral currency asset cash before haircuts and buffers available
    int256 collateralAssetAvailable;
    // Haircut value of nToken holdings denominated in asset cash, will be local or collateral nTokens based
    // on liquidation type
    int256 nTokenHaircutAssetValue;
    // nToken parameters for calculating liquidation amount
    bytes6 nTokenParameters;
    // ETH exchange rate from local currency to ETH
    ETHRate localETHRate;
    // ETH exchange rate from collateral currency to ETH
    ETHRate collateralETHRate;
    // Asset rate for the local currency, used in cross currency calculations to calculate local asset cash required
    AssetRateParameters localAssetRate;
    // Used during currency liquidations if the account has liquidity tokens
    CashGroupParameters cashGroup;
    // Used during currency liquidations if the account has liquidity tokens
    MarketParameters[] markets;
}

/// @notice Internal asset array portfolio state
struct PortfolioState {
    // Array of currently stored assets
    PortfolioAsset[] storedAssets;
    // Array of new assets to add
    PortfolioAsset[] newAssets;
    uint256 lastNewAssetIndex;
    // Holds the length of stored assets after accounting for deleted assets
    uint256 storedAssetLength;
}

/// @notice In memory ETH exchange rate used during free collateral calculation.
struct ETHRate {
    // The decimals (i.e. 10^rateDecimalPlaces) of the exchange rate
    int256 rateDecimals;
    // The exchange rate from base to ETH (if rate invert is required it is already done)
    int256 rate;
    // Amount of buffer to apply to the exchange rate for negative balances.
    int256 buffer;
    // Amount of haircut to apply to the exchange rate for positive balances
    int256 haircut;
    // Liquidation discount for this currency
    int256 liquidationDiscount;
}

/// @notice Internal object used to handle balance state during a transaction
struct BalanceState {
    uint256 currencyId;
    // Cash balance stored in balance state at the beginning of the transaction
    int256 storedCashBalance;
    // nToken balance stored at the beginning of the transaction
    int256 storedNTokenBalance;
    // The net cash change as a result of asset settlement or trading
    int256 netCashChange;
    // Net asset transfers into or out of the account
    int256 netAssetTransferInternalPrecision;
    // Net token transfers into or out of the account
    int256 netNTokenTransfer;
    // Net token supply change from minting or redeeming
    int256 netNTokenSupplyChange;
    // The last time incentives were claimed for this currency
    uint256 lastClaimTime;
    // The last supply amount when tokens were claimed
    uint256 lastClaimSupply;
}

/// @dev Asset rate used to convert between underlying cash and asset cash
struct AssetRateParameters {
    // Address of the asset rate oracle
    address rateOracle;
    // The exchange rate from base to quote (if invert is required it is already done)
    int256 rate;
    // The decimals of the underlying, the rate converts to the underlying decimals
    int256 underlyingDecimals;
}

/// @dev Cash group when loaded into memory
struct CashGroupParameters {
    uint256 currencyId;
    uint256 maxMarketIndex;
    AssetRateParameters assetRate;
    bytes32 data;
}

/// @dev A portfolio asset when loaded in memory
struct PortfolioAsset {
    // Asset currency id
    uint256 currencyId;
    uint256 maturity;
    // Asset type, fCash or liquidity token.
    uint256 assetType;
    // fCash amount or liquidity token amount
    int256 notional;
    // Used for managing portfolio asset state
    uint256 storageSlot;
    // The state of the asset for when it is written to storage
    AssetStorageState storageState;
}

/// @dev Market object as represented in memory
struct MarketParameters {
    bytes32 storageSlot;
    uint256 maturity;
    // Total amount of fCash available for purchase in the market.
    int256 totalfCash;
    // Total amount of cash available for purchase in the market.
    int256 totalAssetCash;
    // Total amount of liquidity tokens (representing a claim on liquidity) in the market.
    int256 totalLiquidity;
    // This is the implied rate that we use to smooth the anchor rate between trades.
    uint256 lastImpliedRate;
    // This is the oracle rate used to value fCash and prevent flash loan attacks
    uint256 oracleRate;
    // This is the timestamp of the previous trade
    uint256 previousTradeTime;
    // Used to determine if the market has been updated
    bytes1 storageState;
}

/// @dev Simplified market object used during settlement
struct SettlementMarket {
    bytes32 storageSlot;
    // Total amount of fCash available for purchase in the market.
    int256 totalfCash;
    // Total amount of cash available for purchase in the market.
    int256 totalAssetCash;
    // Total amount of liquidity tokens (representing a claim on liquidity) in the market.
    int256 totalLiquidity;
    // Un parsed market data used for storage
    bytes32 data;
}

/// @dev Used during settling bitmap assets for calculating bitmap shifts
struct SplitBitmap {
    bytes32 dayBits;
    bytes32 weekBits;
    bytes32 monthBits;
    bytes32 quarterBits;
}

/****** Storage objects ******/

/// @dev Token object in storage
struct TokenStorage {
    // Address of the token
    address tokenAddress;
    // Transfer fees will change token deposit behavior
    bool hasTransferFee;
    TokenType tokenType;
}

/// @dev Exchange rate object as it is represented in storage, total storage is 25 bytes.
struct ETHRateStorage {
    // Address of the rate oracle
    address rateOracle;
    // The decimal places of precision that the rate oracle uses
    uint8 rateDecimalPlaces;
    // True of the exchange rate must be inverted
    bool mustInvert;
    // NOTE: both of these governance values are set with BUFFER_DECIMALS precision
    // Amount of buffer to apply to the exchange rate for negative balances.
    uint8 buffer;
    // Amount of haircut to apply to the exchange rate for positive balances
    uint8 haircut;
    // Liquidation discount in percentage point terms, 106 means a 6% discount
    uint8 liquidationDiscount;
}

/// @dev Asset rate object as it is represented in storage, total storage is 21 bytes.
struct AssetRateStorage {
    // Address of the rate oracle
    address rateOracle;
    // The decimal places of the underlying asset
    uint8 underlyingDecimalPlaces;
}

/// @dev Governance parameters for a cash group, total storage is 7 bytes + 9 bytes for liquidity token haircuts
/// and 9 bytes for rate scalars, total of 25 bytes. Note that this is stored packed in the storage slot so there
/// are no indexes stored for liquidityTokenHaircuts or rateScalars, maxMarketIndex is used instead to determine the
/// length.
struct CashGroupSettings {
    // Index of the AMMs on chain that will be made available. Idiosyncratic fCash
    // that is dated less than the longest AMM will be tradable.
    uint8 maxMarketIndex;
    // Time window in minutes that the rate oracle will be averaged over
    uint8 rateOracleTimeWindowMin;
    // Total fees per trade, specified in BPS
    uint8 totalFeeBPS;
    // Share of the fees given to the protocol, denominated in percentage
    uint8 reserveFeeShare;
    // Debt buffer specified in 5 BPS increments
    uint8 debtBuffer5BPS;
    // fCash haircut specified in 5 BPS increments
    uint8 fCashHaircut5BPS;
    // If an account has a negative cash balance, it can be settled by incurring debt at the 3 month market. This
    // is the basis points for the penalty rate that will be added the current 3 month oracle rate.
    uint8 settlementPenaltyRate5BPS;
    // If an account has fCash that is being liquidated, this is the discount that the liquidator can purchase it for
    uint8 liquidationfCashHaircut5BPS;
    // If an account has fCash that is being liquidated, this is the discount that the liquidator can purchase it for
    uint8 liquidationDebtBuffer5BPS;
    // Liquidity token haircut applied to cash claims, specified as a percentage between 0 and 100
    uint8[] liquidityTokenHaircuts;
    // Rate scalar used to determine the slippage of the market
    uint8[] rateScalars;
}

/// @dev Holds account level context information used to determine settlement and
/// free collateral actions. Total storage is 28 bytes
struct AccountContext {
    // Used to check when settlement must be triggered on an account
    uint40 nextSettleTime;
    // For lenders that never incur debt, we use this flag to skip the free collateral check.
    bytes1 hasDebt;
    // Length of the account's asset array
    uint8 assetArrayLength;
    // If this account has bitmaps set, this is the corresponding currency id
    uint16 bitmapCurrencyId;
    // 9 total active currencies possible (2 bytes each)
    bytes18 activeCurrencies;
}

/// @dev Used in view methods to return account balances in a developer friendly manner
struct AccountBalance {
    uint256 currencyId;
    int256 cashBalance;
    int256 nTokenBalance;
    uint256 lastClaimTime;
    uint256 lastClaimSupplyAmount;
}