// Contract: IFOInitializable
// Target function: function harvestPool(uint8 _pid) external override nonReentrant notContract
 the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
        // for accounts without code, i.e. `keccak256('')`
        bytes32 codehash;
        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly { codehash := extcodehash(account) }
        return (codehash != accountHash && codehash != 0x0);
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
}


/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves.

        // A Solidity high level call has three parts:
        //  1. The target address is checked to verify it contains contract code
        //  2. The call itself is made, and success asserted
        //  3. The return value is decoded, which in turn checks the size of the returned data.
        // solhint-disable-next-line max-line-length
        require(address(token).isContract(), "SafeERC20: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "SafeERC20: low-level call failed");

        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

/** @title IIFOV2.
 * @notice It is an interface for IFOV2.sol
 */
interface IIFOV2 {
    /**
     * @notice It allows users to deposit LP tokens to pool
     * @param _amount: the number of LP token used (18 decimals)
     * @param _pid: poolId
     */
    function depositPool(uint256 _amount, uint8 _pid) external;

    /**
     * @notice It allows users to harvest from pool
     * @param _pid: poolId
     */
    function harvestPool(uint8 _pid) external;

    /**
     * @notice It allows the admin to withdraw funds
     * @param _lpAmount: the number of LP token to withdraw (18 decimals)
     * @param _offerAmount: the number of offering amount to withdraw
     * @dev This function is only callable by admin.
     */
    function finalWithdraw(uint256 _lpAmount, uint256 _offerAmount) external;

    /**
     * @notice It sets parameters for pool
     * @param _offeringAmountPool: offering amount (in tokens)
     * @param _raisingAmountPool: raising amount (in LP tokens)
     * @param _limitPerUserInLP: limit per user (in LP tokens)
     * @param _hasTax: if the pool has a tax
     * @param _pid: poolId
     * @dev This function is only callable by admin.
     */
    function setPool(
        uint256 _offeringAmountPool,
        uint256 _raisingAmountPool,
        uint256 _limitPerUserInLP,
        bool _hasTax,
        uint8 _pid
    ) external;


    /**
     * @notice It returns the pool information
     * @param _pid: poolId
     */
    function viewPoolInformation(uint256 _pid)
        external
        view
        returns (
            uint256,
            uint256,
            uint256,
            bool,
            uint256,
            uint256
        );

    /**
     * @notice It returns the tax overflow rate calculated for a pool
     * @dev 100,000 means 0.1(10%)/ 1 means 0.000001(0.0001%)/ 1,000,000 means 1(100%)
     * @param _pid: poolId
     * @return It returns the tax percentage
     */
    function viewPoolTaxRateOverflow(uint256 _pid) external view returns (uint256);

    /**
     * @notice External view function to see user information
     * @param _user: user address
     * @param _pids[]: array of pids
     */
    function viewUserInfo(address _user, uint8[] calldata _pids)
        external
        view
        returns (uint256[] memory, bool[] memory);

    /**
     * @notice External view function to see user allocations for both pools
     * @param _user: user address
     * @param _pids[]: array of pids
     */
    function viewUserAllocationPools(address _user, uint8[] calldata _pids) external view returns (uint256[] memory);

    /**
     * @notice External view function to see user offering and refunding amounts for both pools
     * @param _user: user address
     * @param _pids: array of pids
     */
    function viewUserOfferingAndRefundingAmountsForPools(address _user, uint8[] calldata _pids)
        external
        view
        returns (uint256[3][] memory);
}


/**
 * @title IFOInitializable
 */

contract IFOInitializable is IIFOV2, ReentrancyGuard, Ownable {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    // The LP token used
    IERC20 public lpToken;

    // The offering token
    IERC20 public offeringToken;

    // Number of pools
    uint8 public constant numberPools = 2;

    // The address of the smart chef factory
    address public immutable IFO_FACTORY;

    // The block number when IFO starts
    uint256 public startBlock;

    // The block number when IFO ends
    uint256 public endBlock;

    // Whether it is initialized
    bool public isInitialized;

    // Array of PoolCharacteristics of size numberPools
    PoolCharacteristics[numberPools] private _poolInformation;

    // It maps the address to pool id to UserInfo
    mapping(address => mapping(uint8 => UserInfo)) private _userInfo;

    // Struct that contains each pool characteristics
    struct PoolCharacteristics {
        uint256 raisingAmountPool; // amount of tokens raised for the pool (in LP tokens)
        uint256 offeringAmountPool; // amount of tokens offered for the pool (in offeringTokens)
        uint256 limitPerUserInLP; // limit of tokens per user (if 0, it is ignored)
        bool hasTax; // tax on the overflow (if any, it works with _calculateTaxOverflow)
        uint256 totalAmountPool; // total amount pool deposited (in LP tokens)
        uint256 sumTaxesOverflow; // total taxes collected (starts at 0, increases with each harvest if overflow)
    }

    // Struct that contains each user information for both pools
    struct UserInfo {
        uint256 amountPool; // How many tokens the user has provided for pool
        bool claimedPool; // Whether the user has claimed (default: false) for pool
    }

    // Admin withdraw events
    event AdminWithdraw(uint256 amountLP, uint256 amountOfferingToken);

    // Admin recovers token
    event AdminTokenRecovery(address tokenAddress, uint256 amountTokens);

    // Deposit event
    event Deposit(address indexed user, uint256 amount, uint8 indexed pid);

    // Harvest event
    event Harvest(address indexed user, uint256 offeringAmount, uint256 excessAmount, uint8 indexed pid);

    // Event for new start & end blocks
    event NewStartAndEndBlocks(uint256 startBlock, uint256 endBlock);

    // Event when parameters are set for one of the pools
    event PoolParametersSet(uint256 offeringAmountPool, uint256 raisingAmountPool, uint8 pid);

    // Modifier to prevent contracts to participate
    modifier notContract() {
        require(!_isContract(msg.sender), "contract not allowed");
        require(msg.sender == tx.origin, "proxy contract not allowed");
        _;
    }

    /**
     * @notice Constructor
     */
    constructor() public {
        IFO_FACTORY = msg.sender;
    }

    /**
     * @notice It initializes the contract
     * @dev It can only be called once.
     * @param _lpToken: the LP token used
     * @param _offeringToken: the token that is offered for the IFO
     * @param _startBlock: the start block for the IFO
     * @param _endBlock: the end block for the IFO
     * @param _adminAddress: the admin address for handling tokens
     */
    function initialize(
        address _lpToken,
        address _offeringToken,
        uint256 _startBlock,
        uint256 _endBlock,
        address _adminAddress
    ) public {
        require(!isInitialized, "Operations: Already initialized");
        require(msg.sender == IFO_FACTORY, "Operations: Not factory");

        // Make this contract initialized
        isInitialized = true;

        lpToken = IERC20(_lpToken);
        offeringToken = IERC20(_offeringToken);
        startBlock = _startBlock;
        endBlock = _endBlock;

        // Transfer ownership to admin
        transferOwnership(_adminAddress);
    }

    /**
     * @notice It allows users to deposit LP tokens to pool
     * @param _amount: the number of LP token used (18 decimals)
     * @param _pid: pool id
     */
    function depositPool(uint256 _amount, uint8 _pid) external override nonReentrant notContract {
        // Checks whether the pool id is valid
        require(_pid < numberPools, "Deposit: Non valid pool id");

        // Checks that pool was set
        require(
            _poolInformation[_pid].offeringAmountPool > 0 && _poolInformation[_pid].raisingAmountPool > 0,
            "Deposit: Pool not set"
        );

        // Checks whether the block number is not too early
        require(block.number > startBlock, "Deposit: Too early");

        // Checks whether the block number is not too late
        require(block.number < endBlock, "Deposit: Too late");

        // Checks that the amount deposited is not inferior to 0
        require(_amount > 0, "Deposit: Amount must be > 0");

        // Transfers funds to this contract
        lpToken.safeTransferFrom(address(msg.sender), address(this), _amount);

        // Update the user status
        _userInfo[msg.sender][_pid].amountPool = _userInfo[msg.sender][_pid].amountPool.add(_amount);

        // Check if the pool has a limit per user
        if (_poolInformation[_pid].limitPerUserInLP > 0) {
            // Checks whether the limit has been reached
            require(
                _userInfo[msg.sender][_pid].amountPool <= _poolInformation[_pid].limitPerUserInLP,
                "Deposit: New amount above user limit"
            );
        }

        // Updates the totalAmount for pool
        _poolInformation[_pid].totalAmountPool = _poolInformation[_pid].totalAmountPool.add(_amount);

        emit Deposit(msg.sender, _amount, _pid);
    }