pragma solidity ^0.4.6;


/*
    Copyright 2016, Jordi Baylina

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/// @title Vault Contract
/// @author Jordi Baylina
/// @notice This contract holds funds for Campaigns and automates payments. For
///  this iteration the funds will come straight from the Giveth Multisig as a
///  safety precaution, but once fully tested and optimized this contract will
///  be a safe place to store funds equipped with optional variable time delays
///  to allow for an optional escape hatch

/// @dev `Owned` is a base level contract that assigns an `owner` that can be
///  later changed
contract Owned {
    /// @dev `owner` is the only address that can call a function with this
    /// modifier
    modifier onlyOwner { if (msg.sender != owner) throw; _; }

    address public owner;

    /// @notice The Constructor assigns the message sender to be `owner`
    function Owned() { owner = msg.sender;}

    /// @notice `owner` can step down and assign some other address to this role
    /// @param _newOwner The address of the new owner. 0x0 can be used to create
    ///  an unowned neutral vault, however that cannot be undone
    function changeOwner(address _newOwner) onlyOwner {
        owner = _newOwner;
    }
}
/// @dev `Escapable` is a base level contract built off of the `Owned`
///  contract that creates an escape hatch function to send its ether to
///  `escapeDestination` when called by the `escapeCaller` in the case that
///  something unexpected happens
contract Escapable is Owned {
    address public escapeCaller;
    address public escapeDestination;

    /// @notice The Constructor assigns the `escapeDestination` and the
    ///  `escapeCaller`
    /// @param _escapeDestination The address of a safe location (usu a
    ///  Multisig) to send the ether held in this contract
    /// @param _escapeCaller The address of a trusted account or contract to
    ///  call `escapeHatch()` to send the ether in this contract to the
    ///  `escapeDestination` it would be ideal that `escapeCaller` cannot move
    ///  funds out of `escapeDestination`
    function Escapable(address _escapeCaller, address _escapeDestination) {
        escapeDestination = _escapeDestination;
        escapeCaller = _escapeCaller;
    }

    /// @dev The addresses preassigned the `escapeCaller` role
    ///  is the only addresses that can call a function with this modifier
    modifier onlyEscapeCallerOrOwner {
        if ((msg.sender != escapeCaller)&&(msg.sender != owner))
            throw;
        _;
    }

    /// @notice The `escapeHatch()` should only be called as a last resort if a
    /// security issue is uncovered or something unexpected happened
    function escapeHatch() onlyEscapeCallerOrOwner {
        uint total = this.balance;
        // Send the total balance of this contract to the `escapeDestination`
        if (!escapeDestination.send(total)) {
            throw;
        }
        EscapeCalled(total);
    }
    /// @notice Changes the address assigned to call `escapeHatch()`
    /// @param _newEscapeCaller The address of a trusted account or contract to
    ///  call `escapeHatch()` to send the ether in this contract to the
    ///  `escapeDestination` it would be ideal that `escapeCaller` cannot
    ///  move funds out of `escapeDestination`
    function changeEscapeCaller(address _newEscapeCaller) onlyEscapeCallerOrOwner {
        escapeCaller = _newEscapeCaller;
    }

    event EscapeCalled(uint amount);
}

/// @dev `Vault` is a higher level contract built off of the `Escapable`
///  contract that holds funds for Campaigns and automates payments.
contract Vault is Escapable {

    /// @dev `Payment` is a public structure that describes the details of
    ///  each payment making it easy to track the movement of funds
    ///  transparently
    struct Payment {
        string description;     // What is the purpose of this payment
        address spender;        // Who is sending the funds
        uint earliestPayTime;   // The earliest a payment can be made (Unix Time)
        bool canceled;         // If True then the payment has been canceled
        bool paid;              // If True then the payment has been paid
        address recipient;      // Who is receiving the funds
        uint amount;            // The amount of wei sent in the payment
        uint securityGuardDelay;// The seconds `securityGuard` can delay payment
    }

    Payment[] public authorizedPayments;

    address public securityGuard;
    uint public absoluteMinTimeLock;
    uint public timeLock;
    uint public maxSecurityGuardDelay;

    /// @dev The white list of approved addresses allowed to set up && receive
    ///  payments from this vault
    mapping (address => bool) public allowedSpenders;

    /// @dev The address assigned the role of `securityGuard` is the only
    ///  addresses that can call a function with this modifier
    modifier onlySecurityGuard { if (msg.sender != securityGuard) throw; _; }

    // @dev Events to make the payment movements easy to find on the blockchain
    event PaymentAuthorized(uint idPayment, address recipient, uint amount);
    event PaymentExecuted(uint idPayment, address recipient, uint amount);
    event PaymentCanceled(uint idPayment);
    event EtherReceived(address from, uint amount);
    event SpenderAuthorization(address spender, bool authorized);

/////////
// Constuctor
/////////

    /// @notice The Constructor creates the Vault on the blockchain
    /// @param _escapeCaller The address of a trusted account or contract to
    ///  call `escapeHatch()` to send the ether in this contract to the
    ///  `escapeDestination` it would be ideal if `escapeCaller` cannot move
    ///  funds out of `escapeDestination`
    /// @param _escapeDestination The address of a safe location (usu a
    ///  Multisig) to send the ether held in this contract in an emergency
    /// @param _absoluteMinTimeLock The minimum number of seconds `timelock` can
    ///  be set to, if set to 0 the `owner` can remove the `timeLock` completely
    /// @param _timeLock Initial number of seconds that payments are delayed
    ///  after they are authorized (a security precaution)
    /// @param _securityGuard Address that will be able to delay the payments
    ///  beyond the initial timelock requirements; can be set to 0x0 to remove
    ///  the `securityGuard` functionality
    /// @param _maxSecurityGuardDelay The maximum number of seconds in total
    ///   that `securityGuard` can delay a payment so that the owner can cancel
    ///   the payment if needed
    function Vault(
        address _escapeCaller,
        address _escapeDestination,
        uint _absoluteMinTimeLock,
        uint _timeLock,
        address _securityGuard,
        uint _maxSecurityGuardDelay) Escapable(_escapeCaller, _escapeDestination)
    {
        securityGuard = _securityGuard;
        timeLock = _timeLock;
        absoluteMinTimeLock = _absoluteMinTimeLock;
        maxSecurityGuardDelay = _maxSecurityGuardDelay;
    }


    /// @notice States the total number of authorized payments in this contract
    function numberOfAuthorizedPayments() constant returns (uint) {
        return authorizedPayments.length;
    }

//////
// Receive Ether
//////

    /// @notice Called anytime ether is sent to the contract && creates an event
    /// to more easily track the incoming transactions
    function receiveEther() payable {
        EtherReceived(msg.sender, msg.value);
    }

    /// @notice The fall back function is called whenever ether is sent to this
    ///  contract
    function () payable {
        receiveEther();
    }

////////
// Spender Interface
////////

    /// @notice only `allowedSpenders[]` Creates a new `Payment`
    /// @param _description Brief description of the payment that is authorized
    /// @param _recipient Destination of the payment
    /// @param _amount Amount to be paid in wei
    /// @param _paymentDelay Number of seconds the payment is to be delayed, if
    ///  this value is below `timeLock` then the `timeLock` determines the delay
    function authorizePayment(
        string _description,
        address _recipient,
        uint _amount,
        uint _paymentDelay
    ) returns(uint) {

        // Fail if you arent on the `allowedSpenders` white list
        if (!allowedSpenders[msg.sender] ) throw;
        uint idPayment = authorizedPayments.length;       // Unique Payment ID
        authorizedPayments.length++;

        // The following lines fill out the payment struct
        Payment p = authorizedPayments[idPayment];
        p.spender = msg.sender;

        // Determines the earliest the recipient can receive payment (Unix time)
        p.earliestPayTime = _paymentDelay >= timeLock ?
                                now + _paymentDelay :
                                now + timeLock;
        p.recipient = _recipient;
        p.amount = _amount;
        p.description = _description;
        PaymentAuthorized(idPayment, p.recipient, p.amount);
        return idPayment;
    }

    /// @notice only `allowedSpenders[]` The recipient of a payment calls this
    ///  function to send themselves the ether after the `earliestPayTime` has
    ///  expired
    /// @param _idPayment The payment ID to be executed
    function collectAuthorizedPayment(uint _idPayment) {

        // Check that the `_idPayment` has been added to the payments struct
        if (_idPayment >= authorizedPayments.length) throw;

        Payment p = authorizedPayments[_idPayment];

        // Checking for reasons not to execute the payment
        if (msg.sender != p.recipient) throw;
        if (!allowedSpenders[p.spender]) throw;
        if (now < p.earliestPayTime) throw;
        if (p.canceled) throw;
        if (p.paid) throw;
        if (this.balance < p.amount) throw;

        p.paid = true; // Set the payment to being paid
        if (!p.recipient.send(p.amount)) {  // Make the payment
            throw;
        }
        PaymentExecuted(_idPayment, p.recipient, p.amount);
     }

/////////
// SecurityGuard Interface
/////////

    /// @notice `onlySecurityGuard` Delays a payment for a set number of seconds
    /// @param _idPayment ID of the payment to be delayed
    /// @param _delay The number of seconds to delay the payment
    function delayPayment(uint _idPayment, uint _delay) onlySecurityGuard {
        if (_idPayment >= authorizedPayments.length) throw;

        Payment p = authorizedPayments[_idPayment];

        if ((p.securityGuardDelay + _delay > maxSecurityGuardDelay) ||
            (p.paid) ||
            (p.canceled))
            throw;

        p.securityGuardDelay += _delay;
        p.earliestPayTime += _delay;
    }

////////
// Owner Interface
///////

    /// @notice `onlyOwner` Cancel a payment all together
    /// @param _idPayment ID of the payment to be canceled.
    function cancelPayment(uint _idPayment) onlyOwner {
        if (_idPayment >= authorizedPayments.length) throw;

        Payment p = authorizedPayments[_idPayment];


        if (p.canceled) throw;
        if (p.paid) throw;

        p.canceled = true;
        PaymentCanceled(_idPayment);
    }

    /// @notice `onlyOwner` Adds a spender to the `allowedSpenders[]` white list
    /// @param _spender The address of the contract being authorized/unauthorized
    /// @param _authorize `true` if authorizing and `false` if unauthorizing
    function authorizeSpender(address _spender, bool _authorize) onlyOwner {
        allowedSpenders[_spender] = _authorize;
        SpenderAuthorization(_spender, _authorize);
    }

    /// @notice `onlyOwner` Sets the address of `securityGuard`
    /// @param _newSecurityGuard Address of the new security guard
    function setSecurityGuard(address _newSecurityGuard) onlyOwner {
        securityGuard = _newSecurityGuard;
    }


    /// @notice `onlyOwner` Changes `timeLock`; the new `timeLock` cannot be
    ///  lower than `absoluteMinTimeLock`
    /// @param _newTimeLock Sets the new minimum default `timeLock` in seconds;
    ///  pending payments maintain their `earliestPayTime`
    function setTimelock(uint _newTimeLock) onlyOwner {
        if (_newTimeLock < absoluteMinTimeLock) throw;
        timeLock = _newTimeLock;
    }

    /// @notice `onlyOwner` Changes the maximum number of seconds
    /// `securityGuard` can delay a payment
    /// @param _maxSecurityGuardDelay The new maximum delay in seconds that
    ///  `securityGuard` can delay the payment's execution in total
    function setMaxSecurityGuardDelay(uint _maxSecurityGuardDelay) onlyOwner {
        maxSecurityGuardDelay = _maxSecurityGuardDelay;
    }
}