EthereumAlarmClock

// Submitted by EthereumHistory (ethereumhistory.com)
// Grove v0.2

/// @title GroveLib - Library for queriable indexed ordered data.
/// @author PiperMerriam - <pipermerriam@gmail.com>
library GroveLib {
        /*
         *  Indexes for ordered data
         *
         *  Address: 0x873fd7d0657079da141d5705989d10ca555ba990
         */
        struct Index {
                bytes32 root;
                mapping (bytes32 => Node) nodes;
        }

        struct Node {
                bytes32 id;
                int value;
                bytes32 parent;
                bytes32 left;
                bytes32 right;
                uint height;
        }

        function max(uint a, uint b) internal returns (uint) {
            if (a >= b) {
                return a;
            }
            return b;
        }

        /*
         *  Node getters
         */
        /// @dev Retrieve the unique identifier for the node.
        /// @param index The index that the node is part of.
        /// @param id The id for the node to be looked up.
        function getNodeId(Index storage index, bytes32 id) constant returns (bytes32) {
            return index.nodes[id].id;
        }

        /// @dev Retrieve the value for the node.
        /// @param index The index that the node is part of.
        /// @param id The id for the node to be looked up.
        function getNodeValue(Index storage index, bytes32 id) constant returns (int) {
            return index.nodes[id].value;
        }

        /// @dev Retrieve the height of the node.
        /// @param index The index that the node is part of.
        /// @param id The id for the node to be looked up.
        function getNodeHeight(Index storage index, bytes32 id) constant returns (uint) {
            return index.nodes[id].height;
        }

        /// @dev Retrieve the parent id of the node.
        /// @param index The index that the node is part of.
        /// @param id The id for the node to be looked up.
        function getNodeParent(Index storage index, bytes32 id) constant returns (bytes32) {
            return index.nodes[id].parent;
        }

        /// @dev Retrieve the left child id of the node.
        /// @param index The index that the node is part of.
        /// @param id The id for the node to be looked up.
        function getNodeLeftChild(Index storage index, bytes32 id) constant returns (bytes32) {
            return index.nodes[id].left;
        }

        /// @dev Retrieve the right child id of the node.
        /// @param index The index that the node is part of.
        /// @param id The id for the node to be looked up.
        function getNodeRightChild(Index storage index, bytes32 id) constant returns (bytes32) {
            return index.nodes[id].right;
        }

        /// @dev Retrieve the node id of the next node in the tree.
        /// @param index The index that the node is part of.
        /// @param id The id for the node to be looked up.
        function getPreviousNode(Index storage index, bytes32 id) constant returns (bytes32) {
            Node storage currentNode = index.nodes[id];

            if (currentNode.id == 0x0) {
                // Unknown node, just return 0x0;
                return 0x0;
            }

            Node memory child;

            if (currentNode.left != 0x0) {
                // Trace left to latest child in left tree.
                child = index.nodes[currentNode.left];

                while (child.right != 0) {
                    child = index.nodes[child.right];
                }
                return child.id;
            }

            if (currentNode.parent != 0x0) {
                // Now we trace back up through parent relationships, looking
                // for a link where the child is the right child of it's
                // parent.
                Node storage parent = index.nodes[currentNode.parent];
                child = currentNode;

                while (true) {
                    if (parent.right == child.id) {
                        return parent.id;
                    }

                    if (parent.parent == 0x0) {
                        break;
                    }
                    child = parent;
                    parent = index.nodes[parent.parent];
                }
            }

            // This is the first node, and has no previous node.
            return 0x0;
        }

        /// @dev Retrieve the node id of the previous node in the tree.
        /// @param index The index that the node is part of.
        /// @param id The id for the node to be looked up.
        function getNextNode(Index storage index, bytes32 id) constant returns (bytes32) {
            Node storage currentNode = index.nodes[id];

            if (currentNode.id == 0x0) {
                // Unknown node, just return 0x0;
                return 0x0;
            }

            Node memory child;

            if (currentNode.right != 0x0) {
                // Trace right to earliest child in right tree.
                child = index.nodes[currentNode.right];

                while (child.left != 0) {
                    child = index.nodes[child.left];
                }
                return child.id;
            }

            if (currentNode.parent != 0x0) {
                // if the node is the left child of it's parent, then the
                // parent is the next one.
                Node storage parent = index.nodes[currentNode.parent];
                child = currentNode;

                while (true) {
                    if (parent.left == child.id) {
                        return parent.id;
                    }

                    if (parent.parent == 0x0) {
                        break;
                    }
                    child = parent;
                    parent = index.nodes[parent.parent];
                }

                // Now we need to trace all the way up checking to see if any parent is the 
            }

            // This is the final node.
            return 0x0;
        }

        /// @dev Updates or Inserts the id into the index at its appropriate location based on the value provided.
        /// @param index The index that the node is part of.
        /// @param id The unique identifier of the data element the index node will represent.
        /// @param value The value of the data element that represents it's total ordering with respect to other elementes.
        function insert(Index storage index, bytes32 id, int value) public {
                if (index.nodes[id].id == id) {
                    // A node with this id already exists.  If the value is
                    // the same, then just return early, otherwise, remove it
                    // and reinsert it.
                    if (index.nodes[id].value == value) {
                        return;
                    }
                    remove(index, id);
                }

                uint leftHeight;
                uint rightHeight;

                bytes32 previousNodeId = 0x0;

                if (index.root == 0x0) {
                    index.root = id;
                }
                Node storage currentNode = index.nodes[index.root];

                // Do insertion
                while (true) {
                    if (currentNode.id == 0x0) {
                        // This is a new unpopulated node.
                        currentNode.id = id;
                        currentNode.parent = previousNodeId;
                        currentNode.value = value;
                        break;
                    }

                    // Set the previous node id.
                    previousNodeId = currentNode.id;

                    // The new node belongs in the right subtree
                    if (value >= currentNode.value) {
                        if (currentNode.right == 0x0) {
                            currentNode.right = id;
                        }
                        currentNode = index.nodes[currentNode.right];
                        continue;
                    }

                    // The new node belongs in the left subtree.
                    if (currentNode.left == 0x0) {
                        currentNode.left = id;
                    }
                    currentNode = index.nodes[currentNode.left];
                }

                // Rebalance the tree
                _rebalanceTree(index, currentNode.id);
        }

        /// @dev Checks whether a node for the given unique identifier exists within the given index.
        /// @param index The index that should be searched
        /// @param id The unique identifier of the data element to check for.
        function exists(Index storage index, bytes32 id) constant returns (bool) {
            return (index.nodes[id].id == id);
        }

        /// @dev Remove the node for the given unique identifier from the index.
        /// @param index The index that should be removed
        /// @param id The unique identifier of the data element to remove.
        function remove(Index storage index, bytes32 id) public {
            Node storage replacementNode;
            Node storage parent;
            Node storage child;
            bytes32 rebalanceOrigin;

            Node storage nodeToDelete = index.nodes[id];

            if (nodeToDelete.id != id) {
                // The id does not exist in the tree.
                return;
            }

            if (nodeToDelete.left != 0x0 || nodeToDelete.right != 0x0) {
                // This node is not a leaf node and thus must replace itself in
                // it's tree by either the previous or next node.
                if (nodeToDelete.left != 0x0) {
                    // This node is guaranteed to not have a right child.
                    replacementNode = index.nodes[getPreviousNode(index, nodeToDelete.id)];
                }
                else {
                    // This node is guaranteed to not have a left child.
                    replacementNode = index.nodes[getNextNode(index, nodeToDelete.id)];
                }
                // The replacementNode is guaranteed to have a parent.
                parent = index.nodes[replacementNode.parent];

                // Keep note of the location that our tree rebalancing should
                // start at.
                rebalanceOrigin = replacementNode.id;

                // Join the parent of the replacement node with any subtree of
                // the replacement node.  We can guarantee that the replacement
                // node has at most one subtree because of how getNextNode and
                // getPreviousNode are used.
                if (parent.left == replacementNode.id) {
                    parent.left = replacementNode.right;
                    if (replacementNode.right != 0x0) {
                        child = index.nodes[replacementNode.right];
                        child.parent = parent.id;
                    }
                }
                if (parent.right == replacementNode.id) {
                    parent.right = replacementNode.left;
                    if (replacementNode.left != 0x0) {
                        child = index.nodes[replacementNode.left];
                        child.parent = parent.id;
                    }
                }

                // Now we replace the nodeToDelete with the replacementNode.
                // This includes parent/child relationships for all of the
                // parent, the left child, and the right child.
                replacementNode.parent = nodeToDelete.parent;
                if (nodeToDelete.parent != 0x0) {
                    parent = index.nodes[nodeToDelete.parent];
                    if (parent.left == nodeToDelete.id) {
                        parent.left = replacementNode.id;
                    }
                    if (parent.right == nodeToDelete.id) {
                        parent.right = replacementNode.id;
                    }
                }
                else {
                    // If the node we are deleting is the root node update the
                    // index root node pointer.
                    index.root = replacementNode.id;
                }

                replacementNode.left = nodeToDelete.left;
                if (nodeToDelete.left != 0x0) {
                    child = index.nodes[nodeToDelete.left];
                    child.parent = replacementNode.id;
                }

                replacementNode.right = nodeToDelete.right;
                if (nodeToDelete.right != 0x0) {
                    child = index.nodes[nodeToDelete.right];
                    child.parent = replacementNode.id;
                }
            }
            else if (nodeToDelete.parent != 0x0) {
                // The node being deleted is a leaf node so we only erase it's
                // parent linkage.
                parent = index.nodes[nodeToDelete.parent];

                if (parent.left == nodeToDelete.id) {
                    parent.left = 0x0;
                }
                if (parent.right == nodeToDelete.id) {
                    parent.right = 0x0;
                }

                // keep note of where the rebalancing should begin.
                rebalanceOrigin = parent.id;
            }
            else {
                // This is both a leaf node and the root node, so we need to
                // unset the root node pointer.
                index.root = 0x0;
            }

            // Now we zero out all of the fields on the nodeToDelete.
            nodeToDelete.id = 0x0;
            nodeToDelete.value = 0;
            nodeToDelete.parent = 0x0;
            nodeToDelete.left = 0x0;
            nodeToDelete.right = 0x0;

            // Walk back up the tree rebalancing
            if (rebalanceOrigin != 0x0) {
                _rebalanceTree(index, rebalanceOrigin);
            }
        }

        bytes2 constant GT = ">";
        bytes2 constant LT = "<";
        bytes2 constant GTE = ">=";
        bytes2 constant LTE = "<=";
        bytes2 constant EQ = "==";

        function _compare(int left, bytes2 operator, int right) internal returns (bool) {
            if (operator == GT) {
                return (left > right);
            }
            if (operator == LT) {
                return (left < right);
            }
            if (operator == GTE) {
                return (left >= right);
            }
            if (operator == LTE) {
                return (left <= right);
            }
            if (operator == EQ) {
                return (left == right);
            }

            // Invalid operator.
            throw;
        }

        function _getMaximum(Index storage index, bytes32 id) internal returns (int) {
                Node storage currentNode = index.nodes[id];

                while (true) {
                    if (currentNode.right == 0x0) {
                        return currentNode.value;
                    }
                    currentNode = index.nodes[currentNode.right];
                }
        }

        function _getMinimum(Index storage index, bytes32 id) internal returns (int) {
                Node storage currentNode = index.nodes[id];

                while (true) {
                    if (currentNode.left == 0x0) {
                        return currentNode.value;
                    }
                    currentNode = index.nodes[currentNode.left];
                }
        }

        /** @dev Query the index for the edge-most node that satisfies the
         *  given query.  For >, >=, and ==, this will be the left-most node
         *  that satisfies the comparison.  For < and <= this will be the
         *  right-most node that satisfies the comparison.
         */
        /// @param index The index that should be queried
        /** @param operator One of '>', '>=', '<', '<=', '==' to specify what
         *  type of comparison operator should be used.
         */
        function query(Index storage index, bytes2 operator, int value) public returns (bytes32) {
                bytes32 rootNodeId = index.root;
                
                if (rootNodeId == 0x0) {
                    // Empty tree.
                    return 0x0;
                }

                Node storage currentNode = index.nodes[rootNodeId];

                while (true) {
                    if (_compare(currentNode.value, operator, value)) {
                        // We have found a match but it might not be the
                        // *correct* match.
                        if ((operator == LT) || (operator == LTE)) {
                            // Need to keep traversing right until this is no
                            // longer true.
                            if (currentNode.right == 0x0) {
                                return currentNode.id;
                            }
                            if (_compare(_getMinimum(index, currentNode.right), operator, value)) {
                                // There are still nodes to the right that
                                // match.
                                currentNode = index.nodes[currentNode.right];
                                continue;
                            }
                            return currentNode.id;
                        }

                        if ((operator == GT) || (operator == GTE) || (operator == EQ)) {
                            // Need to keep traversing left until this is no
                            // longer true.
                            if (currentNode.left == 0x0) {
                                return currentNode.id;
                            }
                            if (_compare(_getMaximum(index, currentNode.left), operator, value)) {
                                currentNode = index.nodes[currentNode.left];
                                continue;
                            }
                            return currentNode.id;
                        }
                    }

                    if ((operator == LT) || (operator == LTE)) {
                        if (currentNode.left == 0x0) {
                            // There are no nodes that are less than the value
                            // so return null.
                            return 0x0;
                        }
                        currentNode = index.nodes[currentNode.left];
                        continue;
                    }

                    if ((operator == GT) || (operator == GTE)) {
                        if (currentNode.right == 0x0) {
                            // There are no nodes that are greater than the value
                            // so return null.
                            return 0x0;
                        }
                        currentNode = index.nodes[currentNode.right];
                        continue;
                    }

                    if (operator == EQ) {
                        if (currentNode.value < value) {
                            if (currentNode.right == 0x0) {
                                return 0x0;
                            }
                            currentNode = index.nodes[currentNode.right];
                            continue;
                        }

                        if (currentNode.value > value) {
                            if (currentNode.left == 0x0) {
                                return 0x0;
                            }
                            currentNode = index.nodes[currentNode.left];
                            continue;
                        }
                    }
                }
        }

        function _rebalanceTree(Index storage index, bytes32 id) internal {
            // Trace back up rebalancing the tree and updating heights as
            // needed..
            Node storage currentNode = index.nodes[id];

            while (true) {
                int balanceFactor = _getBalanceFactor(index, currentNode.id);

                if (balanceFactor == 2) {
                    // Right rotation (tree is heavy on the left)
                    if (_getBalanceFactor(index, currentNode.left) == -1) {
                        // The subtree is leaning right so it need to be
                        // rotated left before the current node is rotated
                        // right.
                        _rotateLeft(index, currentNode.left);
                    }
                    _rotateRight(index, currentNode.id);
                }

                if (balanceFactor == -2) {
                    // Left rotation (tree is heavy on the right)
                    if (_getBalanceFactor(index, currentNode.right) == 1) {
                        // The subtree is leaning left so it need to be
                        // rotated right before the current node is rotated
                        // left.
                        _rotateRight(index, currentNode.right);
                    }
                    _rotateLeft(index, currentNode.id);
                }

                if ((-1 <= balanceFactor) && (balanceFactor <= 1)) {
                    _updateNodeHeight(index, currentNode.id);
                }

                if (currentNode.parent == 0x0) {
                    // Reached the root which may be new due to tree
                    // rotation, so set it as the root and then break.
                    break;
                }

                currentNode = index.nodes[currentNode.parent];
            }
        }

        function _getBalanceFactor(Index storage index, bytes32 id) internal returns (int) {
                Node storage node = index.nodes[id];

                return int(index.nodes[node.left].height) - int(index.nodes[node.right].height);
        }

        function _updateNodeHeight(Index storage index, bytes32 id) internal {
                Node storage node = index.nodes[id];

                node.height = max(index.nodes[node.left].height, index.nodes[node.right].height) + 1;
        }

        function _rotateLeft(Index storage index, bytes32 id) internal {
            Node storage originalRoot = index.nodes[id];

            if (originalRoot.right == 0x0) {
                // Cannot rotate left if there is no right originalRoot to rotate into
                // place.
                throw;
            }

            // The right child is the new root, so it gets the original
            // `originalRoot.parent` as it's parent.
            Node storage newRoot = index.nodes[originalRoot.right];
            newRoot.parent = originalRoot.parent;

            // The original root needs to have it's right child nulled out.
            originalRoot.right = 0x0;

            if (originalRoot.parent != 0x0) {
                // If there is a parent node, it needs to now point downward at
                // the newRoot which is rotating into the place where `node` was.
                Node storage parent = index.nodes[originalRoot.parent];

                // figure out if we're a left or right child and have the
                // parent point to the new node.
                if (parent.left == originalRoot.id) {
                    parent.left = newRoot.id;
                }
                if (parent.right == originalRoot.id) {
                    parent.right = newRoot.id;
                }
            }

            if (newRoot.left != 0) {
                // If the new root had a left child, that moves to be the
                // new right child of the original root node
                Node storage leftChild = index.nodes[newRoot.left];
                originalRoot.right = leftChild.id;
                leftChild.parent = originalRoot.id;
            }

            // Update the newRoot's left node to point at the original node.
            originalRoot.parent = newRoot.id;
            newRoot.left = originalRoot.id;

            if (newRoot.parent == 0x0) {
                index.root = newRoot.id;
            }

            // TODO: are both of these updates necessary?
            _updateNodeHeight(index, originalRoot.id);
            _updateNodeHeight(index, newRoot.id);
        }

        function _rotateRight(Index storage index, bytes32 id) internal {
            Node storage originalRoot = index.nodes[id];

            if (originalRoot.left == 0x0) {
                // Cannot rotate right if there is no left node to rotate into
                // place.
                throw;
            }

            // The left child is taking the place of node, so we update it's
            // parent to be the original parent of the node.
            Node storage newRoot = index.nodes[originalRoot.left];
            newRoot.parent = originalRoot.parent;

            // Null out the originalRoot.left
            originalRoot.left = 0x0;

            if (originalRoot.parent != 0x0) {
                // If the node has a parent, update the correct child to point
                // at the newRoot now.
                Node storage parent = index.nodes[originalRoot.parent];

                if (parent.left == originalRoot.id) {
                    parent.left = newRoot.id;
                }
                if (parent.right == originalRoot.id) {
                    parent.right = newRoot.id;
                }
            }

            if (newRoot.right != 0x0) {
                Node storage rightChild = index.nodes[newRoot.right];
                originalRoot.left = newRoot.right;
                rightChild.parent = originalRoot.id;
            }

            // Update the new root's right node to point to the original node.
            originalRoot.parent = newRoot.id;
            newRoot.right = originalRoot.id;

            if (newRoot.parent == 0x0) {
                index.root = newRoot.id;
            }

            // Recompute heights.
            _updateNodeHeight(index, originalRoot.id);
            _updateNodeHeight(index, newRoot.id);
        }
}

// Accounting v0.1 (not the same as the 0.1 release of this library)

/// @title Accounting Lib - Accounting utilities
/// @author Piper Merriam - <pipermerriam@gmail.com>
library AccountingLib {
        /*
         *  Address: 0x39f631bf138b5eb33e96459f4241e93e13659114
         */
        struct Bank {
            mapping (address => uint) accountBalances;
        }

        /// @dev Low level method for adding funds to an account.  Protects against overflow.
        /// @param self The Bank instance to operate on.
        /// @param accountAddress The address of the account the funds should be added to.
        /// @param value The amount that should be added to the account.
        function addFunds(Bank storage self, address accountAddress, uint value) public {
                if (self.accountBalances[accountAddress] + value < self.accountBalances[accountAddress]) {
                        // Prevent Overflow.
                        throw;
                }
                self.accountBalances[accountAddress] += value;
        }

        event _Deposit(address indexed _from, address indexed accountAddress, uint value);
        /// @dev Function wrapper around the _Deposit event so that it can be used by contracts.  Can be used to log a deposit to an account.
        /// @param _from The address that deposited the funds.
        /// @param accountAddress The address of the account the funds were added to.
        /// @param value The amount that was added to the account.
        function Deposit(address _from, address accountAddress, uint value) public {
            _Deposit(_from, accountAddress, value);
        }

        /// @dev Safe function for depositing funds.  Returns boolean for whether the deposit was successful
        /// @param self The Bank instance to operate on.
        /// @param accountAddress The address of the account the funds should be added to.
        /// @param value The amount that should be added to the account.
        function deposit(Bank storage self, address accountAddress, uint value) public returns (bool) {
                addFunds(self, accountAddress, value);
                return true;
        }

        event _Withdrawal(address indexed accountAddress, uint value);

        /// @dev Function wrapper around the _Withdrawal event so that it can be used by contracts.  Can be used to log a withdrawl from an account.
        /// @param accountAddress The address of the account the funds were withdrawn from.
        /// @param value The amount that was withdrawn to the account.
        function Withdrawal(address accountAddress, uint value) public {
            _Withdrawal(accountAddress, value);
        }

        event _InsufficientFunds(address indexed accountAddress, uint value, uint balance);

        /// @dev Function wrapper around the _InsufficientFunds event so that it can be used by contracts.  Can be used to log a failed withdrawl from an account.
        /// @param accountAddress The address of the account the funds were to be withdrawn from.
        /// @param value The amount that was attempted to be withdrawn from the account.
        /// @param balance The current balance of the account.
        function InsufficientFunds(address accountAddress, uint value, uint balance) public {
            _InsufficientFunds(accountAddress, value, balance);
        }

        /// @dev Low level method for removing funds from an account.  Protects against underflow.
        /// @param self The Bank instance to operate on.
        /// @param accountAddress The address of the account the funds should be deducted from.
        /// @param value The amount that should be deducted from the account.
        function deductFunds(Bank storage self, address accountAddress, uint value) public {
                /*
                 *  Helper function that should be used for any reduction of
                 *  account funds.  It has error checking to prevent
                 *  underflowing the account balance which would be REALLY bad.
                 */
                if (value > self.accountBalances[accountAddress]) {
                        // Prevent Underflow.
                        throw;
                }
                self.accountBalances[accountAddress] -= value;
        }

        /// @dev Safe function for withdrawing funds.  Returns boolean for whether the deposit was successful as well as sending the amount in ether to the account address.
        /// @param self The Bank instance to operate on.
        /// @param accountAddress The address of the account the funds should be withdrawn from.
        /// @param value The amount that should be withdrawn from the account.
        function withdraw(Bank storage self, address accountAddress, uint value) public returns (bool) {
                /*
                 *  Public API for withdrawing funds.
                 */
                if (self.accountBalances[accountAddress] >= value) {
                        deductFunds(self, accountAddress, value);
                        if (!accountAddress.send(value)) {
                                // Potentially sending money to a contract that
                                // has a fallback function.  So instead, try
                                // tranferring the funds with the call api.
                                if (!accountAddress.call.value(value)()) {
                                        // Revert the entire transaction.  No
                                        // need to destroy the funds.
                                        throw;
                                }
                        }
                        return true;
                }
                return false;
        }

        uint constant DEFAULT_SEND_GAS = 100000;

        function sendRobust(address toAddress, uint value) public returns (bool) {
                if (msg.gas < DEFAULT_SEND_GAS) {
                    return sendRobust(toAddress, value, msg.gas);
                }
                return sendRobust(toAddress, value, DEFAULT_SEND_GAS);
        }

        function sendRobust(address toAddress, uint value, uint maxGas) public returns (bool) {
                if (value > 0 && !toAddress.send(value)) {
                        // Potentially sending money to a contract that
                        // has a fallback function.  So instead, try
                        // tranferring the funds with the call api.
                        if (!toAddress.call.gas(maxGas).value(value)()) {
                                return false;
                        }
                }
                return true;
        }
}

library CallLib {
        /*
         *  Address: 0x8deb276d0abe47132849555a3449f26bd1872baa
         */
        struct Call {
                address contractAddress;
                bytes4 abiSignature;
                bytes callData;
                uint anchorGasPrice;
                uint suggestedGas;

                address claimer;
                uint claimAmount;
                uint claimerDeposit;

                bool wasSuccessful;
                bool wasCalled;
                bool isCancelled;
        }

        // The number of blocks that each caller in the pool has to complete their
        // call.
        uint constant CALL_WINDOW_SIZE = 16;

        address constant creator = 0xd3cda913deb6f67967b99d67acdfa1712c293601;

        function extractCallData(Call storage call, bytes data) public {
            call.callData.length = data.length - 4;
            if (data.length > 4) {
                    for (uint i = 0; i < call.callData.length; i++) {
                            call.callData[i] = data[i + 4];
                    }
            }
        }

        function sendSafe(address to_address, uint value) public returns (uint) {
                if (value > address(this).balance) {
                        value = address(this).balance;
                }
                if (value > 0) {
                        AccountingLib.sendRobust(to_address, value);
                        return value;
                }
                return 0;
        }

        function getGasScalar(uint base_gas_price, uint gas_price) constant returns (uint) {
                /*
                 *  Return a number between 0 - 200 to scale the fee based on
                 *  the gas price set for the calling transaction as compared
                 *  to the gas price of the scheduling transaction.
                 *
                 *  - number approaches zero as the transaction gas price goes
                 *  above the gas price recorded when the call was scheduled.
                 *
                 *  - the number approaches 200 as the transaction gas price
                 *  drops under the price recorded when the call was scheduled.
                 *
                 *  This encourages lower gas costs as the lower the gas price
                 *  for the executing transaction, the higher the payout to the
                 *  caller.
                 */
                if (gas_price > base_gas_price) {
                        return 100 * base_gas_price / gas_price;
                }
                else {
                        return 200 - 100 * base_gas_price / (2 * base_gas_price - gas_price);
                }
        }

        event CallExecuted(address indexed executor, uint gasCost, uint payment, uint fee, bool success);

        event _CallAborted(address executor, bytes32 reason);
        function CallAborted(address executor, bytes32 reason) public {
            _CallAborted(executor, reason);
        }

        function execute(Call storage self, uint start_gas, address executor, uint overhead, uint extraGas) public {
            FutureCall call = FutureCall(this);

            // If the pre-execution checks do not pass, exit early.
            if (!call.beforeExecute(executor)) {
                return;
            }
            
            // Mark the call has having been executed.
            self.wasCalled = true;
            // Make the call
            self.wasSuccessful = self.contractAddress.call.gas(msg.gas - overhead)(self.abiSignature, self.callData);

            // Compute the scalar (0 - 200) for the fee.
            uint gasScalar = getGasScalar(self.anchorGasPrice, tx.gasprice);

            uint basePayment;
            if (self.claimer == executor) {
                basePayment = self.claimAmount;
            }
            else {
                basePayment = call.basePayment();
            }
            uint payment = self.claimerDeposit + basePayment * gasScalar / 100; 
            uint fee = call.baseFee() * gasScalar / 100;

            // zero out the deposit
            self.claimerDeposit = 0;

            // Log how much gas this call used.  EXTRA_CALL_GAS is a fixed
            // amount that represents the gas usage of the commands that
            // happen after this line.
            uint gasCost = tx.gasprice * (start_gas - msg.gas + extraGas);

            // Now we need to pay the executor as well as keep fee.
            payment = sendSafe(executor, payment + gasCost);
            fee = sendSafe(creator, fee);

            // Log execution
            CallExecuted(executor, gasCost, payment, fee, self.wasSuccessful);
        }

        event Cancelled(address indexed cancelled_by);

        function cancel(Call storage self, address sender) public {
                Cancelled(sender);
                if (self.claimerDeposit >= 0) {
                    sendSafe(self.claimer, self.claimerDeposit);
                }
                var call = FutureCall(this);
                sendSafe(call.schedulerAddress(), address(this).balance);
                self.isCancelled = true;
        }

        /*
         *  Bid API
         *  - Gas costs for this transaction are not covered so it
         *    must be up to the call executors to ensure that their actions
         *    remain profitable.  Any form of bidding war is likely to eat into
         *    profits.
         */
        event Claimed(address executor, uint claimAmount);

        // The duration (in blocks) during which the maximum claim will slowly rise
        // towards the basePayment amount.
        uint constant CLAIM_GROWTH_WINDOW = 240;

        // The duration (in blocks) after the CLAIM_WINDOW that claiming will
        // remain open.
        uint constant MAXIMUM_CLAIM_WINDOW = 15;

        // The duration (in blocks) before the call's target block during which
        // all actions are frozen.  This includes claiming, cancellation,
        // registering call data.
        uint constant BEFORE_CALL_FREEZE_WINDOW = 10;

        /*
         *  The maximum allowed claim amount slowly rises across a window of
         *  blocks CLAIM_GROWTH_WINDOW prior to the call.  No claimer is
         *  allowed to claim above this value.  This is intended to prevent
         *  bidding wars in that each caller should know how much they are
         *  willing to execute a call for.
         */
        function getClaimAmountForBlock(uint block_number) constant returns (uint) {
            /*
             *   [--growth-window--][--max-window--][--freeze-window--]
             *
             *
             */
            var call = FutureBlockCall(this);

            uint last_block = call.targetBlock() - BEFORE_CALL_FREEZE_WINDOW;
            
            // claim window has closed
            if (block_number > last_block) return call.basePayment();

            uint first_block = last_block - MAXIMUM_CLAIM_WINDOW - CLAIM_GROWTH_WINDOW;
            
            // claim window has not begun
            if (block_number < first_block) return 0;

            // in the maximum claim window.
            if (block_number > last_block - MAXIMUM_CLAIM_WINDOW) return call.basePayment();

            uint x = block_number - first_block;

            return call.basePayment() * x / CLAIM_GROWTH_WINDOW;
        }

        function claim(Call storage self, address executor, uint deposit_amount, uint basePayment) public returns (bool) {
                // Already claimed
                if (self.claimer != 0x0) return false;

                // Insufficient Deposit
                if (deposit_amount < 2 * basePayment) return false;

                var call = FutureBlockCall(this);

                // Too early
                if (block.number < call.targetBlock() - BEFORE_CALL_FREEZE_WINDOW - MAXIMUM_CLAIM_WINDOW - CLAIM_GROWTH_WINDOW) return false;

                // Too late
                if (block.number > call.targetBlock() - BEFORE_CALL_FREEZE_WINDOW) return false;
                self.claimAmount = getClaimAmountForBlock(block.number);
                self.claimer = executor;
                self.claimerDeposit = deposit_amount;

                // Log the claim.
                Claimed(executor, self.claimAmount);
        }

        function checkExecutionAuthorization(Call storage self, address executor, uint block_number) returns (bool) {
                /*
                 *  Check whether the given `executor` is authorized.
                 */
                var call = FutureBlockCall(this);

                uint targetBlock = call.targetBlock();

                // Invalid, not in call window.
                if (block_number < targetBlock || block_number > targetBlock + call.gracePeriod()) throw;

                // Within the reserved call window so if there is a claimer, the
                // executor must be the claimdor.
                if (block_number - targetBlock < CALL_WINDOW_SIZE) {
                    return (self.claimer == 0x0 || self.claimer == executor);
                }

                // Must be in the free-for-all period.
                return true;
        }
}

contract FutureCall {
        address public schedulerAddress;

        uint public basePayment;
        uint public baseFee;

        CallLib.Call call;

        /*
         *  Data accessor functions.
         */
        function contractAddress() constant returns (address) {
            return call.contractAddress;
        }

        function abiSignature() constant returns (bytes4) {
            return call.abiSignature;
        }

        function callData() constant returns (bytes) {
            return call.callData;
        }

        function anchorGasPrice() constant returns (uint) {
            return call.anchorGasPrice;
        }

        function suggestedGas() constant returns (uint) {
            return call.suggestedGas;
        }

        function claimer() constant returns (address) {
            return call.claimer;
        }

        function claimAmount() constant returns (uint) {
            return call.claimAmount;
        }

        function claimerDeposit() constant returns (uint) {
            return call.claimerDeposit;
        }

        function wasSuccessful() constant returns (bool) {
            return call.wasSuccessful;
        }

        function wasCalled() constant returns (bool) {
            return call.wasCalled;
        }

        function isCancelled() constant returns (bool) {
            return call.isCancelled;
        }

        function getClaimAmountForBlock() constant returns (uint) {
            return CallLib.getClaimAmountForBlock(block.number);
        }

        function getClaimAmountForBlock(uint block_number) constant returns (uint) {
            return CallLib.getClaimAmountForBlock(block_number);
        }

        function () {
                // Fallback to allow sending funds to this contract.
                // Also allows call data registration.
                if (msg.sender == schedulerAddress && msg.data.length > 0) {
                        if (call.callData.length != 0) {
                            throw;
                        }
                        call.callData = msg.data;
                }
        }

        modifier notcancelled { if (call.isCancelled) throw; _ }

        // The author (Piper Merriam) address.
        address constant creator = 0xd3cda913deb6f67967b99d67acdfa1712c293601;

        function registerData() public notcancelled {
            if (msg.sender != schedulerAddress || call.callData.length > 0) {
                // cannot write over call data
                throw;
            }
            CallLib.extractCallData(call, msg.data);
        }

        function claim() public notcancelled returns (bool) {
            bool success = CallLib.claim(call, msg.sender, msg.value, basePayment);
            if (!success) {
                if (!AccountingLib.sendRobust(msg.sender, msg.value)) throw;
            }
            return success;
        }

        function checkExecutionAuthorization(address executor, uint block_number) constant returns (bool) {
            return CallLib.checkExecutionAuthorization(call, executor, block_number);
        }

        // API for inherited contracts
        function beforeExecute(address executor) public returns (bool);
        function afterExecute(address executor) internal;
        function getOverhead() constant returns (uint);
        function getExtraGas() constant returns (uint);

        function sendSafe(address to_address, uint value) internal {
            CallLib.sendSafe(to_address, value);
        }

        function execute() public notcancelled {
            uint start_gas = msg.gas;

            // Check that the call should be executed now.
            if (!beforeExecute(msg.sender)) return;

            // Execute the call
            CallLib.execute(call, start_gas, msg.sender, getOverhead(), getExtraGas());

            // Any logic that needs to occur after the call has executed should
            // go in afterExecute
            afterExecute(msg.sender);
        }
}

contract FutureBlockCall is FutureCall {
        uint public targetBlock;
        uint8 public gracePeriod;

        function FutureBlockCall(address _schedulerAddress, uint _targetBlock, uint8 _gracePeriod, address _contractAddress, bytes4 _abiSignature, uint _suggestedGas, uint _basePayment, uint _baseFee) {
                // TODO: split this constructor across this contract and the
                // parent contract FutureCall
                schedulerAddress = _schedulerAddress;

                targetBlock = _targetBlock;
                gracePeriod = _gracePeriod;

                basePayment = _basePayment;
                baseFee = _baseFee;

                call.suggestedGas = _suggestedGas;
                call.anchorGasPrice = tx.gasprice;
                call.contractAddress = _contractAddress;
                call.abiSignature = _abiSignature;
        }

        function beforeExecute(address executor) public returns (bool) {
            if (call.wasCalled) {
                // Not being called within call window.
                CallLib.CallAborted(executor, "ALREADY_CALLED");
                return false;
            }

            if (block.number < targetBlock || block.number > targetBlock + gracePeriod) {
                // Not being called within call window.
                CallLib.CallAborted(executor, "NOT_IN_CALL_WINDOW");
                return false;
            }

            // If they are not authorized to execute the call at this time,
            // exit early.
            if (!CallLib.checkExecutionAuthorization(call, executor, block.number)) {
                CallLib.CallAborted(executor, "NOT_AUTHORIZED");
                return;
            }

            return true;
        }

        function afterExecute(address executor) internal {
            // Refund any leftover funds.
            CallLib.sendSafe(schedulerAddress, address(this).balance);
        }

        uint constant GAS_OVERHEAD = 100000;

        function getOverhead() constant returns (uint) {
                return GAS_OVERHEAD;
        }

        uint constant EXTRA_GAS = 73000;

        function getExtraGas() constant returns (uint) {
                return EXTRA_GAS;
        }

        uint constant CLAIM_GROWTH_WINDOW = 240;
        uint constant MAXIMUM_CLAIM_WINDOW = 15;
        uint constant BEFORE_CALL_FREEZE_WINDOW = 10;

        function cancel() public notcancelled {
            // Before the claim window
            if (block.number < targetBlock - BEFORE_CALL_FREEZE_WINDOW - MAXIMUM_CLAIM_WINDOW - CLAIM_GROWTH_WINDOW) {
                // already cancelled
                if (msg.sender != schedulerAddress) throw;
                CallLib.cancel(call, msg.sender);
                return;
            }
            if (block.number > targetBlock + gracePeriod) {
                // already called
                if (call.wasCalled) throw;
                CallLib.cancel(call, msg.sender);
                return;
            }
            throw;
        }
}

library SchedulerLib {
    /*
     *  Address: 0xac0500b26e61a8b26700289d9cd326adbc17be0e
     */
    /*
     *  Call Scheduling API
     */
    // Ten minutes into the future.
    uint constant MAX_BLOCKS_IN_FUTURE = 40 + 10 + 255;

    // The minimum gas required to execute a scheduled call on a function that
    // does almost nothing.  This is an approximation and assumes the worst
    // case scenario for gas consumption.
    // 
    // Measured Minimum is closer to 150,000
    uint constant MINIMUM_CALL_GAS = 200000;

    event CallScheduled(address call_address);

    event CallRejected(address indexed schedulerAddress, bytes32 reason);

    uint constant CALL_WINDOW_SIZE = 16;

    function getCallWindowSize() constant returns (uint) {
        return CALL_WINDOW_SIZE;
    }

    function getMinimumGracePeriod() constant returns (uint) {
        return 4 * CALL_WINDOW_SIZE;
    }

    function getMinimumCallGas() constant returns (uint) {
        return MINIMUM_CALL_GAS;
    }

    function getMinimumCallCost(uint basePayment, uint baseFee) constant returns (uint) {
        return 2 * (baseFee + basePayment) + MINIMUM_CALL_GAS * tx.gasprice;
    }

    function scheduleCall(GroveLib.Index storage self, address schedulerAddress, address contractAddress, bytes4 abiSignature, uint targetBlock, uint suggestedGas, uint8 gracePeriod, uint basePayment, uint baseFee, uint endowment) public returns (address) {
        /*
        * Primary API for scheduling a call.
        *
        * - No sooner than MAX_BLOCKS_IN_FUTURE
        * - Grace Period must be longer than the minimum grace period.
        * - msg.value must be >= MIN_GAS * tx.gasprice + 2 * (baseFee + basePayment)
        */
        bytes32 reason;

        if (targetBlock < block.number + MAX_BLOCKS_IN_FUTURE) {
            // Don't allow scheduling further than
            // MAX_BLOCKS_IN_FUTURE
            reason = "TOO_SOON";
        }
        else if (gracePeriod < getMinimumGracePeriod()) {
            reason = "GRACE_TOO_SHORT";
        }
        else if (endowment < 2 * (baseFee + basePayment) + MINIMUM_CALL_GAS * tx.gasprice) {
            reason = "INSUFFICIENT_FUNDS";
        }

        if (reason != 0x0) {
            CallRejected(schedulerAddress, reason);
            AccountingLib.sendRobust(schedulerAddress, endowment);
            return;
        }

        var call = new FutureBlockCall.value(endowment)(schedulerAddress, targetBlock, gracePeriod, contractAddress, abiSignature, suggestedGas, basePayment, baseFee);

        // Put the call into the grove index.
        GroveLib.insert(self, bytes32(address(call)), int(call.targetBlock()));

        CallScheduled(address(call));

        return address(call);
    }
}

contract Scheduler {
    /*
     *  Address: 0xe109ecb193841af9da3110c80fdd365d1c23be2a
     */
    GroveLib.Index callIndex;

    /*
     *  Call Scheduling
     */
    function getMinimumGracePeriod() constant returns (uint) {
        return SchedulerLib.getMinimumGracePeriod();
    }

    function getDefaultPayment() constant returns (uint) {
        return 1 ether;
    }

    function getDefaultFee() constant returns (uint) {
        return 100 finney;
    }

    function getMinimumCallGas() constant returns (uint) {
        return SchedulerLib.getMinimumCallGas();
    }

    function getMinimumCallCost() constant returns (uint) {
        return getMinimumCallCost(getDefaultPayment(), getDefaultFee());
    }

    function getMinimumCallCost(uint basePayment) constant returns (uint) {
        return getMinimumCallCost(basePayment, getDefaultFee());
    }

    function getMinimumCallCost(uint basePayment, uint baseFee) constant returns (uint) {
        return SchedulerLib.getMinimumCallCost(basePayment, baseFee);
    }

    function isKnownCall(address callAddress) constant returns (bool) {
        return GroveLib.exists(callIndex, bytes32(callAddress));
    }

    function scheduleCall(address contractAddress, bytes4 abiSignature, uint targetBlock) public returns (address) {
        return scheduleCall(contractAddress, abiSignature, targetBlock, 0, 255, getDefaultPayment(), getDefaultFee());
    }

    function scheduleCall(address contractAddress, bytes4 abiSignature, uint targetBlock, uint suggestedGas) public returns (address) {
        return scheduleCall(contractAddress, abiSignature, targetBlock, suggestedGas, 255, getDefaultPayment(), getDefaultFee());
    }

    function scheduleCall(address contractAddress, bytes4 abiSignature, uint targetBlock, uint suggestedGas, uint8 gracePeriod) public returns (address) {
        return scheduleCall(contractAddress, abiSignature, targetBlock, suggestedGas, gracePeriod, getDefaultPayment(), getDefaultFee());
    }

    function scheduleCall(address contractAddress, bytes4 abiSignature, uint targetBlock, uint suggestedGas, uint8 gracePeriod, uint basePayment) public returns (address) {
        return scheduleCall(contractAddress, abiSignature, targetBlock, suggestedGas, gracePeriod, basePayment, getDefaultFee());
    }

    function scheduleCall(address contractAddress, bytes4 abiSignature, uint targetBlock, uint suggestedGas, uint8 gracePeriod, uint basePayment, uint baseFee) public returns (address) {
        return SchedulerLib.scheduleCall(callIndex, msg.sender, contractAddress, abiSignature, targetBlock, suggestedGas, gracePeriod, basePayment, baseFee, msg.value);
    }

    /*
     *  Next Call API
     */
    function getCallWindowSize() constant returns (uint) {
            return SchedulerLib.getCallWindowSize();
    }

    function getNextCall(uint blockNumber) constant returns (address) {
            return address(GroveLib.query(callIndex, ">=", int(blockNumber)));
    }

    function getNextCallSibling(address callAddress) constant returns (address) {
            return address(GroveLib.getNextNode(callIndex, bytes32(callAddress)));
    }
}