Adding untested message tribute contract

contracts/communication/MessageTribute.sol

@@ -1,68 +1,139 @@
 pragma solidity ^0.4.17;
 
+import "../common/Controlled.sol";
+import "../token/MiniMeToken.sol";
 
-/*
+
-Inspired by one of Satoshi Nakamoto’s original suggested use cases for Bitcoin, 
+/**
-we will be introducing an economics-based anti-spam filter, in our case for 
+ * @title MessageTribute
-receiving messages and “cold” contact requests from users.
+ * @author Richard Ramos (Status Research & Development GmbH) 
-SNT is deposited, and transferred from stakeholders to recipients upon receiving 
+ * @dev Inspired by one of Satoshi Nakamoto’s original suggested use cases for Bitcoin, 
-a reply from the recipient.
+        we will be introducing an economics-based anti-spam filter, in our case for 
+        receiving messages and “cold” contact requests from users.
+        SNT is deposited, and transferred from stakeholders to recipients upon receiving 
+        a reply from the recipient.
  */
+contract MessageTribute is Controlled {
 
- // Uses:
+    MiniMeToken public SNT;
 
-    /*
+    struct Fee {
-    // B will request 100SNT from everyone for messages 
+        uint256 amount;
-    feeCatalog[B_ADDRESS][address(0)] = 100
+        bool tribute;
-    */
+        bool permanent;
-
-    /*
-    // A wants to send a message to B
-    // B requires that A pays 100SNT
-    feeCatalog[B_ADDRESS][A_ADDRESS] = 100;
-    ---------------------------------------
-    // A will check if B has a fee set up
-    bool hasFee = feeCatalog[B_ADDRESS][address(0)] > 0 || feeCatalog[B_ADDRESS][A_ADDRESS] > 0
-    if(hasFee){
-        uint256 fee = feeCatalog[B_ADDRESS][address(0)];
-        if(feeCatalog[B_ADDRESS][A_ADDRESS] > fee)
-            fee = feeCatalog[B_ADDRESS][A_ADDRESS];
-    }
-    ---------------------------------------
-    A will pay or decide to not send the message
-
-    ---------------------------------------
-
-    // B wants a non permanent fee for A
-    // After he pays for the first message, 
-    // All following messages will be free
-    permanentFee[B_ADDRESS][A_ADDRESS] = false;
-
-    Then after applying fee, we should set:
-    feeCatalog[B_ADDRESS][A_ADDRESS] = 0;
-   
-    ---------------------------------------
-
-    // B wants a permanent fee for A 
-    permanentFee[B_ADDRESS][A_ADDRESS] = true;
-
-    */
-contract MessageTribute {
-
-    struct Request {
-        address from;
-        address to;
-        uint256 timestamp;
     }
 
-    mapping(address => mapping(address => uint256)) feeCatalog;
+    mapping(address => mapping(address => Fee)) feeCatalog;
-    mapping(address => mapping(address => bool)) permanentFee;
+    mapping(address => uint256) balances;
-
-    function MessageTribute() public {
 
+    struct Audience {
+        uint256 blockNum;
+        Fee fee;
     }
 
+    mapping(address => mapping(address => Audience)) audienceRequested;
     
 
+    function MessageTribute(address _SNT) public {
+        SNT = MiniMeToken(_SNT);
+    }
+
+    function setRequiredTribute(address _to, uint _amount, bool _isTribute, bool _isPermanent) public {
+        feeCatalog[msg.sender][_to] = Fee(_amount, _isTribute, _isPermanent);
+    }
+
+    function getRequiredFee(address _from) public view 
+        returns (uint256 fee, bool tribute) 
+    {
+        Fee memory f = getFee(_from);
+        fee = f.amount;
+        tribute = f.tribute;
+    }
+
+    function getFee(address _from) internal 
+        returns (Fee) 
+    {
+        Fee memory generalFee  = feeCatalog[_from][address(0)];
+        Fee memory specificFee = feeCatalog[_from][msg.sender];
+        return specificFee.amount > 0 ? specificFee : generalFee;
+    }
+    
+
+    function deposit(uint256 _value) public {
+        require(_value > 0);
+        balances[msg.sender] += _value;
+        require(SNT.transferFrom(msg.sender, this, _value));
+    }
+
+    function balance() public view returns (uint256) {
+        return balances[msg.sender];
+    }
+
+    function widthdraw(uint256 _value) public {
+        require(balances[msg.sender] > 0);
+        require(_value <= balances[msg.sender]);
+        require(SNT.transferFrom(msg.sender, this, _value));
+    }
+
+    event AudienceRequested(address from, address to);
+    event AudienceCancelled(address from, address to);
+    event AudienceGranted(address from, address to, bool approve);
+
+    function requestAudience(address _from)
+        public 
+    {
+        Fee memory f = getFee(_from);
+        require(f.amount <= balances[msg.sender]);
+        AudienceRequested(_from, msg.sender);
+        audienceRequested[_from][msg.sender] = Audience(block.number, f);
+        balances[msg.sender] -= f.amount;
+    }
+
+    function cancelAudienceRequest(address _from) public {
+        if (audienceRequested[_from][msg.sender].blockNum > 0) {
+            AudienceCancelled(_from, msg.sender);
+            balances[msg.sender] += audienceRequested[_from][msg.sender].fee.amount;
+            delete audienceRequested[_from][msg.sender];
+        }
+    }
+
+    function grantAudience(address _to, bool _approve) {
+
+        Audience memory aud = audienceRequested[msg.sender][_to];
+
+        require(aud.blockNum > 0);
+       
+        AudienceGranted(msg.sender, _to, _approve);
+
+        bool isTribute = aud.fee.tribute;
+        uint256 amount = aud.fee.amount;
+
+        delete audienceRequested[msg.sender][_to];
+        clearFee(msg.sender, _to);
+
+        if (isTribute) {
+            if (_approve) {
+                require(SNT.transferFrom(this, msg.sender, amount));  
+            } else {
+                balances[_to] += amount;
+            }
+        }
+    }
+
+    function hasEnoughFundsToTalk(address _to)
+        public
+        view 
+        returns(bool)
+    {
+        return getFee(_to).amount <= balances[msg.sender];
+    }
+
+    function clearFee(address _from, address _to) private {
+        if (!feeCatalog[_from][_to].permanent) {
+            feeCatalog[_from][_to].amount = 0;
+            feeCatalog[_from][_to].tribute = false;
+            feeCatalog[_from][_to].permanent = false;
+        }
+    }
     
 }