Adding heartbeat message andrequired functions for price plugins

gas-relayer/config/config.json

@@ -22,14 +22,28 @@
         }
     },
 
+    "heartbeat": {
+        "enabled": true,
+        "symKey": "0xd0d905c1c62b810b787141430417caf2b3f54cffadb395b7bb39fdeb8f17266b"
+    },
+    
     "tokens": {
         "0x0000000000000000000000000000000000000000": {
             "name": "Ethereum",
-            "symbol": "ETH"
+            "symbol": "ETH",
+            "minAccepted":{
+                "value": 1,
+                "currency": "USD"
+            }
         },
         "0xD10e6dAe987Dcc0B3ADaA375C9f59690a4C97a27": {
             "name": "Status Network Token",
-            "symbol": "SNT"
+            "symbol": "SNT",
+            "minAccepted":{
+                "value": 1,
+                "currency": "USD"
+            },
+            "pricePlugin": "../plugins/token-utils.js"	
         }
     },
 

gas-relayer/src/contract-settings.js

@@ -12,9 +12,19 @@ class ContractSettings {
     }
 
     process(){
+        this._setTokenPricePlugin();
         this._processContracts();
     }
 
+    _setTokenPricePlugin(){	
+        for(let token in this.tokens){	
+            if(this.tokens[token].pricePlugin !== undefined){	
+                let PricePlugin = require(this.tokens[token].pricePlugin);	
+                this.tokens[token].pricePlugin = new PricePlugin(this.tokens[token]);	
+            }	
+        }	
+    }
+
     getToken(token){
         return this.tokens[token];
     }

gas-relayer/src/message-processor.js

@@ -96,6 +96,14 @@ class MessageProcessor {
         }
     }
 
+    _getFactor(input, contract, gasToken){	
+        if(contract.allowedFunctions[input.functionName].isToken){	
+            return this.web3.utils.toBN(this.settings.getToken(gasToken).pricePlugin.getFactor());	
+        } else {	
+            return this.web3.utils.toBN(1);	
+        }	
+    }	
+    
     async getBalance(token, input, gasToken){
         // Determining balances of token used
         if(token.symbol == "ETH"){

gas-relayer/src/service.js

@@ -31,12 +31,14 @@ events.on('web3:connected', connURL => {
 });
 
 
+// Setting up Whisper options
+const shhOptions = {
+  ttl: config.node.whisper.ttl,
+  minPow: config.node.whisper.minPow,
+};
+
 events.on('setup:complete', (settings) => {
-  // Setting up Whisper options
-  const shhOptions = {
-    ttl: config.node.whisper.ttl,
-    minPow: config.node.whisper.minPow,
-  };
+  
 
   let kId;
   let symKId;
@@ -58,6 +60,35 @@ events.on('setup:complete', (settings) => {
       shhOptions.topics = [contract];
       events.emit('server:listen', shhOptions, settings);
     }
+
+
+
+    if(config.heartbeat.enabled){
+      let heartbeatSymKeyId;
+      web3.shh.addSymKey(config.heartbeat.symKey)
+        .then(heartbeatSymKeyId => { 
+
+            // TODO: define minPriceAccepted
+            let heartbeatPayload = {
+              'minPriceAccepted': 0
+            }
+
+            setInterval(() => {
+                web3.shh.post({ 
+                  symKeyID: heartbeatSymKeyId, 
+                  sig: keyId,
+                  ttl: config.node.whisper.ttl, 
+                  powTarget:config.node.whisper.minPow, 
+                  powTime: config.node.whisper.powTime,
+                  // TODO: topic must be a combination of heartbeat + token
+                  topic: web3.utils.toHex("relay-heartbeat").slice(0, 10),
+                  payload: web3.utils.toHex(JSON.stringify(heartbeatPayload))
+              }).catch(console.error);
+            }, 1000);
+      });
+    }
+
+
   });
 });