price calculation implemented & new error handling

app.js

@@ -1,67 +1,57 @@
 import fetch from "node-fetch"
 import express from "express"
+import bodyParser from "body-parser"
 
 const app = express();
+app.use(bodyParser.json());
 
 const CHAIN4ALL_SERVICE_PORT = process.env.CHAIN4ALL_SERVICE_PORT || 3000;
 const IROHA_API_HOST = process.env.IROHA_API_HOST || "http://localhost";
 const IROHA_API_PORT = process.env.IROHA_API_PORT || 5000;
 const IROHA_DOMAIN = process.env.IROHA_DOMAIN || "test";
 
-app.post("/price", (req, res) => {
-    //TODO implement price calculation depending on extent area
-    res.send({
-        price: 33
-    });
+const PRICE_MODIFIER = 0.5;
+
+app.post("/price", (req, res) => {        
+    if(req.body && req.body.extent){            
+        req.body.price = getPrice(req.body.extent);
+        res.send(req.body);
+    }
+    else{
+        res.status(400);
+        res.send();
+    }    
 });
 
 app.get("/users/:userId/assets", async (req, res) => {
-    
-    try{
-        let irohaResponse = await fetchUsersAssets(req.params.userId);
+    let irohaResponse = await fetchUsersAssets(req.params.userId);
 
-        res.status(irohaResponse.status);
+    res.status(irohaResponse.status);
 
-        if(irohaResponse.headers.get("content-length") < 1){            
-            res.send();
-        }
-        else{                        
-            res.send(await irohaResponse.json());
-        }
-
-        
-    }
-    catch(error){
-        console.error(error);
-        res.status(500);
-        res.send(error);
+    if(irohaResponse.headers.get("content-length") < 1){            
+        res.send();
     }
+    else{                        
+        res.send(await irohaResponse.json());
+    }            
 });
 
 app.get("/users/:userId/assets/:assetId", async (req, res) => {
-
-    try{
-        let assets = (await fetchUsersAssets(req.params.userId)).assets;
-        
-        let parsedAssetName = "";
-        let i = 0;
-        for(i; i < assets.length; i++){           
-            parsedAssetName = assets[i].assetId.split('#')[0];
-            if(parsedAssetName === req.params.assetId){
-                res.status(200);
-                res.send(assets[i]);
-                return;
-            }
+    let assets = (await fetchUsersAssets(req.params.userId)).assets;
+    
+    let parsedAssetName = "";
+    let i = 0;
+    for(i; i < assets.length; i++){           
+        parsedAssetName = assets[i].assetId.split('#')[0];
+        if(parsedAssetName === req.params.assetId){
+            res.status(200);
+            res.send(assets[i]);
+            return;
         }
-
-        res.status(204);
-        res.send();
-    }
-    catch(error){
-        console.error(error);
-        res.status(500);
-        res.send(error);
     }
+
+    res.status(204);
+    res.send();   
 });
 
 app.post("/buy", (req, res) => {
@@ -69,10 +59,35 @@ app.post("/buy", (req, res) => {
     res.status(201);
 });
 
-app.listen(CHAIN4ALL_SERVICE_PORT, () => {
-    console.log(`Listening at http://localhost:${CHAIN4ALL_SERVICE_PORT}`)
-});
-
-async function fetchUsersAssets(userId){    
+async function fetchUsersAssets(userId){        
     return await fetch(IROHA_API_HOST + ':' + IROHA_API_PORT + '/accounts/' + userId + '@' + IROHA_DOMAIN + '/assets/');    
 }
+
+function getArea(extent){
+    let y1 = extent[0][1];
+    let y4 = extent[3][1];
+
+    let x1 = extent[0][0];
+    let x2 = extent[1][0];
+
+    let height = Math.abs(y1 - y4);
+    let width = Math.abs(x1 - x2);
+
+    return height * width;
+}
+
+function getPrice(extent){
+    return getArea(extent) * PRICE_MODIFIER;
+}
+
+function error(err, req, res, next){
+    console.log(err);
+    res.status(500);
+    res.send("Something went wrong. Here is the error message: " + err.message);
+}
+
+app.use(error);
+
+app.listen(CHAIN4ALL_SERVICE_PORT, () => {
+    console.log(`Listening at http://localhost:${CHAIN4ALL_SERVICE_PORT}`)
+});

package.json

@@ -11,6 +11,7 @@
   "author": "Daniel Kunický",
   "license": "ISC",
   "dependencies": {
+    "body-parser": "^1.19.1",
     "express": "^4.17.2",
     "node-fetch": "^3.1.0"
   },