buy endpoint impl

app.js

@@ -8,19 +8,20 @@ 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";
 
-const PRICE_MODIFIER = 0.5;
+const IROHA_DOMAIN = process.env.IROHA_DOMAIN || "test";
+const IROHA_ASSET = process.env.IROHA_ASSET || "coin";
+const DATA_OWNER = process.env.DATA_OWNER || "admin"
+const PRICE_MODIFIER = process.env.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);
+app.post("/price", (req, res) => {
+    if (req.body && req.body.extent) {
+        res.send({ price: getPrice(req.body.extent) });
     }
-    else{
+    else {
         res.status(400);
-        res.send();
-    }    
+        throw Error(JSON.stringify({ error: { name: "Error, request has no body with \"extent\" property!" } }));
+    }
 });
 
 app.get("/users/:userId/assets", async (req, res) => {
@@ -28,22 +29,22 @@ app.get("/users/:userId/assets", async (req, res) => {
 
     res.status(irohaResponse.status);
 
-    if(irohaResponse.headers.get("content-length") < 1){            
+    if (irohaResponse.headers.get("content-length") < 1) {
         res.send();
     }
-    else{                        
+    else {
         res.send(await irohaResponse.json());
-    }            
+    }
 });
 
 app.get("/users/:userId/assets/:assetId", async (req, res) => {
     let assets = (await fetchUsersAssets(req.params.userId)).assets;
-    
+
     let parsedAssetName = "";
     let i = 0;
-    for(i; i < assets.length; i++){           
+    for (i; i < assets.length; i++) {
         parsedAssetName = assets[i].assetId.split('#')[0];
-        if(parsedAssetName === req.params.assetId){
+        if (parsedAssetName === req.params.assetId) {
             res.status(200);
             res.send(assets[i]);
             return;
@@ -51,19 +52,75 @@ app.get("/users/:userId/assets/:assetId", async (req, res) => {
     }
 
     res.status(204);
-    res.send();   
+    res.send();
 });
 
-app.post("/buy", (req, res) => {
-    //TODO implement...
-    res.status(201);
+app.post("/buy", async (req, res) => {
+
+    if (!req.body) {
+        res.status(400);
+        throw Error(JSON.stringify({ error: { name: "Error, request has no body!" } }));
+    }
+
+    if (!req.body.extent) {
+        res.status(400);
+        throw Error(JSON.stringify({ error: { name: "Error, request body has no \"extent\" property!" } }));
+    }
+
+    if (!req.body.user) {
+        res.status(400);
+        throw Error(JSON.stringify({ error: { name: "Error, request body has no \"user\" property!" } }));
+    }
+
+    let price = getPrice(req.body.extent);
+
+    let irohaResponse = await forwardBuyRequest(
+        {
+            transfers: [
+                {
+                    asset: IROHA_ASSET + "#" + IROHA_DOMAIN,
+                    source: req.body.user + "@" + IROHA_DOMAIN,
+                    destination: DATA_OWNER + "@" + IROHA_DOMAIN,
+                    description: "test", //TODO: compose uniform description
+                    amount: price
+                }
+            ]
+        }
+    );
+
+    let data = "test - to be implemented"; //TODO implement data extraction 
+
+    res.status(irohaResponse.status);
+
+    if(!irohaResponse.ok){
+        res.send(irohaResponse);
+    }
+
+    let irohaResponseJson = await irohaResponse.json();
+
+    console.log("tx hash: " + irohaResponseJson.transactionHash);   
+
+    res.send({
+        data : data,
+        transactionHash : irohaResponseJson.transactionHash
+    });
 });
 
-async function fetchUsersAssets(userId){        
-    return await fetch(IROHA_API_HOST + ':' + IROHA_API_PORT + '/accounts/' + userId + '@' + IROHA_DOMAIN + '/assets/');    
+async function forwardBuyRequest(body) {
+    return await fetch(IROHA_API_HOST + ':' + IROHA_API_PORT + '/assets/transfer/',
+        {
+            method: 'POST',
+            body: JSON.stringify(body),
+            headers: { 'Content-Type': 'application/json' }
+        }
+    );
+}
+
+async function fetchUsersAssets(userId) {
+    return await fetch(IROHA_API_HOST + ':' + IROHA_API_PORT + '/accounts/' + userId + '@' + IROHA_DOMAIN + '/assets/');
 }
 
-function getArea(extent){
+function getArea(extent) {
     let y1 = extent[0][1];
     let y4 = extent[3][1];
 
@@ -76,14 +133,18 @@ function getArea(extent){
     return height * width;
 }
 
-function getPrice(extent){
+function getPrice(extent) {
     return getArea(extent) * PRICE_MODIFIER;
 }
 
-function error(err, req, res, next){
+function error(err, req, res, next) { //TODO: add custom Exception class
     console.log(err);
-    res.status(500);
-    res.send("Something went wrong. Here is the error message: " + err.message);
+
+    if (!res.status) {
+        res.status(500);
+    }
+
+    res.send(err.message);
 }
 
 app.use(error);