From 7137bf227e1490f5d356474b29885b22cb4a79a0 Mon Sep 17 00:00:00 2001
From: Lakshmi C Rajeev <lakshmi.c.rajeev@sap.com>
Date: Fri, 29 Nov 2019 12:30:07 +0530
Subject: [PATCH] Media-server

---
 package.json                                |  3 +-
 packages/media-server/db/data-model.cds     | 13 ++++
 packages/media-server/index.cds             | 15 ----
 packages/media-server/package.json          |  3 +-
 packages/media-server/srv/media-service.cds |  8 ++
 packages/media-server/srv/media-service.js  | 83 +++++++++++++++++++++
 6 files changed, 108 insertions(+), 17 deletions(-)
 create mode 100644 packages/media-server/db/data-model.cds
 delete mode 100644 packages/media-server/index.cds
 create mode 100644 packages/media-server/srv/media-service.cds
 create mode 100644 packages/media-server/srv/media-service.js

diff --git a/package.json b/package.json
index 08b90658..a9230648 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,8 @@
     "bookshop": "cds watch packages/bookshop",
     "bookstore": "cds watch packages/bookstore",
     "products-service": "cds watch packages/products-service",
-    "reviews-service": "cds watch packages/reviews-service"
+    "reviews-service": "cds watch packages/reviews-service",
+    "media-server": "cds watch packages/media-server"
   },
   "dependencies": {
     "@sap/cds": "latest",
diff --git a/packages/media-server/db/data-model.cds b/packages/media-server/db/data-model.cds
new file mode 100644
index 00000000..2ad6c28e
--- /dev/null
+++ b/packages/media-server/db/data-model.cds
@@ -0,0 +1,13 @@
+namespace sap.capire.media;
+
+entity Media {
+
+   key id:Integer;
+   @Core.MediaType: mediaType
+   content : LargeBinary ;
+
+   @Core.IsMediaType: true
+   mediaType : String;
+   fileName : String;
+   applicationName:String;
+}
\ No newline at end of file
diff --git a/packages/media-server/index.cds b/packages/media-server/index.cds
deleted file mode 100644
index 552aaf97..00000000
--- a/packages/media-server/index.cds
+++ /dev/null
@@ -1,15 +0,0 @@
-namespace sap.capire.media;
-
-service MediaServer {
-  entity Images {
-    key url : URL;
-    type : String enum { jpeg; png; gif; };
-    content : Image;
-  }
-}
-
-type ImageURL : URL;
-// type ImageURL : Association to MediaServer.Images;
-//> would need Assotiations targeting off service to turn into references w/ foreign keys
-type Image : LargeBinary @stream;
-type URL : String(222);
diff --git a/packages/media-server/package.json b/packages/media-server/package.json
index 8c5de4d5..873ff5ea 100644
--- a/packages/media-server/package.json
+++ b/packages/media-server/package.json
@@ -6,6 +6,7 @@
   "license": "SAP SAMPLE CODE LICENSE",
   "dependencies": {
     "@sap/cds": "latest",
-    "express": "*"
+    "express": "*",
+    "lokijs": "^1.5.6"
   }
 }
diff --git a/packages/media-server/srv/media-service.cds b/packages/media-server/srv/media-service.cds
new file mode 100644
index 00000000..09441897
--- /dev/null
+++ b/packages/media-server/srv/media-service.cds
@@ -0,0 +1,8 @@
+using { sap.capire.media as db } from '../db/data-model';
+namespace sap.capire.media;
+
+service MediaServer  {
+    entity Media   as projection on db.Media ;
+}
+
+ 
\ No newline at end of file
diff --git a/packages/media-server/srv/media-service.js b/packages/media-server/srv/media-service.js
new file mode 100644
index 00000000..5f62d865
--- /dev/null
+++ b/packages/media-server/srv/media-service.js
@@ -0,0 +1,83 @@
+module.exports = (srv) => {
+
+    var loki = require('lokijs');
+    var db = new loki('DB');
+    var mediaDB= db.addCollection("Media");
+    var Readable = require('stream').Readable;
+    var PassThroughStream = require('stream').PassThrough;
+
+    srv.before('CREATE', 'Media', (req) => {
+        var obj = mediaDB.insert({media: ""});
+        req.data.id=obj.$loki;
+    })
+
+    srv.on ('UPDATE', 'Media', async (req,next) => {
+        try{ 
+            var url = req._.req.path;
+            if (url.indexOf("content")>0) {
+                const id = req.data.id; 
+                var obj = mediaDB.get(id);
+                if(obj==null) {
+                    req.reject(404,"No record found for the ID");
+                    return;
+                }
+                var stream = new PassThroughStream();
+                let chunks = [];
+                stream.on('data',  (chunk) => {
+                    chunks.push(chunk);
+                });
+                stream.on('end',  () =>{
+                    obj.media = Buffer.concat(chunks).toString('base64');
+                    mediaDB.update(obj);
+                });
+                req.data.content.pipe(stream);
+            }  else return next()
+        }catch(error){
+            req.reject(404,"Media DB error")
+            console.log(error)
+            return 
+        }
+    }) 
+
+    srv.on("READ","Media", (req,next)=>{
+        try{
+            var url = req._.req.path;
+            if (url.indexOf("content")>0) {
+                const id = req.data.id; 
+                if(mediaDB.get(id)==null) {
+                    req.reject(404,"Media not found for the ID");
+                    return ;
+                }
+                var decodedMedia  = new Buffer( mediaDB.get(id).media.split(';base64,').pop(), 'base64');
+                return _formatResult(decodedMedia);
+            }
+            else return next()  //> delegate to next/default handlers
+        }catch(error){
+            req.reject(404,"Media DB error")
+            return 
+        }
+      })  
+
+      srv.on("DELETE","Media", (req,next)=>{
+        try{
+            const id = req.data.id; 
+            var obj=mediaDB.get(id);
+            if(obj!=null) {
+                mediaDB.remove(obj)
+            }
+            return next()  //> delegate to next/default handlers
+        }catch(error){
+            req.reject(404,"Media DB error ")
+        }
+      })  
+
+    function _formatResult (decodedMedia)  {
+        var readable= new Readable
+        var result = new Array()
+        readable.push(decodedMedia)
+        readable.push(null) 
+        result.push({value:readable})
+        return result 
+      }
+
+  }
\ No newline at end of file