From 2c283503a46777606e12ee67f3da38bd427b96ed Mon Sep 17 00:00:00 2001
From: Simon El Nahas Christensen <simon.el.nahas@gmail.com>
Date: Sun, 21 Jul 2019 01:27:28 +0200
Subject: [PATCH 1/2] solution proposal 4

---
 problems/05.md | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)

diff --git a/problems/05.md b/problems/05.md
index c63604a..f818124 100644
--- a/problems/05.md
+++ b/problems/05.md
@@ -9,11 +9,100 @@ we can secure our bank.
 
 ```js
 // bank.js
+var jsonStream = require('duplex-json-stream')
+var net = require('net')
+var fs = require('fs')
+var log = require('./log.json')
+
+function sum() {
+    return log.reduce(
+        function (accu, x) {
+            switch (x.cmd) {
+                case 'deposit':
+                    return accu + x.amount
+                case 'withdraw':
+                    return accu - x.amount
+                default:
+                    return accu
+            }
+        }
+        , 0)
+}
+
+function save() {
+    let data = JSON.stringify(log);
+    fs.writeFileSync('log.json', data);
+}
+
+
+var server = net.createServer(function (socket) {
+    socket = jsonStream(socket)
+    socket.on('data', function (msg) {
+        console.log('Bank received:', msg)
+        let amount = Math.abs(parseInt(msg.amount))
+        switch (msg.cmd){
+            case 'balance':
+                socket.write({ cmd: 'balance', balance: sum() })
+                break
+            case 'deposit':
+                log.push({cmd: 'deposit', amount: amount})
+                save()
+                socket.write({ cmd: 'balance', balance: sum() })
+                break
+            case 'withdraw':
+                if(amount<=sum()){
+                    log.push({cmd: 'withdraw', amount: amount})
+                    save()
+                    socket.write({ cmd: 'balance', balance: sum() })
+                } else {
+                    socket.write("insufficient funds")
+                }
+                break
+            default:
+                break
+        }
+        
+    })
+})
+
+server.listen(3876)
+
+console.log("started bank")
+
 
 ```
 
 ```js
 // teller.js
+var jsonStream = require('duplex-json-stream')
+var net = require('net')
+
+var client = jsonStream(net.connect(3876))
+
+client.on('data', function (msg) {
+  console.log('Teller received:', msg)
+})
+
+const args = process.argv.slice(2)
+const command = args[0]
+const amount = Math.abs(parseInt(args[1]))
+
+switch (command){
+    case 'balance':
+        client.end({cmd: 'balance'})
+        break
+    case 'deposit':
+        client.end({cmd: 'deposit', amount: amount})
+        break
+    case 'withdraw':
+        client.end({cmd: 'withdraw', amount: amount})
+        break
+    default:
+        break
+}
+
+console.log("started teller")
+
 
 ```
 

From 2df9981e9dfaf52c7e6b21d27c63631b9cf4104a Mon Sep 17 00:00:00 2001
From: Simon El Nahas Christensen <simon.el.nahas@gmail.com>
Date: Sun, 21 Jul 2019 01:58:20 +0200
Subject: [PATCH 2/2] Update 05.md

---
 problems/05.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/problems/05.md b/problems/05.md
index f818124..4e6d933 100644
--- a/problems/05.md
+++ b/problems/05.md
@@ -30,7 +30,7 @@ function sum() {
 }
 
 function save() {
-    let data = JSON.stringify(log);
+    let data = JSON.stringify(log, null, 2);
     fs.writeFileSync('log.json', data);
 }