Add IPFS service

Add the `ipfs-api` JS library and a service using the browserified
version of it. The service has functions for storing and reading file
contests.

app/services/ipfs.js

@@ -0,0 +1,32 @@
+import Ember from 'ember';
+import ipfsAPI from 'npm:ipfs-api';
+import config from 'kredits-web/config/environment';
+
+export default Ember.Service.extend({
+
+  ipfsInstance: null,
+
+  ipfs: function() {
+    if (this.get('ipfsInstance')) {
+      return this.get('ipfsInstance');
+    }
+    let ipfs = ipfsAPI(config.ipfs);
+    this.set('ipfsInstance', ipfs);
+    window.ipfs = ipfs;
+    return ipfs;
+  }.property('ipfsInstance'),
+
+  storeFile(content) {
+    let ipfs = this.get('ipfs');
+    return ipfs.add(new ipfs.Buffer(content)).then((res) => {
+      return res[0].hash;
+    });
+  },
+
+  getFile(hash) {
+    return this.get('ipfs').cat(hash, { buffer: true }, (err, res) => {
+      return res.toString();
+    });
+  }
+
+});

app/services/kredits.js

@@ -7,6 +7,8 @@ import kreditsContracts from 'npm:kredits-contracts';
 
 export default Ember.Service.extend({
 
+  ipfs: Ember.inject.service(),
+
   web3Instance: null,
   web3Provided: false, // Web3 provided (using Mist Browser, Metamask et al.)
 

config/environment.js

@@ -22,7 +22,12 @@ module.exports = function(environment) {
     },
 
     web3ProviderUrl: "https://parity.kosmos.org:8545",
-    ethereumChain: "testnet"
+    ethereumChain: "testnet",
+    ipfs: {
+      host: 'localhost',
+      port: '5001',
+      protocol: 'http'
+    }
   };
 
   if (environment === 'development') {

package.json

@@ -39,9 +39,10 @@
     "ember-export-application-global": "^1.0.5",
     "ember-load-initializers": "^0.5.1",
     "ember-resolver": "^2.0.3",
+    "ipfs-api": "^12.1.7",
+    "kredits-contracts": "67P/kredits-contracts",
     "loader.js": "^4.0.10",
-    "web3": "^0.18.2",
-    "kredits-contracts": "67P/kredits-contracts"
+    "web3": "^0.18.2"
   },
   "engines": {
     "node": ">= 0.12.0"

tests/unit/services/ipfs-test.js

@@ -0,0 +1,12 @@
+import { moduleFor, test } from 'ember-qunit';
+
+moduleFor('service:ipfs', 'Unit | Service | ipfs', {
+  // Specify the other units that are required for this test.
+  // needs: ['service:foo']
+});
+
+// Replace this with your real tests.
+test('it exists', function(assert) {
+  let service = this.subject();
+  assert.ok(service);
+});