From ecb56e153929f043d625276d7f874db2158989a7 Mon Sep 17 00:00:00 2001
From: loblao <12ksit@gmail.com>
Date: Mon, 5 Sep 2016 15:54:34 -0300
Subject: [PATCH] Implement gifbot

---
 app.js         |   5 +-
 bots/gifbot.js | 151 +++++++++++++++++++++++++++++++++++++++++++++++++
 package.json   |   4 +-
 3 files changed, 158 insertions(+), 2 deletions(-)
 create mode 100644 bots/gifbot.js

diff --git a/app.js b/app.js
index 53698b7..9978141 100644
--- a/app.js
+++ b/app.js
@@ -28,7 +28,8 @@ tipbot.init(process.env.RPCUSER, process.env.RPCPASSWORD);
 var hashbot = require('./bots/hashbot');
 hashbot.init(slackbot, process.env.MINING_CHANNEL);
 
-
+var gifbot = require('./bots/gifbot');
+gifbot.init(slackbot, process.env.IMGUR_CLIENT_ID);
 
 slackbot.on('start', function() {
   slackbot.on('message', function(data) {
@@ -36,6 +37,8 @@ slackbot.on('start', function() {
       setTimeout(function() { sendWelcomeMessage(data.user.id); }, 2000); //Delay because of slow slack api updates which sometimes does not send msg.
     }
     if (data.text) {
+      gifbot.handle_msg(data.text, data.channel);
+
       var command = data.text.trim().split(' ')[0];
 
       if (command === hashbot.command) {
diff --git a/bots/gifbot.js b/bots/gifbot.js
new file mode 100644
index 0000000..da9db60
--- /dev/null
+++ b/bots/gifbot.js
@@ -0,0 +1,151 @@
+var XMLHttpRequest = require('xmlhttprequest').XMLHttpRequest;
+
+var slackbot;
+var imgur;
+
+var cache = {};
+var cache_timeout = 3600; // 1h
+var output_dir = 'files';
+
+module.exports = {
+  init: init,
+  handle_msg: handle_msg
+};
+
+function init(_slackbot, imgur_client_id)
+{
+    slackbot = _slackbot;
+    imgur = require('imgur');
+    imgur.setClientId(imgur_client_id);
+}
+
+function jsonrpc_call(method, params, callback) {
+  var xhr = new XMLHttpRequest;
+  xhr.addEventListener('load', function() {
+    var response = JSON.parse(xhr.responseText);
+    callback(response);
+  });
+
+  xhr.addEventListener('error', function (e) {
+      callback({error: e})
+  });
+
+  xhr.open('POST', 'http://localhost:5279/lbryapi', true);
+  xhr.send(JSON.stringify({
+    'jsonrpc': '2.0',
+    'method': method,
+    'params': [params],
+    'id': 0
+  }));
+}
+
+function handle_msg(msg, channel)
+{
+    var words = msg.trim().split(' ');
+
+    words.forEach(function(word)
+    {
+        if (word.lastIndexOf('<lbry://', 0) === 0)
+        {
+            word = word.slice(8, -1); // strip <lbry:// and >
+            handle_url(word, channel);
+        }
+    });
+}
+
+function check_url(url, callback)
+{
+    jsonrpc_call('resolve_name', {'name': url}, function(response)
+    {
+        if (response.error)
+        {
+            callback(response.error);
+            return;
+        }
+
+        var resolved = response.result;
+        if (!resolved)
+        {
+            callback(false);
+            return;
+        }
+
+        if (resolved.fee)
+        {
+            callback(false);
+            return;
+        }
+
+        var meta_version = resolved.ver ? resolved.ver : '0.0.1';
+        var field_name = (meta_version == '0.0.1' || meta_version == '0.0.2') ?
+                            'content-type' : 'content_type';
+        var content_type = resolved[field_name];
+        callback(content_type == 'image/gif');
+    });
+}
+
+function handle_url(url, channel)
+{
+    console.log('Detected URL', url, 'on channel', channel);
+
+    if (!cache[channel])
+    {
+        cache[channel] = {};
+    }
+
+    var now = new Date().getTime() / 1000;
+    if (cache[channel][url])
+    {
+        var elapsed = now - cache[channel][url];
+        if (elapsed < cache_timeout)
+        {
+            console.log(url, 'is cached for this channel, ignoring...')
+            return;
+        }
+    }
+
+    cache[channel][url] = now;
+
+    check_url(url, function(valid)
+    {
+        if (valid)
+        {
+            console.log('Fetching', url);
+            fetch_url(url, channel);
+        }
+
+        else
+        {
+            console.log('Ignoring', url);
+        }
+    });
+}
+
+function fetch_url(url, channel)
+{
+    jsonrpc_call('get', {'name': url, 'download_directory': output_dir},
+                 function(response)
+    {
+        var result = response.result;
+        if (!result)
+        {
+            console.warn('Failed to fetch', url);
+            console.warn(response);
+            slackbot.postMessage(channel, 'Unable to fetch URL [' + url + ']. Insufficient funds?');
+            return;
+        }
+
+        var filename = result.path;
+        console.log('Uploading', filename);
+        imgur.uploadFile(filename).then(function(uploaded)
+        {
+            var link = uploaded.data.link;
+            console.log(link);
+            var attachments = [{image_url: link, title: url}];
+            slackbot.postMessage(channel, null, {attachments: attachments})
+        }).catch(function(err)
+        {
+            console.error(err.message);
+        });
+    });
+}
diff --git a/package.json b/package.json
index b84d509..8d7c748 100644
--- a/package.json
+++ b/package.json
@@ -7,7 +7,9 @@
     "bitcoin": "^3.0.1",
     "needle": "^1.0.0",
     "slackbots": "^0.5.1",
-    "request": "^2.74.0"
+    "request": "^2.74.0",
+    "xmlhttprequest": "1.8.0",
+    "imgur": "0.1.7"
   },
   "devDependencies": {},
   "scripts": {