#13 Implement integration with GitHub

 - Added base class of github issue adapter.

LibHooks/lib/PreCommit/Issue/GitHubAdapter.php

@@ -0,0 +1,231 @@
+<?php
+namespace PreCommit\Issue;
+
+use \Github\Client as Api;
+use Zend\Cache\Storage\Adapter\Filesystem as CacheAdapter;
+
+/**
+ * Class GitHubAdapter
+ *
+ * @package PreCommit\Issue
+ */
+class GitHubAdapter extends AdapterAbstract implements AdapterInterface
+{
+    /**
+     * Cache schema version
+     */
+    const CACHE_SCHEMA_VERSION = 0;
+
+    /**
+     * Exception code when issue not found
+     */
+    const EXCEPTION_CODE_ISSUE_NOT_FOUND = 404;
+
+    /**
+     * Issue data
+     *
+     * @var array
+     */
+    protected $_issue;
+
+    /**
+     * Issue key
+     *
+     * @var string
+     */
+    protected $_issueKey;
+
+    /**
+     * Set issue key
+     *
+     * @param string $issueKey
+     */
+    public function __construct($issueKey)
+    {
+        $this->_issueKey = (string)$issueKey;
+    }
+
+    /**
+     * Get issue
+     *
+     * @return array
+     * @throws \PreCommit\Issue\Exception
+     */
+    protected function _getIssue()
+    {
+        if (null === $this->_issue) {
+            $this->_issue = $this->_getCachedResult($this->_issueKey);
+            if (!$this->_issue) {
+                $this->_issue = $this->_loadIssueData();
+                if (!$this->_issue) {
+                    throw new Exception(
+                        "Issue not {$this->_issueKey} found.", self::EXCEPTION_CODE_ISSUE_NOT_FOUND
+                    );
+                }
+                $this->_cacheResult($this->_issueKey, $this->_issue);
+            }
+        }
+        return $this->_issue;
+    }
+
+    /**
+     * Get issue number
+     *
+     * @return int
+     */
+    protected function _getIssueNumber()
+    {
+        return (int)ltrim($this->_issueKey, '#');
+    }
+
+    //region Caching methods
+    /**
+     * Write summary to cache file
+     *
+     * @param string $key
+     * @param array $result
+     * @return $this
+     */
+    protected function _cacheResult($key, $result)
+    {
+        if ($result) {
+            $this->_getCache()->setItem($key, serialize($result));
+        } else {
+            $this->_getCache()->removeItem($key);
+        }
+        return $this;
+    }
+
+    /**
+     * Get cache summary string
+     *
+     * @param string $key
+     * @return string|bool
+     */
+    protected function _getCachedResult($key)
+    {
+        $data = $this->_getCache()->getItem($key);
+        return $data ? unserialize($data) : null;
+    }
+
+    /**
+     * Get cache directory
+     *
+     * @return string
+     */
+    protected function _getCacheDir()
+    {
+        return $this->_getConfig()->getCacheDir(COMMIT_HOOKS_ROOT);
+    }
+
+    /**
+     * Get cache adapter
+     *
+     * @return \Zend\Cache\Storage\Adapter\Filesystem
+     */
+    protected function _getCache()
+    {
+        return new CacheAdapter(
+            array(
+                'cache_dir' => $this->_getCacheDir(),
+                'ttl'       => 7200,
+                'namespace' => 'issue-github-' . self::CACHE_SCHEMA_VERSION
+            )
+        );
+    }
+    //endregion
+
+    //region Interface methods
+    /**
+     * Get issue summary
+     *
+     * @return string
+     */
+    public function getSummary()
+    {
+        return $this->_getIssue()->getSummary();
+    }
+
+    /**
+     * Get issue key
+     *
+     * @return string
+     */
+    public function getKey()
+    {
+        return $this->_getIssue()->getKey();
+    }
+
+    /**
+     * Get issue type
+     *
+     * @return string
+     */
+    public function getOriginalType()
+    {
+        return $this->_getIssue()->getIssueType();
+    }
+
+    /**
+     * Get status name
+     *
+     * @return string
+     */
+    public function getStatus()
+    {
+        return $this->_normalizeName($this->_getIssue()->getStatus());
+    }
+
+    /**
+     * Cache issue
+     *
+     * @return $this
+     */
+    public function ignoreIssue()
+    {
+        $this->_cacheResult($this->_issueKey, array());
+        return $this;
+    }
+    //endregion
+
+    //region API methods
+    /**
+     * Load issue by API
+     *
+     * @return array
+     * @throws Exception
+     */
+    protected function _loadIssueData()
+    {
+        if (!$this->_canRequest()) {
+            throw new Exception('Connection params not fully set.');
+        }
+        return $this->_getApi()->issue()->show(
+            $this->_getConfig()->getNode('github/name'),
+            $this->_getConfig()->getNode('github/repository'),
+            $this->_getIssueNumber()
+        );
+    }
+
+    /**
+     * Get GitHub API
+     *
+     * @return Api
+     */
+    protected function _getApi()
+    {
+        return new Api();
+    }
+
+    /**
+     * Check if can make a request
+     *
+     * @return bool
+     */
+    protected function _canRequest()
+    {
+        return $this->_getConfig()->getNode('tracker/github/name')
+               && $this->_getConfig()->getNode('tracker/github/repository');
+    }
+    //endregion
+}