<?php

function scratchpads_issues_block_menu()
{
    return array(
      'user/%user/inbox' => array(
        'page callback' => 'scratchpads_issues_block_notify_endpoint',
        'page arguments' => array(1),
        'access arguments' => array('access content'),
        'type' => MENU_CALLBACK
      ),
      'issues/%' => array(
        'page callback' => 'scratchpads_issues_block_view_issue',
        'page arguments' => array(1),
        'access arguments' => array('access content')
      )
    );
}

/**
 * Implements hook_block_info_alter()
 */
function scratchpads_issues_block_block_info_alter(&$blocks, $theme, $code_blocks){
  if($theme != 'scratchpads_admin'){
    $blocks['remote_issue_tab'][0]['region'] = 'sidebar';
    $blocks['remote_issue_tab'][0]['status'] = 1;
  }
}

/**
 * Implements hook_issue_tab_settings from remote_issue_tab module
 */
function scratchpads_issues_block_issue_tab_settings() {
  return array(
    "fetch_url" => "https://api.github.com/repos/NaturalHistoryMuseum/scratchpads2/issues",
    "html_link" => "https://github.com/NaturalHistoryMuseum/scratchpads2/issues",
    "footer" => '<h2>Help</h2><p>Not sure what you are doing? Try the <a href="http://help.scratchpads.org/">Scratchpad Help Wiki</a>.',
    "scripts" => array(
      drupal_get_path('module', 'scratchpads_issues_block') . "/js/scratchpads_issues_block.js"
    ),
    "external_scripts" => array(
      "https://cdn.jsdelivr.net/npm/marked/marked.min.js"
    )
  );
}

function scratchpads_issues_block_form_remote_issue_tab_create_form_alter(&$form)
{
      array_unshift($form['#submit'], 'scratchpads_issues_block_alter_description');
}

function scratchpads_issues_block_alter_description($form, &$form_state)
{
    global $user;
    global $base_url;

    $body = $form_state['values']['issue_body'];
    $scratchpad_name = variable_get('site_name');
    $user_page = url("/user/$user->uid", array('absolute' => true));

    $user_link = "[$user->name]($user_page)";

    $form_state['values']['issue_body'] = "- Added by $user_link
- Scratchpad: [$scratchpad_name]($base_url)

### Description:

$body";
}

/**
 * Endpoint that receives a POST notification from the github bridge service
 * and forwards it to the appropriate user.
 */
function scratchpads_issues_block_notify_endpoint($user)
{
    // Validate the request is a post and return proper response code on failure.
    if ($_SERVER['REQUEST_METHOD'] != 'POST') {
        header('HTTP/1.1 405 Only POST method allowed');
        return;
    }

    // Syntax is a subset of ActivityStreams2 in case we want to expand use of this protocol in future
    if (!preg_match('/^application\/((activity|ld)\+)?json(;|$)/i', $_SERVER['CONTENT_TYPE'])) {
        header('HTTP/1.1 415 Only application/json data allowed');
        return;
    }

    // Ensure request comes from a trusted source
    $expected_token = variable_get('github_bridge_token');

    // If this token isn't set we don't want to accept any requests
    if ($expected_token === null) {
        header('HTTP/1.1 501 Not implemented');
        return;
    }

    $auth = $_SERVER['HTTP_AUTHORIZATION'];
    if ($auth !== "Bearer $expected_token") {
        header('HTTP/1.1 401 Invalid auth token');
        return;
    }

    // Get POST body
    $received_json = file_get_contents("php://input", true);
    $json = drupal_json_decode($received_json, true);

    $summary = $json['summary'];
    $link = $json['object']['url'];

    // Send the email.
    drupal_mail(
        'scratchpads_issues_block',
        'notification',
        $user->mail,
        user_preferred_language($user),
        array(
        'summary' => $summary,
        'link' => $link
        )
    );
}

/**
 * Given a link to a GitHub issue, returns the issue number
 */
function scratchpads_issues_block_parse_issue_number($link)
{
    if (preg_match("/[0-9]+(?=\/?$)/", $link, $matches)) {
        return $matches[0];
    }
}

/**
 * Set template for github notification email.
 */
function scratchpads_issues_block_mail($key, &$message, $params)
{
    $summary = $params['summary'];
    $link = $params['link'];
    $body = "View this change on GitHub: $link";

    $issue = scratchpads_issues_block_parse_issue_number($link);

    if ($issue) {
        $link = url("/issues/$issue", array('absolute' => true));
        $scratchpad_name = variable_get('site_name');
        $body = "View this change on $scratchpad_name: $link";
    }

    switch ($key) {
        case 'notification':
            $message['subject'] = $summary;
            $message['body'][] = $body;
            break;
    }
}

/**
 * Implements hook_github_create_issue
 */
function scratchpads_issues_block_github_create_issue($issue)
{
    $number = $issue['number'];

    scratchpads_issues_block_subscribe($number);

    drupal_goto("/issues/$number");
}

/**
 * Here we send the issue follow request to the bridge service
 */
function scratchpads_issues_block_subscribe($issue_id)
{
    global $user;
    $bridge = variable_get('github_bridge_host', 'http://ap-gh-bridge-webserver');
    $token = variable_get('github_bridge_token');
    $inbox = url("/user/$user->uid/inbox", array('absolute' => true));

    if ($token === null) {
        // If the auth token isn't set, skip this step
        return;
    }

    drupal_http_request(
        "$bridge/follow",
        array(
        'headers' => array(
            'Content-Type' => 'application/json',
            'Authorization' => "Bearer $token"
        ),
        'method' => 'POST',
        'data' => json_encode(array(
            'user' => $inbox,
            'issue' => $issue_id
        ))
        )
    );
}

/**
 * Implements hook theme
 * Themes for issues thread and individual comments
 */
function scratchpads_issues_block_theme()
{
    return [
      'scratchpads_issues_block_thread' => [
        'render element' => 'thread',
        'file' => 'scratchpads_issues_block.theme.inc'
      ],
      'scratchpads_issues_block_comment' => [
        'variables' => [
          'author' => '',
          'scratchpad' => '',
          'body' => '',
          'date' => ''
        ],
        'file' => 'scratchpads_issues_block.theme.inc'
      ]
    ];
}

/**
 * Helper function for creating & authenticating the github client
 * Returns array of [ client, organisation name, repo name ]
 */
function scratchpads_issues_block_get_github_client()
{
    $auth_token = variable_get('remote_issue_tab_github_auth_key');
    $repo = variable_get('remote_issue_tab_github_repository');

    list($repo_owner, $repo_name) = explode('/', $repo);

    require_once libraries_get_path('vendor') . '/autoload.php';

    $client = new \Github\Client();
    $client->authenticate($auth_token, null, \Github\Client::AUTH_HTTP_TOKEN);

    return [
        $client,
        $repo_owner,
        $repo_name
    ];
}

/**
 * This is the page that allows us to view a given thread from github
 * and reply to it.
 */
function scratchpads_issues_block_view_issue($id)
{
    // Load the issue from drupal
    list($client, $repo_owner, $repo_name) = scratchpads_issues_block_get_github_client();

    try {
        $issue = $client->api('issue')->show($repo_owner, $repo_name, $id);
    } catch (\Github\Exception\RuntimeException $e) {
        switch($e->getCode()) {
            case 404:
                return drupal_not_found();
            case 401:
                return "There is a configuration problem with scratchpads_issues_block";
            default:
                // Mysterious error - could be host failing to resolve?
                // echo $e->getCode();
                // echo $e->getMessage();
                throw $e;
        }
    }

    // Don't let users see/reply to duplicates
    foreach ($issue['labels'] as $label) {
        // Do we have any other `duplicate` (or other) labels to add to this?
        if ($label['url'] === 'https://api.github.com/repos/NaturalHistoryMuseum/scratchpads2/labels/Redmine%20duplicate') {
            return drupal_not_found();
        }
    }

    $title = $issue['title'];
    $author = $issue['user']['login'];
    $body = $issue['body'];
    $date = $issue['created_at'];
    $url = '';

    // For issues generated by scratchpads we have put the metadata (e.g. author, scratchpad)
    // in the head of the issue and added the body after a "Description" header
    // Let's get that data out and display it nicely
    // This might be worth moving in to the bridge app actually
    if ($author === 'scratchpads' || $author === 'informatics-dev') {
        $parts = explode('### Description:', $body);
        $body = array_pop($parts);
        $meta = array_pop($parts);
    }

    // There are a few types and styles of recording meta data because of
    // the data available at the time the issue was created
    if ($meta) {
        $matches = [];

        // Imported from redmine: `- Added by **User Name**`
        preg_match('/- Added by (\*+)([^*]*)\1/i', $meta, $matches);

        if ($matches[2]) {
            $author = $matches[2];
        }

        // Added through scratchpads: `- Added by [User Name](http://scratchpad.example/user/1)`
        preg_match('/- Added by \[(.*)\]\((.*)\)/i', $meta, $matches);
        if ($matches[1]) {
            $author = l($matches[1], $matches[2]);
        }

        // Imported from redmine: ` - Scratchpads URL: scratchpad.example`
        preg_match('/- Scratchpads URL: (.*)$/im', $meta, $matches)[1];
        if ($matches[1]) {
            $url = ' ( ' . l($matches[1], $matches[1]) . ' )';
        }

        // Added through scratchpads: ` - Scratchpad: [Scratchpad Name](http://scratchpad.example)`
        preg_match('/- Scratchpad: \[(.*)\]\((.*)\)$/im', $meta, $matches)[1];
        if ($matches[1]) {
            $url = ' ( ' . l($matches[1], $matches[2]) . ' )';
        }
    }

    $issue = [
        '#theme' => 'scratchpads_issues_block_thread',
        '#title' => $title,
        '#author' => $author,
        '#scratchpad' => $url,
        '#body' => $body,
        '#date' => $date,
        '#github_url' => $issue['html_url']
    ];

    // Get all comments
    $comments = $client->api('issue')->comments()->all($repo_owner, $repo_name, $id);

    $replies = [];

    foreach ($comments as $comment) {
        $author = $comment['user']['login'];
        $body = $comment['body'];
        $date = $comment['created_at'];

        // The metadata recording style is different for comments.
        // Also we only have user details, not scratchpad name
        if ($author === 'scratchpads' || $author === 'informatics-dev') {
            // Only has an author name
            $comment_match = '/Comment by \*\*(.*)\*\*/';
            if (preg_match($comment_match, $body, $matches)) {
                $author = $matches[1];
                $body = preg_replace($comment_match, '', $body);
            }

            // Has an author name and link
            $comment_match = '/Comment by \[(.*)\]\((.*)\)/';
            if (preg_match($comment_match, $body, $matches)) {
                $author = l($matches[1], $matches[2]);
                $body = preg_replace($comment_match, '', $body);
            }
        }

        $replies[] = [
        '#theme' => 'scratchpads_issues_block_comment',
        '#author' => $author,
        '#body' => $body,
        '#date' => $date
        ];
    }

    $issue['replies'] = $replies;

    return $issue;
}

/**
 * Implements hook_form
 * The form for replying to an issue thread
 */
function scratchpads_issues_block_reply_form($form, &$form_state)
{
    $form['content'] = array(
        '#title' => t('Your reply'),
        '#type' => 'textarea',
        '#required' => true
    );

    $form['submit'] = array(
        '#type' => 'submit',
        '#value' => 'Add Reply'
    );

    return $form;
}

/**
 * Submit handler for issue reply form
 */
function scratchpads_issues_block_reply_form_submit($form, &$form_state)
{
    global $user;

    // Add some metadata: Username and profile page
    $user_page = url("/user/$user->uid", array('absolute' => true));
    $user_link = "[$user->name]($user_page)";

    $issue = arg(1);
    $content = $form_state['values']['content'];

    list($client, $repo_owner, $repo_name) = scratchpads_issues_block_get_github_client();

    $comment = $client->api('issue')->comments()->create(
        $repo_owner,
        $repo_name,
        $issue,
        array(
            'body' => "Comment by $user_link

$content"
        )
    );

    $issue = scratchpads_issues_block_parse_issue_number($comment['issue_url']);

    scratchpads_issues_block_subscribe($issue);
}