<?php
// The MIT License (MIT)
//
// Copyright (C) 2013 TrendSpottr
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

// NOTE:  Before you can run this file successfully, you must edit the third line in the
//        alertsAPIRequest function below and insert your TrendSpottr API Key.  That key
//        can be found by logging into your TrendSpottr.com account, then clicking on your
//        email address in the upper right of any TrendSpottr and selecting "Edit Account"
//        from the menu that will drop down. If you don't do that, the first API call made
//        by this script will fail with an invalid api key, and the script will abort.
try
{
    // Create a webhook, setting the shared secret to be "topsecret!!"  When alert events
    // are posted by the TrendSpottr Alerts API, it will be to this url and the secret will
    // be passed with the event.
    $parameters = array(
        'url'    => 'http://post.foo.com/webhook.php',
        'secret' => 'topsecret!!',
    );
    $result = alertsAPIRequest('setWebhook', $parameters);

    // Read the webhook back
    $parameters = array(
        // No parameters to this api method
    );
    $result = alertsAPIRequest('getWebhook', $parameters);
    echo "webhook set to: {$result->url}, secret: \"{$result->secret}\"\n";

    // Create an alert for a user called "user1".  The userid parameter can be a number or a string
    // or any combination of the above that allows you to uniquely identify a customer of yours on whose
    // behalf you are creating an alert.  When alert events are posted, the userid will be include to
    // identify whose alert triggered.
    $parameters = array(
        'userid'       => 'user1',
        'query_string' => 'Technology',
        'level_filter' => 'All',
    );
    $result = alertsAPIRequest('createAlert', $parameters);
    // The result from create alerts contains the alertid we will need to manipulate the alert in the future
    // you must save this value!
    $alert_id = $result->alert_id;

    // Now change the alert so only High and Extreme alerts are delivered
    $parameters = array(
        'alert_id'     => $alert_id,
        'level_filter' => 'HighAndExtreme',
    );
    $result = alertsAPIRequest('setAlertLevel', $parameters);

    // Pause the alert.  It still exists, but no alerts for it will be delivered while it is paused.
    $parameters = array(
        'alert_id'   => $alert_id,
        'state'      => 'paused',
    );
    $result = alertsAPIRequest('setAlertState', $parameters);

    // Make the active again.
    $parameters = array(
        'alert_id'   => $alert_id,
        'state'      => 'active',
    );
    $result = alertsAPIRequest('setAlertState', $parameters);

    // Retreive all available data about the alert
    $parameters = array(
        'alert_id'   => $alert_id,
    );
    $result = alertsAPIRequest('getAlertInfo', $parameters);
    echo "getAlertInfo:\n";
    print_r($result);

    // Delete the alert
    $parameters = array(
        'alert_id'   => $alert_id,
    );
    $result = alertsAPIRequest('deleteAlert', $parameters);

    // Try to retreive all available data about the alert, this time call will
    // fail because the alert has been deleted.
    $parameters = array(
        'alert_id'   => $alert_id,
    );
    $result = alertsAPIRequest('getAlertInfo', $parameters);

} catch (Exception $e)
{
    echo "Error: " . $e->getMessage() . PHP_EOL;
}

// End of mainline
exit;

// Helper functions
function alertsAPIRequest ($action, $parameters)
{
    $serverURL   = 'https://trendspottr.com/api/v1.5/alerts?';
    $apiKey      = 'ENTER_YOUR_API_KEY_HERE';
    $validateSSL = false;

    // Add two more parameters to whatever was passed to us, the API Key required
    // for all calls, and the action.
    $parameters['key']    = $apiKey;
    $parameters['action'] = $action;

    // Format the full url we are going to call
    $url = $serverURL . http_build_query($parameters);

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_USERAGENT, "curl");
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_FAILONERROR, true);
    curl_setopt($ch, CURLOPT_HTTPGET, true);
    // curl_setopt($ch, CURLOPT_VERBOSE, true);

    if ($validateSSL)
    {
        // The libcurl included in PHP does not come with any of the certificates needed to
        // validate SSL connections built in.  Before you can validate SSL certificates, you
        // must download a current version, install it on your system and change the path in
        // the line below to point to that file.  You can find a pre-built version of the
        // certificates bundle at
        //   http://curl.haxx.se/docs/caextract.html
        // haxx.se is the group responsible for libcurl.  If you don't trust this, you can
        // get the file used by the current version of Firefox from Mozilla.org, but will be
        // in the wrong format. You must convert it to .pem format before it can be used by libcurl.
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
        curl_setopt($ch, CURLOPT_CAINFO, "/path/to/ca-bundle.crt");
    } else
    {
        // Disable SSL verification.  This is NOT recommended.
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    }

    $result = curl_exec($ch);
    if ($result === false)
        throw new Exception ("curl Error: " . curl_error($ch));

    $http_status = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    if ($http_status != 200)
        throw new Exception("Request Failed. http status: " . $http_status);

    curl_close($ch);

    // Trim any whitespace from the front and end of the string and decode it
    $result = json_decode(trim($result));
    if (($error = get_json_error()) !== false) {
        throw new Exception("json_decode failed: " . $error);
    }

    // The API request suceeded, now, did the API request succeed or fail?
    if ($result->status == 'ERROR')
    {
        // Failed
        throw new Exception($action . ': '. $result->error_msg);
    }

    // The API call succeeded, return the decoded object
    return $result;
}

// Function to provide informative error message if the json decode fails.
function get_json_error()
{
    switch (json_last_error())
    {
        case JSON_ERROR_NONE:
            return false;
            break;
        case JSON_ERROR_DEPTH:
            return 'Maximum stack depth exceeded';
            break;
        case JSON_ERROR_STATE_MISMATCH:
            return 'Underflow or the modes mismatch';
            break;
        case JSON_ERROR_CTRL_CHAR:
            return 'Unexpected control character found';
            break;
        case JSON_ERROR_SYNTAX:
            return 'Syntax error, malformed JSON';
            break;
        case JSON_ERROR_UTF8:
            return 'Malformed UTF-8 characters, possibly incorrectly encoded';
            break;
    }
    return 'Unknown error';
}