Issue #23 - Generate a static template page every time an outage is created, updated or deleted.

classes/outagedb.php

@@ -120,6 +120,9 @@ class outagedb {
             self::calendar_update($outage);
         }
 
+        // Trigger static page update.
+        outagelib::updatestaticinfopagefile();
+
         // All done, return the id.
         return $outage->id;
     }
@@ -149,6 +152,9 @@ class outagedb {
         // Delete it and remove from calendar.
         $DB->delete_records('auth_outage', ['id' => $id]);
         self::calendar_delete($id);
+
+        // Trigger static page update.
+        outagelib::updatestaticinfopagefile();
     }
 
     /**
@@ -276,6 +282,37 @@ class outagedb {
         self::save($outage);
     }
 
+    /**
+     * Gets the next outage which has not started yet.
+     * @param null $time Timestamp reference for current time.
+     * @return outage|null The outage or null if not found.
+     */
+    public static function get_next_starting($time = null) {
+        global $DB;
+
+        if ($time === null) {
+            $time = time();
+        }
+        if (!is_int($time) || ($time <= 0)) {
+            throw new InvalidArgumentException('$time must be null or an positive int.');
+        }
+
+        $select = ':datetime <= starttime'; // End condition.
+        $data = $DB->get_records_select(
+            'auth_outage',
+            $select,
+            ['datetime' => $time],
+            'starttime ASC',
+            '*',
+            0,
+            1
+        );
+
+        // Not using $DB->get_record_select instead because there is no 'limit' parameter.
+        // Allowing multiple records still raises an internal error.
+        return (count($data) == 0) ? null : new outage(array_shift($data));
+    }
+
     /**
      * Create an event on the calendar for this outage.
      * @param outage $outage Outage to be added to the calendar.

classes/outagelib.php

@@ -16,8 +16,10 @@
 
 namespace auth_outage;
 
+use auth_outage\models\outage;
 use auth_outage_renderer;
 use Exception;
+use InvalidArgumentException;
 use moodle_url;
 
 defined('MOODLE_INTERNAL') || die();
@@ -118,4 +120,81 @@ class outagelib {
             'css' => file_get_contents($CFG->dirroot . '/auth/outage/views/warningbar.css'),
         ];
     }
+
+    /**
+     * Saves a static info page for the given outage.
+     * @param outage $outage Outage to generate the info page.
+     * @param string $file File to save the static info page.
+     * @throws Exception
+     */
+    public static function savestaticinfopage(outage $outage, $file) {
+        if (!is_string($file)) {
+            throw new InvalidArgumentException('$file is not a string.');
+        }
+
+        $html = self::get_renderer()->renderoutagepagestatic($outage);
+
+        // Sanity check before writing/overwriting old file.
+        if (!is_string($html) || ($html == '')) {
+            throw new Exception('Sanity check failed. Invalid contents on $html.');
+        }
+
+        $dir = dirname($file);
+        if (!file_exists($dir) || !is_dir($dir)) {
+            throw new Exception('Directory must exists: ' . $dir);
+        }
+        file_put_contents($file, $html);
+    }
+
+    /**
+     * Updates the static info page by (re)creating or deleting it as needed.
+     * @param null $file
+     * @throws Exception
+     */
+    public static function updatestaticinfopagefile($file = null) {
+        if (is_null($file)) {
+            $file = self::get_defaulttemplatefile();
+        }
+        if (!is_string($file)) {
+            throw new InvalidArgumentException('$file is not a string.');
+        }
+
+        $outage = outagedb::get_next_starting();
+        if (is_null($outage)) {
+            if (file_exists($file)) {
+                if (is_file($file)) {
+                    unlink($file);
+                } else {
+                    throw new Exception('Cannot remove non-file: ' . $file);
+                }
+            }
+        } else {
+            self::savestaticinfopage($outage, $file);
+        }
+    }
+
+    /**
+     * Given the HTML code for the static page, find the outage id for that page.
+     * @param $html Static info page HTML.
+     * @return int|null Outage id or null if not found.
+     */
+    public static function get_outageidfrominfopage($html) {
+        if (!is_string($html)) {
+            throw new InvalidArgumentException('$html must be a string.');
+        }
+
+        $output = [];
+        if (preg_match('/data-outage-id="(?P<id>\d+)"/', $html, $output)) {
+            return (int)$output['id'];
+        }
+        return null;
+    }
+
+    /**
+     * @return string The default template file to use for static info page.
+     */
+    public static function get_defaulttemplatefile() {
+        global $CFG;
+        return $CFG->dataroot . '/climaintenance.template.html';
+    }
 }