Initial .csv -> .ics file generator for LibrePlanet

As input, the csv comes from a custom Drupal view.

diff --git a/ICS.php b/ICS.php
new file mode 100644 (file)
index 0000000..3d2473a
--- /dev/null
+++ b/ICS.php
@@ -0,0 +1,157 @@
+<?php
+
+/**
+ * This is free and unencumbered software released into the public domain.
+ * 
+ * Anyone is free to copy, modify, publish, use, compile, sell, or
+ * distribute this software, either in source code form or as a compiled
+ * binary, for any purpose, commercial or non-commercial, and by any
+ * means.
+ * 
+ * In jurisdictions that recognize copyright laws, the author or authors
+ * of this software dedicate any and all copyright interest in the
+ * software to the public domain. We make this dedication for the benefit
+ * of the public at large and to the detriment of our heirs and
+ * successors. We intend this dedication to be an overt act of
+ * relinquishment in perpetuity of all present and future rights to this
+ * software under copyright law.
+ * 
+ * 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 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.
+ * 
+ * For more information, please refer to <http://unlicense.org>
+ * 
+ * ICS.php
+ * =============================================================================
+ * Use this class to create an .ics file.
+ * 
+ *
+ * Usage
+ * -----------------------------------------------------------------------------
+ * Basic usage - generate ics file contents (see below for available properties):
+ *   $ics = new ICS($props);
+ *   $ics_file_contents = $ics->to_string();
+ *
+ * Setting properties after instantiation
+ *   $ics = new ICS();
+ *   $ics->set('summary', 'My awesome event');
+ *
+ * You can also set multiple properties at the same time by using an array:
+ *   $ics->set(array(
+ *     'dtstart' => 'now + 30 minutes',
+ *     'dtend' => 'now + 1 hour'
+ *   ));
+ *
+ * Available properties
+ * -----------------------------------------------------------------------------
+ * description
+ *   String description of the event.
+ * dtend
+ *   A date/time stamp designating the end of the event. You can use either a
+ *   DateTime object or a PHP datetime format string (e.g. "now + 1 hour").
+ * dtstart
+ *   A date/time stamp designating the start of the event. You can use either a
+ *   DateTime object or a PHP datetime format string (e.g. "now + 1 hour").
+ * location
+ *   String address or description of the location of the event.
+ * summary
+ *   String short summary of the event - usually used as the title.
+ * url
+ *   A url to attach to the the event. Make sure to add the protocol (http://
+ *   or https://).
+ */
+
+class ICS {
+  const DT_FORMAT = 'Ymd\THis\Z';
+
+  protected $properties = array();
+  private $available_properties = array(
+    'description',
+    'dtend',
+    'dtstart',
+    'location',
+    'summary',
+    'url'
+  );
+
+  public function __construct($props) {
+    $this->set($props);
+  }
+
+  public function set($key, $val = false) {
+    if (is_array($key)) {
+      foreach ($key as $k => $v) {
+        $this->set($k, $v);
+      }
+    } else {
+      if (in_array($key, $this->available_properties)) {
+        $this->properties[$key] = $this->sanitize_val($val, $key);
+      }
+    }
+  }
+
+  public function to_string() {
+    $rows = $this->build_props();
+    return implode("\r\n", $rows);
+  }
+
+  private function build_props() {
+    // Build ICS properties - add header
+    $ics_props = array(
+      'BEGIN:VCALENDAR',
+      'VERSION:2.0',
+      'PRODID:-//hacksw/handcal//NONSGML v1.0//EN',
+      'CALSCALE:GREGORIAN',
+      'BEGIN:VEVENT'
+    );
+
+    // Build ICS properties - add header
+    $props = array();
+    foreach($this->properties as $k => $v) {
+      $props[strtoupper($k . ($k === 'url' ? ';VALUE=URI' : ''))] = $v;
+    }
+
+    // Set some default values
+    $props['DTSTAMP'] = $this->format_timestamp('now');
+    $props['UID'] = uniqid();
+
+    // Append properties
+    foreach ($props as $k => $v) {
+      $ics_props[] = "$k:$v";
+    }
+
+    // Build ICS properties - add footer
+    $ics_props[] = 'END:VEVENT';
+    $ics_props[] = 'END:VCALENDAR';
+
+    return $ics_props;
+  }
+
+  private function sanitize_val($val, $key = false) {
+    switch($key) {
+      case 'dtend':
+      case 'dtstamp':
+      case 'dtstart':
+        $val = $this->format_timestamp($val);
+        break;
+      default:
+        $val = $this->escape_string($val);
+    }
+
+    return $val;
+  }
+
+  private function format_timestamp($timestamp) {
+    $dt = new DateTime($timestamp);
+    return $dt->format(self::DT_FORMAT);
+  }
+
+  private function escape_string($str) {
+    return preg_replace('/([\,;])/','\\\$1', $str);
+  }
+}

diff --git a/generate-ics.php b/generate-ics.php
new file mode 100755 (executable)
index 0000000..375dbb9
--- /dev/null
+++ b/generate-ics.php
@@ -0,0 +1,59 @@
+#! /usr/bin/php
+<?php
+
+// Copyright 2022 Andrew Engelbrecht
+// GPL-3.0-or-later
+
+// expected format:
+//
+// "Saturday","10:00 - 10:15 EDT - Welcome address","Welcome Address by FSF","Jupiter","LibrePlanet special sessions","LibrePlanet  2022","","","http://libreplanet.org/2022/speakers/#5910"
+
+include 'ICS.php';
+
+$csv = array_map('str_getcsv', explode("\n", stream_get_contents(STDIN)));
+
+foreach ($csv as $linenum => $line) {
+
+    if (count($line) <= 1) {
+        continue;
+    }
+
+    // get the date stamp
+    if ($line[0] == "Saturday") {
+        $date = "2022-03-19";
+    } else if ($line[0] == "Sunday") {
+        $date = "2022-03-20";
+    } else {
+        throw new Exception("Invalid date: " . $line[0]);
+    }
+
+    // grab the time string
+    $timestamps = array();
+    preg_match('/([0-9][0-9]:[0-9][0-9]) - ([0-9][0-9]:[0-9][0-9]) EDT.*/', $line[1], $timestamps);
+
+    if (count($timestamps) < 3) {
+        throw new Exception("Invalid time range, title: " . $line[0]);
+    }
+
+    // parse and adjust time zone by 4 hours (to UTC)
+    $start_time = intval(str_replace(':', '', $timestamps[1])) + 400;
+    $end_time = intval(str_replace(':', '', $timestamps[2])) + 400;
+
+    if ($start_time >= 2400 || $end_time >= 2400) {
+        throw new Exception("Invalid times when hackishly converting to UTC: " . $start_time . " - " . $end_time);
+    }
+
+    $ics = new ICS(array(
+        'location' => $line[3],
+        'description' => $line[2],
+        'dtstart' => $date . "T" . $start_time . "Z",
+        'dtend' => $date . "T" . $end_time . "Z",
+        'summary' => $line[4],
+        'url' => str_replace("http:", "https:", $line[8]),
+    ));
+
+    echo $ics->to_string();
+
+    echo "\n\n";
+}
+