From df32a646a57ad35b46dbd72bcce24f84f1d9d2bc Mon Sep 17 00:00:00 2001
From: Stefan Pranger <stefan.pranger@student.tugraz.at>
Date: Fri, 2 Jul 2021 21:32:20 +0200
Subject: [PATCH] Init FSWatcher

---
 calendar-daemon.cpp |  9 ++++++
 db/FSWatcher.cpp    | 79 +++++++++++++++++++++++++++++++++++++++++++++
 db/FSWatcher.h      | 25 ++++++++++++++
 3 files changed, 113 insertions(+)
 create mode 100644 db/FSWatcher.cpp
 create mode 100644 db/FSWatcher.h

diff --git a/calendar-daemon.cpp b/calendar-daemon.cpp
index ed89b38..781af00 100644
--- a/calendar-daemon.cpp
+++ b/calendar-daemon.cpp
@@ -10,17 +10,21 @@
 #include <syslog.h>
 #include <unistd.h>
 #include <vector>
+#include <thread>
 
 
 #include <db/db.h>
 #include <db/create.h>
 #include <db/update.h>
+#include <db/FSWatcher.h>
 #include <util/notifications.h>
 #include <util/calendar_parsing.h>
 #include <ical/IcalObject.h>
 
 #include <io/debug.h>
 const int MINUTE = 1000000;
+const int MINUTE = 60;
+const int SLEEP_INTERVAL = 60 * MINUTE;
 
 sql::Database* init_database(std::string calendar) {
   return db::init(calendar + ".db");
@@ -34,6 +38,10 @@ void update_database(std::string directory, sql::Database *db) {
   }
 }
 
+void init_fswatcher(std::string directory, sql::Database *db) {
+  db::FSWatcher fswatcher(db, directory);
+  fswatcher.run();
+}
 void do_heartbeat(std::string directory, sql::Database *db) {
   util::notify("Updating files from " + directory, "");
   update_database(directory, db);
@@ -104,6 +112,7 @@ int main(void)
   std::string directory = "/home/stefan/.local/share/khal/calendars/" + calendar + "/";
   sql::Database* db = init_database(calendar);
 
+  std::thread thread([&](){ init_fswatcher(directory, db); });
 
   // Enter daemon loop
   while(1)
diff --git a/db/FSWatcher.cpp b/db/FSWatcher.cpp
new file mode 100644
index 0000000..00756c0
--- /dev/null
+++ b/db/FSWatcher.cpp
@@ -0,0 +1,79 @@
+#include <db/FSWatcher.h>
+
+#include <fstream>
+#include <string>
+#include <filesystem>
+
+#include <io/debug.h>
+#include <db/db.h>
+#include <db/update.h>
+#include <util/calendar_parsing.h>
+
+bool is_ics(const std::filesystem::path filepath) {
+  return filepath.extension() == ".ics";
+}
+
+namespace db {
+
+  FSWatcher::FSWatcher(sql::Database *db, const std::string &directory) : m_db(db), m_directory(directory) {}
+
+  void FSWatcher::run() {
+    // Parse the directory to watch
+    std::filesystem::path path(m_directory);
+
+    // Set the event handler which will be used to process particular events
+    auto create_entry = [&](inotify::Notification notification) {
+      create_event(notification.path);
+    };
+
+    auto modify_entry = [&](inotify::Notification notification) {
+      modify_event(notification.path);
+    };
+
+    auto remove_entry = [&](inotify::Notification notification) {
+      delete_event(notification.path);
+    };
+
+    /*
+    auto handleUnexpectedNotification = [](inotify::Notification notification) {
+      std::cout << "Event " << notification.event << " on " << notification.path << " at "
+                << notification.time.time_since_epoch().count()
+                << " was triggered, but was not expected" << std::endl;
+    };
+    */
+
+    auto file_creation = { inotify::Event::create };
+    auto file_deletion = { inotify::Event::remove };
+    auto file_modification = { inotify::Event::moved_to };
+
+    // The notifier is configured to watch the parsed path for the defined events. Particular files
+    // or paths can be ignored(once).
+    auto notifier = inotify::BuildNotifier()
+                        .watchPathRecursively(path)
+                        .onEvents(file_creation,     create_entry)
+                        .onEvents(file_modification, modify_entry)
+                        .onEvents(file_deletion,     remove_entry);
+
+    // The event loop is started in a separate thread context.
+    notifier.run();
+  }
+
+  void FSWatcher::create_event(const std::string event_file) {
+    if(!is_ics(event_file)) return;
+    ical::IcalObject* object = new ical::IcalObject();
+    util::parse_main_component(object, util::parse_ics_file(event_file));
+    db::insert_events(m_db, object);
+    DEBUG << "Created Event " << event_file;
+
+  }
+
+  void FSWatcher::modify_event(const std::string event_file) {
+    if(!is_ics(event_file)) return;
+    DEBUG << "Modified Event " << event_file;
+  }
+
+  void FSWatcher::delete_event(const std::string event_file) {
+    if(!is_ics(event_file)) return;
+    DEBUG << "Removing Event " << event_file;
+  }
+}
diff --git a/db/FSWatcher.h b/db/FSWatcher.h
new file mode 100644
index 0000000..19c81e9
--- /dev/null
+++ b/db/FSWatcher.h
@@ -0,0 +1,25 @@
+#pragma once
+
+#include <inotify-cpp/NotifierBuilder.h>
+#include <filesystem>
+#include <iostream>
+#include <thread>
+#include <chrono>
+
+#include <db/db.h>
+
+namespace db {
+  class FSWatcher {
+  public:
+    FSWatcher(sql::Database *db, const std::string &directory);
+
+    void run();
+
+    void create_event(const std::string event_file);
+    void modify_event(const std::string event_file);
+    void delete_event(const std::string event_file);
+  private:
+    sql::Database* m_db;
+    const std::string m_directory;
+  };
+}