#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), event_file);
    DEBUG << "Created Event " << event_file;
    db::insert_events(m_db, object);
  }

  void FSWatcher::modify_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), event_file);
    DEBUG << "Modified Event " << event_file;
    db::insert_events(m_db, object);
  }

  void FSWatcher::delete_event(const std::string event_file) {
    if(!is_ics(event_file)) return;
    DEBUG << "Removing Event " << event_file;
    db::remove_events(m_db, event_file);
  }
}