use std::path::{Path, PathBuf};

use crate::icalwrap::IcalComponent;
use crate::icalwrap::IcalDuration;
use crate::icalwrap::IcalProperty;
use crate::icalwrap::IcalTime;
use crate::icalwrap::IcalTimeZone;
use crate::icalwrap::IcalVCalendar;
use crate::icalwrap::IcalVEvent;
use crate::KhResult;

pub struct KhEvent {
  event: IcalVEvent,
  instance_timestamp: Option<IcalTime>,
}

impl KhEvent {
  pub fn get_start(&self) -> Option<IcalTime> {
    if self.is_recur_instance() {
      self.instance_timestamp.clone()
    } else {
      self.event.get_dtstart()
    }
  }

  pub fn get_end(&self) -> Option<IcalTime> {
    let dur = self.get_duration().unwrap();
    if self.is_recur_instance() {
      self.instance_timestamp.clone().map(|start| start + dur)
    } else {
      self.get_start().clone().map(|start| start + dur)
    }
  }

  pub fn with_internal_timestamp(&self, timestamp: &IcalTime) -> Self {
    Self {
      //why shallow copy?
      event: self.event.shallow_copy(),
      instance_timestamp: Some(timestamp.clone()),
    }
  }

  pub fn get_calendar_name(&self) -> Option<String> {
    self
      .event
      .get_parent()
      .and_then(|cal| cal.get_calendar_name())
  }

  pub fn get_path(&self) -> Option<&PathBuf> {
    self.event.get_parent()?.get_path()
  }

  pub fn is_allday(&self) -> bool {
    self.event.is_allday()
  }

  pub fn get_duration(&self) -> Option<IcalDuration> {
    self.event.get_duration()
  }

  pub fn get_summary(&self) -> Option<String> {
    self.event.get_summary()
  }

  pub fn get_description(&self) -> Option<String> {
    self.event.get_description()
  }

  pub fn get_location(&self) -> Option<String> {
    self.event.get_location()
  }

  pub fn get_uid(&self) -> String {
    self.event.get_uid()
  }

  pub fn get_dtstamp(&self) -> Option<String> {
    let dtstamp_kind = ical::icalproperty_kind_ICAL_DTSTAMP_PROPERTY;
    self
      .event
      .get_property(dtstamp_kind)
      .map(|prop| prop.get_value())
  }

  pub fn get_last_modified(&self) -> Option<String> {
    let last_modified_kind = ical::icalproperty_kind_ICAL_LASTMODIFIED_PROPERTY;
    self
      .event
      .get_property(last_modified_kind)
      .map(|prop| prop.get_value())
  }

  pub fn get_last_relevant_date(&self) -> Option<IcalTime> {
    //TODO this is still wrong
    //events can end at 00:00
    if self.is_allday() {
      self.get_end().map(|dtend| dtend.pred())
    } else {
      self.get_end().map(|dtend| dtend)
    }
  }

  pub fn is_recur_master(&self) -> bool {
    self.event.has_property_rrule() && self.instance_timestamp.is_none()
  }

  pub fn is_recur_instance(&self) -> bool {
    self.event.has_property_rrule() && self.instance_timestamp.is_some()
  }


  pub fn is_recur_valid(&self) -> bool {
    if self.is_recur_master() {
      true
    } else if let Some(ref timestamp) = self.instance_timestamp {
      let recur_times = self.event.get_recur_datetimes();
      recur_times.contains(timestamp)
    } else {
      self.instance_timestamp.is_none()
    }
  }

  pub fn get_recur_instances(&self) -> impl Iterator<Item = KhEvent> + '_ {
    self
      .get_recur_datetimes()
      .into_iter()
      .map(|recur_utc| recur_utc.with_timezone(&IcalTimeZone::local()))
      .map(move |recur_local| self.with_internal_timestamp(&recur_local))
  }

  pub fn get_recur_datetimes(&self) -> Vec<IcalTime> {
    self.event.get_recur_datetimes()
  }

  pub fn get_properties_by_name(&self, property_name: &str) -> Vec<IcalProperty> {
    self.event.get_properties_by_name(property_name)
  }

  pub fn from_event(event: IcalVEvent) -> Self {
    Self {
      event,
      instance_timestamp: None,
    }
  }

  pub fn from_event_with_timestamp(
    event: IcalVEvent,
    instance_timestamp: Option<IcalTime>,
  ) -> Self {
    Self {
      event,
      instance_timestamp,
    }
  }

  pub fn from_str(input: &str, path: Option<&Path>) -> KhResult<Self> {
    let cal = IcalVCalendar::from_str(input, path)?;
    Ok(cal.get_principal_khevent())
  }
}

#[cfg(test)]
mod tests {
  use super::*;
  use crate::icalwrap::IcalTimeZone;
  use crate::testdata;

  #[test]
  fn test_is_recur_valid_master() {
    let event = KhEvent::from_str(testdata::TEST_EVENT_RECUR, None).unwrap();

    assert!(event.is_recur_valid());
  }

  #[test]
  fn test_is_recur_valid_dtstart() {
    let event = KhEvent::from_str(testdata::TEST_EVENT_RECUR, None).unwrap();
    let start = &event.get_start().unwrap();

    let event = event.with_internal_timestamp(start);

    assert!(event.is_recur_valid());
  }

  #[test]
  fn test_is_recur_valid_incorrect() {
    let event = KhEvent::from_str(testdata::TEST_EVENT_RECUR, None).unwrap();

    let event = event.with_internal_timestamp(&IcalTime::floating_ymd(2010, 01, 01));

    assert!(!event.is_recur_valid());
  }

  #[test]
  fn test_is_recur_valid_other() {
    let event = KhEvent::from_str(testdata::TEST_EVENT_RECUR, None).unwrap();

    let event = event.with_internal_timestamp(&IcalTime::floating_ymd(2018, 10, 25));

    assert!(event.is_recur_valid());
  }

  #[test]
  fn test_is_recur_valid_nonrecur() {
    let event = KhEvent::from_str(testdata::TEST_EVENT_ONE_MEETING, None).unwrap();

    assert!(event.is_recur_valid());
  }

  #[test]
  fn test_is_recur_master_instance() {
    let event = KhEvent::from_str(testdata::TEST_EVENT_RECUR, None).unwrap();
    let event = event.with_internal_timestamp(&IcalTime::floating_ymd(2018, 01, 01));
    assert!(!event.is_recur_master());
  }

  #[test]
  fn test_is_recur_master() {
    let event = KhEvent::from_str(testdata::TEST_EVENT_RECUR, None).unwrap();
    assert!(event.is_recur_master());
  }

  #[test]
  fn test_is_recur_master_invalid() {
    let event = KhEvent::from_str(testdata::TEST_EVENT_ONE_MEETING, None).unwrap();
    assert!(!event.is_recur_master());
  }

  #[test]
  fn recur_datetimes_test() {
    let event = KhEvent::from_str(testdata::TEST_EVENT_RECUR, None).unwrap();

    let mut recur_instances = event.get_recur_instances();
    let local = IcalTimeZone::local();
    assert_eq!(
      IcalTime::floating_ymd(2018, 10, 11).with_timezone(&local),
      recur_instances.next().unwrap().get_start().unwrap()
    );
    assert_eq!(
      IcalTime::floating_ymd(2018, 10, 18).with_timezone(&local),
      recur_instances.next().unwrap().get_start().unwrap()
    );
  }

  #[test]
  fn recur_iterator_test() {
    testdata::setup();
    let event = KhEvent::from_str(testdata::TEST_EVENT_RECUR, None).unwrap();

    assert_eq!(IcalTime::floating_ymd(2018, 10, 11), event.get_start().unwrap());
    assert_eq!(IcalTime::floating_ymd(2018, 10, 13), event.get_end().unwrap());
    assert_eq!("RRULE:FREQ=WEEKLY;COUNT=10", event.event.get_property(ical::icalproperty_kind_ICAL_RRULE_PROPERTY).unwrap().as_ical_string());
    assert_eq!(10, event.get_recur_datetimes().len());
    assert_eq!(10, event.get_recur_instances().count());
  }

  #[test]
  fn get_duration_test() {
    let event = KhEvent::from_str(testdata::TEST_DTSTART_ONLY_DATE, None).unwrap();

    assert!(event.is_allday());
    assert_eq!(
      Some(IcalDuration::from_seconds(24 * 60 * 60)),
      event.get_duration()
    );
  }

  #[test]
  fn test_get_dtstart() {
    let event = KhEvent::from_str(testdata::TEST_DTSTART_ONLY_DATE, None).unwrap();

    assert!(event.is_allday());
    assert_eq!(
      Some(IcalDuration::from_seconds(24 * 60 * 60)),
      event.get_duration()
    );
  }
}