use std::{
  marker::PhantomData,
  sync::{Arc, RwLock},
  time::Duration,
};

use mio::Evented;
use mio_extras::channel::{self as mio_channel, Receiver};

use serde::Serialize;
use log::{error, warn};

use crate::{
  discovery::discovery::DiscoveryCommand, serialization::CDRSerializerAdapter,
  dds::qos::policy::Liveliness, structure::time::Timestamp,
};
use crate::structure::entity::{RTPSEntity};
use crate::structure::{
  dds_cache::DDSCache,
  guid::{GUID, EntityId},
  topic_kind::TopicKind,
};

use crate::dds::pubsub::Publisher;
use crate::dds::topic::Topic;
use crate::log_and_err_precondition_not_met;
use crate::dds::values::result::{ Result, Error, };
use crate::dds::statusevents::*;
use crate::dds::traits::dds_entity::DDSEntity;
use crate::dds::traits::key::*;
use crate::dds::traits::TopicDescription;

use crate::dds::qos::{
  HasQoSPolicy, QosPolicies,
  policy::{Reliability},
};
use crate::dds::traits::serde_adapters::SerializerAdapter;
use crate::dds::with_key::datasample::DataSample;
use crate::{discovery::data_types::topic_data::SubscriptionBuiltinTopicData, dds::ddsdata::DDSData};
use super::super::{datasample_cache::DataSampleCache, writer::WriterCommand, };

/// DDS DataWriter for keyed topics
///
/// # Examples
///
/// ```
/// use serde::{Serialize, Deserialize};
/// use rustdds::dds::DomainParticipant;
/// use rustdds::dds::qos::QosPolicyBuilder;
/// use rustdds::dds::data_types::TopicKind;
/// use rustdds::dds::With_Key_DataWriter as DataWriter;
/// use rustdds::dds::traits::Keyed;
/// use rustdds::serialization::CDRSerializerAdapter;
///
/// let domain_participant = DomainParticipant::new(0);
/// let qos = QosPolicyBuilder::new().build();
/// let publisher = domain_participant.create_publisher(&qos).unwrap();
///
/// #[derive(Serialize, Deserialize)]
/// struct SomeType { a: i32 }
/// impl Keyed for SomeType {
///   type K = i32;
///
///   fn get_key(&self) -> Self::K {
///     self.a
///   }
/// }
///
/// // WithKey is important
/// let topic = domain_participant.create_topic("some_topic", "SomeType", &qos, TopicKind::WithKey).unwrap();
/// let data_writer = publisher.create_datawriter::<SomeType, CDRSerializerAdapter<_>>(None, topic, None);
/// ```
pub struct DataWriter<D: Keyed + Serialize, SA: SerializerAdapter<D> = CDRSerializerAdapter<D>>
{
  my_publisher: Publisher,
  my_topic: Topic,
  qos_policy: QosPolicies,
  my_guid: GUID,
  cc_upload: mio_channel::SyncSender<WriterCommand>,
  discovery_command: mio_channel::SyncSender<DiscoveryCommand>,
  dds_cache: Arc<RwLock<DDSCache>>,
  datasample_cache: DataSampleCache<D>,
  phantom: PhantomData<SA>,
  status_receiver: StatusReceiver<DataWriterStatus>,
}

impl<D, SA> Drop for DataWriter<D, SA>
where
  D: Keyed + Serialize,
  SA: SerializerAdapter<D>,
{
  fn drop(&mut self) {
    match self
      .discovery_command
      .send(DiscoveryCommand::REMOVE_LOCAL_WRITER {
        guid: self.get_guid(),
      }) {
      Ok(_) => {}
      Err(e) => error!(
        "Failed to send REMOVE_LOCAL_WRITER DiscoveryCommand. {:?}",
        e
      ),
    }
  }
}

impl<D, SA> DataWriter<D, SA>
where
  D: Keyed + Serialize,
  <D as Keyed>::K: Key,
  SA: SerializerAdapter<D>,
{
  pub(crate) fn new(
    publisher: Publisher,
    topic: Topic,
    guid: Option<GUID>,
    cc_upload: mio_channel::SyncSender<WriterCommand>,
    discovery_command: mio_channel::SyncSender<DiscoveryCommand>,
    dds_cache: Arc<RwLock<DDSCache>>,
    status_receiver_rec: Receiver<DataWriterStatus>,
  ) -> Result<DataWriter<D, SA>> {
    let entity_id = match guid {
      Some(g) => g.entityId.clone(),
      None => EntityId::ENTITYID_UNKNOWN,
    };

    let dp = match publisher.get_participant() {
      Some(dp) => dp,
      None => return 
        log_and_err_precondition_not_met!("Cannot create new DataWriter, DomainParticipant doesn't exist.") ,
    };

    let my_guid = GUID::new_with_prefix_and_id(dp.get_guid_prefix().clone(), entity_id );

    match dds_cache.write() {
      Ok(mut cache) => cache.add_new_topic(
        &String::from(topic.get_name()),
        TopicKind::NoKey,
        topic.get_type(),
      ),
      Err(e) => panic!("DDSCache is poisoned. {:?}", e),
    };

    match topic.get_qos().liveliness {
      Some(lv) => match lv {
        Liveliness::Automatic { lease_duration: _ } => (),
        Liveliness::ManualByParticipant { lease_duration: _ } => {
          match discovery_command.send(DiscoveryCommand::MANUAL_ASSERT_LIVELINESS) {
            Ok(_) => (),
            Err(e) => {
              error!("Failed to send DiscoveryCommand - Refresh. {:?}", e);
            }
          }
        }
        Liveliness::ManualByTopic { lease_duration: _ } => (),
      },
      None => (),
    };
    let qos = topic.get_qos().clone();
    Ok(DataWriter {
      my_publisher: publisher,
      my_topic: topic,
      qos_policy: qos.clone(),
      my_guid,
      cc_upload,
      discovery_command,
      dds_cache,
      datasample_cache: DataSampleCache::new(qos),
      phantom: PhantomData,
      status_receiver: StatusReceiver::new(status_receiver_rec),
    })
  }

  // This one function provides both get_matched_subscrptions and get_matched_subscription_data
  // TODO: Maybe we could return references to the subscription data to avoid copying?
  // But then what if the result set changes while the application processes it?

  /// Manually refreshes liveliness if QoS allows it
  ///
  /// # Examples
  ///
  /// ```
  /// # use serde::{Serialize, Deserialize};
  /// # use rustdds::dds::DomainParticipant;
  /// # use rustdds::dds::qos::QosPolicyBuilder;
  /// # use rustdds::dds::data_types::TopicKind;
  /// # use rustdds::dds::With_Key_DataWriter as DataWriter;
  /// # use rustdds::dds::traits::Keyed;
  /// # use rustdds::serialization::CDRSerializerAdapter;
  /// #
  /// let domain_participant = DomainParticipant::new(0);
  /// let qos = QosPolicyBuilder::new().build();
  /// let publisher = domain_participant.create_publisher(&qos).unwrap();
  ///
  /// #[derive(Serialize, Deserialize)]
  /// struct SomeType { a: i32 }
  /// impl Keyed for SomeType {
  ///   type K = i32;
  ///
  ///   fn get_key(&self) -> Self::K {
  ///     self.a
  ///   }
  /// }
  ///
  /// // WithKey is important
  /// let topic = domain_participant.create_topic("some_topic", "SomeType", &qos, TopicKind::WithKey).unwrap();
  /// let data_writer = publisher.create_datawriter::<SomeType, CDRSerializerAdapter<_>>(None, topic, None).unwrap();
  ///
  /// data_writer.refresh_manual_liveliness();
  /// ```

  // TODO: What is this function? To what part of DDS spec does it correspond to?
  pub fn refresh_manual_liveliness(&self) {
    match self.get_qos().liveliness {
      Some(lv) => match lv {
        Liveliness::Automatic { lease_duration: _ } => (),
        Liveliness::ManualByParticipant { lease_duration: _ } => {
          match self
            .discovery_command
            .send(DiscoveryCommand::MANUAL_ASSERT_LIVELINESS)
          {
            Ok(_) => (),
            Err(e) => {
              error!("Failed to send DiscoveryCommand - Refresh. {:?}", e);
            }
          }
        }
        Liveliness::ManualByTopic { lease_duration: _ } => (),
      },
      None => (),
    };
  }

  /// Writes single data instance to a topic.
  ///
  /// # Examples
  ///
  /// ```
  /// # use serde::{Serialize, Deserialize};
  /// # use rustdds::dds::DomainParticipant;
  /// # use rustdds::dds::qos::QosPolicyBuilder;
  /// # use rustdds::dds::data_types::TopicKind;
  /// # use rustdds::dds::With_Key_DataWriter as DataWriter;
  /// # use rustdds::dds::traits::Keyed;
  /// # use rustdds::serialization::CDRSerializerAdapter;
  /// #
  /// let domain_participant = DomainParticipant::new(0);
  /// let qos = QosPolicyBuilder::new().build();
  /// let publisher = domain_participant.create_publisher(&qos).unwrap();
  ///
  /// #[derive(Serialize, Deserialize)]
  /// struct SomeType { a: i32 }
  /// impl Keyed for SomeType {
  ///   type K = i32;
  ///
  ///   fn get_key(&self) -> Self::K {
  ///     self.a
  ///   }
  /// }
  ///
  /// // WithKey is important
  /// let topic = domain_participant.create_topic("some_topic", "SomeType", &qos, TopicKind::WithKey).unwrap();
  /// let data_writer = publisher.create_datawriter::<SomeType, CDRSerializerAdapter<_>>(None, topic, None).unwrap();
  ///
  /// let some_data = SomeType { a: 1 };
  /// data_writer.write(some_data, None).unwrap();
  /// ```
  pub fn write(&self, data: D, source_timestamp: Option<Timestamp>) -> Result<()> {
    let mut ddsdata = DDSData::from(&data, source_timestamp);
    // TODO key value should be unique always. This is not always unique.
    // If sample with same values is given then hash is same for both samples.
    // TODO FIX THIS
    ddsdata.value_key_hash = data.get_key().into_hash_key();

    let _data_sample = match source_timestamp {
      // TODO: fix this to use something else than new_deprecated.
      // We cannot generate DataSample at the writer side, because most of the
      // SampleInfo fields cannot be known.
      Some(t) => DataSample::new_deprecated(t, data, self.get_guid()),
      None => DataSample::new_deprecated(Timestamp::now(), data, self.get_guid()),
    };

    match self
      .cc_upload
      .try_send(WriterCommand::DDSData { data: ddsdata })
    {
      Ok(_) => {
        self.refresh_manual_liveliness();
        Ok(())
      }
      Err(e) => {
        warn!("Failed to write new data. {:?}", e);
        Err(Error::OutOfResources)
      }
    }
  }

  /// Waits for all acknowledgements to finish
  ///
  /// # Examples
  ///
  /// ```
  /// # use serde::{Serialize, Deserialize};
  /// # use rustdds::dds::DomainParticipant;
  /// # use rustdds::dds::qos::QosPolicyBuilder;
  /// # use rustdds::dds::data_types::TopicKind;
  /// # use rustdds::dds::With_Key_DataWriter as DataWriter;
  /// # use rustdds::dds::traits::Keyed;
  /// # use rustdds::serialization::CDRSerializerAdapter;
  /// #
  /// let domain_participant = DomainParticipant::new(0);
  /// let qos = QosPolicyBuilder::new().build();
  /// let publisher = domain_participant.create_publisher(&qos).unwrap();
  ///
  /// #[derive(Serialize, Deserialize)]
  /// struct SomeType { a: i32 }
  /// impl Keyed for SomeType {
  ///   type K = i32;
  ///
  ///   fn get_key(&self) -> Self::K {
  ///     self.a
  ///   }
  /// }
  ///
  /// // WithKey is important
  /// let topic = domain_participant.create_topic("some_topic", "SomeType", &qos, TopicKind::WithKey).unwrap();
  /// let data_writer = publisher.create_datawriter::<SomeType, CDRSerializerAdapter<_>>(None, topic, None).unwrap();
  ///
  /// let some_data = SomeType { a: 1 };
  /// data_writer.write(some_data, None).unwrap();
  /// data_writer.wait_for_acknowledgments(std::time::Duration::from_millis(100));
  /// ```
  pub fn wait_for_acknowledgments(&self, _max_wait: Duration) -> Result<()> {
    match &self.qos_policy.reliability {
      Some(rel) => match rel {
        Reliability::BestEffort => return Ok(()),
        Reliability::Reliable {
          max_blocking_time: _,
        } =>
        // TODO: implement actual waiting for acks
        {
          ()
        }
      },
      None => return Ok(()),
    };

    // TODO: wait for actual acknowledgements to writers writes
    return Err(Error::Unsupported);
  }
  /*
  /// Gets mio Receiver for all status changes
  ///
  /// # Examples
  ///
  /// ```
  /// # use serde::{Serialize, Deserialize};
  /// # use rustdds::dds::DomainParticipant;
  /// # use rustdds::dds::qos::QosPolicyBuilder;
  /// # use rustdds::dds::data_types::TopicKind;
  /// # use rustdds::dds::With_Key_DataWriter as DataWriter;
  /// # use rustdds::dds::traits::Keyed;
  /// # use rustdds::serialization::CDRSerializerAdapter;
  /// #
  /// let domain_participant = DomainParticipant::new(0);
  /// let qos = QosPolicyBuilder::new().build();
  /// let publisher = domain_participant.create_publisher(&qos).unwrap();
  ///
  /// #[derive(Serialize, Deserialize)]
  /// struct SomeType { a: i32 }
  /// impl Keyed for SomeType {
  ///   type K = i32;
  ///
  ///   fn get_key(&self) -> Self::K {
  ///     self.a
  ///   }
  /// }
  ///
  /// // WithKey is important
  /// let topic = domain_participant.create_topic("some_topic", "SomeType", &qos, TopicKind::WithKey).unwrap();
  /// let data_writer = publisher.create_datawriter::<SomeType, CDRSerializerAdapter<_>>(None, topic, None).unwrap();
  ///
  /// // Some status has changed
  ///
  /// while let Ok(sc) = data_writer.get_status_listener().try_recv() {
  ///   // do something
  /// }
  /// ```
  pub fn get_status_listener(&self) -> &Receiver<StatusChange> {
    match self
      .cc_upload
      .try_send(WriterCommand::ResetOfferedDeadlineMissedStatus {
        writer_guid: self.get_guid(),
      }) {
      Ok(_) => (),
      Err(e) => error!("Unable to send ResetOfferedDeadlineMissedStatus. {:?}", e),
    };
    &self.status_receiver
  }

  /// Unimplemented. <b>Do not use</b>.
  ///
  /// # Examples
  ///
  /// ```no_run
  // TODO: enable when functional
  /// # use serde::{Serialize, Deserialize};
  /// # use rustdds::dds::DomainParticipant;
  /// # use rustdds::dds::qos::QosPolicyBuilder;
  /// # use rustdds::dds::data_types::TopicKind;
  /// # use rustdds::dds::With_Key_DataWriter as DataWriter;
  /// # use rustdds::dds::traits::Keyed;
  /// # use rustdds::serialization::CDRSerializerAdapter;
  /// #
  /// let domain_participant = DomainParticipant::new(0);
  /// let qos = QosPolicyBuilder::new().build();
  /// let publisher = domain_participant.create_publisher(&qos).unwrap();
  ///
  /// #[derive(Serialize, Deserialize)]
  /// struct SomeType { a: i32 }
  /// impl Keyed for SomeType {
  ///   type K = i32;
  ///
  ///   fn get_key(&self) -> Self::K {
  ///     self.a
  ///   }
  /// }
  ///
  /// // WithKey is important
  /// let topic = domain_participant.create_topic("some_topic", "SomeType", &qos, TopicKind::WithKey).unwrap();
  /// let data_writer = publisher.create_datawriter::<SomeType, CDRSerializerAdapter<_>>(None, topic, None).unwrap();
  ///
  /// // Liveliness lost status has changed
  ///
  /// if let Ok(lls) = data_writer.get_liveliness_lost_status() {
  ///   // do something
  /// }
  /// ```
  pub fn get_liveliness_lost_status(&self) -> Result<LivelinessLostStatus> {
    todo!()
  }

  /// Should get latest offered deadline missed status. <b>Do not use yet</b> use `get_status_lister` instead for the moment.
  ///
  /// # Examples
  ///
  /// ```
  /// # use serde::{Serialize, Deserialize};
  /// # use rustdds::dds::DomainParticipant;
  /// # use rustdds::dds::qos::QosPolicyBuilder;
  /// # use rustdds::dds::data_types::TopicKind;
  /// # use rustdds::dds::With_Key_DataWriter as DataWriter;
  /// # use rustdds::dds::traits::Keyed;
  /// # use rustdds::serialization::CDRSerializerAdapter;
  /// #
  /// let domain_participant = DomainParticipant::new(0);
  /// let qos = QosPolicyBuilder::new().build();
  /// let publisher = domain_participant.create_publisher(&qos).unwrap();
  ///
  /// #[derive(Serialize, Deserialize)]
  /// struct SomeType { a: i32 }
  /// impl Keyed for SomeType {
  ///   type K = i32;
  ///
  ///   fn get_key(&self) -> Self::K {
  ///     self.a
  ///   }
  /// }
  ///
  /// // WithKey is important
  /// let topic = domain_participant.create_topic("some_topic", "SomeType", &qos, TopicKind::WithKey).unwrap();
  /// let data_writer = publisher.create_datawriter::<SomeType, CDRSerializerAdapter<_>>(None, topic, None).unwrap();
  ///
  /// // Deadline missed status has changed
  ///
  /// if let Ok(odms) = data_writer.get_offered_deadline_missed_status() {
  ///   // do something
  /// }
  /// ```
  pub fn get_offered_deadline_missed_status(&self) -> Result<OfferedDeadlineMissedStatus> {
    let mut fstatus = OfferedDeadlineMissedStatus::new();
    while let Ok(status) = self.status_receiver.try_recv() {
      match status {
        StatusChange::OfferedDeadlineMissedStatus(status) => fstatus = status,
        // TODO: possibly save old statuses
        _ => (),
      }
    }

    match self
      .cc_upload
      .try_send(WriterCommand::ResetOfferedDeadlineMissedStatus {
        writer_guid: self.get_guid(),
      }) {
      Ok(_) => (),
      Err(e) => error!("Unable to send ResetOfferedDeadlineMissedStatus. {:?}", e),
    };

    Ok(fstatus)
  }

  /// Unimplemented. <b>Do not use</b>.
  ///
  /// # Examples
  ///
  /// ```no_run
  // TODO: enable when functional
  /// # use serde::{Serialize, Deserialize};
  /// # use rustdds::dds::DomainParticipant;
  /// # use rustdds::dds::qos::QosPolicyBuilder;
  /// # use rustdds::dds::data_types::TopicKind;
  /// # use rustdds::dds::With_Key_DataWriter as DataWriter;
  /// # use rustdds::dds::traits::Keyed;
  /// # use rustdds::serialization::CDRSerializerAdapter;
  /// #
  /// let domain_participant = DomainParticipant::new(0);
  /// let qos = QosPolicyBuilder::new().build();
  /// let publisher = domain_participant.create_publisher(&qos).unwrap();
  ///
  /// #[derive(Serialize, Deserialize)]
  /// struct SomeType { a: i32 }
  /// impl Keyed for SomeType {
  ///   type K = i32;
  ///
  ///   fn get_key(&self) -> Self::K {
  ///     self.a
  ///   }
  /// }
  ///
  /// // WithKey is important
  /// let topic = domain_participant.create_topic("some_topic", "SomeType", &qos, TopicKind::WithKey).unwrap();
  /// let data_writer = publisher.create_datawriter::<SomeType, CDRSerializerAdapter<_>>(None, topic, None).unwrap();
  ///
  /// // Liveliness lost status has changed
  ///
  /// if let Ok(oiqs) = data_writer.get_offered_incompatible_qos_status() {
  ///   // do something
  /// }
  /// ```
  pub fn get_offered_incompatible_qos_status(&self) -> Result<OfferedIncompatibleQosStatus> {
    todo!()
  }

  /// Unimplemented. <b>Do not use</b>.
  ///
  /// # Examples
  ///
  /// ```no_run
  // TODO: enable when functional
  /// # use serde::{Serialize, Deserialize};
  /// # use rustdds::dds::DomainParticipant;
  /// # use rustdds::dds::qos::QosPolicyBuilder;
  /// # use rustdds::dds::data_types::TopicKind;
  /// # use rustdds::dds::With_Key_DataWriter as DataWriter;
  /// # use rustdds::dds::traits::Keyed;
  /// # use rustdds::serialization::CDRSerializerAdapter;
  /// #
  /// let domain_participant = DomainParticipant::new(0);
  /// let qos = QosPolicyBuilder::new().build();
  /// let publisher = domain_participant.create_publisher(&qos).unwrap();
  ///
  /// #[derive(Serialize, Deserialize)]
  /// struct SomeType { a: i32 }
  /// impl Keyed for SomeType {
  ///   type K = i32;
  ///
  ///   fn get_key(&self) -> Self::K {
  ///     self.a
  ///   }
  /// }
  ///
  /// // WithKey is important
  /// let topic = domain_participant.create_topic("some_topic", "SomeType", &qos, TopicKind::WithKey).unwrap();
  /// let data_writer = publisher.create_datawriter::<SomeType, CDRSerializerAdapter<_>>(None, topic, None).unwrap();
  ///
  /// // Liveliness lost status has changed
  ///
  /// if let Ok(pms) = data_writer.get_publication_matched_status() {
  ///   // do something
  /// }
  /// ```
  pub fn get_publication_matched_status(&self) -> Result<PublicationMatchedStatus> {
    todo!()
  }
  
  */

  /// Topic assigned to this DataWriter
  ///
  /// # Examples
  ///
  /// ```
  /// # use serde::{Serialize, Deserialize};
  /// # use rustdds::dds::DomainParticipant;
  /// # use rustdds::dds::qos::QosPolicyBuilder;
  /// # use rustdds::dds::data_types::TopicKind;
  /// # use rustdds::dds::With_Key_DataWriter as DataWriter;
  /// # use rustdds::dds::traits::Keyed;
  /// # use rustdds::serialization::CDRSerializerAdapter;
  /// #
  /// let domain_participant = DomainParticipant::new(0);
  /// let qos = QosPolicyBuilder::new().build();
  /// let publisher = domain_participant.create_publisher(&qos).unwrap();
  ///
  /// #[derive(Serialize, Deserialize)]
  /// struct SomeType { a: i32 }
  /// impl Keyed for SomeType {
  ///   type K = i32;
  ///
  ///   fn get_key(&self) -> Self::K {
  ///     self.a
  ///   }
  /// }
  ///
  /// // WithKey is important
  /// let topic = domain_participant.create_topic("some_topic", "SomeType", &qos, TopicKind::WithKey).unwrap();
  /// let data_writer = publisher.create_datawriter::<SomeType, CDRSerializerAdapter<_>>(None, topic.clone(), None).unwrap();
  ///
  /// assert_eq!(data_writer.get_topic(), &topic);
  /// ```
  pub fn get_topic(&self) -> &Topic {
    &self.my_topic
  }

  /// Publisher assigned to this DataWriter
  ///
  /// # Examples
  ///
  /// ```
  /// # use serde::{Serialize, Deserialize};
  /// # use rustdds::dds::DomainParticipant;
  /// # use rustdds::dds::qos::QosPolicyBuilder;
  /// # use rustdds::dds::data_types::TopicKind;
  /// # use rustdds::dds::With_Key_DataWriter as DataWriter;
  /// # use rustdds::dds::traits::Keyed;
  /// # use rustdds::serialization::CDRSerializerAdapter;
  /// #
  /// let domain_participant = DomainParticipant::new(0);
  /// let qos = QosPolicyBuilder::new().build();
  /// let publisher = domain_participant.create_publisher(&qos).unwrap();
  ///
  /// #[derive(Serialize, Deserialize)]
  /// struct SomeType { a: i32 }
  /// impl Keyed for SomeType {
  ///   type K = i32;
  ///
  ///   fn get_key(&self) -> Self::K {
  ///     self.a
  ///   }
  /// }
  ///
  /// // WithKey is important
  /// let topic = domain_participant.create_topic("some_topic", "SomeType", &qos, TopicKind::WithKey).unwrap();
  /// let data_writer = publisher.create_datawriter::<SomeType, CDRSerializerAdapter<_>>(None, topic, None).unwrap();
  ///
  /// assert_eq!(data_writer.get_publisher(), &publisher);
  pub fn get_publisher(&self) -> &Publisher {
    &self.my_publisher
  }

  /// Manually asserts liveliness (use this instead of refresh) according to QoS
  ///
  /// # Examples
  ///
  /// ```
  /// # use serde::{Serialize, Deserialize};
  /// # use rustdds::dds::DomainParticipant;
  /// # use rustdds::dds::qos::QosPolicyBuilder;
  /// # use rustdds::dds::data_types::TopicKind;
  /// # use rustdds::dds::With_Key_DataWriter as DataWriter;
  /// # use rustdds::dds::traits::Keyed;
  /// # use rustdds::serialization::CDRSerializerAdapter;
  /// #
  /// let domain_participant = DomainParticipant::new(0);
  /// let qos = QosPolicyBuilder::new().build();
  /// let publisher = domain_participant.create_publisher(&qos).unwrap();
  ///
  /// #[derive(Serialize, Deserialize)]
  /// struct SomeType { a: i32 }
  /// impl Keyed for SomeType {
  ///   type K = i32;
  ///
  ///   fn get_key(&self) -> Self::K {
  ///     self.a
  ///   }
  /// }
  ///
  /// // WithKey is important
  /// let topic = domain_participant.create_topic("some_topic", "SomeType", &qos, TopicKind::WithKey).unwrap();
  /// let data_writer = publisher.create_datawriter::<SomeType, CDRSerializerAdapter<_>>(None, topic, None).unwrap();
  ///
  /// data_writer.assert_liveliness().unwrap();
  /// ```

  //TODO: This cannot really fail, so could change type to () (alternatively, make send error visible)
  pub fn assert_liveliness(&self) -> Result<()> {
    self.refresh_manual_liveliness();

    match self.get_qos().liveliness {
      Some(Liveliness::ManualByTopic { lease_duration: _ }) => {
        self.discovery_command
          .send(DiscoveryCommand::ASSERT_TOPIC_LIVELINESS {
            writer_guid: self.get_guid(),
            manual_assertion: true, // by definition of this function
            })
          .unwrap_or_else( |e| error!("assert_liveness - Failed to send DiscoveryCommand. {:?}", e))
        }
      _other => (),
    }
    Ok(())
  }

  /// Unimplemented. <b>Do not use</b>.
  ///
  /// # Examples
  ///
  /// ```no_run
  // TODO: enable when available
  /// # use serde::{Serialize, Deserialize};
  /// # use rustdds::dds::DomainParticipant;
  /// # use rustdds::dds::qos::QosPolicyBuilder;
  /// # use rustdds::dds::data_types::TopicKind;
  /// # use rustdds::dds::With_Key_DataWriter as DataWriter;
  /// # use rustdds::dds::traits::Keyed;
  /// # use rustdds::serialization::CDRSerializerAdapter;
  /// #
  /// let domain_participant = DomainParticipant::new(0);
  /// let qos = QosPolicyBuilder::new().build();
  /// let publisher = domain_participant.create_publisher(&qos).unwrap();
  ///
  /// #[derive(Serialize, Deserialize)]
  /// struct SomeType { a: i32 }
  /// impl Keyed for SomeType {
  ///   type K = i32;
  ///
  ///   fn get_key(&self) -> Self::K {
  ///     self.a
  ///   }
  /// }
  ///
  /// // WithKey is important
  /// let topic = domain_participant.create_topic("some_topic", "SomeType", &qos, TopicKind::WithKey).unwrap();
  /// let data_writer = publisher.create_datawriter::<SomeType, CDRSerializerAdapter<_>>(None, topic, None).unwrap();
  ///
  /// for sub in data_writer.get_matched_subscriptions().iter() {
  ///   // do something
  /// }
  pub fn get_matched_subscriptions(&self) -> Vec<SubscriptionBuiltinTopicData> {
    todo!()
  }

  /// Disposes data instance with specified key
  ///
  /// # Arguments
  ///
  /// * `key` - Key of the instance
  /// * `source_timestamp` - DDS source timestamp (None uses now as time as specified in DDS spec)
  ///
  /// # Examples
  ///
  /// ```
  /// # use serde::{Serialize, Deserialize};
  /// # use rustdds::dds::DomainParticipant;
  /// # use rustdds::dds::qos::QosPolicyBuilder;
  /// # use rustdds::dds::data_types::TopicKind;
  /// # use rustdds::dds::With_Key_DataWriter as DataWriter;
  /// # use rustdds::dds::traits::Keyed;
  /// # use rustdds::serialization::CDRSerializerAdapter;
  /// #
  /// let domain_participant = DomainParticipant::new(0);
  /// let qos = QosPolicyBuilder::new().build();
  /// let publisher = domain_participant.create_publisher(&qos).unwrap();
  ///
  /// #[derive(Serialize, Deserialize)]
  /// struct SomeType { a: i32, val: usize }
  /// impl Keyed for SomeType {
  ///   type K = i32;
  ///
  ///   fn get_key(&self) -> Self::K {
  ///     self.a
  ///   }
  /// }
  ///
  /// // WithKey is important
  /// let topic = domain_participant.create_topic("some_topic", "SomeType", &qos, TopicKind::WithKey).unwrap();
  /// let data_writer = publisher.create_datawriter::<SomeType, CDRSerializerAdapter<_>>(None, topic, None).unwrap();
  ///
  /// let some_data_1_1 = SomeType { a: 1, val: 3};
  /// let some_data_1_2 = SomeType { a: 1, val: 4};
  /// // different key
  /// let some_data_2_1 = SomeType { a: 2, val: 5};
  /// let some_data_2_2 = SomeType { a: 2, val: 6};
  ///
  /// data_writer.write(some_data_1_1, None).unwrap();
  /// data_writer.write(some_data_1_2, None).unwrap();
  /// data_writer.write(some_data_2_1, None).unwrap();
  /// data_writer.write(some_data_2_2, None).unwrap();
  ///
  /// // disposes both some_data_1_1 and some_data_1_2. They are no longer offered by this writer to this topic.
  /// data_writer.dispose(1, None).unwrap();
  /// ```
  pub fn dispose(&self, key: <D as Keyed>::K, source_timestamp: Option<Timestamp>) -> Result<()> {
    /*

    Removing this for now, as there is need to redesign the mechanism of transmitting dispose actions
    to RTPS Writer. Then the RTPS writer needs to execute the dispose. That is done by sending a DATA
    submessage with the serialized key instead of data, and sending inline QoS parameter
    StatusInfo_t (see RTPS spec 9.6.3.4) to indicate "disposed"
    */

    let mut ddsdata = DDSData::from_dispose::<D>(key.clone(), source_timestamp);
    // TODO key value should be unique always. This is not always unique.
    // If sample with same values is given then hash is same for both samples.
    // TODO FIX THIS
    ddsdata.value_key_hash = key.into_hash_key();

    // What does this block of code do? What is the purpose of _data_sample?
    let _data_sample: DataSample<D> = match source_timestamp {
      Some(t) => DataSample::<D>::new_disposed::<<D as Keyed>::K>(t, key, self.get_guid()),
      None => DataSample::new_disposed::<<D as Keyed>::K>(Timestamp::now(), key, self.get_guid()),
    };

    match self
      .cc_upload
      .try_send(WriterCommand::DDSData { data: ddsdata })
    {
      Ok(_) => {
        self.refresh_manual_liveliness();
        Ok(())
      }
      Err(huh) => {
        warn!("Error: {:?}", huh);
        Err(Error::OutOfResources)
      }
    }
  }
}

impl <D,SA> StatusEvented<DataWriterStatus> for DataWriter<D,SA>
where
  D: Keyed + Serialize,
  SA: SerializerAdapter<D>,
{
  fn as_status_evented(&mut self) -> &dyn Evented {
    self.status_receiver.as_status_evented()
  }

  fn try_recv_status(&self) -> Option<DataWriterStatus> {
    self.status_receiver.try_recv_status()
  }  
}

impl<D, SA> RTPSEntity for DataWriter<D, SA>
where
  D: Keyed + Serialize,
  SA: SerializerAdapter<D>,
{
  fn get_guid(&self) -> GUID {
    self.my_guid
  }
}

impl<D, SA> HasQoSPolicy for DataWriter<D, SA>
where
  D: Keyed + Serialize,
  SA: SerializerAdapter<D>,
{
  // fn set_qos(&mut self, policy: &QosPolicies) -> Result<()> {
  //   // TODO: check liveliness of qos_policy
  //   self.qos_policy = policy.clone();
  //   Ok(())
  // }

  fn get_qos(&self) -> QosPolicies {
    self.qos_policy.clone()
  }
}

impl<D, SA> DDSEntity for DataWriter<D, SA>
where
  D: Keyed + Serialize,
  SA: SerializerAdapter<D>,
{
}

#[cfg(test)]
mod tests {
  use super::*;
  use crate::dds::participant::DomainParticipant;
  use crate::test::random_data::*;
  use std::thread;
  use crate::dds::traits::key::Keyed;
  use crate::serialization::cdr_serializer::CDRSerializerAdapter;
  use byteorder::LittleEndian;
  use log::info;

  #[test]
  fn dw_write_test() {
    let domain_participant = DomainParticipant::new(0);
    let qos = QosPolicies::qos_none();
    let _default_dw_qos = QosPolicies::qos_none();
    let publisher = domain_participant
      .create_publisher(&qos)
      .expect("Failed to create publisher");
    let topic = domain_participant
      .create_topic("Aasii", "Huh?", &qos, TopicKind::WithKey)
      .expect("Failed to create topic");

    let data_writer: DataWriter<RandomData, CDRSerializerAdapter<RandomData, LittleEndian>> =
      publisher
        .create_datawriter(None, topic, None)
        .expect("Failed to create datawriter");

    let mut data = RandomData {
      a: 4,
      b: "Fobar".to_string(),
    };

    data_writer
      .write(data.clone(), None)
      .expect("Unable to write data");

    data.a = 5;
    let timestamp = Timestamp::now();
    data_writer
      .write(data, Some(timestamp))
      .expect("Unable to write data with timestamp");

    // TODO: verify that data is sent/writtent correctly
    // TODO: write also with timestamp
  }

  #[test]
  fn dw_dispose_test() {
    let domain_participant = DomainParticipant::new(0);
    let qos = QosPolicies::qos_none();
    let publisher = domain_participant
      .create_publisher(&qos)
      .expect("Failed to create publisher");
    let topic = domain_participant
      .create_topic("Aasii", "Huh?", &qos, TopicKind::WithKey)
      .expect("Failed to create topic");

    let data_writer: DataWriter<RandomData, CDRSerializerAdapter<RandomData, LittleEndian>> =
      publisher
        .create_datawriter(None, topic, None)
        .expect("Failed to create datawriter");

    let data = RandomData {
      a: 4,
      b: "Fobar".to_string(),
    };

    let key = &data.get_key().into_hash_key();
    info!("key: {:?}", key);

    data_writer
      .write(data.clone(), None)
      .expect("Unable to write data");

    thread::sleep(Duration::from_millis(100));
    data_writer
      .dispose(data.get_key(), None)
      .expect("Unable to dispose data");

    // TODO: verify that dispose is sent correctly
  }

  #[test]
  fn dw_wait_for_ack_test() {
    let domain_participant = DomainParticipant::new(0);
    let qos = QosPolicies::qos_none();
    let publisher = domain_participant
      .create_publisher(&qos)
      .expect("Failed to create publisher");
    let topic = domain_participant
      .create_topic("Aasii", "Huh?", &qos, TopicKind::WithKey)
      .expect("Failed to create topic");

    let data_writer: DataWriter<RandomData, CDRSerializerAdapter<RandomData, LittleEndian>> =
      publisher
        .create_datawriter(None, topic, None)
        .expect("Failed to create datawriter");

    let data = RandomData {
      a: 4,
      b: "Fobar".to_string(),
    };

    data_writer.write(data, None).expect("Unable to write data");

    let res = data_writer
      .wait_for_acknowledgments(Duration::from_secs(5))
      .unwrap();
    assert_eq!(res, ());
  }
}