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#[cfg(feature = "with_kafka")]
extern crate kafka;

mod varint;

pub mod error;
pub mod consumer;
pub mod converter;

#[cfg(feature = "with_kafka")]
pub mod kafka_consumer {
    use kafka::consumer::{Consumer, FetchOffset};
    use std::{thread, time};
    use error::StreamDelimitError;
    use std;
    use consumer::GenericConsumer;

    pub struct KafkaConsumer {
        consumer: Consumer,
        messages: Vec<Vec<u8>>,
    }

    impl GenericConsumer for KafkaConsumer {
        fn get_single_message(&mut self) -> Option<Vec<u8>> {
            if self.messages.is_empty() {
                let kafka_consumer = &mut self.consumer;
                loop {
                    match kafka_consumer.poll() {
                        Ok(x) => {
                            match x.iter().take(1).next() {
                                Some(y) => {
                                    self.messages.append(&mut y.messages()
                                        .iter()
                                        .map(|z| z.value.to_vec())
                                        .collect::<Vec<_>>());
                                    kafka_consumer.consume_messageset(y).expect(
                                        "Couldn't mark messageset as consumed",
                                    );
                                    kafka_consumer.commit_consumed().expect(
                                        "Couldn't commit consumption",
                                    );
                                    break;
                                }
                                None => {
                                    thread::sleep(time::Duration::from_secs(1));
                                    continue;
                                }
                            }
                        }
                        Err(_) => return None,
                    }
                }
            }
            self.messages.pop()
        }
    }

    impl KafkaConsumer {
        pub fn new(
            brokers: &str,
            topic: &str,
            from_beginning: bool,
        ) -> Result<KafkaConsumer, StreamDelimitError> {
            let fetch_offset = if from_beginning {
                FetchOffset::Earliest
            } else {
                FetchOffset::Latest
            };
            match Consumer::from_hosts(
                brokers
                    .split(',')
                    .map(std::borrow::ToOwned::to_owned)
                    .collect::<Vec<String>>(),
            ).with_topic_partitions(topic.to_owned(), &[0, 1])
                .with_fallback_offset(fetch_offset)
                .create() {
                Ok(consumer) => {
                    Ok(KafkaConsumer {
                        consumer: consumer,
                        messages: vec![],
                    })
                }
                Err(_) => Err(StreamDelimitError::KafkaInitializeError),
            }
        }
    }
}