use quick_xml::events::Event;
use quick_xml::Reader;

pub fn pubmed_len(buffer: &[u8]) -> usize {
    let mut reader = Reader::from_reader(buffer);
    let mut in_content = 0usize;
    let mut total = 0usize;

    loop {
        match reader.read_event() {
            Ok(Event::Start(e)) => {
                if in_content != 0 {
                    in_content += 1;
                } else {
                    if e.name().as_ref() == b"abstract"
                    || e.name().as_ref()== b"body" {
                        in_content = 1;
                    }
                }
            }

            Ok(Event::End(_)) => {
                if in_content != 0 {
                    in_content -= 1;
                }
            }

            Ok(Event::Text(e)) => {
                if in_content != 0 {
                    total += e.len();
                }
            }

            Ok(Event::Eof) => break,

            Ok(_) => {}
            Err(_) => unreachable!("buffer is valid PMC XML"),
        }
    }

    total
}

pub fn pubmed_len_with_entities(buffer: &[u8]) -> usize {
    let mut reader = Reader::from_reader(buffer);
    let mut in_content = 0usize;
    let mut total = 0usize;

    loop {
        match reader.read_event() {
            Ok(Event::Start(e)) => {
                if in_content != 0 {
                    in_content += 1;
                } else if e.name().as_ref() == b"abstract"
                    || e.name().as_ref() == b"body"
                {
                    in_content = 1;
                }
            }

            Ok(Event::End(_)) => {
                if in_content != 0 {
                    in_content -= 1;
                }
            }

            Ok(Event::Text(e)) => {
                if in_content != 0 {
                    total += e.decode().unwrap().len();
                }
            }

            Ok(Event::Eof) => break,

            Ok(_) => {}
            Err(_) => unreachable!("buffer is valid PMC XML"),
        }
    }

    total
}