use std::fmt;
use std::str::FromStr;

use crate::types::ProtocolVersion;
use crate::utils::tag;
use crate::{Error, RequiredVersion};

/// # [4.4.3.4. EXT-X-ENDLIST]
/// The [`ExtXEndList`] tag indicates, that no more [`Media Segment`]s will be
/// added to the [`Media Playlist`] file.
///
/// Its format is:
/// ```text
/// #EXT-X-ENDLIST
/// ```
///
/// [`Media Segment`]: crate::MediaSegment
/// [`Media Playlist`]: crate::MediaPlaylist
/// [4.4.3.4. EXT-X-ENDLIST]:
/// https://tools.ietf.org/html/draft-pantos-hls-rfc8216bis-04#section-4.4.3.4
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct ExtXEndList;

impl ExtXEndList {
    pub(crate) const PREFIX: &'static str = "#EXT-X-ENDLIST";
}

impl RequiredVersion for ExtXEndList {
    fn required_version(&self) -> ProtocolVersion { ProtocolVersion::V1 }
}

impl fmt::Display for ExtXEndList {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { Self::PREFIX.fmt(f) }
}

impl FromStr for ExtXEndList {
    type Err = Error;

    fn from_str(input: &str) -> Result<Self, Self::Err> {
        tag(input, Self::PREFIX)?;
        Ok(Self)
    }
}

#[cfg(test)]
mod test {
    use super::*;

    #[test]
    fn test_display() {
        assert_eq!(ExtXEndList.to_string(), "#EXT-X-ENDLIST".to_string());
    }

    #[test]
    fn test_parser() {
        assert_eq!(ExtXEndList, "#EXT-X-ENDLIST".parse().unwrap());
    }

    #[test]
    fn test_required_version() {
        assert_eq!(ExtXEndList.required_version(), ProtocolVersion::V1);
    }
}