use crate::format::matroska::read::EbmlSize;

use self::read::EbmlReader;
use anyhow::{bail, Result};
use log::debug;

pub mod matroska;
pub mod read;

#[derive(Debug, Clone)]
pub enum Master {
    Start,
    End,
}

#[derive(Debug, Clone)]
pub enum MatroskaTag {
    Ebml(Master),
    EbmlVersion(u64),
    EbmlReadVersion(u64),
    EbmlMaxIdLength(u64),
    EbmlMaxSizeLength(u64),
    DocType(String),
    DocTypeVersion(u64),
    DocTypeReadVersion(u64),
    DocTypeExtension(Master),
}

impl EbmlReader {
    pub fn read_tag(&mut self) -> Result<MatroskaTag> {
        let id = self.read_tag_id()?;
        let size = EbmlSize::from_vint(self.read_vint_len()?);
        debug!("tag id={id:x}, size={size:?}");
        Ok(match id {
            0x1a45dfa3 => MatroskaTag::Ebml(Master::Start),
            0x4286 => MatroskaTag::EbmlVersion(self.read_vint()?),
            0x42f7 => MatroskaTag::EbmlReadVersion(self.read_vint()?),
            0x42f2 => MatroskaTag::EbmlMaxIdLength(self.read_vint()?),
            0x42f3 => MatroskaTag::EbmlMaxSizeLength(self.read_vint()?),
            0x4282 => MatroskaTag::DocType(self.read_utf8(size)?),
            0x4287 => MatroskaTag::DocTypeVersion(self.read_vint()?),
            0x4285 => MatroskaTag::DocTypeReadVersion(self.read_vint()?),
            0x4281 => MatroskaTag::DocTypeExtension(Master::Start),

            _ => bail!("thats not a tag we know..."),
        })
    }
}