use crate::payload::{Decode, Encode, SeStringChunkKind};
use std::io::{Read, Seek};
use crate::Payload;

#[derive(Debug, PartialEq)]
pub struct EmphasisPayload(pub bool);

impl EmphasisPayload {
    pub fn enable() -> Self {
        Self(true)
    }

    pub fn disable() -> Self {
        Self(false)
    }

    pub fn enabled(&self) -> bool {
        self.0
    }
}

impl From<bool> for EmphasisPayload {
    fn from(enabled: bool) -> Self {
        Self(enabled)
    }
}

impl Decode for EmphasisPayload {
    fn decode<R: Read + Seek>(reader: R, _chunk_len: usize) -> Result<Self, crate::Error> {
        let enabled = Self::read_integer(reader)?;
        Ok(Self(enabled == 1))
    }
}

impl Encode for EmphasisPayload {
    fn encode(&self) -> Vec<u8> {
        use std::iter::once;

        let enabled = Self::make_integer(if self.0 { 1 } else { 0 });
        let chunk_len = enabled.len() + 1;

        once(Payload::START_BYTE)
            .chain(once(SeStringChunkKind::Emphasis.as_u8()))
            .chain(once(chunk_len as u8))
            .chain(enabled.into_iter())
            .chain(once(Payload::END_BYTE))
            .collect()
    }
}