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

#[derive(Debug, PartialEq)]
pub struct QuestPayload(pub u32);

impl QuestPayload {
    const OFFSET: u32 = 65536;
}

impl From<u32> for QuestPayload {
    fn from(id: u32) -> Self {
        Self(id)
    }
}

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

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

        let id = Self::make_integer(self.0 - Self::OFFSET);
        let chunk_len = id.len() + 4;

        once(Payload::START_BYTE)
            .chain(once(SeStringChunkKind::Interactable.as_u8()))
            .chain(once(chunk_len as u8))
            .chain(once(SeInteractableKind::QuestLink.as_u8()))
            .chain(id.into_iter())
            .chain(once(0x01))
            .chain(once(0x01))
            .chain(once(Payload::END_BYTE))
            .collect()
    }
}