use heapless::Vec;
use scpi::{
    error::{Error as ScpiError, ErrorCode},
    tree::prelude::ResponseUnit,
};

struct ScpiResponse<const N: usize>(Vec<u8, N>);

impl<const N: usize> scpi::parser::response::Formatter for ScpiResponse<N> {
    fn push_str(&mut self, s: &[u8]) -> scpi::error::Result<()> {
        self.0
            .extend_from_slice(s)
            .map_err(|_| ScpiError::from(ErrorCode::OutOfMemory))
    }

    fn push_byte(&mut self, b: u8) -> scpi::error::Result<()> {
        self.0
            .push(b)
            .map_err(|_| ScpiError::from(ErrorCode::OutOfMemory))
    }

    fn as_slice(&self) -> &[u8] {
        self.0.as_slice()
    }

    fn clear(&mut self) {
        self.0.clear();
    }

    fn len(&self) -> usize {
        self.0.len()
    }

    fn message_start(&mut self) -> scpi::error::Result<()> {
        Ok(())
    }

    fn message_end(&mut self) -> scpi::error::Result<()> {
        self.push_byte(b'\n')
    }

    fn response_unit(&mut self) -> scpi::error::Result<scpi::tree::prelude::ResponseUnit> {
        if !self.0.is_empty() {
            self.push_byte(b';')?;
        }
        Ok(ResponseUnit {
            fmt: self,
            result: Ok(()),
            has_header: false,
            has_data: false,
        })
    }
}