// Copyright 2024 Gabriel Bjørnager Jensen.
//
// This file is part of bzipper.
//
// bzipper is free software: you can redistribute
// it and/or modify it under the terms of the GNU
// Lesser General Public License as published by
// the Free Software Foundation, either version 3
// of the License, or (at your option) any later
// version.
//
// bzipper is distributed in the hope that it will
// be useful, but WITHOUT ANY WARRANTY; without
// even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Less-
// er General Public License along with bzipper. If
// not, see <https://www.gnu.org/licenses/>.

use crate::{Dstream, Serialise};

use std::fmt::{Debug, Formatter};
use std::mem::size_of;

/// Byte stream for serialisation.
///
/// The bytes themselves are contained by the type.
/// The stream may be converted to [`Dstream`] using [`as_dstream`](Sstream::as_dstream)
#[derive(Clone, Eq, PartialEq)]
pub struct Sstream(pub(in crate) Vec<u8>);

impl Sstream {
	/// Constructs a new, empty byte stream.
	#[inline(always)]
	#[must_use]
	pub const fn new() -> Self { Self(Vec::new()) }

	/// Extends the byte stream.
	pub fn append(&mut self, extra: &[u8]) {
		self.0.extend(extra);
	}

	/// Extends the byte stream by a single byte.
	pub fn append_byte(&mut self, extra: u8) {
		self.0.push(extra);
	}

	/// Converts the stream to a `Dstream` object.
	///
	/// The returned object references the original stream.
	#[inline(always)]
	#[must_use]
	pub fn as_dstream(&self) -> Dstream { Dstream::new(&self.0) }
}

impl AsRef<[u8]> for Sstream {
	#[inline(always)]
	fn as_ref(&self) -> &[u8] { self.0.as_ref() }
}

impl Debug for Sstream {
	fn fmt(&self, f: &mut Formatter) -> std::fmt::Result {
		write!(f, "[")?;

		for v in &self.0 { write!(f, "{v:#02X},")? };

		write!(f, "]")?;

		Ok(())
	}
}

impl Default for Sstream {
	#[inline(always)]
	fn default() -> Self { Self::new() }
}

impl<T: Serialise> From<&T> for Sstream {
	fn from(value: &T) -> Self {
		let mut stream = Self(Vec::with_capacity(size_of::<T>()));
		value.serialise(&mut stream);

		stream
	}
}

impl From<Sstream> for Box<[u8]> {
	#[inline(always)]
	fn from(value: Sstream) -> Self { value.0.into_boxed_slice() }
}