scuffle-ffmpeg 0.0.1

use ffmpeg_sys_next::*;

use crate::error::FfmpegError;
use crate::smart_object::SmartPtr;
use crate::utils::check_i64;

pub struct Packets<'a> {
	context: &'a mut AVFormatContext,
}

/// Safety: `Packets` is safe to send between threads.
unsafe impl Send for Packets<'_> {}

impl<'a> Packets<'a> {
	pub fn new(context: &'a mut AVFormatContext) -> Self {
		Self { context }
	}

	pub fn receive(&mut self) -> Result<Option<Packet>, FfmpegError> {
		let mut packet = Packet::new()?;

		// Safety: av_read_frame is safe to call, 'packet' is a valid pointer
		let ret = unsafe { av_read_frame(self.context, packet.as_mut_ptr()) };

		match ret {
			0 => Ok(Some(packet)),
			AVERROR_EOF => Ok(None),
			_ => Err(FfmpegError::Code(ret.into())),
		}
	}
}

impl Iterator for Packets<'_> {
	type Item = Result<Packet, FfmpegError>;

	fn next(&mut self) -> Option<Self::Item> {
		self.receive().transpose()
	}
}

pub struct Packet(SmartPtr<AVPacket>);

/// Safety: `Packet` is safe to send between threads.
unsafe impl Send for Packet {}

impl std::fmt::Debug for Packet {
	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
		f.debug_struct("Packet")
			.field("stream_index", &self.stream_index())
			.field("pts", &self.pts())
			.field("dts", &self.dts())
			.field("duration", &self.duration())
			.field("pos", &self.pos())
			.field("is_key", &self.is_key())
			.field("is_corrupt", &self.is_corrupt())
			.field("is_discard", &self.is_discard())
			.field("is_trusted", &self.is_trusted())
			.field("is_disposable", &self.is_disposable())
			.finish()
	}
}

impl Clone for Packet {
	fn clone(&self) -> Self {
		unsafe { Self::wrap(av_packet_clone(self.0.as_ptr())).expect("failed to clone packet") }
	}
}

impl Packet {
	pub fn new() -> Result<Self, FfmpegError> {
		// Safety: av_packet_alloc is safe to call, and the pointer it returns is valid.
		unsafe { Self::wrap(av_packet_alloc()) }.ok_or(FfmpegError::Alloc)
	}

	/// Safety: `ptr` must be a valid pointer to a packet.
	unsafe fn wrap(ptr: *mut AVPacket) -> Option<Self> {
		Some(Self(SmartPtr::wrap_non_null(ptr, |ptr| av_packet_free(ptr))?))
	}

	pub fn as_ptr(&self) -> *const AVPacket {
		self.0.as_ptr()
	}

	pub fn as_mut_ptr(&mut self) -> *mut AVPacket {
		self.0.as_mut_ptr()
	}

	pub fn stream_index(&self) -> i32 {
		self.0.as_deref_except().stream_index
	}

	pub fn set_stream_index(&mut self, stream_index: i32) {
		self.0.as_deref_mut_except().stream_index = stream_index as _;
	}

	pub fn pts(&self) -> Option<i64> {
		check_i64(self.0.as_deref_except().pts)
	}

	pub fn set_pts(&mut self, pts: Option<i64>) {
		self.0.as_deref_mut_except().pts = pts.unwrap_or(AV_NOPTS_VALUE);
	}

	pub fn dts(&self) -> Option<i64> {
		check_i64(self.0.as_deref_except().dts)
	}

	pub fn set_dts(&mut self, dts: Option<i64>) {
		self.0.as_deref_mut_except().dts = dts.unwrap_or(AV_NOPTS_VALUE);
	}

	pub fn duration(&self) -> Option<i64> {
		check_i64(self.0.as_deref_except().duration)
	}

	pub fn set_duration(&mut self, duration: Option<i64>) {
		self.0.as_deref_mut_except().duration = duration.unwrap_or(AV_NOPTS_VALUE);
	}

	pub fn rescale_timebase(&mut self, from: AVRational, to: AVRational) {
		// Safety: av_rescale_q_rnd is safe to call
		self.set_pts(
			self.pts()
				.map(|pts| unsafe { av_rescale_q_rnd(pts, from, to, AVRounding::AV_ROUND_NEAR_INF) }),
		);

		// Safety: av_rescale_q_rnd is safe to call
		self.set_dts(
			self.dts()
				.map(|dts| unsafe { av_rescale_q_rnd(dts, from, to, AVRounding::AV_ROUND_NEAR_INF) }),
		);

		// Safety: av_rescale_q is safe to call
		self.set_duration(self.duration().map(|duration| unsafe { av_rescale_q(duration, from, to) }));
	}

	pub fn pos(&self) -> Option<i64> {
		check_i64(self.0.as_deref_except().pos)
	}

	pub fn set_pos(&mut self, pos: Option<i64>) {
		self.0.as_deref_mut_except().pos = pos.unwrap_or(AV_NOPTS_VALUE);
	}

	pub fn data(&self) -> &[u8] {
		if self.0.as_deref_except().size <= 0 {
			return &[];
		}

		// Safety: `self.0` is a valid pointer.
		unsafe { std::slice::from_raw_parts(self.0.as_deref_except().data, self.0.as_deref_except().size as usize) }
	}

	pub fn is_key(&self) -> bool {
		self.0.as_deref_except().flags & AV_PKT_FLAG_KEY != 0
	}

	pub fn is_corrupt(&self) -> bool {
		self.0.as_deref_except().flags & AV_PKT_FLAG_CORRUPT != 0
	}

	pub fn is_discard(&self) -> bool {
		self.0.as_deref_except().flags & AV_PKT_FLAG_DISCARD != 0
	}

	pub fn is_trusted(&self) -> bool {
		self.0.as_deref_except().flags & AV_PKT_FLAG_TRUSTED != 0
	}

	pub fn is_disposable(&self) -> bool {
		self.0.as_deref_except().flags & AV_PKT_FLAG_DISPOSABLE != 0
	}
}