pinray-core 0.2.4

use crate::audio::AudioFrame;

/// An axis-aligned rectangle in pixels, used for crop regions and damage.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct Rect {
    pub x: i32,
    pub y: i32,
    pub width: u32,
    pub height: u32,
}

/// Pixel layout of [`VideoFrame::data`].
///
/// All backends deliver `Bgra8888` natively and can swizzle to `Rgba8888`;
/// the remaining formats exist for future zero-copy paths.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum PixelFormat {
    /// 8-bit B, G, R, A byte order — the native format everywhere.
    Bgra8888,
    /// 8-bit R, G, B, A byte order (CPU swizzle from BGRA).
    Rgba8888,
    /// 24-bit packed RGB, no alpha.
    Rgb888,
    /// Biplanar 4:2:0 YCbCr (Y plane + interleaved CbCr).
    Nv12,
    /// Planar 4:2:0 YCbCr.
    I420,
}

impl PixelFormat {
    /// Bytes per pixel for packed RGB/RGBA formats.
    ///
    /// `None` for the planar/biplanar YUV formats, where a single
    /// `width * bytes_per_pixel` row size doesn't apply (each plane has its
    /// own stride and subsampling).
    pub fn bytes_per_pixel(self) -> Option<usize> {
        match self {
            PixelFormat::Bgra8888 | PixelFormat::Rgba8888 => Some(4),
            PixelFormat::Rgb888 => Some(3),
            PixelFormat::Nv12 | PixelFormat::I420 => None,
        }
    }
}

/// Color space hint for interpreting pixel values.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ColorSpace {
    Srgb,
    DisplayP3,
    Bt709,
    Bt2020,
}

/// A Linux DMA-BUF plane handle (zero-copy path, not yet produced).
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct DmabufFrame {
    pub fd: i32,
    pub offset: u32,
    pub size: u32,
    pub stride: u32,
    pub modifier: u64,
}

/// A macOS `CVPixelBuffer` pointer (zero-copy path, not yet produced).
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct CvPixelBufferHandle {
    pub ptr: usize,
}

/// A Windows `ID3D11Texture2D` pointer (zero-copy path, not yet produced).
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct D3D11TextureHandle {
    pub ptr: usize,
}

/// Where a frame's pixels live.
///
/// Every backend currently produces `Host` (a plain CPU byte buffer); the
/// native-handle variants are reserved for opt-in zero-copy support.
#[derive(Debug, Clone, PartialEq)]
pub enum FrameData {
    /// CPU memory, rows packed at [`VideoFrame::stride`] bytes.
    Host(Vec<u8>),
    Dmabuf(DmabufFrame),
    CvPixelBuffer(CvPixelBufferHandle),
    D3D11Texture(D3D11TextureHandle),
}

/// One captured video frame with complete layout and timing metadata.
#[derive(Debug, Clone, PartialEq)]
pub struct VideoFrame {
    /// Capture timestamp in nanoseconds, monotonic within a session and
    /// comparable with [`AudioFrame::stream_time_ns`] of the same session.
    /// The epoch is platform-dependent (boot time on macOS/Windows,
    /// process-relative on Linux).
    pub stream_time_ns: i64,
    /// Per-stream counter advanced once per delivered frame; a jump means
    /// frames were dropped.
    pub sequence: u64,
    pub width: u32,
    pub height: u32,
    /// Bytes from the start of one row to the next in [`FrameData::Host`].
    pub stride: u32,
    pub pixel_format: PixelFormat,
    pub color_space: Option<ColorSpace>,
    pub data: FrameData,
    /// Changed regions since the previous frame, when the backend knows.
    pub damage: Option<Vec<Rect>>,
}

impl VideoFrame {
    /// Returns [`FrameData::Host`] bytes with row padding stripped, i.e.
    /// `width * bytes_per_pixel` bytes per row instead of `stride`.
    ///
    /// `stride` can be wider than the tightly-packed row size (platform row
    /// alignment); copying `data` directly into something that assumes tight
    /// packing (a `rawvideo` pipe, an image encoder) silently skews every row
    /// after the first. Use this instead of touching `data` directly.
    ///
    /// Returns `None` for non-[`FrameData::Host`] variants, or for pixel
    /// formats without a well-defined bytes-per-pixel (see
    /// [`PixelFormat::bytes_per_pixel`]).
    ///
    /// # Examples
    ///
    /// ```
    /// use pinray_core::{FrameData, PixelFormat, VideoFrame};
    ///
    /// let (width, height, stride) = (2u32, 2u32, 12u32); // 4 padding bytes/row
    /// let mut data = Vec::new();
    /// for row in 0..height {
    ///     data.extend(std::iter::repeat_n(row as u8, width as usize * 4));
    ///     data.extend(std::iter::repeat_n(0xAA, (stride - width * 4) as usize));
    /// }
    /// let frame = VideoFrame {
    ///     stream_time_ns: 0,
    ///     sequence: 0,
    ///     width,
    ///     height,
    ///     stride,
    ///     pixel_format: PixelFormat::Bgra8888,
    ///     color_space: None,
    ///     data: FrameData::Host(data),
    ///     damage: None,
    /// };
    ///
    /// let tight = frame.to_tight_bytes().unwrap();
    /// assert_eq!(tight.len(), (width * height * 4) as usize);
    /// assert!(tight.iter().all(|&b| b != 0xAA)); // padding is gone
    /// ```
    pub fn to_tight_bytes(&self) -> Option<Vec<u8>> {
        let FrameData::Host(buf) = &self.data else {
            return None;
        };
        let bpp = self.pixel_format.bytes_per_pixel()?;
        let row_bytes = self.width as usize * bpp;
        if self.stride as usize == row_bytes {
            return Some(buf.clone());
        }
        let mut out = Vec::with_capacity(row_bytes * self.height as usize);
        for row in 0..self.height as usize {
            let start = row * self.stride as usize;
            out.extend_from_slice(&buf[start..start + row_bytes]);
        }
        Some(out)
    }
}

/// Why a [`GapEvent`] was emitted.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum GapReason {
    /// Frames were dropped because the consumer fell behind.
    Dropped,
    /// The stream format changed mid-session.
    FormatChanged,
    /// The backend recovered from losing its capture source (e.g. a display
    /// mode switch invalidating DXGI duplication).
    BackendRestarted,
    Unknown,
}

/// A discontinuity notice: frames were lost or the stream restarted.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct GapEvent {
    pub stream_time_ns: i64,
    pub reason: GapReason,
    pub dropped_frames: Option<u32>,
}

/// What [`CaptureSession::next_event`](crate::CaptureSession::next_event)
/// yields.
#[derive(Debug, Clone, PartialEq)]
pub enum CaptureEvent {
    Video(VideoFrame),
    Audio(AudioFrame),
    Gap(GapEvent),
    /// The stream ended and no further events will arrive.
    End,
}