use std::{
	mem,
	ops::{Deref, DerefMut},
	slice,
};

use libc::c_int;

use super::Frame;
use crate::{
	color,
	ffi::*,
	picture,
	util::{chroma, format},
	Rational,
};

#[derive(PartialEq, Eq)]
pub struct Video(Frame);

impl Video {
	#[inline(always)]
	pub unsafe fn wrap(ptr: *mut AVFrame) -> Self {
		Video(Frame::wrap(ptr))
	}

	#[inline]
	pub unsafe fn alloc(&mut self, format: format::Pixel, width: u32, height: u32) {
		self.set_format(format);
		self.set_width(width);
		self.set_height(height);

		av_frame_get_buffer(self.as_mut_ptr(), 32);
	}
}

impl Video {
	#[inline(always)]
	pub fn empty() -> Self {
		unsafe { Video(Frame::empty()) }
	}

	#[inline]
	pub fn new(format: format::Pixel, width: u32, height: u32) -> Self {
		unsafe {
			let mut frame = Video::empty();
			frame.alloc(format, width, height);

			frame
		}
	}

	#[inline]
	pub fn format(&self) -> format::Pixel {
		unsafe {
			if (*self.as_ptr()).format == -1 {
				format::Pixel::None
			}
			else {
				format::Pixel::from(mem::transmute::<_, AVPixelFormat>((*self.as_ptr()).format))
			}
		}
	}

	#[inline]
	pub fn set_format(&mut self, value: format::Pixel) {
		unsafe {
			(*self.as_mut_ptr()).format = mem::transmute::<AVPixelFormat, c_int>(value.into());
		}
	}

	#[inline]
	pub fn kind(&self) -> picture::Type {
		unsafe { picture::Type::from((*self.as_ptr()).pict_type) }
	}

	#[inline]
	pub fn set_kind(&mut self, value: picture::Type) {
		unsafe {
			(*self.as_mut_ptr()).pict_type = value.into();
		}
	}

	#[inline]
	pub fn is_interlaced(&self) -> bool {
		unsafe { (*self.as_ptr()).interlaced_frame != 0 }
	}

	#[inline]
	pub fn is_top_first(&self) -> bool {
		unsafe { (*self.as_ptr()).top_field_first != 0 }
	}

	#[inline]
	pub fn has_palette_changed(&self) -> bool {
		unsafe { (*self.as_ptr()).palette_has_changed != 0 }
	}

	#[inline]
	pub fn width(&self) -> u32 {
		unsafe { (*self.as_ptr()).width as u32 }
	}

	#[inline]
	pub fn set_width(&mut self, value: u32) {
		unsafe {
			(*self.as_mut_ptr()).width = value as c_int;
		}
	}

	#[inline]
	pub fn height(&self) -> u32 {
		unsafe { (*self.as_ptr()).height as u32 }
	}

	#[inline]
	pub fn set_height(&mut self, value: u32) {
		unsafe {
			(*self.as_mut_ptr()).height = value as c_int;
		}
	}

	#[inline]
	pub fn color_space(&self) -> color::Space {
		unsafe { color::Space::from(av_frame_get_colorspace(self.as_ptr())) }
	}

	#[inline]
	pub fn set_color_space(&mut self, value: color::Space) {
		unsafe {
			av_frame_set_colorspace(self.as_mut_ptr(), value.into());
		}
	}

	#[inline]
	pub fn color_range(&self) -> color::Range {
		unsafe { color::Range::from(av_frame_get_color_range(self.as_ptr())) }
	}

	#[inline]
	pub fn set_color_range(&mut self, value: color::Range) {
		unsafe {
			av_frame_set_color_range(self.as_mut_ptr(), value.into());
		}
	}

	#[inline]
	pub fn color_primaries(&self) -> color::Primaries {
		unsafe { color::Primaries::from((*self.as_ptr()).color_primaries) }
	}

	#[inline]
	pub fn set_color_primaries(&mut self, value: color::Primaries) {
		unsafe {
			(*self.as_mut_ptr()).color_primaries = value.into();
		}
	}

	#[inline]
	pub fn color_transfer_characteristic(&self) -> color::TransferCharacteristic {
		unsafe { color::TransferCharacteristic::from((*self.as_ptr()).color_trc) }
	}

	#[inline]
	pub fn set_color_transfer_characteristic(&mut self, value: color::TransferCharacteristic) {
		unsafe {
			(*self.as_mut_ptr()).color_trc = value.into();
		}
	}

	#[inline]
	pub fn chroma_location(&self) -> chroma::Location {
		unsafe { chroma::Location::from((*self.as_ptr()).chroma_location) }
	}

	#[inline]
	pub fn aspect_ratio(&self) -> Rational {
		unsafe { Rational::from((*self.as_ptr()).sample_aspect_ratio) }
	}

	#[inline]
	pub fn coded_number(&self) -> usize {
		unsafe { (*self.as_ptr()).coded_picture_number as usize }
	}

	#[inline]
	pub fn display_number(&self) -> usize {
		unsafe { (*self.as_ptr()).display_picture_number as usize }
	}

	#[inline]
	pub fn repeat(&self) -> f64 {
		unsafe { f64::from((*self.as_ptr()).repeat_pict) }
	}

	#[inline]
	pub fn stride(&self, index: usize) -> usize {
		if index >= self.planes() {
			panic!("out of bounds");
		}

		unsafe { (*self.as_ptr()).linesize[index] as usize }
	}

	#[inline]
	pub fn planes(&self) -> usize {
		for i in 0..8 {
			unsafe {
				if (*self.as_ptr()).linesize[i] == 0 {
					return i;
				}
			}
		}

		8
	}

	#[inline]
	pub fn plane_width(&self, index: usize) -> u32 {
		if index >= self.planes() {
			panic!("out of bounds");
		}

		// Logic taken from image_get_linesize().
		if index != 1 && index != 2 {
			return self.width();
		}

		if let Some(desc) = self.format().descriptor() {
			let s = desc.log2_chroma_w();
			(self.width() + (1 << s) - 1) >> s
		}
		else {
			self.width()
		}
	}

	#[inline]
	pub fn plane_height(&self, index: usize) -> u32 {
		if index >= self.planes() {
			panic!("out of bounds");
		}

		// Logic taken from av_image_fill_pointers().
		if index != 1 && index != 2 {
			return self.height();
		}

		if let Some(desc) = self.format().descriptor() {
			let s = desc.log2_chroma_h();
			(self.height() + (1 << s) - 1) >> s
		}
		else {
			self.height()
		}
	}

	#[inline]
	pub fn plane<T: Component>(&self, index: usize) -> &[T] {
		if index >= self.planes() {
			panic!("out of bounds");
		}

		if !<T as Component>::is_valid(self.format()) {
			panic!("unsupported type");
		}

		unsafe {
			slice::from_raw_parts(
				(*self.as_ptr()).data[index] as *const T,
				self.stride(index) * self.plane_height(index) as usize / mem::size_of::<T>(),
			)
		}
	}

	#[inline]
	pub fn plane_mut<T: Component>(&mut self, index: usize) -> &mut [T] {
		if index >= self.planes() {
			panic!("out of bounds");
		}

		if !<T as Component>::is_valid(self.format()) {
			panic!("unsupported type");
		}

		unsafe {
			slice::from_raw_parts_mut(
				(*self.as_mut_ptr()).data[index] as *mut T,
				self.stride(index) * self.plane_height(index) as usize / mem::size_of::<T>(),
			)
		}
	}

	#[inline]
	pub fn data(&self, index: usize) -> &[u8] {
		if index >= self.planes() {
			panic!("out of bounds");
		}

		unsafe {
			slice::from_raw_parts(
				(*self.as_ptr()).data[index],
				self.stride(index) * self.plane_height(index) as usize,
			)
		}
	}

	#[inline]
	pub fn data_mut(&mut self, index: usize) -> &mut [u8] {
		if index >= self.planes() {
			panic!("out of bounds");
		}

		unsafe {
			slice::from_raw_parts_mut(
				(*self.as_mut_ptr()).data[index],
				self.stride(index) * self.plane_height(index) as usize,
			)
		}
	}
}

impl Deref for Video {
	type Target = Frame;

	#[inline]
	fn deref(&self) -> &Frame {
		&self.0
	}
}

impl DerefMut for Video {
	#[inline]
	fn deref_mut(&mut self) -> &mut Frame {
		&mut self.0
	}
}

impl Clone for Video {
	#[inline]
	fn clone(&self) -> Self {
		let mut cloned = Video::new(self.format(), self.width(), self.height());
		cloned.clone_from(self);

		cloned
	}

	#[inline]
	fn clone_from(&mut self, source: &Self) {
		unsafe {
			av_frame_copy(self.as_mut_ptr(), source.as_ptr());
			av_frame_copy_props(self.as_mut_ptr(), source.as_ptr());
		}
	}
}

impl From<Frame> for Video {
	#[inline]
	fn from(frame: Frame) -> Self {
		Video(frame)
	}
}

pub unsafe trait Component {
	fn is_valid(format: format::Pixel) -> bool;
}

#[cfg(feature = "image")]
unsafe impl Component for ::image::Luma<u8> {
	#[inline(always)]
	fn is_valid(format: format::Pixel) -> bool {
		format == format::Pixel::GRAY8
	}
}

#[cfg(feature = "image")]
unsafe impl Component for ::image::Rgb<u8> {
	#[inline(always)]
	fn is_valid(format: format::Pixel) -> bool {
		format == format::Pixel::RGB24
	}
}

#[cfg(feature = "image")]
unsafe impl Component for ::image::Rgba<u8> {
	#[inline(always)]
	fn is_valid(format: format::Pixel) -> bool {
		format == format::Pixel::RGBA
	}
}

unsafe impl Component for [u8; 3] {
	#[inline(always)]
	fn is_valid(format: format::Pixel) -> bool {
		format == format::Pixel::RGB24 || format == format::Pixel::BGR24
	}
}

unsafe impl Component for (u8, u8, u8) {
	#[inline(always)]
	fn is_valid(format: format::Pixel) -> bool {
		format == format::Pixel::RGB24 || format == format::Pixel::BGR24
	}
}

unsafe impl Component for [u8; 4] {
	#[inline(always)]
	fn is_valid(format: format::Pixel) -> bool {
		format == format::Pixel::RGBA
			|| format == format::Pixel::BGRA
			|| format == format::Pixel::ARGB
			|| format == format::Pixel::ABGR
			|| format == format::Pixel::RGBZ
			|| format == format::Pixel::BGRZ
			|| format == format::Pixel::ZRGB
			|| format == format::Pixel::ZBGR
	}
}

unsafe impl Component for (u8, u8, u8, u8) {
	#[inline(always)]
	fn is_valid(format: format::Pixel) -> bool {
		format == format::Pixel::RGBA
			|| format == format::Pixel::BGRA
			|| format == format::Pixel::ARGB
			|| format == format::Pixel::ABGR
			|| format == format::Pixel::RGBZ
			|| format == format::Pixel::BGRZ
			|| format == format::Pixel::ZRGB
			|| format == format::Pixel::ZBGR
	}
}
