use crate::{
    format::ser::{Sink, Source},
    helpers::{pixel::Pixel, vector::Vec2},
    view::View,
};
use std::ops::{Index, IndexMut};

#[derive(Debug, Clone)]
pub struct Frame {
    pub size: Vec2<isize>,
    buffer: Vec<Pixel>,
}

impl Frame {
    pub fn new(size: Vec2<isize>) -> Self {
        Self {
            size,
            buffer: (0..size.x * size.y).map(|_| Pixel::default()).collect(),
        }
    }
    pub fn read(source: &mut impl Source, size: Vec2<isize>) -> anyhow::Result<Self> {
        let mut frame = Frame::new(size);
        for y in 0..size.y {
            for x in 0..size.x {
                let pixel = source.get::<Pixel>()?;
                frame[(x, y)] = pixel;
            }
        }
        Ok(frame)
    }
    pub fn write(&self, sink: &mut impl Sink) -> anyhow::Result<()> {
        for y in 0..self.size.y {
            for x in 0..self.size.x {
                sink.put(self[(x, y)])?;
            }
        }
        Ok(())
    }
    pub fn view<'a>(&'a self) -> View<&'a Frame> {
        View::new(self, Vec2::<isize>::ZERO, self.size)
    }
    pub fn view_mut<'a>(&'a mut self) -> View<&'a mut Frame> {
        View::new(self, Vec2::<isize>::ZERO, self.size)
    }
    pub fn view_area<'a>(&'a self, offset: Vec2<isize>, size: Vec2<isize>) -> View<&'a Frame> {
        View::new(self, offset, size)
    }
    pub fn view_area_mut<'a>(
        &'a mut self,
        offset: Vec2<isize>,
        size: Vec2<isize>,
    ) -> View<&'a mut Frame> {
        View::new(self, offset, size)
    }
    pub fn set(&mut self, pos: Vec2<isize>, color: Pixel) {
        if pos.x >= 0 && pos.y >= 0 && pos.x < self.size.x && pos.y < self.size.y {
            self[pos] = color
        }
    }
}

impl Index<Vec2<isize>> for Frame {
    type Output = Pixel;
    #[inline]
    fn index(&self, Vec2 { x, y }: Vec2<isize>) -> &Self::Output {
        if x >= 0 && y >= 0 && x < self.size.x && y < self.size.y {
            &self.buffer[(x + y * self.size.x) as usize]
        } else {
            &Pixel::BLACK
        }
    }
}
impl IndexMut<Vec2<isize>> for Frame {
    #[inline]
    fn index_mut(&mut self, Vec2 { x, y }: Vec2<isize>) -> &mut Self::Output {
        &mut self.buffer[(x + y * self.size.x) as usize]
    }
}

impl Frame {
    #[inline]
    pub fn sample(&self, p: Vec2<f32>) -> Pixel {
        self[Vec2 {
            x: p.x as isize,
            y: p.y as isize,
        }]
        // let fx = p.x.floor() as isize;
        // let fy = p.y.floor() as isize;
        // let cx = p.x.ceil() as isize;
        // let cy = p.y.ceil() as isize;

        // // TODO dont loose accuracy here
        // Pixel::average(
        //     Pixel::average(self[Vec2 { x: fx, y: fy }], self[Vec2 { x: fx, y: cy }]),
        //     Pixel::average(self[Vec2 { x: cx, y: fx }], self[Vec2 { x: cx, y: fy }]),
        // )
    }
}

impl Index<(isize, isize)> for Frame {
    type Output = Pixel;
    #[inline]
    fn index(&self, (x, y): (isize, isize)) -> &Self::Output {
        &self[Vec2 { x, y }]
    }
}
impl IndexMut<(isize, isize)> for Frame {
    #[inline]
    fn index_mut(&mut self, (x, y): (isize, isize)) -> &mut Self::Output {
        &mut self[Vec2 { x, y }]
    }
}