use crate::{
    pixel::Pixel,
    ser::{Sink, Source},
    vec2::Vec2,
    view::View,
};
use std::ops::{Index, IndexMut};

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

impl Frame {
    pub fn new(size: Vec2) -> Self {
        Self {
            size,
            buffer: (0..size.x * size.y).map(|_| Pixel::default()).collect(),
        }
    }
    pub fn read(source: &mut impl Source, size: Vec2) -> 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::ZERO, self.size)
    }
    pub fn view_mut<'a>(&'a mut self) -> View<&'a mut Frame> {
        View::new(self, Vec2::ZERO, self.size)
    }
    pub fn view_area<'a>(&'a self, offset: Vec2, size: Vec2) -> View<&'a Frame> {
        View::new(self, offset, size)
    }
    pub fn view_area_mut<'a>(&'a mut self, offset: Vec2, size: Vec2) -> View<&'a mut Frame> {
        View::new(self, offset, size)
    }
}

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

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 }]
    }
}