use embedded_graphics::{
    prelude::*,
    pixelcolor::Rgb888,
    primitives::Rectangle
};
use embedded_graphics::pixelcolor::RgbColor;
use ws2812_esp32_rmt_driver::lib_embedded_graphics::{Ws2812DrawTarget, LedPixelShape};

use running_average::RealTimeRunningAverage;
use std::io;

use crate::power;
use crate::power::AsMilliwatts;
use crate::lib8::*;
use crate::render::*;
use crate::time::Periodically;
use crate::task::Task;
use crate::geometry::*;

impl<T: RgbColor> AsMilliwatts for T {
    fn as_milliwatts(&self) -> u32 {
        const RED_MW : u32   = 16 * 5; //< 16mA @ 5v = 80mW
        const GREEN_MW : u32 = 11 * 5; //< 11mA @ 5v = 55mW
        const BLUE_MW : u32  = 15 * 5; //< 15mA @ 5v = 75mW
        const DARK_MW : u32  =  1 * 5; //<  1mA @ 5v =  5mW

        let red = (self.r() as u32 * RED_MW).wrapping_shr(8);
        let green = (self.g() as u32 * GREEN_MW).wrapping_shr(8);
        let blue = (self.b() as u32 * BLUE_MW).wrapping_shr(8);

        return red + green + blue + DARK_MW;
    }
}

pub struct EmbeddedDisplay<T, S>
where
T: DrawTarget,
S: Surface {
    surfaces : SurfacePool<S>,
    target: T,
    total_mw: u32,
    max_mw: u32,
    fps: RealTimeRunningAverage<u32>,
    frame: u32,
    fps_display: Periodically
}

impl<T: LedPixelShape, S: Surface> Task for EmbeddedDisplay<Ws2812DrawTarget<'_, T>, S> {
    fn start(&mut self) {
        self.target.set_brightness(0);
    }

    fn name(&self) -> &'static str { "Renderer" }

    fn tick(&mut self) {
        self.start_frame();
        self.render_frame();
        self.end_frame();
    }
}

impl<T, S> EmbeddedDisplay<T, S>
where
T: DrawTarget,
S: Surface {
    pub fn new(target: T, max_mw: u32) -> Self {
        EmbeddedDisplay {
            surfaces: SurfacePool::new(),
            target: target,
            max_mw: max_mw,
            total_mw: 0,
            fps: RealTimeRunningAverage::default(),
            frame: 0,
            fps_display: Periodically::new_every_n_seconds(5)
        }
    }
}

impl<T, S> Surfaces<S> for EmbeddedDisplay<T, S>
where
T: DrawTarget,
S: Surface {
    fn new_surface(&mut self) -> Result<S, io::Error> {
        self.surfaces.new_surface()
    }
}

impl<T: LedPixelShape, S: Surface> Display<S> for EmbeddedDisplay<Ws2812DrawTarget<'_, T>, S> {

    fn start_frame(&mut self) {
        self.total_mw = 0;
        self.frame = self.frame.wrapping_add(1);
    }

    fn end_frame(&mut self) {
        let brightness = power::brightness_for_mw(self.total_mw, 255, self.max_mw);
        self.target.set_brightness(brightness);
        self.target.flush().unwrap();
        self.fps.insert(1);
        self.fps_display.run(|| {
            log::info!("FPS: {} frame={} brightness={} mw={}", self.fps.measurement(), self.frame, brightness, self.total_mw);
        });
    }

    fn render_frame(&mut self) {
        let size = T::size();
        let xStride: u8 = 255 / (size.width as u8);
        let yStride: u8 = 255 / (size.height as u8);
        let area = Rectangle::new(Point::new(0, 0), size);

        self.target.draw_iter(
            area.points()
            .map(|pos| {
                let virtCoords = VirtualCoordinates::new(pos.x as u8 * xStride, pos.y as u8 * yStride);
                let mut pixel = RGB8::new(0, 0, 0);
                for surface in self.surfaces.iter() {
                    surface.with_shader(|shader| {
                        pixel = shader.draw(virtCoords.clone());
                    })
                }
                self.total_mw += pixel.as_milliwatts();
                return Pixel(pos, Rgb888::new(pixel.red, pixel.green, pixel.blue));
            })
        ).unwrap();
    }
}