use smart_leds_trait::SmartLedsWrite;

use crate::lib8::interpolate::Fract8Ops;
use crate::render::{Display, HardwarePixel, PixelView, Sample, Surface, Surfaces};
use crate::buffers::SurfacePool;
use crate::power::{brightness_for_mw, AsMilliwatts};
use crate::geometry::*;
use crate::mappings::*;
use std::fmt::{Debug, Formatter};

use std::io;
use std::ops::IndexMut;

pub trait Pixbuf: AsMilliwatts + IndexMut<usize, Output=Self::Pixel> {
    type Pixel: HardwarePixel;
    fn new() -> Self;
    fn blank(&mut self);
    fn iter_with_brightness(&self, brightness: u8) -> impl Iterator<Item = Self::Pixel> + Send;
}

struct StrideSampler<'a, P: Pixbuf> {
    pixbuf: &'a mut P,
    selection: StrideView<'a>
}

impl<'a, P: Pixbuf> PixelView for StrideSampler<'a, P> {
    type Pixel = P::Pixel;
    fn next(&mut self) -> Option<(Coordinates<Virtual>, &mut Self::Pixel)> {
        if let Some((virt, coords)) = self.selection.next() {
            let idx = self.selection.map.strides[coords.x as usize].pixel_idx_for_offset(coords.y);
            Some((virt, &mut self.pixbuf[idx]))
        } else {
            None
        }
    }
}

struct StrideOutput<P: Pixbuf> {
    pixbuf: P,
    stride_map: StrideMapping
}

impl<P: Pixbuf> Sample for StrideOutput<P> {
    type Pixel = P::Pixel;
    fn sample(&mut self, rect: &Rectangle<Virtual>) -> impl PixelView<Pixel = Self::Pixel> {
        StrideSampler {
            pixbuf: &mut self.pixbuf,
            selection: self.stride_map.select(rect)
        }
    }
}

impl<T: HardwarePixel, const PIXEL_NUM: usize> Pixbuf for [T; PIXEL_NUM] {
    type Pixel = T;
    fn new() -> Self {
        [T::default(); PIXEL_NUM]
    }

    fn blank(&mut self) {
        self.fill(T::default())
    }

    fn iter_with_brightness(&self, brightness: u8) -> impl Iterator<Item=T> + Send {
        self.iter().map(move |x| { x.scale8(brightness)})
    }
}

struct SmartLedDisplay<T: FastWrite, S: Surface, P: Pixbuf<Pixel = T::Color>> {
    surfaces : Option<SurfacePool<S>>,
    output: StrideOutput<P>,
    target: T,
    max_mw: u32,
    frame: usize
}

impl<T: FastWrite, S: Surface, P: Pixbuf<Pixel = T::Color>> Debug for SmartLedDisplay<T, S, P> {
    fn fmt(&self, f: &mut Formatter) -> Result<(), std::fmt::Error> {
        f.debug_struct("SmartLedDisplay")
            .field("total_mw", &self.output.pixbuf.as_milliwatts())
            .field("surfaces", &self.surfaces)
            .finish()
    }
}

impl<T: FastWrite, S: Surface, P: Pixbuf<Pixel = T::Color>> SmartLedDisplay<T, S, P> {
    fn new(target: T, max_mw: u32, pixmap: StrideMapping, pixbuf: P) -> Self {
        SmartLedDisplay {
            output: StrideOutput { pixbuf: pixbuf, stride_map: pixmap },
            surfaces: Some(SurfacePool::new()),
            target,
            max_mw,
            frame: 0
        }
    }
}

impl<T, S, P> Surfaces<S> for SmartLedDisplay<T, S, P> where
T: FastWrite,
S: Surface,
P: Pixbuf<Pixel = T::Color> {
    fn new_surface(&mut self, area: &Rectangle<Virtual>) -> Result<S, io::Error> {
        if let Some(ref mut s) = self.surfaces {
            s.new_surface(area)
        } else {
            panic!("Could not grab surface list")
        }
    }
}

impl<T, S, P> Display<S> for SmartLedDisplay<T, S, P> where
T: FastWrite,
S: Surface,
P: Pixbuf<Pixel = T::Color> {
    fn start_frame(&mut self) {
        self.output.pixbuf.blank();
    }

    fn render_frame(&mut self) {
        let surfaces = self.surfaces.take().unwrap();
        for surface in surfaces.iter() {
            let rect = surface.rect();
            let opacity = surface.opacity();
            if opacity > 0 {
                let mut sample = self.output.sample(&rect);
                surface.with_shader(|shader| {
                    while let Some((virt_coords, pixel)) = sample.next() {
                        *pixel = pixel.blend8(shader.draw(&virt_coords, self.frame).into(), opacity);
                    }
                })
            }
        }
        self.surfaces = Some(surfaces);
    }

    fn end_frame(&mut self) {
        let b = brightness_for_mw(self.output.pixbuf.as_milliwatts(), 255, self.max_mw);
        if self.target.fast_write(self.output.pixbuf.iter_with_brightness(b)).is_err() {
            panic!("Could not write frame!");
        };
        self.frame += 1;
    }
}

trait FastWrite {
    type Target: SmartLedsWrite;
    type Color: HardwarePixel;
    type Error;
    fn fast_write<T, I>(&mut self, iterator: T) -> Result<(), Self::Error> where
    T: IntoIterator<Item = I>,
    I: Into<Self::Color>,
    <T as IntoIterator>::IntoIter: Send;
}

#[cfg(feature="rmt")]
pub mod rmt {
    use esp_idf_svc::hal::prelude::Peripherals;
    use ws2812_esp32_rmt_driver::driver::color::LedPixelColorGrb24;
    use smart_leds::SmartLedsWrite;
    use rgb::Rgb;
    use ws2812_esp32_rmt_driver::LedPixelEsp32Rmt;

    use crate::mappings::StrideMapping;
    use crate::render::{Display, Surface};
    use crate::platform::DisplayInit;

    use super::{Pixbuf, FastWrite, SmartLedDisplay};

    pub type FastWs2812Esp32Rmt<'a> = LedPixelEsp32Rmt<'a, Rgb<u8>, LedPixelColorGrb24>;

    impl FastWrite for FastWs2812Esp32Rmt<'_> {
        type Color = <Self as SmartLedsWrite>::Color;
        type Error = <Self as SmartLedsWrite>::Error;
        type Target = Self;
        fn fast_write<T, I>(&mut self, iterator: T) -> Result<(), Self::Error> where
            T: IntoIterator<Item = I>,
            I: Into<Self::Color>,
            <T as IntoIterator>::IntoIter: Send {
                self.write_nocopy(iterator)
        }
    }

    impl DisplayInit for FastWs2812Esp32Rmt<'_> {
        fn new_display<S: Surface>() -> impl Display<S> {
            let peripherals = Peripherals::take().unwrap();
            let led_pin = peripherals.pins.gpio14;
            //let led_pin = peripherals.pins.gpio5;
            let channel = peripherals.rmt.channel0;

            const POWER_VOLTS : u32 = 5;
            const POWER_MA : u32 = 500;
            const MAX_POWER_MW : u32 = POWER_VOLTS * POWER_MA;

            //let pixbuf: [Rgb<u8>; 310] = Pixbuf::new();
            let pixbuf: [<Self as FastWrite>::Color; 310] = Pixbuf::new();
            let pixmap = StrideMapping::new_jar();

            assert!(pixmap.pixel_count <= pixbuf.len(), "map needs {} pixels, I only have PIXEL_NUM={}", pixmap.pixel_count, pixbuf.len());

            let target = Self::new(channel, led_pin).unwrap();
            return SmartLedDisplay::new(target, MAX_POWER_MW, pixmap, pixbuf);
        }
    }
}

#[cfg(feature="spi")]
pub mod spi {
    use smart_leds::SmartLedsWrite;
    use ws2812_spi::prerendered::Ws2812;

    use crate::render::{Display, Surface};
    use crate::platform::smart_leds_lib::SmartLedDisplay;
    use crate::DisplayInit;
    use super::FastWrite;

    use esp_idf_svc::hal::{
        prelude::*,
        gpio::AnyIOPin,
        spi::{
            config::{Config, DriverConfig},
            Dma,
            SpiBusDriver,
            SpiDriver,
        }
    };

    impl<'a> FastWrite for Ws2812<'_, SpiBusDriver<'a, SpiDriver<'a>>> {
        type Color = <Self as SmartLedsWrite>::Color;
        type Error = <Self as SmartLedsWrite>::Error;
        type Target = Self;

        fn fast_write<T, I>(&mut self, iterator: T) -> Result<(), Self::Error> where
            T: IntoIterator<Item = I>,
            I: Into<Self::Color>,
            <T as IntoIterator>::IntoIter: Send {
                let resp = self.write(iterator);
                if let Err(e) = resp {
                    panic!("Could not write SPI frame! {:?}", e)
                } else {
                    resp
                }
        }
    }

    static mut STATIC_BUFFER: [u8; 400 * 12] = [0; 400 * 12];

    pub struct SPIDisplay {}
    impl DisplayInit for SPIDisplay {
        fn new_display<S: Surface>() -> impl Display<S> {
            let peripherals = Peripherals::take().unwrap();

            let driver = SpiDriver::new_without_sclk(
                peripherals.spi2,
                peripherals.pins.gpio5,
                Option::<AnyIOPin>::None,
                &DriverConfig::new().dma(Dma::Auto(4092))
            ).unwrap();

            let cfg = Config::new().baudrate(3.MHz().into());

            let spi = SpiBusDriver::new(driver, &cfg).unwrap();

            const POWER_VOLTS : u32 = 5;
            const POWER_MA : u32 = 500;
            const MAX_POWER_MW : u32 = POWER_VOLTS * POWER_MA;
            unsafe {
                let target = Ws2812::new(spi, &mut STATIC_BUFFER);
                return SmartLedDisplay::<Ws2812<SpiBusDriver<'_, SpiDriver<'_>>>, S, 310>::new(target, MAX_POWER_MW);
            }
        }
    }
}