//! A simple Driver for the Waveshare 1.54" E-Ink Display via SPI
//!
//! # Example for the 1.54 in E-Ink Display
//!
//!```rust, no_run
//!# use embedded_hal_mock::*;
//!# fn main() -> Result<(), MockError> {
//!use embedded_graphics::{
//!    pixelcolor::BinaryColor::On as Black, prelude::*, primitives::{Line, PrimitiveStyleBuilder},
//!};
//!use epd_waveshare::{epd1in54::*, prelude::*};
//!#
//!# let expectations = [];
//!# let mut spi = spi::Mock::new(&expectations);
//!# let expectations = [];
//!# let cs_pin = pin::Mock::new(&expectations);
//!# let busy_in = pin::Mock::new(&expectations);
//!# let dc = pin::Mock::new(&expectations);
//!# let rst = pin::Mock::new(&expectations);
//!# let mut delay = delay::MockNoop::new();
//!
//!// Setup EPD
//!let mut epd = Epd1in54::new(&mut spi, cs_pin, busy_in, dc, rst, &mut delay)?;
//!
//!// Use display graphics from embedded-graphics
//!let mut display = Display1in54::default();
//!
//!// Use embedded graphics for drawing a line
//!let style = PrimitiveStyleBuilder::new()
//!    .stroke_color(Black)
//!    .stroke_width(1)
//!    .build();
//!let _ = Line::new(Point::new(0, 120), Point::new(0, 295))
//!    .into_styled(style)
//!    .draw(&mut display);
//!
//!// Display updated frame
//!epd.update_frame(&mut spi, &display.buffer(), &mut delay)?;
//!epd.display_frame(&mut spi, &mut delay)?;
//!
//!// Set the EPD to sleep
//!epd.sleep(&mut spi, &mut delay)?;
//!# Ok(())
//!# }
//!```

/// Width of the display
pub const WIDTH: u32 = 200;
/// Height of the display
pub const HEIGHT: u32 = 200;
/// Default Background Color
pub const DEFAULT_BACKGROUND_COLOR: Color = Color::White;
//const DPI: u16 = 184;
const IS_BUSY_LOW: bool = false;

use embedded_hal::{
    blocking::{delay::*, spi::Write},
    digital::v2::*,
};

use crate::type_a::{
    command::Command,
    constants::{LUT_FULL_UPDATE, LUT_PARTIAL_UPDATE},
};

use crate::color::Color;

use crate::traits::{RefreshLut, WaveshareDisplay};

use crate::interface::DisplayInterface;

#[cfg(feature = "graphics")]
mod graphics;
#[cfg(feature = "graphics")]
pub use crate::epd1in54::graphics::Display1in54;

/// Epd1in54 driver
pub struct Epd1in54<SPI, CS, BUSY, DC, RST, DELAY> {
    /// SPI
    interface: DisplayInterface<SPI, CS, BUSY, DC, RST, DELAY>,
    /// Color
    background_color: Color,
    /// Refresh LUT
    refresh: RefreshLut,
}

impl<SPI, CS, BUSY, DC, RST, DELAY> Epd1in54<SPI, CS, BUSY, DC, RST, DELAY>
where
    SPI: Write<u8>,
    CS: OutputPin,
    BUSY: InputPin,
    DC: OutputPin,
    RST: OutputPin,
    DELAY: DelayMs<u8>,
{
    fn init(&mut self, spi: &mut SPI, delay: &mut DELAY) -> Result<(), SPI::Error> {
        self.interface.reset(delay, 10);

        // 3 Databytes:
        // A[7:0]
        // 0.. A[8]
        // 0.. B[2:0]
        // Default Values: A = Height of Screen (0x127), B = 0x00 (GD, SM and TB=0?)
        self.interface.cmd_with_data(
            spi,
            Command::DriverOutputControl,
            &[HEIGHT as u8, (HEIGHT >> 8) as u8, 0x00],
        )?;

        // 3 Databytes: (and default values from datasheet and arduino)
        // 1 .. A[6:0]  = 0xCF | 0xD7
        // 1 .. B[6:0]  = 0xCE | 0xD6
        // 1 .. C[6:0]  = 0x8D | 0x9D
        //TODO: test
        self.interface
            .cmd_with_data(spi, Command::BoosterSoftStartControl, &[0xD7, 0xD6, 0x9D])?;

        // One Databyte with value 0xA8 for 7V VCOM
        self.interface
            .cmd_with_data(spi, Command::WriteVcomRegister, &[0xA8])?;

        // One Databyte with default value 0x1A for 4 dummy lines per gate
        self.interface
            .cmd_with_data(spi, Command::SetDummyLinePeriod, &[0x1A])?;

        // One Databyte with default value 0x08 for 2us per line
        self.interface
            .cmd_with_data(spi, Command::SetGateLineWidth, &[0x08])?;

        // One Databyte with default value 0x03
        //  -> address: x increment, y increment, address counter is updated in x direction
        self.interface
            .cmd_with_data(spi, Command::DataEntryModeSetting, &[0x03])?;

        self.set_lut(spi, None)?;

        self.wait_until_idle();
        Ok(())
    }
}

impl<SPI, CS, BUSY, DC, RST, E, DELAY> WaveshareDisplay<SPI, CS, BUSY, DC, RST, DELAY>
    for Epd1in54<SPI, CS, BUSY, DC, RST, DELAY>
where
    SPI: Write<u8, Error = E>,
    CS: OutputPin,
    BUSY: InputPin,
    DC: OutputPin,
    RST: OutputPin,
    DELAY: DelayMs<u8>,
{
    type DisplayColor = Color;
    fn width(&self) -> u32 {
        WIDTH
    }

    fn height(&self) -> u32 {
        HEIGHT
    }

    fn new(
        spi: &mut SPI,
        cs: CS,
        busy: BUSY,
        dc: DC,
        rst: RST,
        delay: &mut DELAY,
    ) -> Result<Self, SPI::Error> {
        let interface = DisplayInterface::new(cs, busy, dc, rst);

        let mut epd = Epd1in54 {
            interface,
            background_color: DEFAULT_BACKGROUND_COLOR,
            refresh: RefreshLut::Full,
        };

        epd.init(spi, delay)?;

        Ok(epd)
    }

    fn wake_up(&mut self, spi: &mut SPI, delay: &mut DELAY) -> Result<(), SPI::Error> {
        self.init(spi, delay)
    }

    fn sleep(&mut self, spi: &mut SPI, _delay: &mut DELAY) -> Result<(), SPI::Error> {
        self.wait_until_idle();
        // 0x00 for Normal mode (Power on Reset), 0x01 for Deep Sleep Mode
        //TODO: is 0x00 needed here or would 0x01 be even more efficient?
        self.interface
            .cmd_with_data(spi, Command::DeepSleepMode, &[0x00])?;
        Ok(())
    }

    fn update_frame(
        &mut self,
        spi: &mut SPI,
        buffer: &[u8],
        _delay: &mut DELAY,
    ) -> Result<(), SPI::Error> {
        self.wait_until_idle();
        self.use_full_frame(spi)?;
        self.interface
            .cmd_with_data(spi, Command::WriteRam, buffer)?;
        Ok(())
    }

    //TODO: update description: last 3 bits will be ignored for width and x_pos
    fn update_partial_frame(
        &mut self,
        spi: &mut SPI,
        buffer: &[u8],
        x: u32,
        y: u32,
        width: u32,
        height: u32,
    ) -> Result<(), SPI::Error> {
        self.wait_until_idle();
        self.set_ram_area(spi, x, y, x + width, y + height)?;
        self.set_ram_counter(spi, x, y)?;

        self.interface
            .cmd_with_data(spi, Command::WriteRam, buffer)?;
        Ok(())
    }

    fn display_frame(&mut self, spi: &mut SPI, _delay: &mut DELAY) -> Result<(), SPI::Error> {
        self.wait_until_idle();
        // enable clock signal, enable cp, display pattern -> 0xC4 (tested with the arduino version)
        //TODO: test control_1 or control_2 with default value 0xFF (from the datasheet)
        self.interface
            .cmd_with_data(spi, Command::DisplayUpdateControl2, &[0xC4])?;

        self.interface.cmd(spi, Command::MasterActivation)?;
        // MASTER Activation should not be interupted to avoid currption of panel images
        // therefore a terminate command is send
        self.interface.cmd(spi, Command::Nop)?;
        Ok(())
    }

    fn update_and_display_frame(
        &mut self,
        spi: &mut SPI,
        buffer: &[u8],
        delay: &mut DELAY,
    ) -> Result<(), SPI::Error> {
        self.update_frame(spi, buffer, delay)?;
        self.display_frame(spi, delay)?;
        Ok(())
    }

    fn clear_frame(&mut self, spi: &mut SPI, _delay: &mut DELAY) -> Result<(), SPI::Error> {
        self.wait_until_idle();
        self.use_full_frame(spi)?;

        // clear the ram with the background color
        let color = self.background_color.get_byte_value();

        self.interface.cmd(spi, Command::WriteRam)?;
        self.interface
            .data_x_times(spi, color, WIDTH / 8 * HEIGHT)?;
        Ok(())
    }

    fn set_background_color(&mut self, background_color: Color) {
        self.background_color = background_color;
    }

    fn background_color(&self) -> &Color {
        &self.background_color
    }

    fn set_lut(
        &mut self,
        spi: &mut SPI,
        refresh_rate: Option<RefreshLut>,
    ) -> Result<(), SPI::Error> {
        if let Some(refresh_lut) = refresh_rate {
            self.refresh = refresh_lut;
        }
        match self.refresh {
            RefreshLut::Full => self.set_lut_helper(spi, &LUT_FULL_UPDATE),
            RefreshLut::Quick => self.set_lut_helper(spi, &LUT_PARTIAL_UPDATE),
        }
    }

    fn is_busy(&self) -> bool {
        self.interface.is_busy(IS_BUSY_LOW)
    }
}

impl<SPI, CS, BUSY, DC, RST, DELAY> Epd1in54<SPI, CS, BUSY, DC, RST, DELAY>
where
    SPI: Write<u8>,
    CS: OutputPin,
    BUSY: InputPin,
    DC: OutputPin,
    RST: OutputPin,
    DELAY: DelayMs<u8>,
{
    fn wait_until_idle(&mut self) {
        let _ = self.interface.wait_until_idle(IS_BUSY_LOW);
    }

    pub(crate) fn use_full_frame(&mut self, spi: &mut SPI) -> Result<(), SPI::Error> {
        // choose full frame/ram
        self.set_ram_area(spi, 0, 0, WIDTH - 1, HEIGHT - 1)?;

        // start from the beginning
        self.set_ram_counter(spi, 0, 0)
    }

    pub(crate) fn set_ram_area(
        &mut self,
        spi: &mut SPI,
        start_x: u32,
        start_y: u32,
        end_x: u32,
        end_y: u32,
    ) -> Result<(), SPI::Error> {
        self.wait_until_idle();
        assert!(start_x < end_x);
        assert!(start_y < end_y);

        // x is positioned in bytes, so the last 3 bits which show the position inside a byte in the ram
        // aren't relevant
        self.interface.cmd_with_data(
            spi,
            Command::SetRamXAddressStartEndPosition,
            &[(start_x >> 3) as u8, (end_x >> 3) as u8],
        )?;

        // 2 Databytes: A[7:0] & 0..A[8] for each - start and end
        self.interface.cmd_with_data(
            spi,
            Command::SetRamYAddressStartEndPosition,
            &[
                start_y as u8,
                (start_y >> 8) as u8,
                end_y as u8,
                (end_y >> 8) as u8,
            ],
        )?;
        Ok(())
    }

    pub(crate) fn set_ram_counter(
        &mut self,
        spi: &mut SPI,
        x: u32,
        y: u32,
    ) -> Result<(), SPI::Error> {
        self.wait_until_idle();
        // x is positioned in bytes, so the last 3 bits which show the position inside a byte in the ram
        // aren't relevant
        self.interface
            .cmd_with_data(spi, Command::SetRamXAddressCounter, &[(x >> 3) as u8])?;

        // 2 Databytes: A[7:0] & 0..A[8]
        self.interface.cmd_with_data(
            spi,
            Command::SetRamYAddressCounter,
            &[y as u8, (y >> 8) as u8],
        )?;
        Ok(())
    }

    fn set_lut_helper(&mut self, spi: &mut SPI, buffer: &[u8]) -> Result<(), SPI::Error> {
        self.wait_until_idle();
        assert!(buffer.len() == 30);

        self.interface
            .cmd_with_data(spi, Command::WriteLutRegister, buffer)?;
        Ok(())
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn epd_size() {
        assert_eq!(WIDTH, 200);
        assert_eq!(HEIGHT, 200);
        assert_eq!(DEFAULT_BACKGROUND_COLOR, Color::White);
    }
}