use atmega_hal::{
    pac::TC0,
    port::{mode::Output, Pin, PB0, PB1, PD5},
    Spi,
};
use si5351::{ClockOutput, Si5351, Si5351Device, PLL};

mod channel;
mod home;
mod setup;
mod splash;

use crate::{
    assets::{OFF, ON, PLL_A, PLL_B},
    eeprom,
    lcd::Lcd,
    I2c, Input, BACKLIGHT,
};
pub use channel::Channel;
pub use home::Home;
pub use setup::Setup;
pub use splash::Splash;

// TODO: Only update changes instead of whole screen

pub enum Event {
    Screen(Screens),
    Backlight(u8),
    Contrast(u8),
    Channel(ClockChannel),
    None,
}

#[derive(Clone, Copy)]
pub struct ClockChannel {
    output: ClockOutput,
    freq: u32,
    enabled: bool,
    pll: PLL,
}

impl ClockChannel {
    fn print(&self, lcd: &mut Lcd, page: u8) {
        lcd.print_freq(25, page, self.freq);
        lcd.print_icon(91, page, if self.enabled { &ON } else { &OFF });
        lcd.print_icon(
            94,
            page + 1,
            match self.pll {
                PLL::A => &PLL_A,
                PLL::B => &PLL_B,
            },
        );
    }

    fn update(&self, si5351: &mut Si5351Device<I2c>) {
        si5351
            .set_frequency(self.pll, self.output, self.freq)
            .unwrap();
        si5351.set_clock_enabled(self.output, self.enabled);
        si5351.flush_output_enabled().unwrap();
    }
}

pub enum Screens {
    Splash(Splash),
    Home(Home),
    Setup(Setup),
    Channel(Channel),
}

impl Screens {
    pub fn input(&mut self, input: &Input, channels: [ClockChannel; 3]) -> Event {
        match self {
            Screens::Splash(_) => Event::None,
            Screens::Home(home) => home.input(input, channels),
            Screens::Setup(setup) => setup.input(input),
            Screens::Channel(channel) => channel.input(input),
        }
    }
}

pub struct Screen {
    lcd: Lcd,
    tc0: TC0,
    pwm: Pin<Output, PD5>,
    screen: Screens,
    si5351: Si5351Device<I2c>,
    channels: [ClockChannel; 3],
}

impl Screen {
    pub fn new(
        tc0: TC0,
        spi: Spi,
        pwm: Pin<Output, PD5>,
        cd: Pin<Output, PB0>,
        rst: Pin<Output, PB1>,
        i2c: I2c,
    ) -> Self {
        Self {
            lcd: Lcd::new(spi, cd, rst),
            tc0,
            pwm,
            screen: Screens::Splash(Splash),
            si5351: Si5351Device::new_adafruit_module(i2c),
            channels: [
                ClockChannel {
                    output: ClockOutput::Clk0,
                    freq: 1_000_000,
                    enabled: false,
                    pll: PLL::A,
                },
                ClockChannel {
                    output: ClockOutput::Clk1,
                    freq: 1_000_000,
                    enabled: false,
                    pll: PLL::A,
                },
                ClockChannel {
                    output: ClockOutput::Clk2,
                    freq: 1_000_000,
                    enabled: false,
                    pll: PLL::A,
                },
            ],
        }
    }

    pub fn init(&mut self) {
        // Init display backlight
        self.tc0.ocr0a.write(|w| unsafe { w.bits(255) });
        self.tc0.tccr0a.write(|w| {
            w.wgm0().pwm_fast();
            w.com0b().match_clear()
        });
        self.set_backlight(nb::block!(eeprom::read_byte(&BACKLIGHT)).unwrap());

        // Init lcd display
        self.lcd.init();
        self.draw();

        // Init Si5351
        self.si5351.init_adafruit_module().unwrap();
    }

    fn set_backlight(&mut self, backlight: u8) {
        match backlight {
            0 => {
                self.tc0.tccr0b.write(|w| w.cs0().no_clock());
                self.pwm.set_low();
            }
            1..=5 => {
                self.tc0.tccr0b.write(|w| {
                    w.wgm02().set_bit();
                    w.cs0().prescale_256()
                });
                self.tc0.ocr0b.write(|w| unsafe { w.bits(backlight - 1) });
            }
            _ => {
                self.tc0.tccr0b.write(|w| {
                    w.wgm02().set_bit();
                    w.cs0().prescale_64()
                });
                self.tc0.ocr0b.write(|w| unsafe { w.bits(backlight - 6) });
            }
        }
    }

    pub fn draw(&mut self) {
        self.lcd.fill_area(0, 0, 102, 8, 0x00);

        match &self.screen {
            Screens::Splash(splash) => splash.draw(&mut self.lcd),
            Screens::Home(home) => home.draw(&mut self.lcd, self.channels),
            Screens::Setup(setup) => setup.draw(&mut self.lcd),
            Screens::Channel(channel) => channel.draw(&mut self.lcd),
        }
    }

    pub fn input(&mut self, input: &Input) {
        match self.screen.input(input, self.channels) {
            Event::Screen(screen) => self.screen = screen,
            Event::Backlight(backlight) => self.set_backlight(backlight),
            Event::Contrast(contrast) => self.lcd.set_contrast(contrast),
            Event::Channel(channel) => {
                match channel.output {
                    ClockOutput::Clk0 => self.channels[0] = channel,
                    ClockOutput::Clk1 => self.channels[1] = channel,
                    ClockOutput::Clk2 => self.channels[2] = channel,
                    _ => unimplemented!(),
                }

                channel.update(&mut self.si5351);
            }
            Event::None => {}
        }

        self.draw();
    }

    pub fn change(&mut self, screen: Screens) {
        self.screen = screen;
        self.draw();
    }
}