#![no_std]
#![no_main]

use cortex_m_rt::entry;
use embedded_hal::digital::v2::{InputPin, OutputPin};
use stm32f1xx_hal::{delay::Delay, pac, prelude::*};

// Halt the MCU when panic
#[allow(unused_imports)]
use panic_halt;

mod io;

mod seq;
pub use seq::{LayerSelect, SeqLayer, Sequencer};

#[entry]
fn main() -> ! {
    // Grab handles for the underlying hardware objects
    let dp = pac::Peripherals::take().unwrap();
    let cp = cortex_m::Peripherals::take().unwrap();

    // Initialise GPIOC via the HAL
    let mut rcc = dp.RCC.constrain();
    let mut gpioa = dp.GPIOA.split(&mut rcc.apb2);
    let mut gpiob = dp.GPIOB.split(&mut rcc.apb2);

    // Create an LED output
    let mut led1 = gpioa.pa1.into_push_pull_output(&mut gpioa.crl);
    let mut led2 = gpioa.pa2.into_push_pull_output(&mut gpioa.crl);
    let mut led3 = gpioa.pa3.into_push_pull_output(&mut gpioa.crl);
    let mut led4 = gpioa.pa4.into_push_pull_output(&mut gpioa.crl);

    // Create a button input
    let btn1 = gpiob.pb0.into_pull_down_input(&mut gpiob.crl);
    let btn2 = gpiob.pb1.into_pull_down_input(&mut gpiob.crl);
    let btn3 = gpiob.pb5.into_pull_down_input(&mut gpiob.crl);
    let btn4 = gpiob.pb6.into_pull_down_input(&mut gpiob.crl);

    // Eurorack clock input/ gate output
    let clk = gpiob.pb7.into_pull_down_input(&mut gpiob.crl);
    let gate = gpiob.pb8.into_push_pull_output(&mut gpiob.crh);

    // Setup the I/O states
    let mut io = io::Io {
        led1,
        led2,
        led3,
        led4,
        btn1,
        btn2,
        btn3,
        btn4,
        btn1_last: false,
        btn2_last: false,
        btn3_last: false,
        btn4_last: false,
        clk,
        clk_last: false,
        gate,
    };

    let mut seq = Sequencer::default();

    // Initialize the delay object with the MCU frequency
    let mut flash = dp.FLASH.constrain();
    let clocks = rcc
        .cfgr
        .use_hse(8.mhz())
        .sysclk(48.mhz())
        .pclk1(24.mhz())
        .freeze(&mut flash.acr);
    let mut delay = Delay::new(cp.SYST, clocks);

    loop {
        // Update sequencer state based on inputs
        io.update_sequence(&mut seq);

        // Write out gate CV
        io.update_cv(&mut seq);

        // Wait 5ms until we do it again
        delay.delay_ms(5_u16);
    }
}