#![no_std]
#![no_main]

use core::cell::Cell;

use critical_section::Mutex;

use esp_hal::clock::ClockControl;
use esp_hal::delay::Delay;
use esp_hal::gpio::{Event, IO};
use esp_hal::ledc::{channel, timer, LSGlobalClkSource, LEDC};
use esp_hal::peripherals::Peripherals;
use esp_hal::prelude::*;
use esp_hal::systimer::SystemTimer;

use panic_halt as _;

const BUTTON_TIMEOUT: u64 = SystemTimer::TICKS_PER_SECOND / 10;

const COLORS: [[u8; 3]; 6] = [
    [1, 0, 0],
    [1, 1, 0],
    [0, 1, 0],
    [0, 1, 1],
    [0, 0, 1],
    [1, 0, 1],
];

static LAST_TRIGGERED: Mutex<Cell<u64>> = Mutex::new(Cell::new(0));

static STOP_CHASE: Mutex<Cell<bool>> = Mutex::new(Cell::new(false));

#[entry]
fn main() -> ! {
    let p = Peripherals::take();
    let sys = p.SYSTEM.split();
    let clocks = ClockControl::boot_defaults(sys.clock_control).freeze();

    let mut ledc = LEDC::new(p.LEDC, &clocks);
    ledc.set_global_slow_clock(LSGlobalClkSource::APBClk);

    let mut timer = ledc.get_timer(timer::Number::Timer0);
    timer
        .configure(timer::config::Config {
            clock_source: timer::LSClockSource::APBClk,
            duty: timer::config::Duty::Duty8Bit,
            frequency: 24.kHz(),
        })
        .unwrap();

    let mut io = IO::new(p.GPIO, p.IO_MUX);

    io.set_interrupt_handler(gpio_handler);

    let mut r = ledc.get_channel(
        channel::Number::Channel0,
        io.pins.gpio5.into_push_pull_output(),
    );
    let mut g = ledc.get_channel(
        channel::Number::Channel1,
        io.pins.gpio6.into_push_pull_output(),
    );
    let mut b = ledc.get_channel(
        channel::Number::Channel2,
        io.pins.gpio7.into_push_pull_output(),
    );

    r.configure(channel::config::Config {
        duty_pct: 0,
        pin_config: channel::config::PinConfig::PushPull,
        timer: &timer,
    })
    .unwrap();
    g.configure(channel::config::Config {
        duty_pct: 0,
        pin_config: channel::config::PinConfig::PushPull,
        timer: &timer,
    })
    .unwrap();
    b.configure(channel::config::Config {
        duty_pct: 0,
        pin_config: channel::config::PinConfig::PushPull,
        timer: &timer,
    })
    .unwrap();

    io.pins.gpio9.into_pull_up_input().listen(Event::RisingEdge);

    let delay = Delay::new(&clocks);

    for [r_duty, g_duty, b_duty] in COLORS.iter().cycle() {
        let stop_chase = critical_section::with(|cs| STOP_CHASE.borrow(cs).get());
        if !stop_chase {
            let _ = r.set_duty(*r_duty);
            let _ = g.set_duty(*g_duty);
            let _ = b.set_duty(*b_duty);
        }

        delay.delay_millis(200u32);
    }

    loop {}
}

#[handler]
fn gpio_handler() {
    critical_section::with(|cs| {
        let last_triggered = LAST_TRIGGERED.borrow(cs);
        if last_triggered.get() + BUTTON_TIMEOUT > SystemTimer::now() {
            return;
        }

        let stop_chase = STOP_CHASE.borrow(cs);
        stop_chase.set(!stop_chase.get());

        last_triggered.set(SystemTimer::now());
    });
}