#![no_main]
#![no_std]

use defmt::info;
use panic_probe as _;

use defmt_rtt as _; // global logger

use core::fmt::Write;

use cortex_m_rt::entry;
use hal::{pac, prelude::*, rcc::Config};
use hd44780_driver::HD44780;

#[defmt::panic_handler]
fn panic() -> ! {
    cortex_m::asm::udf()
}

#[entry]
fn main() -> ! {
    let dp = pac::Peripherals::take().unwrap();
    let cp = cortex_m::Peripherals::take().unwrap();

    let mut rcc = dp.RCC.freeze(Config::hsi16());

    let gpioa = dp.GPIOA.split(&mut rcc);
    let gpiob = dp.GPIOB.split(&mut rcc);
    let gpioc = dp.GPIOC.split(&mut rcc);

    // literal D4-D7 ports etc as written on the nucleo board, mapped to the D4-D7 ports of the LCD
    // controller
    let d4 = gpiob.pb5.into_push_pull_output();
    let d5 = gpiob.pb4.into_push_pull_output();
    let d6 = gpiob.pb10.into_push_pull_output();
    let d7 = gpioa.pa8.into_push_pull_output();

    // clock enable on D9
    let en = gpioc.pc7.into_push_pull_output();
    // register select on D8, the lib wants that but I'd just put it on ground otherwise
    let rs = gpioa.pa9.into_push_pull_output();

    // See https://en.wikipedia.org/wiki/Hitachi_HD44780_LCD_controller#Interface
    // for the pins of the LCD

    let mut delay = cp.SYST.delay(rcc.clocks);

    let mut led = gpioa.pa5.into_push_pull_output();
    let mut lcd = HD44780::new_4bit(rs, en, d4, d5, d6, d7, &mut delay)
        .expect("could not init HD44780 driver");
    lcd.set_display_mode(
        hd44780_driver::DisplayMode {
            cursor_visibility: hd44780_driver::Cursor::Visible,
            cursor_blink: hd44780_driver::CursorBlink::On,
            display: hd44780_driver::Display::On,
        },
        &mut delay,
    )
    .expect("could not set display properties");
    lcd.reset(&mut delay).expect("could not reset the lcd");
    lcd.write_str("Hello world!", &mut delay)
        .expect("could not write to LCD");

    let mut i = 0;
    loop {
        led.set_high().unwrap();
        info!("Writing to LCD...");
        lcd.write_str("Hello world!\nGoing on", &mut delay)
            .expect("could not write to LCD");

        info!("Done!");
        led.set_low().unwrap();

        delay.delay_ms(500_u16);

        i += 1;
    }
}