#![no_std]
#![no_main]

use cortex_m::prelude::_embedded_hal_PwmPin;

use defmt::info;
use defmt::println;
use defmt_rtt as _;
use panic_probe as _;

use rp2040_hal::pll::PLLConfig;
use rp2040_hal::pll::common_configs::PLL_USB_48MHZ;
// Alias for our HAL crate
use rp2040_hal as hal;

use hal::fugit::RateExtU32;
use hal::pac;

use embedded_hal::digital::InputPin;
use embedded_hal::digital::OutputPin;
use sh1106_pico_rs::graphics::GraphicsBuf;
use sh1106_pico_rs::sh1106::SH1106Dev;

/// NB if OVERCLOCKING
/// you MUST use a BOOT_LOADER which can tolerate the OC
/// the GENERIC_03H one cannot (unsure why) but W25Q080 has been solid for me
#[unsafe(link_section = ".boot_loader")]
#[used]
pub static BOOT2: [u8; 256] = rp2040_boot2::BOOT_LOADER_W25Q080;

/// External high-speed crystal on the Raspberry Pi Pico board is 12 MHz. Adjust
/// if your board has a different frequency
const XTAL_FREQ_HZ: u32 = 12_000_000u32;

#[rp2040_hal::entry]
fn main() -> ! {
    // Grab our singleton objects
    let mut pac = pac::Peripherals::take().unwrap();
    let core = pac::CorePeripherals::take().unwrap();

    // Set up the watchdog driver - needed by the clock setup code
    // let mut watchdog = hal::Watchdog::new(pac.WATCHDOG);

    hal::vreg::set_voltage(
        &mut pac.VREG_AND_CHIP_RESET,
        pac::vreg_and_chip_reset::vreg::VSEL_A::VOLTAGE1_30,
    );
    // settle
    // cortex_m::asm::delay(3_000_000);

    let xosc = hal::xosc::setup_xosc_blocking_custom_delay(pac.XOSC, XTAL_FREQ_HZ.Hz(), 128)
        .map_err(|_x| false)
        .unwrap();

    // watchdog.enable_tick_generation((XTAL_FREQ_HZ / 1_000_000) as u8);

    // Configure the clocks
    let mut clocks = hal::clocks::ClocksManager::new(pac.CLOCKS);

    let pll_usb = rp2040_hal::pll::setup_pll_blocking(
        pac.PLL_USB,
        xosc.operating_frequency(),
        PLL_USB_48MHZ,
        &mut clocks,
        &mut pac.RESETS,
    )
    .unwrap();

    let pll_sys = hal::pll::setup_pll_blocking(
        pac.PLL_SYS,
        xosc.operating_frequency(),
        PLLConfig {
            vco_freq: 1500.MHz(),
            refdiv: 1,
            post_div1: 5,
            post_div2: 1,
        },
        &mut clocks,
        &mut pac.RESETS,
    )
    .unwrap();

    clocks.init_default(&xosc, &pll_sys, &pll_usb).unwrap();

    // let mut delay = cortex_m::delay::Delay::new(core.SYST, 200_000_000);

    // The single-cycle I/O block controls our GPIO pins
    let sio = hal::Sio::new(pac.SIO);

    // Set the pins to their default state
    let pins = hal::gpio::Pins::new(
        pac.IO_BANK0,
        pac.PADS_BANK0,
        sio.gpio_bank0,
        &mut pac.RESETS,
    );

    let mut led_pin = pins.gpio25.into_push_pull_output();
    led_pin.set_high();

    // Init PWMs
    let mut pwm_slices = hal::pwm::Slices::new(pac.PWM, &mut pac.RESETS);

    // Configure PWM0
    let pwm0 = &mut pwm_slices.pwm0;
    pwm0.clr_ph_correct();
    pwm0.set_div_int(1);
    pwm0.set_div_frac(0);
    pwm0.clear_interrupt();
    pwm0.enable();

    let mut pwm_pin = pins.gpio16;
    pwm_pin.set_drive_strength(rp2040_hal::gpio::OutputDriveStrength::TwelveMilliAmps);
    pwm0.channel_a.output_to(pwm_pin);

    let mut on_off_input = pins.gpio15.into_pull_up_input();

    let mut tune_up_input = pins.gpio14.into_pull_up_input();
    let mut tune_dn_input = pins.gpio13.into_pull_up_input();

    let mut tick = 0u32;
    let mut last_input = 0u32;

    let mut broadcast_on = false;

    let mut current_tune = 10;

    const MAX_TUNE: u16 = 350u16;
    const MIN_TUNE: u16 = 4u16;

    pwm0.set_top(current_tune);
    pwm0.channel_a.set_duty(current_tune / 2);

    // Create the I²C drive
    let mut i2c = hal::I2C::i2c0(
        pac.I2C0,
        pins.gpio8.reconfigure(),
        pins.gpio9.reconfigure(),
        400.kHz(),
        &mut pac.RESETS,
        &clocks.system_clock,
    );

    let mut delay = cortex_m::delay::Delay::new(core.SYST, 200_000);

    let mut sh1106_dev = SH1106Dev::new(&mut delay, &mut i2c);
    sh1106_dev.set_vertical_flip(&mut i2c, true);
    let sh1106_dev = sh1106_dev;
    let mut gfx_buf = GraphicsBuf::new();
    let mut last_gfx_update = 0u32;

    loop {
        tick = tick.wrapping_add(1);

        if tick.wrapping_sub(last_gfx_update) > 500_000 {
            gfx_buf.clear();
            gfx_buf.draw_string(20, 14, "Hello Radio!");

            let tuned_freq = 272_000u32 / (current_tune as u32);
            let mut tune_str_buf = [0u8; 5];
            let len = u32_into_str(tuned_freq, &mut tune_str_buf);
            let tune_str = str::from_utf8(&tune_str_buf[tune_str_buf.len() - len..]).unwrap();
            // info!("val {}, len {}", tuned_freq, len);
            // info!("{}, {}", tune_str, tune_str.len());
            gfx_buf.draw_string(20, 28, tune_str);
            gfx_buf.sprites[0].y = match gfx_buf.sprites[0].y {
                32 => 33,
                _ => 32,
            };

            let len = u32_into_str(current_tune as u32, &mut tune_str_buf);
            let tune_str = str::from_utf8(&tune_str_buf[tune_str_buf.len() - len..]).unwrap();
            // info!("len {}", len);

            gfx_buf.draw_string(64, 28, tune_str);

            match broadcast_on {
                true => gfx_buf.draw_string(20, 42, "ON THE AIR"),
                false => gfx_buf.draw_string(20, 48, "Offline"),
            }

            gfx_buf.redraw();
            sh1106_dev.blit_framebuffer(&mut i2c, &mut gfx_buf);
            last_gfx_update = tick;
        }

        if tick.wrapping_sub(last_input) < 5_000_000 {
            continue;
        }

        if on_off_input.is_low().unwrap() {
            info!("Broadcast toggle");
            last_input = tick;
            broadcast_on = !broadcast_on;

            match broadcast_on {
                true => pwm0.enable(),
                false => pwm0.disable(),
            }
            continue;
        }

        if tune_up_input.is_low().unwrap() {
            info!("Tune UP");
            last_input = tick;
            current_tune = MAX_TUNE.min(current_tune + 2);
            pwm0.set_top(current_tune);
            pwm0.channel_a.set_duty(current_tune / 2);
            continue;
        }

        if tune_dn_input.is_low().unwrap() {
            info!("Tune DOWN");
            last_input = tick;
            current_tune = MIN_TUNE.max(current_tune - 2);
            pwm0.set_top(current_tune);
            pwm0.channel_a.set_duty(current_tune / 2);
        }
    }
}

// returns the length of the final str removing leading zeroes
fn u32_into_str(mut value: u32, str_buf: &mut [u8]) -> usize {
    let mut len = str_buf.len();

    // info!("val {}", value);
    for i in 0..len {
        // info!("val {}, i {}, digit {}", value, i, value % 10);
        str_buf[len - i - 1] = b'0' + (value % 10) as u8;
        value /= 10;

        if value <= 0 {
            // info!("Ran out of digits at {}", i);
            len = i + 1;
            break;
        }
    }
    // info!("utf8 buf {}, len {}", str_buf, len);

    len
}