#![no_std]
#![no_main]

use defmt::*;
use defmt_rtt as _; // global logger
use embassy_executor::Spawner;
use embassy_stm32::Config;
use embassy_stm32::gpio::OutputType;
use embassy_stm32::rcc::{
    AHB5Prescaler, AHBPrescaler, APBPrescaler, PllDiv, PllMul, PllPreDiv, PllSource, Sysclk, VoltageScale,
};
use embassy_stm32::time::khz;
use embassy_stm32::timer::simple_pwm::{PwmPin, SimplePwm};
use embassy_time::Timer;
use panic_probe as _;

#[embassy_executor::main]
async fn main(_spawner: Spawner) {
    info!("Hello World!");

    let mut config = Config::default();
    // Fine-tune PLL1 dividers/multipliers
    config.rcc.pll1 = Some(embassy_stm32::rcc::Pll {
        source: PllSource::HSI,
        prediv: PllPreDiv::DIV1,  // PLLM = 1 → HSI / 1 = 16 MHz
        mul: PllMul::MUL30,       // PLLN = 30 → 16 MHz * 30 = 480 MHz VCO
        divr: Some(PllDiv::DIV5), // PLLR = 5 → 96 MHz (Sysclk)
        // divq: Some(PllDiv::DIV10), // PLLQ = 10 → 48 MHz (NOT USED)
        divq: None,
        divp: Some(PllDiv::DIV30), // PLLP = 30 → 16 MHz (USBOTG)
        frac: Some(0),             // Fractional part (enabled)
    });

    config.rcc.ahb_pre = AHBPrescaler::DIV1;
    config.rcc.apb1_pre = APBPrescaler::DIV1;
    config.rcc.apb2_pre = APBPrescaler::DIV1;
    config.rcc.apb7_pre = APBPrescaler::DIV1;
    config.rcc.ahb5_pre = AHB5Prescaler::DIV4;

    // voltage scale for max performance
    config.rcc.voltage_scale = VoltageScale::RANGE1;
    // route PLL1_P into the USB‐OTG‐HS block
    config.rcc.sys = Sysclk::PLL1_R;

    let p = embassy_stm32::init(config);

    let ch1_pin = PwmPin::new(p.PA2, OutputType::PushPull);
    let mut pwm = SimplePwm::new(p.TIM3, Some(ch1_pin), None, None, None, khz(10), Default::default());
    let mut ch1 = pwm.ch1();
    ch1.enable();

    info!("PWM initialized");
    info!("PWM max duty {}", ch1.max_duty_cycle());

    loop {
        ch1.set_duty_cycle_fully_off();
        Timer::after_millis(300).await;
        ch1.set_duty_cycle_fraction(1, 4);
        Timer::after_millis(300).await;
        ch1.set_duty_cycle_fraction(1, 2);
        Timer::after_millis(300).await;
        ch1.set_duty_cycle(ch1.max_duty_cycle() - 1);
        Timer::after_millis(300).await;
    }
}