//! Blinks an LED

#![no_std]
#![no_main]

extern crate cortex_m;
#[macro_use]
extern crate cortex_m_rt as rt;
extern crate cortex_m_semihosting as sh;
extern crate panic_semihosting;
extern crate stm32l4xx_hal as hal;

use crate::hal::prelude::*;

use crate::hal::i2c;
use crate::hal::i2c::I2c;
use crate::rt::entry;
use crate::rt::ExceptionFrame;

use crate::sh::hio;
use core::fmt::Write;

#[entry]
fn main() -> ! {
    let mut hstdout = hio::hstdout().unwrap();

    // writeln!(hstdout, "Hello, world!").unwrap();

    // let cp = cortex_m::Peripherals::take().unwrap();
    let dp = hal::stm32::Peripherals::take().unwrap();

    let mut flash = dp.FLASH.constrain();
    let mut rcc = dp.RCC.constrain();
    let mut pwr = dp.PWR.constrain(&mut rcc.apb1r1);

    let clocks = rcc.cfgr.freeze(&mut flash.acr, &mut pwr);

    let mut gpioa = dp.GPIOA.split(&mut rcc.ahb2);

    let mut scl =
        gpioa
            .pa9
            .into_alternate_open_drain(&mut gpioa.moder, &mut gpioa.otyper, &mut gpioa.afrh);
    scl.internal_pull_up(&mut gpioa.pupdr, true);

    let mut sda =
        gpioa
            .pa10
            .into_alternate_open_drain(&mut gpioa.moder, &mut gpioa.otyper, &mut gpioa.afrh);
    sda.internal_pull_up(&mut gpioa.pupdr, true);

    let mut i2c = I2c::i2c1(
        dp.I2C1,
        (scl, sda),
        i2c::Config::new(100.kHz(), clocks),
        &mut rcc.apb1r1,
    );

    // i2c.write(0x3C, &[0xCC, 0xAA]).unwrap();
    let mut buffer = [0u8; 2];
    // 0x08 is version reg
    // i2c.write(0x6C, &[0x08],).unwrap();
    // let val = i2c.read(0x36, &mut buffer).unwrap();
    const MAX17048_ADDR: u8 = 0x6C;
    i2c.write_read(MAX17048_ADDR, &[0x08], &mut buffer).unwrap();
    let version: u16 = (buffer[0] as u16) << 8 | buffer[1] as u16;
    writeln!(hstdout, "Silicon Version: {}", version).ok();

    // let soc: u16 = (buffer[0] as u16) + (buffer[1] as u16 / 256);  //& 0xFF00
    // let soc: u16 = (buffer[0] as u16) << 8 & 0xFF00 | (buffer[1] as u16) & 0x00FF;
    i2c.write_read(MAX17048_ADDR, &[0x04], &mut buffer).unwrap();
    let soc: u16 = (buffer[0] as u16) << 8 | buffer[1] as u16;
    writeln!(hstdout, "Batt SoC: {}%", soc / 256).ok();

    i2c.write_read(MAX17048_ADDR, &[0x02], &mut buffer).unwrap();
    let vlt: u16 = (buffer[0] as u16) << 8 | buffer[1] as u16;
    writeln!(hstdout, "Volt: {}", vlt as f32 * 0.000078125).ok();

    loop {
        continue;
    }
}

#[exception]
unsafe fn HardFault(ef: &ExceptionFrame) -> ! {
    panic!("{:#?}", ef);
}