#![no_std]
#![no_main]

use hal::{
    clock::ClockControl,
    gpio::IO,
    i2c::I2C,
    peripherals::Peripherals,
    prelude::*,
    Rtc,
    Delay,
};
use embedded_graphics::{
    mono_font::{
        ascii::{FONT_6X10, FONT_10X20},
        MonoTextStyleBuilder,
    },
    pixelcolor::BinaryColor,
    prelude::*,
    text::{Alignment, Text},
};
use core::cell::RefCell;
use embedded_hal_bus::i2c as i2c_bus;
use esp_backtrace as _;
use esp_println::println;
use ssd1306::{prelude::*, I2CDisplayInterface, Ssd1306};
use max3010x::{Max3010x};

#[entry]
fn main() -> ! {
    let peripherals = Peripherals::take();
    let system = peripherals.SYSTEM.split();
    let clocks = ClockControl::boot_defaults(system.clock_control).freeze();
    let mut delay = Delay::new(&clocks);

    let mut rtc = Rtc::new(peripherals.RTC_CNTL);

    // Disable watchdog timer
    rtc.rwdt.disable();

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

    // Create a new peripheral object with the described wiring
    // and standard I2C clock speed
    // https://docs.rs/esp32-hal/latest/esp32_hal/i2c/struct.I2C.html
    let mut i2c0 = I2C::new(
        peripherals.I2C0,
        io.pins.gpio21,
        io.pins.gpio22,
        100u32.kHz(),
        &clocks,
    );

    let i2c_ref_cell = RefCell::new(i2c0);

    // Initialize display
    let interface = I2CDisplayInterface::new(i2c_bus::RefCellDevice::new(&i2c_ref_cell));
    let mut display = Ssd1306::new(interface, DisplaySize128x64, DisplayRotation::Rotate0)
        .into_buffered_graphics_mode();
    display.init().unwrap();

    // Specify different text styles
    let text_style = MonoTextStyleBuilder::new()
        .font(&FONT_6X10)
        .text_color(BinaryColor::On)
        .build();
    let text_style_big = MonoTextStyleBuilder::new()
        .font(&FONT_10X20)
        .text_color(BinaryColor::On)
        .build();

    // Initialize Pulse Oximeter
    let mut oximeter = Max3010x::new_max30102(i2c_bus::RefCellDevice::new(&i2c_ref_cell));
    let mut oximeter = oximeter.into_oximeter().unwrap();
    oximeter
        .set_pulse_amplitude(max3010x::Led::All, 200)
        .unwrap();
    // Options: 69, 118, 215, 411
    oximeter
        .set_pulse_width(max3010x::LedPulseWidth::Pw411)
        .unwrap();
    // 1000 is best but needs processing power
    // Options: 50, 100, 200, 400, 800, 1000, 1600, 3200
    oximeter
        .set_sampling_rate(max3010x::SamplingRate::Sps400)
        .unwrap();
    // Options: 1, 2, 4, 8, 16, 32
    oximeter
        .set_sample_averaging(max3010x::SampleAveraging::Sa16)
        .unwrap();
    // Options: 2048, 4096, 8192, 16384
    oximeter
        .set_adc_range(max3010x::AdcRange::Fs16k)
        .unwrap();
    oximeter.enable_fifo_rollover().unwrap();
    oximeter.clear_fifo().unwrap();

    loop {
        // Fill display bufffer with a centered text with two lines (and two text
        // styles)
        Text::with_alignment(
            "esp-hal",
            display.bounding_box().center() + Point::new(0, 0),
            text_style_big,
            Alignment::Center,
        )
        .draw(&mut display)
        .unwrap();

        Text::with_alignment(
            "Chip: ESP32",
            display.bounding_box().center() + Point::new(0, 14),
            text_style,
            Alignment::Center,
        )
        .draw(&mut display)
        .unwrap();

        // Write buffer to display
        display.flush().unwrap();
        // Clear display buffer
        let _ = display.clear(BinaryColor::Off);

        // Wait 1 seconds
        delay.delay_ms(1000u32);

        // Write single-line centered text "Haruo World" to buffer
        Text::with_alignment(
            "Haruo World!",
            display.bounding_box().center(),
            text_style_big,
            Alignment::Center,
        )
        .draw(&mut display)
        .unwrap();

        // Write buffer to display
        display.flush().unwrap();
        // Clear display buffer
        let _ = display.clear(BinaryColor::Off);

        // Wait 3 seconds
        delay.delay_ms(3000u32);
    }
}