#![no_std]
#![no_main]
#![feature(macro_metavar_expr)]

extern crate alloc;

mod keymap;
mod matrix;
mod peripherals;
mod vial;

use core::alloc::Layout;

use alloc::boxed::Box;
use alloc::vec;
use bt_hci::controller::ExternalController;
use embassy_executor::Spawner;
use esp_alloc::{HeapRegion, MemoryCapability};
use esp_hal::clock::CpuClock;
use esp_hal::dma::{BurstConfig, DmaDescriptor, DmaTxBuf, ExternalBurstConfig};
use esp_hal::gpio::{Flex, Input, InputConfig, Io, Level, Output, OutputConfig, Pull};
use esp_hal::handler;
use esp_hal::i2c::master::{I2c, I2cAddress};
use esp_hal::interrupt::Priority;
use esp_hal::interrupt::software::SoftwareInterruptControl;
use esp_hal::lcd_cam::LcdCam;
use esp_hal::lcd_cam::lcd::dpi::Dpi;
use esp_hal::mcpwm::{McPwm, PeripheralClockConfig};
use esp_hal::psram::{FlashFreq, PsramConfig, PsramSize, SpiRamFreq, SpiTimingConfigCoreClock};
use esp_hal::rng::TrngSource;
use esp_hal::system::Stack;
use esp_hal::timer::timg::TimerGroup;
use esp_hal::uart::Uart;
use esp_hal::{Blocking, ram};
use esp_radio::Controller;
use esp_radio::ble::controller::BleConnector;
use esp_rtos::embassy::InterruptExecutor;
use esp_storage::FlashStorage;
use itertools::chain;
use log::{error, info};
use rmk::channel::EVENT_CHANNEL;
use rmk::config::{BehaviorConfig, PositionalConfig, RmkConfig, StorageConfig, VialConfig};
use rmk::debounce::default_debouncer::DefaultDebouncer;
use rmk::embassy_futures::yield_now;
use rmk::input_device::Runnable;
use rmk::join_all;
use rmk::keyboard::Keyboard;
use rmk::storage::async_flash_wrapper;
use rmk::{initialize_keymap_and_storage, run_devices, run_rmk};
use static_cell::StaticCell;
use {esp_alloc as _, esp_backtrace as _};

use crate::matrix::IoeMatrix;
use crate::peripherals::st7701s::St7701s;
use crate::vial::{VIAL_KEYBOARD_DEF, VIAL_KEYBOARD_ID};

// This creates a default app-descriptor required by the esp-idf bootloader.
// For more information see: <https://docs.espressif.com/projects/esp-idf/en/stable/esp32/api-reference/system/app_image_format.html#application-description>
esp_bootloader_esp_idf::esp_app_desc!();

static PSRAM_ALLOCATOR: esp_alloc::EspHeap = esp_alloc::EspHeap::empty();

#[esp_rtos::main]
async fn main(_spawner: Spawner) {
    esp_println::logger::init_logger_from_env();
    info!("Logger initialized!");

    let config = esp_hal::Config::default()
        .with_cpu_clock(CpuClock::max())
        .with_psram(PsramConfig {
            size: PsramSize::AutoDetect,
            core_clock: Some(SpiTimingConfigCoreClock::SpiTimingConfigCoreClock80m),
            flash_frequency: FlashFreq::default(),
            ram_frequency: SpiRamFreq::Freq80m,
        });
    let peripherals: esp_hal::peripherals::Peripherals = esp_hal::init(config);
    info!("System initialized!");

    // Use the internal DRAM as the heap.
    esp_alloc::heap_allocator!(#[unsafe(link_section = ".dram2_uninit")] size: 64 * 1024);
    info!("Heap initialized! {:#?}", esp_alloc::HEAP.stats());

    // Initialize the PSRAM allocator.
    {
        let (psram_offset, psram_size) = esp_hal::psram::psram_raw_parts(&peripherals.PSRAM);
        unsafe {
            PSRAM_ALLOCATOR.add_region(HeapRegion::new(
                psram_offset,
                psram_size,
                MemoryCapability::External.into(),
            ));
        }
    }

    let mut io = Io::new(peripherals.IO_MUX);
    io.set_interrupt_handler(interrupt_handler);

    // Enable pull-up on GPIO0 to prevent booting into download mode.
    let gpio0 = Output::new(
        peripherals.GPIO0,
        Level::High,
        OutputConfig::default().with_pull(Pull::Up),
    );

    // Enable LDO2
    let _ = Output::new(peripherals.GPIO17, Level::High, OutputConfig::default());

    // Enable antenna
    let _ = Output::new(peripherals.GPIO11, Level::Low, OutputConfig::default());

    // TODO: Use PWM to control the pwm_pin.
    let mut _pwm = McPwm::new(peripherals.MCPWM0, PeripheralClockConfig::with_prescaler(1));
    let mut _pwm_pin = Output::new(peripherals.GPIO21, Level::High, OutputConfig::default());

    let timg0 = TimerGroup::new(peripherals.TIMG0);
    let software_interrupt = SoftwareInterruptControl::new(peripherals.SW_INTERRUPT);
    esp_rtos::start(
        timg0.timer0, /*, software_interrupt.software_interrupt0 */
    );
    // Enable the TRNG source, so `Trng` can be constructed.
    let _trng_source = TrngSource::new(peripherals.RNG, peripherals.ADC1);
    let mut rng = esp_hal::rng::Trng::try_new().unwrap();
    static RADIO: StaticCell<Controller<'static>> = StaticCell::new();
    let radio = RADIO.init(esp_radio::init().unwrap());
    let bluetooth = peripherals.BT;
    let connector = BleConnector::new(radio, bluetooth, Default::default()).unwrap();
    let controller: ExternalController<_, 20> = ExternalController::new(connector);
    let central_addr = [0x18, 0xe2, 0x21, 0x80, 0xc0, 0xc7];
    #[cfg(feature = "ble")]
    let mut host_resources = rmk::HostResources::new();
    #[cfg(feature = "ble")]
    let stack =
        rmk::ble::build_ble_stack(controller, central_addr, &mut rng, &mut host_resources).await;

    // Initialize USB
    #[cfg(not(feature = "no_usb"))]
    let usb_driver = {
        use core::ptr::addr_of_mut;
        use esp_hal::otg_fs::Usb;
        use esp_hal::otg_fs::asynch::{Config, Driver};

        static mut EP_MEMORY: [u8; 1024] = [0; 1024];
        let usb = Usb::new(peripherals.USB0, peripherals.GPIO20, peripherals.GPIO19);
        // Create the driver, from the HAL.
        let config = Config::default();
        Driver::new(usb, unsafe { &mut *addr_of_mut!(EP_MEMORY) }, config)
    };

    // Initialize the flash
    let flash = FlashStorage::new(peripherals.FLASH);
    let flash = async_flash_wrapper(flash);

    let sck = Output::new(peripherals.GPIO36, Level::High, OutputConfig::default());
    let mosi = Flex::new(peripherals.GPIO35);
    let cs = Output::new(peripherals.GPIO6, Level::High, OutputConfig::default());

    let lcd = LcdCam::new(peripherals.LCD_CAM).lcd;
    let unconfigured_dpi = Dpi::new(lcd, peripherals.DMA_CH2, Default::default())
        .unwrap()
        .with_de(peripherals.GPIO37)
        .with_pclk(peripherals.GPIO34)
        .with_hsync(peripherals.GPIO44)
        .with_vsync(peripherals.GPIO43)
        // Blue
        .with_data0(peripherals.GPIO38)
        .with_data1(peripherals.GPIO39)
        .with_data2(peripherals.GPIO40)
        .with_data3(peripherals.GPIO41)
        .with_data4(peripherals.GPIO42)
        // Green
        .with_data5(peripherals.GPIO5)
        .with_data6(peripherals.GPIO12)
        .with_data7(peripherals.GPIO13)
        .with_data8(peripherals.GPIO14)
        .with_data9(peripherals.GPIO15)
        .with_data10(peripherals.GPIO16)
        // Red
        .with_data11(gpio0)
        .with_data12(peripherals.GPIO1)
        .with_data13(peripherals.GPIO2)
        .with_data14(peripherals.GPIO3)
        .with_data15(peripherals.GPIO4);

    let st7701s = St7701s::new(sck, mosi, cs, unconfigured_dpi).await;

    // RMK config
    let vial_config = VialConfig::new(VIAL_KEYBOARD_ID, VIAL_KEYBOARD_DEF, &[(0, 0), (1, 1)]);
    let storage_config = StorageConfig {
        start_addr: 0x3f0000,
        num_sectors: 16,
        ..Default::default()
    };
    let rmk_config = RmkConfig {
        vial_config,
        storage_config,
        ..Default::default()
    };

    // Initialze keyboard stuffs
    // Initialize the storage and keymap
    let mut default_keymap = keymap::get_default_keymap();
    let mut behavior_config = BehaviorConfig::default();
    let mut per_key_config = PositionalConfig::default();
    let (keymap, mut storage) = initialize_keymap_and_storage(
        &mut default_keymap,
        flash,
        &storage_config,
        &mut behavior_config,
        &mut per_key_config,
    )
    .await;

    // Initialize the matrix and keyboard
    const I2C_ADDR_MATRIX_LEFT: I2cAddress = I2cAddress::SevenBit(0b0100000);
    const I2C_ADDR_MATRIX_RIGHT: I2cAddress = I2cAddress::SevenBit(0b0100001);

    let i2c = I2c::new(peripherals.I2C0, Default::default())
        .unwrap()
        .with_sda(peripherals.GPIO8)
        .with_scl(peripherals.GPIO9);

    let matrix_interrupt_low = Input::new(peripherals.GPIO7, InputConfig::default());

    let mut matrix = IoeMatrix::new(
        matrix_interrupt_low,
        i2c.into_async(),
        DefaultDebouncer::new(),
        [I2C_ADDR_MATRIX_LEFT, I2C_ADDR_MATRIX_RIGHT],
    )
    .await;
    let mut keyboard = Keyboard::new(&keymap); // Initialize the light controller

    // spawner.must_spawn(run_lcd(st7701s));
    static SECOND_CORE_STACK: StaticCell<Stack<8192>> = StaticCell::new();
    let second_core_stack = SECOND_CORE_STACK.init(Stack::new());
    esp_rtos::start_second_core(
        peripherals.CPU_CTRL,
        software_interrupt.software_interrupt0,
        software_interrupt.software_interrupt1,
        second_core_stack,
        move || {
            static EXECUTOR: StaticCell<InterruptExecutor<2>> = StaticCell::new();
            let exec = EXECUTOR.init(InterruptExecutor::new(
                software_interrupt.software_interrupt2,
            ));
            let spawner = exec.start(Priority::Priority3);
            spawner.must_spawn(run_lcd_task(st7701s));
            // static EXECUTOR: StaticCell<Executor> = StaticCell::new();
            // let executor: &mut Executor = EXECUTOR.init(Executor::new());
            // executor.run(|spawner| {
            //     let task = run_lcd_task(st7701s);
            //     spawner.must_spawn(task);
            // });
        },
    );

    join_all![
        run_devices! (
            (matrix) => EVENT_CHANNEL,
        ),
        keyboard.run(), // Keyboard is special
        run_rmk(
            &keymap,
            #[cfg(not(feature = "no_usb"))]
            usb_driver,
            #[cfg(feature = "ble")]
            &stack,
            &mut storage,
            rmk_config,
        )  // run_lcd(st7701s)
    ]
    .await;
}

#[embassy_executor::task]
async fn run_lcd_task(st7701s: St7701s<'static, Blocking>) {
    run_lcd(st7701s).await
}

async fn run_lcd(mut st7701s: St7701s<'static, Blocking>) {
    const PADDING_LEFT: usize = 121;
    const PADDING_RIGHT: usize = 7;
    const COLORS_WIDTH: usize = 240;
    const COLORS_HEIGHT: usize = 960;

    const MAX_RED: u8 = (1 << 5) - 1;
    const MAX_GREEN: u8 = (1 << 6) - 1;
    const MAX_BLUE: u8 = (1 << 5) - 1;

    fn rgb(r: u8, g: u8, b: u8) -> u16 {
        (((r & MAX_RED) as u16) << 11) | (((g & MAX_GREEN) as u16) << 5) | ((b & MAX_BLUE) as u16)
    }

    fn row(edge: u16) -> impl Iterator<Item = u16> + Clone {
        chain![
            core::iter::repeat_n(rgb(0, 0, 0xFF), PADDING_LEFT),
            core::iter::once(rgb(0xFF, 0xFF, 0xFF)),
            core::iter::repeat_n(edge, COLORS_WIDTH - 2),
            core::iter::once(rgb(0xFF, 0xFF, 0xFF)),
            core::iter::repeat_n(rgb(0, 0, 0xFF), PADDING_RIGHT),
        ]
    }

    let mut colors = chain![
        row(rgb(0xFF, 0, 0)),
        core::iter::repeat_n(row(0), COLORS_HEIGHT - 2).flatten(),
        row(rgb(0xFF, 0xFF, 0)),
    ];

    const BUFFER_LEN: usize = core::mem::size_of::<u16>()
        * (360 + /* TODO: Figure out why more bytes are needed: */ 8)
        * 960;
    // Allocate the framebuffer in the external PSRAM memory.
    // Note: We just leak this buffer.
    let buffer_ptr = unsafe {
        // ⚠️ Note: For chips that support DMA to/from PSRAM (ESP32-S3) DMA transfers to/from PSRAM
        // have extra alignment requirements. The address and size of the buffer pointed to by each
        // descriptor must be a multiple of the cache line (block) size. This is 32 bytes on ESP32-S3.
        PSRAM_ALLOCATOR.alloc_caps(
            MemoryCapability::External.into(),
            Layout::from_size_align(BUFFER_LEN, 32).unwrap(),
        )
    };
    let buffer = unsafe { core::slice::from_raw_parts_mut(buffer_ptr, BUFFER_LEN) };
    let burst_config: BurstConfig = ExternalBurstConfig::Size16.into();

    info!(
        "PSRAM SPI burst config: max_compatible_chunk_size={}",
        burst_config.max_compatible_chunk_size()
    );
    let dma_buf_descs_len =
        esp_hal::dma::descriptor_count(BUFFER_LEN, burst_config.max_compatible_chunk_size(), false);
    // Descriptors are initialized by `DmaTxBuf::new`.
    let dma_buf_descs = Box::leak(vec![DmaDescriptor::EMPTY; dma_buf_descs_len].into_boxed_slice());
    let mut dma_buf = DmaTxBuf::new(dma_buf_descs, buffer).unwrap();

    {
        for (chunk, color) in dma_buf.as_mut_slice().chunks_mut(2).zip(&mut colors) {
            chunk.copy_from_slice(&color.to_le_bytes());
        }

        info!("chunk addr: {}", dma_buf.as_slice().as_ptr() as usize);
        // colors.next(); // Shift colors
    }

    loop {
        // Timer::after(Duration::from_millis(100)).await;
        yield_now().await;

        // TODO: Use bounce buffers:
        // https://docs.espressif.com/projects/esp-idf/en/v5.0/esp32s3/api-reference/peripherals/lcd.html#bounce-buffer-with-single-psram-frame-buffer
        // They need to be implemented in esp-hal.
        let transfer = match st7701s.dpi.send(false, dma_buf) {
            Err((error, result_dpi, result_dma_buf)) => {
                error!(
                    "An error occurred while initiating transfer of the framebuffer to the LCD display: {error:?}"
                );
                st7701s.dpi = result_dpi;
                dma_buf = result_dma_buf;
                continue;
            }
            Ok(transfer) => transfer,
        };
        let result;
        (result, st7701s.dpi, dma_buf) = transfer.wait();

        if let Err(error) = result {
            error!(
                "An error occurred while transferring framebuffer to the LCD display: {error:?}"
            );
        }
    }
}

#[handler]
#[ram] // TODO: Is this necessary?
fn interrupt_handler() {
    esp_println::println!(
        "GPIO Interrupt with priority {}",
        esp_hal::xtensa_lx::interrupt::get_level()
    );
}