#![no_std]
#![feature(rustc_private)]
extern crate fusible;

use core::net::Ipv4Addr;
use core::num::NonZeroU8;
use core::pin::Pin;

use imxrt_rt as _;
use imxrt1170evk_fcb as _;
use rust_threadx_cortex_m as _;
use rust_threadx_imxrt::*;
use rust_threadx_stdio_semihosting as _;

use drivers::{enet, gpio};

use imxrt1170::interrupt;

use fusible::netx_duo::{
    ip::{Ip, IpContext},
    packet::{PacketPool, PacketPoolContext, StaticPacketStorage, packet_storage_size},
};

#[doc(hidden)]
#[unsafe(no_mangle)]
pub unsafe extern "C" fn _tx_initialize_low_level() {
    use cortex_m::{
        Peripherals,
        peripheral::{scb::SystemHandler, syst::SystClkSource},
    };

    cortex_m::interrupt::disable();

    unsafe {
        let Peripherals {
            mut SYST, mut SCB, ..
        } = Peripherals::steal();

        SCB.set_priority(SystemHandler::SysTick, 0x40);
        SCB.set_priority(SystemHandler::PendSV, 0xff);
        SCB.set_priority(SystemHandler::SVCall, 0xff);

        SYST.set_clock_source(SystClkSource::External);
        SYST.set_reload(100_000 / 100 - 1);
        SYST.clear_current();
        SYST.enable_interrupt();
        SYST.enable_counter();
    }
}

use fusible::thread::{StaticStack, Thread, ThreadContext};
static STACK: StaticStack<512> = StaticStack::new();
static THREAD: ThreadContext = Thread::context();

#[unsafe(no_mangle)]
#[doc(hidden)]
pub extern "C" fn __rust_threadx_app_define() {
    configure_clocks();
    configure_pins();

    unsafe {
        cortex_m::peripheral::NVIC::unmask(interrupt::ENET);

        let gpio3 = GPIO3.create(const { imxrt1170::instances::gpio3() });
        let gpio6 = GPIO6.create(const { imxrt1170::instances::gpio6() });

        let led = gpio3.make_output(gpio::IO::IO03);
        let phy_rst = gpio6.make_output(gpio::IO::IO12);

        let enet = ENET.create(
            imxrt1170::instances::enet(),
            ENET_TX_RING.as_slice(),
            ENET_RX_RING.as_slice(),
            rust_threadx_net_phys::ksz8081::Ksz8081::new(),
            phy_rst,
            BUS_FREQUENCY_HZ,
        );

        let pool = PacketPool::create(
            Pin::static_ref(&PACKET_POOL),
            PACKET_STORAGE.0.take().unwrap(),
            1536 / 12,
            &Default::default(),
        )
        .unwrap();

        let ip = Ip::create(
            Pin::static_ref(&IP),
            Ipv4Addr::new(192, 168, 5, 1),
            0xffff_ff00,
            pool,
            enet,
            IP_THREAD_STACK.take().unwrap(),
            &Default::default(),
        )
        .unwrap();

        ip.set_physical_address(0x0011, 0x22334456);
        ip.enable_arp();
        ip.enable_udp();
        ip.enable_icmp();

        Thread::create(
            Pin::static_ref(&THREAD),
            STACK.take().unwrap(),
            &Default::default(),
            move || loop {
                fusible::thread::sleep(25);
                led.toggle();
            },
        )
        .unwrap();
    }
}

#[unsafe(no_mangle)]
#[doc(hidden)]
pub extern "C" fn __rust_threadx_ip() -> Option<&'static Ip> {
    Pin::static_ref(&IP).try_created()
}

fn configure_clocks() {
    use imxrt1170::{ccm, gpc_cpu_mode_ctrl as gpc_cpu, pmu};

    let ccm = unsafe { imxrt1170::instances::ccm() };
    let pmu = unsafe { imxrt1170::instances::pmu() };
    let gpc_cpu = unsafe { imxrt1170::instances::gpc_cpu_mode_ctrl0() };
    let pll = unsafe { imxrt1170::instances::pll() };

    // Switch the core to something stable before we
    // start changing upstream sources.
    ccm::set_clock_root(
        ccm,
        ccm::ClockRoot::M7,
        const { ccm::mux(ccm::ClockRoot::M7, ccm::ClockSource::Xtal) },
        NO_DIVIDER,
    );
    ccm::set_clock_root(
        ccm,
        ccm::ClockRoot::Bus,
        const { ccm::mux(ccm::ClockRoot::Bus, ccm::ClockSource::Xtal) },
        NO_DIVIDER,
    );
    ccm::set_clock_root(
        ccm,
        ccm::ClockRoot::BusLpsr,
        const { ccm::mux(ccm::ClockRoot::BusLpsr, ccm::ClockSource::Xtal) },
        NO_DIVIDER,
    );
    ccm::set_clock_root(
        ccm,
        ccm::ClockRoot::M7Systick,
        const { ccm::mux(ccm::ClockRoot::M7Systick, ccm::ClockSource::Xtal) },
        const { NonZeroU8::new(240).unwrap() },
    );

    pmu::enable_pll_reference_voltage(pmu, true);
    pmu::set_phy_ldo_setpoints(pmu, u16::MAX);
    pmu::enable_phy_ldo_setpoints(pmu);
    pmu::enable_pll_reference_setpoints(pmu);

    for clock_source in {
        use ccm::ClockSource::*;
        [
            Pll1, Pll1Clk, Pll1Div2, Pll1Div5, ArmPll, ArmPllClk, //
            Pll2, Pll2Clk, Pll2Pfd0, Pll2Pfd1, Pll2Pfd2, Pll2Pfd3, //
            Pll3, Pll3Clk, Pll3Div2, Pll3Pfd0, Pll3Pfd1, Pll3Pfd2, Pll3Pfd3, //
        ]
    } {
        ccm::set_source_setpoints(ccm, clock_source, u16::MAX, 0);
        ccm::enable_source_setpoints(ccm, clock_source).unwrap();
    }

    ccm::pll::enable_sys_pll1_setpoints(pll);
    ccm::pll::enable_arm_pll_setpoints(pll, ARM_PLL_POST_DIV, ARM_PLL_DIV_SELECT);
    ccm::pll::enable_sys_pll2_setpoints(pll);
    ccm::pll::enable_sys_pll3_setpoints(pll);

    gpc_cpu::request_setpoint_transition(gpc_cpu, 1).unwrap();

    ccm::pll::set_pll3_pfd_fracs(
        pll,
        [
            SYS_PLL3_PFD0_DIV,
            SYS_PLL3_PFD1_DIV,
            SYS_PLL3_PFD2_DIV,
            SYS_PLL3_PFD3_DIV,
        ],
    );
    ccm::pll::update_pll3_pfd_fracs(pll, [true, true, true, true]);

    ccm::set_clock_root(
        ccm,
        ccm::ClockRoot::M7,
        const { ccm::mux(ccm::ClockRoot::M7, ccm::ClockSource::ArmPll) },
        M7_DIVIDER,
    );

    ccm::set_clock_root(
        ccm,
        ccm::ClockRoot::Bus,
        const { ccm::mux(ccm::ClockRoot::Bus, ccm::ClockSource::Pll1Div5) },
        BUS_DIVIDER,
    );

    ccm::set_clock_root(
        ccm,
        ccm::ClockRoot::Enet,
        const { ccm::mux(ccm::ClockRoot::Enet, ccm::ClockSource::Pll1Div2) },
        const { NonZeroU8::new((SYS_PLL1_DIV2_FREQUENCY_HZ / ENET_FREQUENCY_HZ) as u8).unwrap() },
    );
}

const NO_DIVIDER: NonZeroU8 = NonZeroU8::new(1).unwrap();
const M7_DIVIDER: NonZeroU8 = NonZeroU8::new(1).unwrap();
const BUS_DIVIDER: NonZeroU8 = NonZeroU8::new(1).unwrap();
const FLEXSPI1_DIVIDER: NonZeroU8 = NonZeroU8::new(2).unwrap();

pub const XTAL_FREQUENCY_HZ: u32 = 24_000_000;
pub const BUS_FREQUENCY_HZ: u32 = SYS_PLL1_DIV5_FREQUENCY_HZ / BUS_DIVIDER.get() as u32;
pub const ENET_FREQUENCY_HZ: u32 = 50_000_000;
pub const SYS_PLL1_FREQUENCY_HZ: u32 = 1_000_000_000;
pub const SYS_PLL1_DIV2_FREQUENCY_HZ: u32 = SYS_PLL1_FREQUENCY_HZ / 2;
pub const SYS_PLL1_DIV5_FREQUENCY_HZ: u32 = SYS_PLL1_FREQUENCY_HZ / 5;
pub const M7_FREQUENCY_HZ: u32 = ARM_PLL_FREQUENCY_HZ / M7_DIVIDER.get() as u32;
pub const SYS_PLL2_FREQUENCY_HZ: u32 = 528_000_000;
pub const SYS_PLL3_FREQUENCY_HZ: u32 = 480_000_000;
pub const FLEXSPI1_FREQUENCY_HZ: u32 =
    SYS_PLL3_FREQUENCY_HZ / SYS_PLL3_PFD0_DIV.get() as u32 / FLEXSPI1_DIVIDER.get() as u32 * 18;

const ARM_PLL_DIV_SELECT: imxrt1170::ccm::pll::ArmPllDivSelect =
    imxrt1170::ccm::pll::ArmPllDivSelect::new(200).unwrap();
const ARM_PLL_POST_DIV: imxrt1170::ccm::pll::ArmPllPostDiv =
    imxrt1170::ccm::pll::ArmPllPostDiv::Div4;
const ARM_PLL_FREQUENCY_HZ: u32 =
    imxrt1170::ccm::pll::arm_pll_frequency(ARM_PLL_POST_DIV, ARM_PLL_DIV_SELECT);
const SYS_PLL3_PFD0_DIV: imxrt1170::ccm::pll::PfdFrac =
    imxrt1170::ccm::pll::PfdFrac::new(33).unwrap();
const SYS_PLL3_PFD1_DIV: imxrt1170::ccm::pll::PfdFrac =
    imxrt1170::ccm::pll::PfdFrac::new(27).unwrap();
const SYS_PLL3_PFD2_DIV: imxrt1170::ccm::pll::PfdFrac =
    imxrt1170::ccm::pll::PfdFrac::new(21).unwrap();
const SYS_PLL3_PFD3_DIV: imxrt1170::ccm::pll::PfdFrac =
    imxrt1170::ccm::pll::PfdFrac::new(17).unwrap();

fn configure_pins() {
    use imxrt1170::{
        iomuxc::{self, select_input},
        iomuxc_gpr, iomuxc_lpsr,
    };

    let iomuxc = unsafe { imxrt1170::instances::iomuxc() };
    let iomuxc_gpr = unsafe { imxrt1170::instances::iomuxc_gpr() };
    let iomuxc_lpsr = unsafe { imxrt1170::instances::iomuxc_lpsr() };

    // ENET_REF_CLK driven as output.
    modify_reg!(iomuxc_gpr, iomuxc_gpr, GPR[4], |gpr| gpr | (1 << 1));
    // ERR050396 handling.
    modify_reg!(iomuxc_gpr, iomuxc_gpr, GPR[28], |gpr| gpr
        | (1 << 5)
        | (1 << 7));

    // LED.
    write_reg!(iomuxc, iomuxc, SW_MUX_CTL_PAD.GPIO_AD[4], MUX_MODE: 5);
    write_reg!(iomuxc, iomuxc, SW_PAD_CTL_PAD.GPIO_AD[4], PUE: 0);

    // ENET PHY_RST.
    write_reg!(iomuxc_lpsr, iomuxc_lpsr, SW_MUX_CTL_PAD[12], MUX_MODE: 5);

    // ENET RMII.
    write_reg!(iomuxc, iomuxc, SW_MUX_CTL_PAD.GPIO_AD[32], MUX_MODE: 3, SION: 0); // MDC
    write_reg!(iomuxc, iomuxc, SW_MUX_CTL_PAD.GPIO_AD[33], MUX_MODE: 3, SION: 0); // MDIO
    write_reg!(iomuxc, iomuxc, SW_MUX_CTL_PAD.GPIO_DISP_B2[2], MUX_MODE: 1, SION: 0); // TX_DATA0
    write_reg!(iomuxc, iomuxc, SW_MUX_CTL_PAD.GPIO_DISP_B2[3], MUX_MODE: 1, SION: 0); // TX_DATA1
    write_reg!(iomuxc, iomuxc, SW_MUX_CTL_PAD.GPIO_DISP_B2[4], MUX_MODE: 1, SION: 0); // TX_EN
    write_reg!(iomuxc, iomuxc, SW_MUX_CTL_PAD.GPIO_DISP_B2[5], MUX_MODE: 2, SION: 1); // REF_CLK
    write_reg!(iomuxc, iomuxc, SW_MUX_CTL_PAD.GPIO_DISP_B2[6], MUX_MODE: 1, SION: 1); // RX_DATA0
    write_reg!(iomuxc, iomuxc, SW_MUX_CTL_PAD.GPIO_DISP_B2[7], MUX_MODE: 1, SION: 1); // RX_DATA1
    write_reg!(iomuxc, iomuxc, SW_MUX_CTL_PAD.GPIO_DISP_B2[8], MUX_MODE: 1, SION: 0); // RX_EN
    write_reg!(iomuxc, iomuxc, SW_MUX_CTL_PAD.GPIO_DISP_B2[9], MUX_MODE: 1, SION: 0); // RX_ER

    write_reg!(iomuxc, iomuxc, SW_PAD_CTL_PAD.GPIO_AD[32], PUE: 1, PUS: PULL_UP, ODE: 0); // MDC
    write_reg!(iomuxc, iomuxc, SW_PAD_CTL_PAD.GPIO_AD[33], PUE: 1, PUS: PULL_UP, ODE: 1); // MDIO
    write_reg!(iomuxc, iomuxc, SW_PAD_CTL_PAD.GPIO_DISP_B2[2], PUE: 0, SRE: SLOW, DSE: HIGH, ODE: 0); // TX_DATA0
    write_reg!(iomuxc, iomuxc, SW_PAD_CTL_PAD.GPIO_DISP_B2[3], PUE: 0, SRE: SLOW, DSE: HIGH, ODE: 0); // TX_DATA1
    write_reg!(iomuxc, iomuxc, SW_PAD_CTL_PAD.GPIO_DISP_B2[4], PUE: 0, SRE: SLOW, DSE: HIGH, ODE: 0); // TX_EN
    write_reg!(iomuxc, iomuxc, SW_PAD_CTL_PAD.GPIO_DISP_B2[5], PUE: 0, SRE: SLOW, DSE: HIGH, ODE: 0); // REF_CLK
    write_reg!(iomuxc, iomuxc, SW_PAD_CTL_PAD.GPIO_DISP_B2[6], PUE: 0, SRE: SLOW, DSE: HIGH, ODE: 0); // RX_DATA0
    write_reg!(iomuxc, iomuxc, SW_PAD_CTL_PAD.GPIO_DISP_B2[7], PUE: 0, SRE: SLOW, DSE: HIGH, ODE: 0); // RX_DATA1
    write_reg!(iomuxc, iomuxc, SW_PAD_CTL_PAD.GPIO_DISP_B2[8], PUE: 0, SRE: SLOW, DSE: HIGH, ODE: 0); // RX_EN
    write_reg!(iomuxc, iomuxc, SW_PAD_CTL_PAD.GPIO_DISP_B2[9], PUE: 0, SRE: SLOW, DSE: HIGH, ODE: 0); // RX_ER

    for select_input in [
        select_input::ENET_IPG_CLK_RMII,
        select_input::ENET_MAC0_MDIO,
        select_input::ENET_MAC0_RXDATA_0,
        select_input::ENET_MAC0_RXDATA_1,
        select_input::ENET_MAC0_RXEN,
        select_input::ENET_MAC0_RXERR,
    ] {
        write_reg!(iomuxc, iomuxc, SELECT_INPUT[select_input], 1);
    }
}

type Enet = drivers::enet::Enet<rust_threadx_net_phys::ksz8081::Ksz8081>;

static ENET: enet::EnetContext = enet::EnetContext::new();
static ENET_TX_RING: enet::TxRing<16> = enet::TxRing::ZEROED;
static ENET_RX_RING: enet::RxRing<16> = enet::RxRing::ZEROED;
static IP: IpContext<Enet> = Ip::context();

#[repr(align(64))]
pub struct AlignedPacketStorage(StaticPacketStorage<{ packet_storage_size(8 * 12, 1536 / 12) }>);

static PACKET_POOL: PacketPoolContext = PacketPool::context();
static PACKET_STORAGE: AlignedPacketStorage = AlignedPacketStorage(StaticPacketStorage::new());
static IP_THREAD_STACK: StaticStack<4096> = StaticStack::new();

static GPIO3: gpio::GpioContext = gpio::GpioContext::new();
static GPIO6: gpio::GpioContext = gpio::GpioContext::new();

#[imxrt_rt::interrupt]
fn ENET() {
    unsafe {
        ENET.on_interrupt(
            const { imxrt1170::instances::enet() },
            Pin::static_ref(&IP).assume_created(),
        )
    }
}