#![no_std]
#![allow(async_fn_in_trait)]
#![doc = include_str!("../README.md")]
#![warn(missing_docs)]

//! ## Feature flags
#![doc = document_features::document_features!(feature_label = r#"<span class="stab portability"><code>{feature}</code></span>"#)]

#[cfg(not(any(feature = "mimxrt633s", feature = "mimxrt685s",)))]
compile_error!(
    "No chip feature activated. You must activate exactly one of the following features:
    mimxrt633s,
    mimxrt685s,
    "
);

// This mod MUST go first, so that the others see its macros.
pub(crate) mod fmt;

pub mod clocks;
pub mod crc;
pub mod dma;
pub mod flexcomm;
pub mod gpio;
pub mod iopctl;
pub mod rng;

#[cfg(feature = "_time-driver")]
pub mod time_driver;

// This mod MUST go last, so that it sees all the `impl_foo!' macros
#[cfg_attr(feature = "mimxrt633s", path = "chips/mimxrt633s.rs")]
#[cfg_attr(feature = "mimxrt685s", path = "chips/mimxrt685s.rs")]
mod chip;

// Reexports
pub use chip::interrupts::*;
#[cfg(feature = "unstable-pac")]
pub use chip::pac;
#[cfg(not(feature = "unstable-pac"))]
pub(crate) use chip::pac;
pub use chip::{peripherals, Peripherals};
pub use embassy_hal_internal::{Peri, PeripheralType};

#[cfg(feature = "rt")]
pub use crate::pac::NVIC_PRIO_BITS;

/// Macro to bind interrupts to handlers.
///
/// This defines the right interrupt handlers, and creates a unit struct (like `struct Irqs;`)
/// and implements the right \[`Binding`\]s for it. You can pass this struct to drivers to
/// prove at compile-time that the right interrupts have been bound.
///
/// Example of how to bind one interrupt:
///
/// ```rust,ignore
/// use embassy_imxrt::{bind_interrupts, flexspi, peripherals};
///
/// bind_interrupts!(struct Irqs {
///     FLEXSPI_IRQ => flexspi::InterruptHandler<peripherals::FLEXSPI>;
/// });
/// ```
///
// developer note: this macro can't be in `embassy-hal-internal` due to the use of `$crate`.
#[macro_export]
macro_rules! bind_interrupts {
    ($vis:vis struct $name:ident { $($irq:ident => $($handler:ty),*;)* }) => {
            #[derive(Copy, Clone)]
            $vis struct $name;

        $(
            #[allow(non_snake_case)]
            #[no_mangle]
            unsafe extern "C" fn $irq() {
                $(
                    <$handler as $crate::interrupt::typelevel::Handler<$crate::interrupt::typelevel::$irq>>::on_interrupt();
                )*
            }

            $(
                unsafe impl $crate::interrupt::typelevel::Binding<$crate::interrupt::typelevel::$irq, $handler> for $name {}
            )*
        )*
    };
}

/// HAL configuration for iMX RT600.
pub mod config {
    use crate::clocks::ClockConfig;

    /// HAL configuration passed when initializing.
    #[non_exhaustive]
    pub struct Config {
        /// Clock configuration.
        pub clocks: ClockConfig,

        /// RTC Time driver interrupt priority.
        #[cfg(feature = "_time-driver")]
        pub time_interrupt_priority: crate::interrupt::Priority,
    }

    impl Default for Config {
        fn default() -> Self {
            Self {
                clocks: ClockConfig::crystal(),
                #[cfg(feature = "_time-driver")]
                time_interrupt_priority: crate::interrupt::Priority::P0,
            }
        }
    }

    impl Config {
        /// Create a new configuration with the provided clock config.
        pub fn new(clocks: ClockConfig) -> Self {
            Self {
                clocks,
                #[cfg(feature = "_time-driver")]
                time_interrupt_priority: crate::interrupt::Priority::P0,
            }
        }
    }
}

/// Initialize the `embassy-imxrt` HAL with the provided configuration.
///
/// This returns the peripheral singletons that can be used for creating drivers.
///
/// This should only be called once at startup, otherwise it panics.
pub fn init(config: config::Config) -> Peripherals {
    // Do this first, so that it panics if user is calling `init` a second time
    // before doing anything important.
    let peripherals = Peripherals::take();

    #[cfg(feature = "_time-driver")]
    time_driver::init(config.time_interrupt_priority);

    unsafe {
        if let Err(e) = clocks::init(config.clocks) {
            error!("unable to initialize Clocks for reason: {:?}", e);
            // Panic here?
        }
        dma::init();
    }
    gpio::init();

    peripherals
}

pub(crate) mod sealed {
    pub trait Sealed {}
}

#[cfg(feature = "rt")]
struct BitIter(u32);

#[cfg(feature = "rt")]
impl Iterator for BitIter {
    type Item = u32;

    fn next(&mut self) -> Option<Self::Item> {
        match self.0.trailing_zeros() {
            32 => None,
            b => {
                self.0 &= !(1 << b);
                Some(b)
            }
        }
    }
}