#![macro_use]

use core::marker::PhantomData;

use crate::dma::NoDma;
use crate::interrupt;

#[cfg_attr(i2c_v1, path = "v1.rs")]
#[cfg_attr(i2c_v2, path = "v2.rs")]
mod _version;
pub use _version::*;
use embassy_sync::waitqueue::AtomicWaker;

use crate::peripherals;

#[derive(Debug, PartialEq, Eq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub enum Error {
    Bus,
    Arbitration,
    Nack,
    Timeout,
    Crc,
    Overrun,
    ZeroLengthTransfer,
}

pub(crate) mod sealed {
    use super::*;

    pub struct State {
        #[allow(unused)]
        pub waker: AtomicWaker,
    }

    impl State {
        pub const fn new() -> Self {
            Self {
                waker: AtomicWaker::new(),
            }
        }
    }

    pub trait Instance: crate::rcc::RccPeripheral {
        fn regs() -> crate::pac::i2c::I2c;
        fn state() -> &'static State;
    }
}

pub trait Instance: sealed::Instance + 'static {
    type EventInterrupt: interrupt::typelevel::Interrupt;
    type ErrorInterrupt: interrupt::typelevel::Interrupt;
}

pin_trait!(SclPin, Instance);
pin_trait!(SdaPin, Instance);
dma_trait!(RxDma, Instance);
dma_trait!(TxDma, Instance);

/// Interrupt handler.
pub struct EventInterruptHandler<T: Instance> {
    _phantom: PhantomData<T>,
}

impl<T: Instance> interrupt::typelevel::Handler<T::EventInterrupt> for EventInterruptHandler<T> {
    unsafe fn on_interrupt() {
        _version::on_interrupt::<T>()
    }
}

pub struct ErrorInterruptHandler<T: Instance> {
    _phantom: PhantomData<T>,
}

impl<T: Instance> interrupt::typelevel::Handler<T::ErrorInterrupt> for ErrorInterruptHandler<T> {
    unsafe fn on_interrupt() {
        _version::on_interrupt::<T>()
    }
}

foreach_peripheral!(
    (i2c, $inst:ident) => {
        impl sealed::Instance for peripherals::$inst {
            fn regs() -> crate::pac::i2c::I2c {
                crate::pac::$inst
            }

            fn state() -> &'static sealed::State {
                static STATE: sealed::State = sealed::State::new();
                &STATE
            }
        }

        impl Instance for peripherals::$inst {
            type EventInterrupt = crate::_generated::peripheral_interrupts::$inst::EV;
            type ErrorInterrupt = crate::_generated::peripheral_interrupts::$inst::ER;
        }
    };
);

impl<'d, T: Instance> embedded_hal_02::blocking::i2c::Read for I2c<'d, T> {
    type Error = Error;

    fn read(&mut self, address: u8, buffer: &mut [u8]) -> Result<(), Self::Error> {
        self.blocking_read(address, buffer)
    }
}

impl<'d, T: Instance> embedded_hal_02::blocking::i2c::Write for I2c<'d, T> {
    type Error = Error;

    fn write(&mut self, address: u8, write: &[u8]) -> Result<(), Self::Error> {
        self.blocking_write(address, write)
    }
}

impl<'d, T: Instance> embedded_hal_02::blocking::i2c::WriteRead for I2c<'d, T> {
    type Error = Error;

    fn write_read(&mut self, address: u8, write: &[u8], read: &mut [u8]) -> Result<(), Self::Error> {
        self.blocking_write_read(address, write, read)
    }
}

impl embedded_hal_1::i2c::Error for Error {
    fn kind(&self) -> embedded_hal_1::i2c::ErrorKind {
        match *self {
            Self::Bus => embedded_hal_1::i2c::ErrorKind::Bus,
            Self::Arbitration => embedded_hal_1::i2c::ErrorKind::ArbitrationLoss,
            Self::Nack => {
                embedded_hal_1::i2c::ErrorKind::NoAcknowledge(embedded_hal_1::i2c::NoAcknowledgeSource::Unknown)
            }
            Self::Timeout => embedded_hal_1::i2c::ErrorKind::Other,
            Self::Crc => embedded_hal_1::i2c::ErrorKind::Other,
            Self::Overrun => embedded_hal_1::i2c::ErrorKind::Overrun,
            Self::ZeroLengthTransfer => embedded_hal_1::i2c::ErrorKind::Other,
        }
    }
}

impl<'d, T: Instance, TXDMA, RXDMA> embedded_hal_1::i2c::ErrorType for I2c<'d, T, TXDMA, RXDMA> {
    type Error = Error;
}

impl<'d, T: Instance> embedded_hal_1::i2c::I2c for I2c<'d, T, NoDma, NoDma> {
    fn read(&mut self, address: u8, read: &mut [u8]) -> Result<(), Self::Error> {
        self.blocking_read(address, read)
    }

    fn write(&mut self, address: u8, write: &[u8]) -> Result<(), Self::Error> {
        self.blocking_write(address, write)
    }

    fn write_read(&mut self, address: u8, write: &[u8], read: &mut [u8]) -> Result<(), Self::Error> {
        self.blocking_write_read(address, write, read)
    }

    fn transaction(
        &mut self,
        _address: u8,
        _operations: &mut [embedded_hal_1::i2c::Operation<'_>],
    ) -> Result<(), Self::Error> {
        todo!();
    }
}

impl<'d, T: Instance, TXDMA: TxDma<T>, RXDMA: RxDma<T>> embedded_hal_async::i2c::I2c for I2c<'d, T, TXDMA, RXDMA> {
    async fn read(&mut self, address: u8, read: &mut [u8]) -> Result<(), Self::Error> {
        self.read(address, read).await
    }

    async fn write(&mut self, address: u8, write: &[u8]) -> Result<(), Self::Error> {
        self.write(address, write).await
    }

    async fn write_read(&mut self, address: u8, write: &[u8], read: &mut [u8]) -> Result<(), Self::Error> {
        self.write_read(address, write, read).await
    }

    async fn transaction(
        &mut self,
        address: u8,
        operations: &mut [embedded_hal_1::i2c::Operation<'_>],
    ) -> Result<(), Self::Error> {
        let _ = address;
        let _ = operations;
        todo!()
    }
}