some-serial 0.4.0

use core::{num::NonZeroU32, ptr::NonNull};

use rdif_serial::{
    BSerial, InterfaceRaw, SerialDyn, SetBackError, TIrqHandler, TSender, TransBytesError,
    TransferError,
};
use tock_registers::{interfaces::*, register_bitfields, register_structs, registers::*};

use crate::{
    Config, ConfigError, DataBits, InterruptMask, Parity, RawReciever, RawSender, StopBits,
};

register_bitfields! [
    u32,

    /// Data Register
    UARTDR [
        DATA OFFSET(0) NUMBITS(8) [],
        FE OFFSET(8) NUMBITS(1) [],
        PE OFFSET(9) NUMBITS(1) [],
        BE OFFSET(10) NUMBITS(1) [],
        OE OFFSET(11) NUMBITS(1) []
    ],

    /// Receive Status Register / Error Clear Register
    UARTRSR_ECR [
        FE OFFSET(0) NUMBITS(1) [],
        PE OFFSET(1) NUMBITS(1) [],
        BE OFFSET(2) NUMBITS(1) [],
        OE OFFSET(3) NUMBITS(1) []
    ],

    /// Flag Register
    UARTFR [
        CTS OFFSET(0) NUMBITS(1) [],
        DSR OFFSET(1) NUMBITS(1) [],
        DCD OFFSET(2) NUMBITS(1) [],
        BUSY OFFSET(3) NUMBITS(1) [],
        RXFE OFFSET(4) NUMBITS(1) [],
        TXFF OFFSET(5) NUMBITS(1) [],
        RXFF OFFSET(6) NUMBITS(1) [],
        TXFE OFFSET(7) NUMBITS(1) [],
        RI OFFSET(8) NUMBITS(1) []
    ],

    /// Integer Baud Rate Register
    UARTIBRD [
        BAUD_DIVINT OFFSET(0) NUMBITS(16) []
    ],

    /// Fractional Baud Rate Register
    UARTFBRD [
        BAUD_DIVFRAC OFFSET(0) NUMBITS(6) []
    ],

    /// Line Control Register
    UARTLCR_H [
        BRK OFFSET(0) NUMBITS(1) [],
        PEN OFFSET(1) NUMBITS(1) [],
        EPS OFFSET(2) NUMBITS(1) [],
        STP2 OFFSET(3) NUMBITS(1) [],
        FEN OFFSET(4) NUMBITS(1) [],
        WLEN OFFSET(5) NUMBITS(2) [
            FiveBit = 0,
            SixBit = 1,
            SevenBit = 2,
            EightBit = 3
        ],
        SPS OFFSET(7) NUMBITS(1) []
    ],

    /// Control Register
    UARTCR [
        UARTEN OFFSET(0) NUMBITS(1) [],
        SIREN OFFSET(1) NUMBITS(1) [],
        SIRLP OFFSET(2) NUMBITS(1) [],
        LBE OFFSET(7) NUMBITS(1) [],
        TXE OFFSET(8) NUMBITS(1) [],
        RXE OFFSET(9) NUMBITS(1) [],
        DTR OFFSET(10) NUMBITS(1) [],
        RTS OFFSET(11) NUMBITS(1) [],
        OUT1 OFFSET(12) NUMBITS(1) [],
        OUT2 OFFSET(13) NUMBITS(1) [],
        RTSEN OFFSET(14) NUMBITS(1) [],
        CTSEN OFFSET(15) NUMBITS(1) []
    ],

    /// Interrupt FIFO Level Select Register
    UARTIFLS [
        TXIFLSEL OFFSET(0) NUMBITS(3) [],
        RXIFLSEL OFFSET(3) NUMBITS(3) []
    ],

    /// Interrupt Mask Set/Clear Register
    UARTIS [
        RIM OFFSET(0) NUMBITS(1) [],
        CTSM OFFSET(1) NUMBITS(1) [],
        DCDM OFFSET(2) NUMBITS(1) [],
        DSRM OFFSET(3) NUMBITS(1) [],
        RX OFFSET(4) NUMBITS(1) [],
        TX OFFSET(5) NUMBITS(1) [],
        RT OFFSET(6) NUMBITS(1) [],
        FE OFFSET(7) NUMBITS(1) [],
        PE OFFSET(8) NUMBITS(1) [],
        BE OFFSET(9) NUMBITS(1) [],
        OE OFFSET(10) NUMBITS(1) []
    ],

    /// DMA Control Register
    UARTDMACR [
        RXDMAE OFFSET(0) NUMBITS(1) [],
        TXDMAE OFFSET(1) NUMBITS(1) [],
        DMAONERR OFFSET(2) NUMBITS(1) []
    ]
];

register_structs! {
    pub Pl011Registers {
        (0x000 => uartdr: ReadWrite<u32, UARTDR::Register>),        // 数据寄存器（收发数据/错误标志）
        (0x004 => uartrsr_ecr: ReadWrite<u32, UARTRSR_ECR::Register>), // 接收状态/错误清除寄存器
        (0x008 => _reserved1),                                      // 保留
        (0x018 => uartfr: ReadOnly<u32, UARTFR::Register>),         // 标志寄存器（状态标志，如忙/空/满等）
        (0x01c => _reserved2),                                      // 保留
        (0x020 => uartilpr: ReadWrite<u32>),                        // 红外低功耗波特率寄存器（很少用）
        (0x024 => uartibrd: ReadWrite<u32, UARTIBRD::Register>),    // 整数波特率分频寄存器
        (0x028 => uartfbrd: ReadWrite<u32, UARTFBRD::Register>),    // 小数波特率分频寄存器
        (0x02c => uartlcr_h: ReadWrite<u32, UARTLCR_H::Register>),  // 线路控制寄存器（数据位、停止位、校验等）
        (0x030 => uartcr: ReadWrite<u32, UARTCR::Register>),        // 控制寄存器（UART使能、收发使能等）
        (0x034 => uartifls: ReadWrite<u32, UARTIFLS::Register>),    // FIFO中断触发级别选择寄存器
        (0x038 => uartimsc: ReadWrite<u32, UARTIS::Register>),      // 中断屏蔽设置/清除寄存器
        (0x03c => uartris: ReadOnly<u32, UARTIS::Register>),        // 原始中断状态寄存器
        (0x040 => uartmis: ReadOnly<u32, UARTIS::Register>),        // 屏蔽后的中断状态寄存器
        (0x044 => uarticr: WriteOnly<u32, UARTIS::Register>),       // 中断清除寄存器
        (0x048 => uartdmacr: ReadWrite<u32, UARTDMACR::Register>),  // DMA控制寄存器
        (0x04c => _reserved3),                                      // 保留
        (0x1000 => @END),
    }
}

// SAFETY: PL011 寄存器访问是原子的，硬件保证了内存映射寄存器的线程安全
unsafe impl Sync for Pl011Registers {}

/// PL011 UART 驱动结构体
pub struct Pl011 {
    base: Reg,
    clock_freq: u32,
    tx: Option<Pl011Sender>,
    rx: Option<Pl011Reciever>,
    irq: Option<Pl011IrqHandler>,
}

impl Pl011 {
    /// 创建新的 PL011 实例（仅基地址，使用默认配置）
    ///
    /// # Arguments
    /// * `base` - UART 寄存器基地址
    pub fn new_no_clock(base: NonNull<u8>) -> Self {
        // 自动检测时钟频率或使用合理的默认值
        let clock_freq = Self::detect_clock_frequency(base.as_ptr() as usize);
        Self::new(base, clock_freq)
    }

    pub fn new(base: NonNull<u8>, clock_freq: u32) -> Self {
        let base = Reg(base.cast());

        Self {
            base,
            clock_freq,
            tx: Some(Pl011Sender { base }),
            rx: Some(Pl011Reciever { base }),
            irq: Some(Pl011IrqHandler { base }),
        }
    }

    pub fn new_boxed(base: NonNull<u8>, clock_freq: u32) -> BSerial {
        let mut serial = Self::new(base, clock_freq);
        serial.open();
        SerialDyn::new_boxed(serial)
    }

    fn registers(&self) -> &Pl011Registers {
        unsafe { &*self.base.0.as_ptr() }
    }

    /// 自动检测或确定合理的时钟频率
    fn detect_clock_frequency(base: usize) -> u32 {
        // 尝试读取当前波特率设置来反向推算时钟频率
        let registers = unsafe { &*(base as *const Pl011Registers) };

        use tock_registers::interfaces::Readable;
        let ibrd = registers.uartibrd.read(UARTIBRD::BAUD_DIVINT);

        // 如果有设置值，假设波特率为 115200 来估算时钟频率
        if ibrd > 0 && ibrd <= 0xFFFF {
            // 假设波特率为 115200，计算时钟频率
            // FUARTCLK = 16 * BAUDDIV * Baud rate
            let estimated_clock = 16 * ibrd * 115200;

            // 合理的时钟频率范围：1MHz - 100MHz
            if (1_000_000..=100_000_000).contains(&estimated_clock) {
                return estimated_clock;
            }
        }

        // 默认使用 24MHz（最常见）
        24_000_000
    }

    // 内部私有方法，用于配置
    fn set_baudrate_internal(&self, baudrate: u32) -> Result<(), ConfigError> {
        // PL011 波特率计算公式：
        // BAUDDIV = (FUARTCLK / (16 * Baud rate))
        // IBRD = integer(BAUDDIV)
        // FBRD = integer((BAUDDIV - IBRD) * 64 + 0.5)

        let bauddiv = self.clock_freq / (16 * baudrate);
        let remainder = self.clock_freq % (16 * baudrate);
        let fbrd = (remainder * 64 + (16 * baudrate / 2)) / (16 * baudrate);

        if bauddiv == 0 || bauddiv > 0xFFFF {
            return Err(ConfigError::InvalidBaudrate);
        }

        self.registers()
            .uartibrd
            .write(UARTIBRD::BAUD_DIVINT.val(bauddiv));
        self.registers()
            .uartfbrd
            .write(UARTFBRD::BAUD_DIVFRAC.val(fbrd));

        Ok(())
    }

    fn set_data_bits_internal(&self, bits: DataBits) -> Result<(), ConfigError> {
        let wlen = match bits {
            DataBits::Five => UARTLCR_H::WLEN::FiveBit,
            DataBits::Six => UARTLCR_H::WLEN::SixBit,
            DataBits::Seven => UARTLCR_H::WLEN::SevenBit,
            DataBits::Eight => UARTLCR_H::WLEN::EightBit,
        };

        self.registers().uartlcr_h.modify(wlen);
        Ok(())
    }

    fn set_stop_bits_internal(&self, bits: StopBits) -> Result<(), ConfigError> {
        match bits {
            StopBits::One => self.registers().uartlcr_h.modify(UARTLCR_H::STP2::CLEAR),
            StopBits::Two => self.registers().uartlcr_h.modify(UARTLCR_H::STP2::SET),
        }

        Ok(())
    }

    fn set_parity_internal(&self, parity: Parity) -> Result<(), ConfigError> {
        match parity {
            Parity::None => {
                // PEN = 0, 无奇偶校验
                self.registers().uartlcr_h.modify(UARTLCR_H::PEN::CLEAR);
            }
            Parity::Odd => {
                // PEN = 1, EPS = 0 (奇校验), SPS = 0
                self.registers()
                    .uartlcr_h
                    .modify(UARTLCR_H::PEN::SET + UARTLCR_H::EPS::CLEAR + UARTLCR_H::SPS::CLEAR);
            }
            Parity::Even => {
                // PEN = 1, EPS = 1 (偶校验), SPS = 0
                self.registers()
                    .uartlcr_h
                    .modify(UARTLCR_H::PEN::SET + UARTLCR_H::EPS::SET + UARTLCR_H::SPS::CLEAR);
            }
            Parity::Mark => {
                // PEN = 1, SPS = 1, EPS = 0 (奇校验)
                self.registers()
                    .uartlcr_h
                    .modify(UARTLCR_H::PEN::SET + UARTLCR_H::EPS::CLEAR + UARTLCR_H::SPS::SET);
            }
            Parity::Space => {
                // PEN = 1, EPS = 1 (偶校验), SPS = 1
                self.registers()
                    .uartlcr_h
                    .modify(UARTLCR_H::PEN::SET + UARTLCR_H::EPS::SET + UARTLCR_H::SPS::SET);
            }
        }

        Ok(())
    }

    /// 初始化 PL011 UART
    fn init(&self) {
        // 禁用 UART
        self.registers().uartcr.modify(UARTCR::UARTEN::CLEAR);

        // 等待当前传输完成
        while self.registers().uartfr.is_set(UARTFR::BUSY) {
            core::hint::spin_loop();
        }

        // 清除发送 FIFO
        self.registers().uartlcr_h.modify(UARTLCR_H::FEN::CLEAR);

        // 启用 FIFO
        self.registers().uartlcr_h.modify(UARTLCR_H::FEN::SET);

        // 调试信息：输出 FIFO 配置
        #[cfg(debug_assertions)]
        {
            let ifls = self.registers().uartifls.get();
            let lcr_h = self.registers().uartlcr_h.get();
            log::debug!("UART IFLS: 0x{:02x}, LCR_H: 0x{:02x}", ifls, lcr_h);
            log::debug!("  FIFO enabled: {}", lcr_h & (1 << 4) != 0);
            log::debug!("  RX trigger level: 1/8");
            log::debug!("  TX trigger level: 1/2");
        }
        self.registers().uartimsc.set(0); // 禁用所有中断
        // 启用 UART
        self.registers()
            .uartcr
            .modify(UARTCR::UARTEN::SET + UARTCR::TXE::SET + UARTCR::RXE::SET);
    }

    pub fn task_tx(&mut self) -> Option<crate::Sender> {
        self.tx.take().map(crate::Sender::Pl011Sender)
    }

    pub fn task_rx(&mut self) -> Option<crate::Reciever> {
        self.rx.take().map(crate::Reciever::Pl011Reciever)
    }
}

#[derive(Clone, Copy, PartialEq, Eq)]
struct Reg(NonNull<Pl011Registers>);

unsafe impl Send for Reg {}

impl Reg {
    fn registers(&self) -> &Pl011Registers {
        unsafe { self.0.as_ref() }
    }
}

pub struct Pl011Sender {
    base: Reg,
}

impl TSender for Pl011Sender {
    fn write_byte(&mut self, byte: u8) -> bool {
        RawSender::write_byte(self, byte)
    }
}

impl RawSender for Pl011Sender {
    fn write_byte(&mut self, byte: u8) -> bool {
        if self.base.registers().uartfr.is_set(UARTFR::TXFF) {
            return false;
        }

        self.base.registers().uartdr.set(byte as _);

        true
    }
}

pub struct Pl011Reciever {
    base: Reg,
}

impl RawReciever for Pl011Reciever {
    fn read_byte(&mut self) -> Option<Result<u8, TransferError>> {
        if self.base.registers().uartfr.is_set(UARTFR::RXFE) {
            return None;
        }

        let dr = self.base.registers().uartdr.extract();
        let data = dr.read(UARTDR::DATA) as u8;

        if dr.is_set(UARTDR::FE) {
            return Some(Err(TransferError::Framing));
        }

        if dr.is_set(UARTDR::PE) {
            return Some(Err(TransferError::Parity));
        }

        if dr.is_set(UARTDR::OE) {
            return Some(Err(TransferError::Overrun(data)));
        }

        if dr.is_set(UARTDR::BE) {
            return Some(Err(TransferError::Break));
        }

        Some(Ok(data))
    }

    fn read_bytes(&mut self, bytes: &mut [u8]) -> Result<usize, TransBytesError> {
        let mut count = 0;
        let mut overrun_data = None;
        for byte in bytes.iter_mut() {
            match self.read_byte() {
                Some(Ok(b)) => {
                    *byte = b;
                }
                Some(Err(TransferError::Overrun(b))) => {
                    overrun_data = Some(b);
                    *byte = b;
                }
                Some(Err(e)) => {
                    return Err(TransBytesError {
                        bytes_transferred: count,
                        kind: e,
                    });
                }
                None => {
                    if let Some(data) = overrun_data {
                        count = count.saturating_sub(1);

                        return Err(TransBytesError {
                            bytes_transferred: count,
                            kind: TransferError::Overrun(data),
                        });
                    }
                    break;
                }
            }
            count += 1;
        }
        Ok(count)
    }
}

pub struct Pl011IrqHandler {
    base: Reg,
}

unsafe impl Sync for Pl011IrqHandler {}

impl TIrqHandler for Pl011IrqHandler {
    fn clean_interrupt_status(&self) -> InterruptMask {
        let mis = self.base.registers().uartmis.extract();
        let mut mask = InterruptMask::empty();

        if mis.is_set(UARTIS::RX) {
            mask |= InterruptMask::RX_AVAILABLE;
        }
        if mis.is_set(UARTIS::TX) {
            mask |= InterruptMask::TX_EMPTY;
        }

        self.base.registers().uarticr.set(mis.get());

        mask
    }
}

impl InterfaceRaw for Pl011 {
    type IrqHandler = Pl011IrqHandler;

    type Sender = crate::Sender;

    type Reciever = crate::Reciever;

    fn name(&self) -> &str {
        "PL011 UART"
    }

    fn set_config(&mut self, config: &Config) -> Result<(), ConfigError> {
        use tock_registers::interfaces::Readable;

        // 根据ARM文档的建议配置流程：
        // 1. 禁用UART
        let original_enable = self.registers().uartcr.is_set(UARTCR::UARTEN); // 保存原始使能状态
        self.registers().uartcr.modify(UARTCR::UARTEN::CLEAR); // 禁用UART

        // 2. 等待当前字符传输完成
        while self.registers().uartfr.is_set(UARTFR::BUSY) {
            core::hint::spin_loop();
        }

        // 3. 刷新发送FIFO（通过设置FEN=0）
        self.registers().uartlcr_h.modify(UARTLCR_H::FEN::CLEAR);

        // 4. 配置各项参数
        if let Some(baudrate) = config.baudrate {
            self.set_baudrate_internal(baudrate)?;
        }
        if let Some(data_bits) = config.data_bits {
            self.set_data_bits_internal(data_bits)?;
        }
        if let Some(stop_bits) = config.stop_bits {
            self.set_stop_bits_internal(stop_bits)?;
        }
        if let Some(parity) = config.parity {
            self.set_parity_internal(parity)?;
        }

        // 5. 重新启用FIFO
        self.registers().uartlcr_h.modify(UARTLCR_H::FEN::SET);

        // 6. 恢复UART使能状态
        if original_enable {
            self.registers().uartcr.modify(UARTCR::UARTEN::SET); // 重新启用UART
        }

        Ok(())
    }

    fn baudrate(&self) -> u32 {
        let ibrd = self.registers().uartibrd.read(UARTIBRD::BAUD_DIVINT);
        let fbrd = self.registers().uartfbrd.read(UARTFBRD::BAUD_DIVFRAC);

        // 反向计算波特率
        // Baud rate = FUARTCLK / (16 * (IBRD + FBRD/64))
        let divisor = ibrd * 64 + fbrd;
        if divisor == 0 {
            return 0;
        }

        self.clock_freq * 64 / (16 * divisor)
    }

    fn data_bits(&self) -> DataBits {
        let wlen = self.registers().uartlcr_h.read(UARTLCR_H::WLEN);

        match wlen {
            0 => DataBits::Five,
            1 => DataBits::Six,
            2 => DataBits::Seven,
            3 => DataBits::Eight,
            _ => DataBits::Eight, // 默认值
        }
    }

    fn stop_bits(&self) -> StopBits {
        if self.registers().uartlcr_h.is_set(UARTLCR_H::STP2) {
            StopBits::Two
        } else {
            StopBits::One
        }
    }

    fn parity(&self) -> Parity {
        if !self.registers().uartlcr_h.is_set(UARTLCR_H::PEN) {
            Parity::None
        } else if self.registers().uartlcr_h.is_set(UARTLCR_H::SPS) {
            // Stick parity
            if self.registers().uartlcr_h.is_set(UARTLCR_H::EPS) {
                Parity::Space
            } else {
                Parity::Mark
            }
        } else {
            // Normal parity
            if self.registers().uartlcr_h.is_set(UARTLCR_H::EPS) {
                Parity::Even
            } else {
                Parity::Odd
            }
        }
    }

    fn open(&mut self) {
        self.init()
    }

    fn close(&mut self) {
        // 禁用 UART
        self.registers().uartcr.modify(UARTCR::UARTEN::CLEAR);
    }

    fn clock_freq(&self) -> Option<NonZeroU32> {
        self.clock_freq.try_into().ok()
    }

    fn enable_loopback(&mut self) {
        self.registers().uartcr.modify(UARTCR::LBE::SET);
    }

    fn disable_loopback(&mut self) {
        self.registers().uartcr.modify(UARTCR::LBE::CLEAR);
    }

    fn is_loopback_enabled(&self) -> bool {
        self.registers().uartcr.is_set(UARTCR::LBE)
    }

    fn set_irq_mask(&mut self, mask: InterruptMask) {
        let mut imsc = 0;
        if mask.contains(InterruptMask::RX_AVAILABLE) {
            imsc += UARTIS::RX::SET.value;
        }
        if mask.contains(InterruptMask::TX_EMPTY) {
            imsc += UARTIS::TX::SET.value;
        }

        self.registers().uartimsc.set(imsc);
    }

    fn get_irq_mask(&self) -> InterruptMask {
        let imsc = self.registers().uartimsc.extract();
        let mut mask = InterruptMask::empty();

        if imsc.is_set(UARTIS::RX) {
            mask |= InterruptMask::RX_AVAILABLE;
        }
        if imsc.is_set(UARTIS::TX) {
            mask |= InterruptMask::TX_EMPTY;
        }

        mask
    }

    fn base_addr(&self) -> usize {
        self.base.0.as_ptr() as usize
    }

    fn irq_handler(&mut self) -> Option<Self::IrqHandler> {
        self.irq.take()
    }

    fn take_tx(&mut self) -> Option<Self::Sender> {
        self.task_tx()
    }

    fn take_rx(&mut self) -> Option<Self::Reciever> {
        self.task_rx()
    }

    fn set_tx(&mut self, tx: Self::Sender) -> Result<(), SetBackError> {
        let tx = match tx {
            crate::Sender::Pl011Sender(s) => s,
            _ => {
                return Err(SetBackError::new(
                    self.base.0.as_ptr() as _,
                    0, // 不匹配的发送器类型
                ));
            }
        };

        if self.base != tx.base {
            return Err(SetBackError::new(
                self.base.0.as_ptr() as _,
                tx.base.0.as_ptr() as _,
            ));
        }

        self.tx = Some(tx);
        Ok(())
    }

    fn set_rx(&mut self, rx: Self::Reciever) -> Result<(), SetBackError> {
        let rx = match rx {
            crate::Reciever::Pl011Reciever(r) => r,
            _ => {
                return Err(SetBackError::new(
                    self.base.0.as_ptr() as _,
                    0, // 不匹配的接收器类型
                ));
            }
        };
        if self.base != rx.base {
            return Err(SetBackError::new(
                self.base.0.as_ptr() as _,
                rx.base.0.as_ptr() as _,
            ));
        }
        self.rx = Some(rx);
        Ok(())
    }
}

// 额外的便利方法，用于 FIFO 和流控制
impl Pl011 {
    /// 启用或禁用 FIFO
    pub fn enable_fifo(&self, enable: bool) {
        if enable {
            self.registers().uartlcr_h.modify(UARTLCR_H::FEN::SET);
        } else {
            self.registers().uartlcr_h.modify(UARTLCR_H::FEN::CLEAR);
        }
    }

    /// 设置 FIFO 触发级别
    pub fn set_fifo_trigger_level(&self, rx_level: u8, tx_level: u8) {
        // PL011 FIFO 触发级别：
        // 0b000: 1/8 full
        // 0b001: 1/4 full
        // 0b010: 1/2 full
        // 0b011: 3/4 full
        // 0b100: 7/8 full

        let rx_iflsel = match rx_level {
            0..=2 => 0b000,  // 1/8
            3..=4 => 0b001,  // 1/4
            5..=8 => 0b010,  // 1/2
            9..=12 => 0b011, // 3/4
            _ => 0b100,      // 7/8
        };

        let tx_iflsel = match tx_level {
            0..=2 => 0b000,  // 1/8
            3..=4 => 0b001,  // 1/4
            5..=8 => 0b010,  // 1/2
            9..=12 => 0b011, // 3/4
            _ => 0b100,      // 7/8
        };

        self.registers()
            .uartifls
            .write(UARTIFLS::RXIFLSEL.val(rx_iflsel) + UARTIFLS::TXIFLSEL.val(tx_iflsel));
    }
}

// ModemStatus 现在在 lib.rs 中定义，这里只是导出