//! HackRF One API.
//!
//! To get started take a look at [`HackRfOne::new`].
#![doc(html_root_url = "https://docs.rs/hackrfone/0.1.0")]
#![cfg_attr(docsrs, feature(doc_cfg))]
#![deny(missing_docs)]

pub use rusb;

use rusb::{request_type, Direction, GlobalContext, Recipient, RequestType, UsbContext, Version};
use std::{convert::TryFrom, time::Duration};

#[cfg(feature = "num-complex")]
#[cfg_attr(docsrs, doc(cfg(feature = "num-complex")))]
pub use num_complex;

/// HackRF USB vendor ID.
const HACKRF_USB_VID: u16 = 0x1D50;
/// HackRF One USB product ID.
const HACKRF_ONE_USB_PID: u16 = 0x6089;

#[allow(dead_code)]
#[repr(u8)]
enum Request {
    SetTransceiverMode = 1,
    Max2837Write = 2,
    Max2837Read = 3,
    Si5351CWrite = 4,
    Si5351CRead = 5,
    SampleRateSet = 6,
    BasebandFilterBandwidthSet = 7,
    Rffc5071Write = 8,
    Rffc5071Read = 9,
    SpiflashErase = 10,
    SpiflashWrite = 11,
    SpiflashRead = 12,
    BoardIdRead = 14,
    VersionStringRead = 15,
    SetFreq = 16,
    AmpEnable = 17,
    BoardPartidSerialnoRead = 18,
    SetLnaGain = 19,
    SetVgaGain = 20,
    SetTxvgaGain = 21,
    AntennaEnable = 23,
    SetFreqExplicit = 24,
    UsbWcidVendorReq = 25,
    InitSweep = 26,
    OperacakeGetBoards = 27,
    OperacakeSetPorts = 28,
    SetHwSyncMode = 29,
    Reset = 30,
    OperacakeSetRanges = 31,
    ClkoutEnable = 32,
    SpiflashStatus = 33,
    SpiflashClearStatus = 34,
    OperacakeGpioTest = 35,
    CpldChecksum = 36,
    UiEnable = 37,
}

impl From<Request> for u8 {
    fn from(r: Request) -> Self {
        r as u8
    }
}

#[allow(dead_code)]
#[repr(u8)]
enum TranscieverMode {
    Off = 0,
    Receive = 1,
    Transmit = 2,
    Ss = 3,
    CpldUpdate = 4,
    RxSweep = 5,
}

impl From<TranscieverMode> for u8 {
    fn from(tm: TranscieverMode) -> Self {
        tm as u8
    }
}

impl From<TranscieverMode> for u16 {
    fn from(tm: TranscieverMode) -> Self {
        tm as u16
    }
}

/// HackRF One errors.
#[derive(Debug)]
pub enum Error {
    /// USB error.
    Usb(rusb::Error),
    /// Failed to transfer all bytes in a control transfer.
    CtrlTransfer {
        /// Control transfer direction.
        dir: Direction,
        /// Actual amount of bytes transferred.
        actual: usize,
        /// Excepted number of bytes transferred.
        expected: usize,
    },
    /// An API call is not supported by your hardware.
    ///
    /// Try updating the firmware on your device.
    Version {
        /// Current device version.
        device: Version,
        /// Minimum version required.
        min: Version,
    },
    /// A provided argument was out of range.
    Argument,
}

impl From<rusb::Error> for Error {
    fn from(e: rusb::Error) -> Self {
        Error::Usb(e)
    }
}

/// Typestate for RX mode.
#[derive(Debug)]
pub struct RxMode;

/// Typestate for an unknown mode.
#[derive(Debug)]
pub struct UnknownMode;

/// HackRF One software defined radio.
pub struct HackRfOne<MODE> {
    dh: rusb::DeviceHandle<GlobalContext>,
    desc: rusb::DeviceDescriptor,
    #[allow(dead_code)]
    mode: MODE,
    to: Duration,
}

impl HackRfOne<UnknownMode> {
    /// Open a new HackRF One.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use hackrfone::{HackRfOne, UnknownMode};
    ///
    /// let mut radio: HackRfOne<UnknownMode> = HackRfOne::new().unwrap();
    /// ```
    pub fn new() -> Option<HackRfOne<UnknownMode>> {
        let ctx: GlobalContext = GlobalContext {};
        let devices = match ctx.devices() {
            Ok(d) => d,
            Err(_) => return None,
        };

        for device in devices.iter() {
            let desc = match device.device_descriptor() {
                Ok(d) => d,
                Err(_) => continue,
            };

            if desc.vendor_id() == HACKRF_USB_VID && desc.product_id() == HACKRF_ONE_USB_PID {
                match device.open() {
                    Ok(handle) => {
                        return Some(HackRfOne {
                            dh: handle,
                            desc,
                            mode: UnknownMode,
                            to: Duration::from_secs(1),
                        })
                    }
                    Err(_) => continue,
                }
            }
        }

        None
    }
}

impl<MODE> HackRfOne<MODE> {
    fn read_control<const N: usize>(
        &self,
        request: Request,
        value: u16,
        index: u16,
    ) -> Result<[u8; N], Error> {
        let mut buf: [u8; N] = [0; N];
        let n: usize = self.dh.read_control(
            request_type(Direction::In, RequestType::Vendor, Recipient::Device),
            request.into(),
            value,
            index,
            &mut buf,
            self.to,
        )?;
        if n != buf.len() {
            Err(Error::CtrlTransfer {
                dir: Direction::In,
                actual: n,
                expected: buf.len(),
            })
        } else {
            Ok(buf)
        }
    }

    fn write_control(
        &mut self,
        request: Request,
        value: u16,
        index: u16,
        buf: &[u8],
    ) -> Result<(), Error> {
        let n: usize = self.dh.write_control(
            request_type(Direction::Out, RequestType::Vendor, Recipient::Device),
            request.into(),
            value,
            index,
            &buf,
            self.to,
        )?;
        if n != buf.len() {
            Err(Error::CtrlTransfer {
                dir: Direction::Out,
                actual: n,
                expected: buf.len(),
            })
        } else {
            Ok(())
        }
    }

    fn check_api_version(&self, min: Version) -> Result<(), Error> {
        fn version_to_u32(v: Version) -> u32 {
            ((v.major() as u32) << 16) | ((v.minor() as u32) << 8) | (v.sub_minor() as u32)
        }

        let v: Version = self.device_version();
        let v_cmp: u32 = version_to_u32(v);
        let min_cmp: u32 = version_to_u32(min);

        if v_cmp >= min_cmp {
            Ok(())
        } else {
            Err(Error::Version { device: v, min })
        }
    }

    /// Get the device version from the USB descriptor.
    ///
    /// The HackRF C API calls the equivalent of this function
    /// `hackrf_usb_api_version_read`.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use hackrfone::{rusb, HackRfOne, UnknownMode};
    ///
    /// let mut radio: HackRfOne<UnknownMode> = HackRfOne::new().unwrap();
    /// assert_eq!(radio.device_version(), rusb::Version(1, 0, 4));
    /// ```
    pub fn device_version(&self) -> Version {
        self.desc.device_version()
    }

    /// Set the timeout for USB transfers.
    ///
    /// # Example
    ///
    /// Set a 100ms timeout.
    ///
    /// ```no_run
    /// use hackrfone::{HackRfOne, UnknownMode};
    /// use std::time::Duration;
    ///
    /// let mut radio: HackRfOne<UnknownMode> = HackRfOne::new().unwrap();
    /// radio.set_timeout(Duration::from_millis(100))
    /// ```
    pub fn set_timeout(&mut self, duration: Duration) {
        self.to = duration;
    }

    /// Read the board ID.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use hackrfone::{HackRfOne, UnknownMode};
    ///
    /// let mut radio: HackRfOne<UnknownMode> = HackRfOne::new().unwrap();
    /// assert_eq!(radio.board_id()?, 0x02);
    /// # Ok::<(), hackrfone::Error>(())
    /// ```
    pub fn board_id(&self) -> Result<u8, Error> {
        let data: [u8; 1] = self.read_control(Request::BoardIdRead, 0, 0)?;
        Ok(data[0])
    }

    /// Read the firmware version.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use hackrfone::{HackRfOne, UnknownMode};
    ///
    /// let mut radio: HackRfOne<UnknownMode> = HackRfOne::new().unwrap();
    /// assert_eq!(radio.version()?, "2021.03.1");
    /// # Ok::<(), hackrfone::Error>(())
    /// ```
    pub fn version(&self) -> Result<String, Error> {
        let mut buf: [u8; 16] = [0; 16];
        let n: usize = self.dh.read_control(
            request_type(Direction::In, RequestType::Vendor, Recipient::Device),
            Request::VersionStringRead.into(),
            0,
            0,
            &mut buf,
            self.to,
        )?;
        Ok(String::from_utf8_lossy(&buf[0..n]).into())
    }

    /// Set the center frequency.
    ///
    /// # Example
    ///
    /// Set the frequency to 915MHz.
    ///
    /// ```no_run
    /// use hackrfone::{HackRfOne, UnknownMode};
    ///
    /// let mut radio: HackRfOne<UnknownMode> = HackRfOne::new().unwrap();
    /// radio.set_freq(915_000_000)?;
    /// # Ok::<(), hackrfone::Error>(())
    /// ```
    pub fn set_freq(&mut self, hz: u64) -> Result<(), Error> {
        let buf: [u8; 8] = freq_params(hz);
        self.write_control(Request::SetFreq, 0, 0, &buf)
    }

    /// Enable the RX/TX RF amplifier.
    ///
    /// # Example
    ///
    /// Disable the amplifier.
    ///
    /// ```no_run
    /// use hackrfone::{HackRfOne, UnknownMode};
    ///
    /// let mut radio: HackRfOne<UnknownMode> = HackRfOne::new().unwrap();
    /// radio.set_amp_enable(false)?;
    /// # Ok::<(), hackrfone::Error>(())
    /// ```
    pub fn set_amp_enable(&mut self, en: bool) -> Result<(), Error> {
        self.write_control(Request::AmpEnable, en.into(), 0, &[])
    }

    /// Set the baseband filter bandwidth.
    ///
    /// This is automatically set when the sample rate is changed with
    /// [`set_sample_rate`].
    ///
    /// # Example
    ///
    /// Set the filter bandwidth to 70% of the sample rate.
    ///
    /// ```no_run
    /// use hackrfone::{HackRfOne, UnknownMode};
    ///
    /// const SAMPLE_HZ: u32 = 20_000_000;
    /// const SAMPLE_DIV: u32 = 2;
    /// const FILTER_BW: u32 = (0.7 * (SAMPLE_HZ as f32) / (SAMPLE_DIV as f32)) as u32;
    ///
    /// let mut radio: HackRfOne<UnknownMode> = HackRfOne::new().unwrap();
    /// radio.set_sample_rate(SAMPLE_HZ, SAMPLE_DIV)?;
    /// radio.set_baseband_filter_bandwidth(FILTER_BW)?;
    /// # Ok::<(), hackrfone::Error>(())
    /// ```
    ///
    /// [`set_sample_rate`]: crate::HackRfOne::set_sample_rate
    pub fn set_baseband_filter_bandwidth(&mut self, hz: u32) -> Result<(), Error> {
        self.write_control(
            Request::BasebandFilterBandwidthSet,
            (hz & 0xFFFF) as u16,
            (hz >> 16) as u16,
            &[],
        )
    }

    /// Set the sample rate.
    ///
    /// For anti-aliasing, the baseband filter bandwidth is automatically set to
    /// the widest available setting that is no more than 75% of the sample rate.
    /// This happens every time the sample rate is set.
    /// If you want to override the baseband filter selection, you must do so
    /// after setting the sample rate.
    ///
    /// Limits are 8MHz - 20MHz.
    /// Preferred rates are 8, 10, 12.5, 16, 20MHz due to less jitter.
    ///
    /// # Example
    ///
    /// Set the sample rate to 10 MHz.
    ///
    /// ```no_run
    /// use hackrfone::{HackRfOne, UnknownMode};
    ///
    /// let mut radio: HackRfOne<UnknownMode> = HackRfOne::new().unwrap();
    /// radio.set_sample_rate(20_000_000, 2)?;
    /// # Ok::<(), hackrfone::Error>(())
    /// ```
    pub fn set_sample_rate(&mut self, hz: u32, div: u32) -> Result<(), Error> {
        let hz: u32 = hz.to_le();
        let div: u32 = div.to_le();
        let buf: [u8; 8] = [
            (hz & 0xFF) as u8,
            ((hz >> 8) & 0xFF) as u8,
            ((hz >> 16) & 0xFF) as u8,
            ((hz >> 24) & 0xFF) as u8,
            (div & 0xFF) as u8,
            ((div >> 8) & 0xFF) as u8,
            ((div >> 16) & 0xFF) as u8,
            ((div >> 24) & 0xFF) as u8,
        ];
        self.write_control(Request::SampleRateSet, 0, 0, &buf)?;
        self.set_baseband_filter_bandwidth((0.75 * (hz as f32) / (div as f32)) as u32)
    }

    /// Set the LNA (low noise amplifier) gain.
    ///
    /// Range 0 to 40dB in 8dB steps.
    pub fn set_lna_gain(&mut self, gain: u16) -> Result<(), Error> {
        if gain > 40 {
            Err(Error::Argument)
        } else {
            let buf: [u8; 1] = self.read_control(Request::SetVgaGain, gain & !0x07, 0)?;
            if buf[0] == 0 {
                Err(Error::Argument)
            } else {
                Ok(())
            }
        }
    }

    /// Set the VGA (variable gain amplifier) gain.
    ///
    /// Range 0 to 62dB in 2dB steps.
    pub fn set_vga_gain(&mut self, gain: u16) -> Result<(), Error> {
        if gain > 62 {
            Err(Error::Argument)
        } else {
            let buf: [u8; 1] = self.read_control(Request::SetVgaGain, gain & !0b1, 0)?;
            if buf[0] == 0 {
                Err(Error::Argument)
            } else {
                Ok(())
            }
        }
    }

    /// Set the transmit VGA gain.
    ///
    /// Range 0 to 47dB in 1db steps.
    pub fn set_txvga_gain(&mut self, gain: u16) -> Result<(), Error> {
        if gain > 47 {
            Err(Error::Argument)
        } else {
            let buf: [u8; 1] = self.read_control(Request::SetTxvgaGain, gain, 0)?;
            if buf[0] == 0 {
                Err(Error::Argument)
            } else {
                Ok(())
            }
        }
    }

    /// Antenna power port control.
    ///
    /// The source docs are a little lacking in terms of explanations here.
    pub fn set_antenna_enable(&mut self, value: u8) -> Result<(), Error> {
        self.write_control(Request::AntennaEnable, value.into(), 0, &[])
    }

    /// CLKOUT enable.
    ///
    /// The source docs are a little lacking in terms of explanations here.
    pub fn set_clkout_enable(&mut self, en: bool) -> Result<(), Error> {
        self.check_api_version(Version::from_bcd(0x0103))?;
        self.write_control(Request::ClkoutEnable, en.into(), 0, &[])
    }

    /// Reset the HackRF radio.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use hackrfone::{HackRfOne, UnknownMode};
    ///
    /// let mut radio: HackRfOne<UnknownMode> = HackRfOne::new().unwrap();
    /// let mut radio: HackRfOne<UnknownMode> = radio.reset()?;
    /// # Ok::<(), hackrfone::Error>(())
    /// ```
    pub fn reset(mut self) -> Result<HackRfOne<UnknownMode>, Error> {
        self.check_api_version(Version::from_bcd(0x0102))?;
        self.write_control(Request::Reset, 0, 0, &[])?;
        Ok(HackRfOne {
            dh: self.dh,
            desc: self.desc,
            mode: UnknownMode,
            to: self.to,
        })
    }

    fn set_transceiver_mode(&mut self, mode: TranscieverMode) -> Result<(), Error> {
        self.write_control(Request::SetTransceiverMode, mode.into(), 0, &[])
    }

    /// Change the radio mode to RX.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use hackrfone::{HackRfOne, RxMode, UnknownMode};
    ///
    /// let mut radio: HackRfOne<UnknownMode> = HackRfOne::new().unwrap();
    /// let mut radio: HackRfOne<RxMode> = radio.into_rx_mode()?;
    /// # Ok::<(), hackrfone::Error>(())
    /// ```
    pub fn into_rx_mode(mut self) -> Result<HackRfOne<RxMode>, Error> {
        self.set_transceiver_mode(TranscieverMode::Receive)?;
        Ok(HackRfOne {
            dh: self.dh,
            desc: self.desc,
            mode: RxMode,
            to: self.to,
        })
    }
}

impl HackRfOne<RxMode> {
    /// Receive data from the radio.
    ///
    /// This uses a bulk transfer to get one MTU (maximum transmission unit)
    /// of data in a single shot.  The data format is pairs of signed 8-bit IQ.
    /// Use the [`iq_to_cplx`] helper to convert the data to a more manageable
    /// format.
    ///
    /// Unlike `libhackrf` this does not spawn a sampling thread.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use hackrfone::{HackRfOne, RxMode, UnknownMode};
    ///
    /// let mut radio: HackRfOne<UnknownMode> = HackRfOne::new().unwrap();
    /// let mut radio: HackRfOne<RxMode> = radio.into_rx_mode()?;
    /// let data: Vec<u8> = radio.rx()?;
    /// radio.stop_rx()?;
    /// # Ok::<(), hackrfone::Error>(())
    /// ```
    ///
    /// [`iq_to_cplx`]: crate::iq_to_cplx
    pub fn rx(&mut self) -> Result<Vec<u8>, Error> {
        const ENDPOINT: u8 = 0x81;
        const MTU: usize = 128 * 1024;
        let mut buf: Vec<u8> = vec![0; MTU];
        let n: usize = self.dh.read_bulk(ENDPOINT, &mut buf, self.to)?;
        buf.truncate(n);
        Ok(buf)
    }

    /// Stop receiving.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use hackrfone::{HackRfOne, RxMode, UnknownMode};
    ///
    /// let mut radio: HackRfOne<UnknownMode> = HackRfOne::new().unwrap();
    /// let mut radio: HackRfOne<RxMode> = radio.into_rx_mode()?;
    /// let data: Vec<u8> = radio.rx()?;
    /// radio.stop_rx()?;
    /// # Ok::<(), hackrfone::Error>(())
    /// ```
    pub fn stop_rx(mut self) -> Result<HackRfOne<UnknownMode>, Error> {
        self.set_transceiver_mode(TranscieverMode::Off)?;
        Ok(HackRfOne {
            dh: self.dh,
            desc: self.desc,
            mode: UnknownMode,
            to: self.to,
        })
    }
}

// Helper for set_freq
fn freq_params(hz: u64) -> [u8; 8] {
    const MHZ: u64 = 1_000_000;

    let l_freq_mhz: u32 = u32::try_from(hz / MHZ).unwrap_or(u32::MAX).to_le();
    let l_freq_hz: u32 = u32::try_from(hz - u64::from(l_freq_mhz) * MHZ)
        .unwrap_or(u32::MAX)
        .to_le();

    [
        (l_freq_mhz & 0xFF) as u8,
        ((l_freq_mhz >> 8) & 0xFF) as u8,
        ((l_freq_mhz >> 16) & 0xFF) as u8,
        ((l_freq_mhz >> 24) & 0xFF) as u8,
        (l_freq_hz & 0xFF) as u8,
        ((l_freq_hz >> 8) & 0xFF) as u8,
        ((l_freq_hz >> 16) & 0xFF) as u8,
        ((l_freq_hz >> 24) & 0xFF) as u8,
    ]
}

#[cfg(test)]
mod freq_params {
    use super::freq_params;

    #[test]
    fn nominal() {
        assert_eq!(freq_params(915_000_000), [0x93, 0x03, 0, 0, 0, 0, 0, 0]);
        assert_eq!(freq_params(915_000_001), [0x93, 0x03, 0, 0, 1, 0, 0, 0]);
        assert_eq!(
            freq_params(123456789),
            [0x7B, 0, 0, 0, 0x55, 0xF8, 0x06, 0x00]
        );
    }

    #[test]
    fn min() {
        assert_eq!(freq_params(0), [0; 8]);
    }

    #[test]
    fn max() {
        assert_eq!(freq_params(u64::MAX), [0xFF; 8]);
    }
}

/// Convert an IQ sample pair to a complex number.
///
/// # Example
///
/// Post-processing sample data.
///
/// ```no_run
/// use hackrfone::{iq_to_cplx, HackRfOne, RxMode, UnknownMode};
///
/// let mut radio: HackRfOne<UnknownMode> = HackRfOne::new().unwrap();
/// let mut radio: HackRfOne<RxMode> = radio.into_rx_mode()?;
/// let data: Vec<u8> = radio.rx()?;
/// radio.stop_rx()?;
///
/// for iq in data.chunks_exact(2) {
///     let cplx: num_complex::Complex32 = iq_to_cplx(iq[0], iq[1]);
///     // .. do whatever you want with cplx here
/// }
///
/// # Ok::<(), hackrfone::Error>(())
/// ```
///
/// Guide level explanation.
///
/// ```
/// use hackrfone::iq_to_cplx;
/// use num_complex::Complex32;
///
/// assert_eq!(iq_to_cplx(255, 1), Complex32::new(-1.0, 1.0));
/// ```
#[cfg(feature = "num-complex")]
#[cfg_attr(docsrs, doc(cfg(feature = "num-complex")))]
pub fn iq_to_cplx(i: u8, q: u8) -> num_complex::Complex32 {
    num_complex::Complex32::new(f32::from(i as i8), f32::from(q as i8))
}