adb_client 3.1.0

use std::{sync::Arc, time::Duration};

use rusb::{
    Device, DeviceHandle, Direction, GlobalContext, TransferType,
    constants::LIBUSB_CLASS_VENDOR_SPEC,
};

use crate::{
    Result, RustADBError,
    adb_transport::ADBTransport,
    message_devices::{
        adb_message_transport::ADBMessageTransport,
        adb_transport_message::{ADBTransportMessage, ADBTransportMessageHeader},
        message_commands::MessageCommand,
    },
};

#[derive(Clone, Debug)]
struct Endpoint {
    iface: u8,
    address: u8,
    max_packet_size: usize,
}

/// Transport running on USB
#[derive(Debug, Clone)]
pub struct USBTransport {
    device: Device<GlobalContext>,
    handle: Option<Arc<DeviceHandle<GlobalContext>>>,
    read_endpoint: Option<Endpoint>,
    write_endpoint: Option<Endpoint>,
}

impl USBTransport {
    /// Instantiate a new [`USBTransport`].
    /// Only the first device with given `vendor_id` and `product_id` is returned.
    pub fn new(vendor_id: u16, product_id: u16) -> Result<Self> {
        for device in rusb::devices()?.iter() {
            if let Ok(descriptor) = device.device_descriptor()
                && descriptor.vendor_id() == vendor_id
                && descriptor.product_id() == product_id
            {
                return Ok(Self::new_from_device(device));
            }
        }

        Err(RustADBError::DeviceNotFound(format!(
            "cannot find USB device with vendor_id={vendor_id} and product_id={product_id}",
        )))
    }

    /// Instantiate a new [`USBTransport`] from a [`rusb::Device`].
    ///
    /// Devices can be enumerated using [`rusb::devices()`] and then filtered out to get desired device.
    #[must_use]
    pub fn new_from_device(rusb_device: rusb::Device<GlobalContext>) -> Self {
        Self {
            device: rusb_device,
            handle: None,
            read_endpoint: None,
            write_endpoint: None,
        }
    }

    pub(crate) fn get_raw_connection(&self) -> Result<Arc<DeviceHandle<GlobalContext>>> {
        self.handle
            .as_ref()
            .ok_or(RustADBError::IOError(std::io::Error::new(
                std::io::ErrorKind::NotConnected,
                "not connected",
            )))
            .cloned()
    }

    fn get_read_endpoint(&self) -> Result<Endpoint> {
        self.read_endpoint
            .as_ref()
            .ok_or(RustADBError::IOError(std::io::Error::new(
                std::io::ErrorKind::NotConnected,
                "no read endpoint setup",
            )))
            .cloned()
    }

    fn get_write_endpoint(&self) -> Result<&Endpoint> {
        self.write_endpoint
            .as_ref()
            .ok_or(RustADBError::IOError(std::io::Error::new(
                std::io::ErrorKind::NotConnected,
                "no write endpoint setup",
            )))
    }

    fn configure_endpoint(handle: &DeviceHandle<GlobalContext>, endpoint: &Endpoint) -> Result<()> {
        match handle.claim_interface(endpoint.iface) {
            Ok(()) => Ok(()),
            // busy state likely indicates an ADB server is running and has taken the lock over the device
            Err(rusb::Error::Busy) => Err(RustADBError::DeviceBusy),
            Err(err) => Err(err.into()),
        }
    }

    fn find_endpoints(handle: &DeviceHandle<GlobalContext>) -> Result<(Endpoint, Endpoint)> {
        let mut read_endpoint: Option<Endpoint> = None;
        let mut write_endpoint: Option<Endpoint> = None;

        for n in 0..handle.device().device_descriptor()?.num_configurations() {
            let Ok(config_desc) = handle.device().config_descriptor(n) else {
                continue;
            };

            for interface in config_desc.interfaces() {
                for interface_desc in interface.descriptors() {
                    for endpoint_desc in interface_desc.endpoint_descriptors() {
                        if endpoint_desc.transfer_type() == TransferType::Bulk
                            && interface_desc.class_code() == LIBUSB_CLASS_VENDOR_SPEC
                            && interface_desc.sub_class_code() == 0x42
                            && interface_desc.protocol_code() == 0x01
                        {
                            let endpoint = Endpoint {
                                iface: interface_desc.interface_number(),
                                address: endpoint_desc.address(),
                                max_packet_size: endpoint_desc.max_packet_size() as usize,
                            };
                            match endpoint_desc.direction() {
                                Direction::In => {
                                    if let Some(write_endpoint) = write_endpoint {
                                        return Ok((endpoint, write_endpoint));
                                    }
                                    read_endpoint = Some(endpoint);
                                }
                                Direction::Out => {
                                    if let Some(read_endpoint) = read_endpoint {
                                        return Ok((read_endpoint, endpoint));
                                    }
                                    write_endpoint = Some(endpoint);
                                }
                            }
                        }
                    }
                }
            }
        }

        Err(RustADBError::USBNoDescriptorFound)
    }

    fn write_bulk_data(&self, data: &[u8], timeout: Duration) -> Result<()> {
        let endpoint = self.get_write_endpoint()?;
        let handle = self.get_raw_connection()?;
        let max_packet_size = endpoint.max_packet_size;

        let mut offset = 0;
        let data_len = data.len();
        while offset < data_len {
            let end = (offset + max_packet_size).min(data_len);
            let write_amount = handle.write_bulk(endpoint.address, &data[offset..end], timeout)?;
            offset += write_amount;

            log::trace!("wrote chunk of size {write_amount} - {offset}/{data_len}",);
        }

        if offset % max_packet_size == 0 {
            log::trace!("must send final zero-length packet");
            handle.write_bulk(endpoint.address, &[], timeout)?;
        }

        Ok(())
    }
}

impl ADBTransport for USBTransport {
    fn connect(&mut self) -> crate::Result<()> {
        let device = self.device.open()?;

        let (read_endpoint, write_endpoint) = Self::find_endpoints(&device)?;

        Self::configure_endpoint(&device, &read_endpoint)?;
        log::debug!("got read endpoint: {read_endpoint:?}");
        self.read_endpoint = Some(read_endpoint);

        Self::configure_endpoint(&device, &write_endpoint)?;
        log::debug!("got write endpoint: {write_endpoint:?}");
        self.write_endpoint = Some(write_endpoint);

        self.handle = Some(Arc::new(device));

        Ok(())
    }

    fn disconnect(&mut self) -> crate::Result<()> {
        if self.handle.is_none() {
            // device has not been initialized, nothing to do
            return Ok(());
        }

        let message = ADBTransportMessage::try_new(MessageCommand::Clse, 0, 0, &[])?;
        if let Err(e) = self.write_message(message) {
            log::error!("error while sending CLSE message: {e}");
        }

        if let Some(handle) = &self.handle {
            let endpoint = self.read_endpoint.as_ref().or(self.write_endpoint.as_ref());
            if let Some(endpoint) = &endpoint {
                match handle.release_interface(endpoint.iface) {
                    Ok(()) => log::debug!("succesfully released interface"),
                    Err(e) => log::error!("error while release interface: {e}"),
                }
            }
        }

        Ok(())
    }
}

impl ADBMessageTransport for USBTransport {
    fn write_message_with_timeout(
        &mut self,
        message: ADBTransportMessage,
        timeout: Duration,
    ) -> Result<()> {
        let message_bytes = message.header().as_bytes();
        self.write_bulk_data(&message_bytes, timeout)?;

        log::trace!("successfully write header: {} bytes", message_bytes.len());

        let payload = message.into_payload();
        if !payload.is_empty() {
            self.write_bulk_data(&payload, timeout)?;
            log::trace!("successfully write payload: {} bytes", payload.len());
        }

        Ok(())
    }

    fn read_message_with_timeout(&mut self, timeout: Duration) -> Result<ADBTransportMessage> {
        let endpoint = self.get_read_endpoint()?;
        let handle = self.get_raw_connection()?;
        let max_packet_size = endpoint.max_packet_size;

        let mut data = [0u8; 24];
        let mut offset = 0;
        while offset < data.len() {
            let end = (offset + max_packet_size).min(data.len());
            let chunk = &mut data[offset..end];
            offset += handle.read_bulk(endpoint.address, chunk, timeout)?;
        }

        let header = ADBTransportMessageHeader::try_from(data)?;
        log::trace!("received header {header:?}");

        if header.data_length() != 0 {
            let mut msg_data = vec![0_u8; header.data_length() as usize];
            let mut offset = 0;
            while offset < msg_data.len() {
                let end = (offset + max_packet_size).min(msg_data.len());
                let chunk = &mut msg_data[offset..end];
                offset += handle.read_bulk(endpoint.address, chunk, timeout)?;
            }

            let message = ADBTransportMessage::from_header_and_payload(header, msg_data);

            // Check message integrity
            if !message.check_message_integrity() {
                return Err(RustADBError::InvalidIntegrity(
                    ADBTransportMessageHeader::compute_crc32(message.payload()),
                    message.header().data_crc32(),
                ));
            }

            return Ok(message);
        }

        Ok(ADBTransportMessage::from_header_and_payload(header, vec![]))
    }
}