#include "UsbInterface.hpp"

#include <limits>

#include "src/Logger/Logger.hpp"

#include "src/TargetController/Exceptions/DeviceInitializationFailure.hpp"
#include "src/TargetController/Exceptions/DeviceCommunicationFailure.hpp"

namespace Usb
{
    using namespace Exceptions;

    UsbInterface::UsbInterface(
        std::uint8_t interfaceNumber,
        ::libusb_device_handle* deviceHandle
    )
        : interfaceNumber(interfaceNumber)
        , deviceHandle(deviceHandle)
    {}

    void UsbInterface::init() {
        Logger::debug("Claiming USB interface (number: " + std::to_string(this->interfaceNumber) + ")");

        const auto statusCode = ::libusb_claim_interface(this->deviceHandle, this->interfaceNumber);
        if (statusCode != 0) {
            throw DeviceInitializationFailure(
                "Failed to claim USB interface (number: " + std::to_string(this->interfaceNumber) + ") - error code: "
                    + std::to_string(statusCode)
            );
        }

        this->claimed = true;
    }

    void UsbInterface::close() {
        if (this->claimed) {
            const auto statusCode = ::libusb_release_interface(this->deviceHandle, this->interfaceNumber);
            if (statusCode != 0) {
                Logger::error(
                    "Failed to release USB interface (number: " + std::to_string(this->interfaceNumber)
                        + ") - error code: " + std::to_string(statusCode)
                );
            }
        }
    }

    std::vector<unsigned char> UsbInterface::readBulk(
        std::uint8_t endpointAddress,
        std::optional<std::chrono::milliseconds> timeout
    ) {
        auto output = std::vector<unsigned char>();

        constexpr auto transferSize = 512;
        auto bytesTransferred = int(0);
        auto totalByteCount = std::size_t(0);

        do {
            output.resize(totalByteCount + transferSize, 0x00);

            const auto statusCode = ::libusb_bulk_transfer(
                this->deviceHandle,
                endpointAddress,
                output.data() + totalByteCount,
                transferSize,
                &bytesTransferred,
                timeout.has_value() ? static_cast<unsigned int>(timeout->count()) : 0
            );

            if (statusCode != 0) {
                throw DeviceCommunicationFailure("Failed to read from bulk endpoint");
            }

            if (totalByteCount == 0) {
                // After the first read, set the timeout to 1 millisecond, as we don't want to wait for subsequent data
                timeout = std::chrono::milliseconds(1);
            }

            totalByteCount += static_cast<std::size_t>(bytesTransferred);

        } while (bytesTransferred >= transferSize);

        output.resize(totalByteCount, 0x00);
        return output;
    }

    void UsbInterface::writeBulk(std::uint8_t endpointAddress, std::vector<unsigned char>&& buffer) {
        if (buffer.size() > std::numeric_limits<int>::max()) {
            throw DeviceCommunicationFailure("Attempted to send too much data to bulk endpoint");
        }

        const auto length = static_cast<int>(buffer.size());
        auto bytesTransferred = int(0);

        const auto statusCode = ::libusb_bulk_transfer(
            this->deviceHandle,
            endpointAddress,
            buffer.data(),
            length,
            &bytesTransferred,
            0
        );

        if (statusCode != 0 || bytesTransferred != length) {
            Logger::debug(
                "Attempted to write " + std::to_string(length) + " bytes to USB bulk endpoint. Bytes written: "
                    + std::to_string(bytesTransferred) + ". Status code: " + std::to_string(statusCode)
            );
            throw DeviceCommunicationFailure("Failed to write data to bulk endpoint");
        }
    }
}