//
// Copyright 2010-2012 Ettus Research LLC
// Copyright 2018 Ettus Research, a National Instruments Company
//
// SPDX-License-Identifier: GPL-3.0-or-later
//

#include <uhd/exception.hpp>
#include <uhd/transport/usb_control.hpp>
#include <uhd/utils/log.hpp>
#include <uhdlib/usrp/common/fx2_ctrl.hpp>
#include <stdint.h>
#include <boost/functional/hash.hpp>
#include <chrono>
#include <cstring>
#include <fstream>
#include <sstream>
#include <string>
#include <thread>
#include <vector>

using namespace uhd;
using namespace uhd::usrp;

#define FX2_FIRMWARE_LOAD 0xa0

static const bool load_img_msg = true;

typedef uint32_t hash_type;

/***********************************************************************
 * Helper Functions
 **********************************************************************/
/*!
 * Create a file hash
 * The hash will be used to identify the loaded firmware and fpga image
 * \param filename file used to generate hash value
 * \return hash value in a size_t type
 */
static hash_type generate_hash(const char* filename)
{
    std::ifstream file(filename);
    if (not file) {
        throw uhd::io_error(std::string("cannot open input file ") + filename);
    }

    size_t hash = 0;

    char ch;
    while (file.get(ch)) {
        boost::hash_combine(hash, ch);
    }

    if (not file.eof()) {
        throw uhd::io_error(std::string("file error ") + filename);
    }

    file.close();
    return hash_type(hash);
}


/*!
 * Verify checksum of a Intel HEX record
 * \param record a line from an Intel HEX file
 * \return true if record is valid, false otherwise
 */
static bool checksum(std::string* record)
{
    size_t len = record->length();
    unsigned int i;
    unsigned char sum = 0;
    unsigned int val;

    for (i = 1; i < len; i += 2) {
        std::istringstream(record->substr(i, 2)) >> std::hex >> val;
        sum += val;
    }

    if (sum == 0)
        return true;
    else
        return false;
}


/*!
 * Parse Intel HEX record
 *
 * \param record a line from an Intel HEX file
 * \param len output length of record
 * \param addr output address
 * \param type output type
 * \param data output data
 * \return true if record is sucessfully read, false on error
 */
bool parse_record(std::string* record,
    unsigned int& len,
    unsigned int& addr,
    unsigned int& type,
    unsigned char* data)
{
    unsigned int i;
    std::string _data;
    unsigned int val;

    if (record->substr(0, 1) != ":")
        return false;

    std::istringstream(record->substr(1, 2)) >> std::hex >> len;
    std::istringstream(record->substr(3, 4)) >> std::hex >> addr;
    std::istringstream(record->substr(7, 2)) >> std::hex >> type;

    if (len > (2 * (record->length() - 9))) // sanity check to prevent buffer overrun
        return false;

    for (i = 0; i < len; i++) {
        std::istringstream(record->substr(9 + 2 * i, 2)) >> std::hex >> val;
        data[i] = (unsigned char)val;
    }

    return true;
}


/*!
 * USRP control implementation for device discovery and configuration
 */
class fx2_ctrl_impl : public fx2_ctrl
{
public:
    fx2_ctrl_impl(uhd::transport::usb_control::sptr ctrl_transport)
    {
        _ctrl_transport = ctrl_transport;
    }

    void usrp_fx2_reset(void) override
    {
        unsigned char reset_y = 1;
        unsigned char reset_n = 0;
        usrp_control_write(FX2_FIRMWARE_LOAD, 0xe600, 0, &reset_y, 1);
        usrp_control_write(FX2_FIRMWARE_LOAD, 0xe600, 0, &reset_n, 1);
        // wait for things to settle
        std::this_thread::sleep_for(std::chrono::milliseconds(2000));
    }

    void usrp_load_firmware(std::string filestring, bool force) override
    {
        const char* filename = filestring.c_str();

        hash_type hash = generate_hash(filename);

        hash_type loaded_hash;
        usrp_get_firmware_hash(loaded_hash);

        if (not force and (hash == loaded_hash))
            return;

        // FIXME: verify types
        unsigned int len;
        unsigned int addr;
        unsigned int type;
        unsigned char data[512];

        std::ifstream file;
        file.open(filename, std::ifstream::in);

        if (!file.good()) {
            throw uhd::io_error("usrp_load_firmware: cannot open firmware input file");
        }

        unsigned char reset_y = 1;
        unsigned char reset_n = 0;

        // hit the reset line
        if (load_img_msg)
            UHD_LOGGER_INFO("FX2") << "Loading firmware image: " << filestring << "...";
        usrp_control_write(FX2_FIRMWARE_LOAD, 0xe600, 0, &reset_y, 1);

        while (!file.eof()) {
            std::string record;
            file >> record;

            if (!(record.length() > 0))
                continue;

            // check for valid record
            if (not checksum(&record)
                or not parse_record(&record, len, addr, type, data)) {
                throw uhd::io_error("usrp_load_firmware: bad record checksum");
            }

            // type 0x00 is data
            if (type == 0x00) {
                int ret = usrp_control_write(FX2_FIRMWARE_LOAD, addr, 0, data, len);
                if (ret < 0)
                    throw uhd::io_error("usrp_load_firmware: usrp_control_write failed");
            }
            // type 0x01 is end
            else if (type == 0x01) {
                usrp_set_firmware_hash(hash); // set hash before reset
                usrp_control_write(FX2_FIRMWARE_LOAD, 0xe600, 0, &reset_n, 1);
                file.close();

                // wait for things to settle
                std::this_thread::sleep_for(std::chrono::milliseconds(1000));
                if (load_img_msg)
                    UHD_LOGGER_INFO("FX2") << "Firmware loaded";
                return;
            }
            // type anything else is unhandled
            else {
                throw uhd::io_error("usrp_load_firmware: unsupported record");
            }
        }

        // file did not end
        throw uhd::io_error("usrp_load_firmware: bad record");
    }

    void usrp_init(void) override
    {
        // disable
        usrp_rx_enable(false);
        usrp_tx_enable(false);

        // toggle resets
        usrp_rx_reset(true);
        usrp_tx_reset(true);
        usrp_rx_reset(false);
        usrp_tx_reset(false);
    }

    void usrp_load_fpga(std::string filestring) override
    {
        const char* filename = filestring.c_str();

        hash_type hash = generate_hash(filename);

        hash_type loaded_hash;
        usrp_get_fpga_hash(loaded_hash);

        if (hash == loaded_hash)
            return;
        const int ep0_size = 64;
        unsigned char buf[ep0_size];

        if (load_img_msg)
            UHD_LOGGER_INFO("FX2") << "Loading FPGA image: " << filestring << "...";
        std::ifstream file;
        file.open(filename, std::ios::in | std::ios::binary);
        if (not file.good()) {
            throw uhd::io_error("usrp_load_fpga: cannot open fpga input file");
        }

        usrp_fpga_reset(true); // holding the fpga in reset while loading

        if (usrp_control_write_cmd(VRQ_FPGA_LOAD, 0, FL_BEGIN) < 0) {
            throw uhd::io_error("usrp_load_fpga: fpga load error");
        }

        while (not file.eof()) {
            file.read((char*)buf, sizeof(buf));
            const std::streamsize n = file.gcount();
            if (n == 0)
                continue;
            int ret = usrp_control_write(VRQ_FPGA_LOAD, 0, FL_XFER, buf, uint16_t(n));
            if (ret < 0 or std::streamsize(ret) != n) {
                throw uhd::io_error("usrp_load_fpga: fpga load error");
            }
        }

        if (usrp_control_write_cmd(VRQ_FPGA_LOAD, 0, FL_END) < 0) {
            throw uhd::io_error("usrp_load_fpga: fpga load error");
        }

        usrp_set_fpga_hash(hash);

        usrp_fpga_reset(false); // done loading, take fpga out of reset

        file.close();
        if (load_img_msg)
            UHD_LOGGER_INFO("FX2") << "FPGA image loaded";
    }

    void usrp_load_eeprom(std::string filestring) override
    {
        if (load_img_msg)
            UHD_LOGGER_INFO("FX2") << "Loading EEPROM image: " << filestring << "...";
        const char* filename    = filestring.c_str();
        const uint16_t i2c_addr = 0x50;

        unsigned int addr;
        unsigned char data[256];
        unsigned char sendbuf[17];

        std::ifstream file;
        file.open(filename, std::ifstream::in);

        if (not file.good()) {
            throw uhd::io_error("usrp_load_eeprom: cannot open EEPROM input file");
        }

        file.read((char*)data, 256);
        std::streamsize len = file.gcount();

        if (len == 256) {
            throw uhd::io_error("usrp_load_eeprom: image size too large");
        }

        const int pagesize = 16;
        addr               = 0;
        while (len > 0) {
            sendbuf[0] = addr;
            memcpy(sendbuf + 1, &data[addr], len > pagesize ? pagesize : size_t(len));
            int ret = usrp_i2c_write(
                i2c_addr, sendbuf, (len > pagesize ? pagesize : size_t(len)) + 1);
            if (ret < 0) {
                throw uhd::io_error("usrp_load_eeprom: usrp_i2c_write failed");
            }
            addr += pagesize;
            len -= pagesize;
            std::this_thread::sleep_for(std::chrono::milliseconds(100));
        }
        file.close();
        if (load_img_msg)
            UHD_LOGGER_INFO("FX2") << "EEPROM image loaded";
    }


    void usrp_set_led(int led_num, bool on)
    {
        UHD_ASSERT_THROW(usrp_control_write_cmd(VRQ_SET_LED, on, led_num) >= 0);
    }


    void usrp_get_firmware_hash(hash_type& hash)
    {
        UHD_ASSERT_THROW(
            usrp_control_read(
                0xa0, USRP_HASH_SLOT_0_ADDR, 0, (unsigned char*)&hash, sizeof(hash))
            >= 0);
    }


    void usrp_set_firmware_hash(hash_type hash)
    {
        UHD_ASSERT_THROW(
            usrp_control_write(
                0xa0, USRP_HASH_SLOT_0_ADDR, 0, (unsigned char*)&hash, sizeof(hash))
            >= 0);
    }


    void usrp_get_fpga_hash(hash_type& hash)
    {
        UHD_ASSERT_THROW(
            usrp_control_read(
                0xa0, USRP_HASH_SLOT_1_ADDR, 0, (unsigned char*)&hash, sizeof(hash))
            >= 0);
    }


    void usrp_set_fpga_hash(hash_type hash)
    {
        UHD_ASSERT_THROW(
            usrp_control_write(
                0xa0, USRP_HASH_SLOT_1_ADDR, 0, (unsigned char*)&hash, sizeof(hash))
            >= 0);
    }

    void usrp_tx_enable(bool on) override
    {
        UHD_ASSERT_THROW(usrp_control_write_cmd(VRQ_FPGA_SET_TX_ENABLE, on, 0) >= 0);
    }


    void usrp_rx_enable(bool on) override
    {
        UHD_ASSERT_THROW(usrp_control_write_cmd(VRQ_FPGA_SET_RX_ENABLE, on, 0) >= 0);
    }


    void usrp_tx_reset(bool on)
    {
        UHD_ASSERT_THROW(usrp_control_write_cmd(VRQ_FPGA_SET_TX_RESET, on, 0) >= 0);
    }


    void usrp_rx_reset(bool on)
    {
        UHD_ASSERT_THROW(usrp_control_write_cmd(VRQ_FPGA_SET_RX_RESET, on, 0) >= 0);
    }

    void usrp_fpga_reset(bool on) override
    {
        UHD_ASSERT_THROW(usrp_control_write_cmd(VRQ_FPGA_SET_RESET, on, 0) >= 0);
    }

    int usrp_control_write(uint8_t request,
        uint16_t value,
        uint16_t index,
        unsigned char* buff,
        uint16_t length) override
    {
        return _ctrl_transport->submit(VRT_VENDOR_OUT, // bmReqeustType
            request, // bRequest
            value, // wValue
            index, // wIndex
            buff, // data
            length); // wLength
    }


    int usrp_control_read(uint8_t request,
        uint16_t value,
        uint16_t index,
        unsigned char* buff,
        uint16_t length) override
    {
        return _ctrl_transport->submit(VRT_VENDOR_IN, // bmReqeustType
            request, // bRequest
            value, // wValue
            index, // wIndex
            buff, // data
            length); // wLength
    }


    int usrp_control_write_cmd(uint8_t request, uint16_t value, uint16_t index)
    {
        return usrp_control_write(request, value, index, 0, 0);
    }

    byte_vector_t read_eeprom(uint16_t addr, uint16_t offset, size_t num_bytes) override
    {
        this->write_i2c(addr, byte_vector_t(1, uint8_t(offset)));
        return this->read_i2c(addr, num_bytes);
    }

    int usrp_i2c_write(uint16_t i2c_addr, unsigned char* buf, uint16_t len) override
    {
        return usrp_control_write(VRQ_I2C_WRITE, i2c_addr, 0, buf, len);
    }

    int usrp_i2c_read(uint16_t i2c_addr, unsigned char* buf, uint16_t len) override
    {
        return usrp_control_read(VRQ_I2C_READ, i2c_addr, 0, buf, len);
    }

    static const bool iface_debug          = false;
    static const size_t max_i2c_data_bytes = 64;

    void write_i2c(uint16_t addr, const byte_vector_t& bytes) override
    {
        UHD_ASSERT_THROW(bytes.size() < max_i2c_data_bytes);

        int ret =
            this->usrp_i2c_write(addr, (unsigned char*)&bytes.front(), bytes.size());

        if (iface_debug && (ret < 0))
            uhd::runtime_error("USRP: failed i2c write");
    }

    byte_vector_t read_i2c(uint16_t addr, size_t num_bytes) override
    {
        UHD_ASSERT_THROW(num_bytes < max_i2c_data_bytes);

        byte_vector_t bytes(num_bytes);
        int ret = this->usrp_i2c_read(addr, (unsigned char*)&bytes.front(), num_bytes);

        if (iface_debug && ((ret < 0) || (unsigned)ret < (num_bytes)))
            uhd::runtime_error("USRP: failed i2c read");

        return bytes;
    }


private:
    uhd::transport::usb_control::sptr _ctrl_transport;
};

/***********************************************************************
 * Public make function for fx2_ctrl interface
 **********************************************************************/
fx2_ctrl::sptr fx2_ctrl::make(uhd::transport::usb_control::sptr ctrl_transport)
{
    return sptr(new fx2_ctrl_impl(ctrl_transport));
}