//
// Copyright 2010-2013 Ettus Research LLC
// Copyright 2018 Ettus Research, a National Instruments Company
//
// SPDX-License-Identifier: GPL-3.0-or-later
//

#pragma once

#include <uhd/config.hpp>
#include <cstddef>
#include <cstdint>
#include <memory>
#include <string>
#include <vector>

namespace uhd {

/*!
 * Byte vector typedef for passing data in and out of I2C interfaces.
 */
typedef std::vector<uint8_t> byte_vector_t;

/*!
 * The i2c interface class:
 * Provides i2c and eeprom functionality.
 * A subclass should only have to implement the i2c routines.
 * An eeprom implementation comes for free with the interface.
 *
 * The eeprom routines are implemented on top of i2c.
 * The built in eeprom implementation only does single
 * byte reads and byte writes over the i2c interface,
 * so it should be portable across multiple eeproms.
 * Override the eeprom routines if this is not acceptable.
 */
class UHD_API i2c_iface
{
public:
    typedef std::shared_ptr<i2c_iface> sptr;

    virtual ~i2c_iface(void);

    //! Create an i2c_iface than can talk to 16 bit addressable EEPROMS
    i2c_iface::sptr eeprom16(void);

    /*!
     * Write bytes over the i2c.
     * \param addr the address
     * \param buf the vector of bytes
     */
    virtual void write_i2c(uint16_t addr, const byte_vector_t& buf) = 0;

    /*!
     * Read bytes over the i2c.
     * \param addr the address
     * \param num_bytes number of bytes to read
     * \return a vector of bytes
     */
    virtual byte_vector_t read_i2c(uint16_t addr, size_t num_bytes) = 0;

    /*!
     * Write bytes to an eeprom.
     * \param addr the address
     * \param offset byte offset
     * \param buf the vector of bytes
     */
    virtual void write_eeprom(uint16_t addr, uint16_t offset, const byte_vector_t& buf);

    /*!
     * Read bytes from an eeprom.
     * \param addr the address
     * \param offset byte offset
     * \param num_bytes number of bytes to read
     * \return a vector of bytes
     */
    virtual byte_vector_t read_eeprom(uint16_t addr, uint16_t offset, size_t num_bytes);
};

/*!
 * The SPI configuration struct:
 * Used to configure a SPI transaction interface.
 */
struct UHD_API spi_config_t
{
    /*!
     * The edge type specifies when data is valid
     * relative to the edge of the serial clock.
     */
    enum edge_t : uint32_t { EDGE_RISE = 'r', EDGE_FALL = 'f' };

    //! on what edge is the mosi data valid?
    edge_t mosi_edge;

    //! on what edge is the miso data valid?
    edge_t miso_edge;

    //! Set the clock speed for this transaction
    bool use_custom_divider;

    //! Optionally set the SPI clock divider for this transaction
    size_t divider;

    /*!
     * Create a new spi config.
     * \param edge the default edge for mosi and miso
     */
    spi_config_t(edge_t edge = EDGE_RISE);

    /*!
     * Create a new spi config with custom divider.
     * \param edge the default edge for mosi and miso
     * \param divider the divider setting to use
     */
    spi_config_t(edge_t edge, size_t divider);
};

/*!
 * The SPI interface class.
 * Provides routines to transact SPI and do other useful things which haven't been defined
 * yet.
 */
class UHD_API spi_iface
{
public:
    typedef std::shared_ptr<spi_iface> sptr;

    virtual ~spi_iface(void);

    /*!
     * Perform a spi transaction.
     * \param which_slave the slave device number
     * \param config spi config args
     * \param data the bits to write
     * \param num_bits how many bits in data
     * \param readback true to readback a value
     * \return spi data if readback set
     */
    virtual uint32_t transact_spi(int which_slave,
        const spi_config_t& config,
        uint32_t data,
        size_t num_bits,
        bool readback) = 0;

    /*!
     * Read from the SPI bus.
     * \param which_slave the slave device number
     * \param config spi config args
     * \param data the bits to write out (be sure to set write bit)
     * \param num_bits how many bits in data
     * \return spi data
     */
    virtual uint32_t read_spi(
        int which_slave, const spi_config_t& config, uint32_t data, size_t num_bits);

    /*!
     * Write to the SPI bus.
     * \param which_slave the slave device number
     * \param config spi config args
     * \param data the bits to write
     * \param num_bits how many bits in data
     */
    virtual void write_spi(
        int which_slave, const spi_config_t& config, uint32_t data, size_t num_bits);
};

/*!
 * UART interface to write and read strings.
 */
class UHD_API uart_iface
{
public:
    typedef std::shared_ptr<uart_iface> sptr;

    virtual ~uart_iface(void);

    /*!
     * Write to a serial port.
     * \param buf the data to write
     */
    virtual void write_uart(const std::string& buf) = 0;

    /*!
     * Read a line from a serial port.
     * \param timeout the timeout in seconds
     * \return the line or empty string upon timeout
     */
    virtual std::string read_uart(double timeout) = 0;
};

} // namespace uhd
