/*
 * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#pragma once

#include "esp_err.h"
#include "esp_openthread_types.h"
#include "driver/spi_master.h"
#include "lib/spinel/spinel_interface.hpp"

namespace esp {
namespace openthread {

class SpiSpinelInterface : public ot::Spinel::SpinelInterface {
public:
    /**
     * @brief   This constructor of object.
     */
    SpiSpinelInterface();

    /**
     * @brief   This destructor of the object.
     *
     */
    ~SpiSpinelInterface(void);

    /**
     * Initializes the interface to the Radio Co-processor (RCP).
     *
     * @note This method should be called before reading and sending spinel frames to the interface.
     *
     * @param[in] aCallback         Callback on frame received
     * @param[in] aCallbackContext  Callback context
     * @param[in] aFrameBuffer      A reference to a `RxFrameBuffer` object.
     *
     * @retval OT_ERROR_NONE       The interface is initialized successfully
     * @retval OT_ERROR_ALREADY    The interface is already initialized.
     * @retval OT_ERROR_FAILED     Failed to initialize the interface.
     *
     */
    otError Init(ReceiveFrameCallback aCallback, void *aCallbackContext, RxFrameBuffer &aFrameBuffer);

    /**
     * Deinitializes the interface to the RCP.
     *
     */
    void Deinit(void);

    /**
     * @brief   This method encodes and sends a spinel frame to Radio Co-processor (RCP) over the socket.
     *
     * @param[in] frame     A pointer to buffer containing the spinel frame to send.
     * @param[in] length    The length (number of bytes) in the frame.
     *
     * @return
     *      -OT_ERROR_NONE     Successfully encoded and sent the spinel frame.
     *      -OT_ERROR_NO_BUFS  Insufficient buffer space available to encode the frame.
     *      -OT_ERROR_FAILED   Failed to send due to socket not becoming writable within `kMaxWaitTime`.
     *
     */
    otError SendFrame(const uint8_t *frame, uint16_t length);

    /**
     * This method waits for receiving part or all of spinel frame within specified timeout.
     *
     * @param[in]  timeout_us  The timeout value in microseconds.
     *
     * @return
     *      -OT_ERROR_NONE             Part or all of spinel frame is received.
     *      -OT_ERROR_RESPONSE_TIMEOUT No spinel frame is received within @p timeout_us.
     *
     */
    otError WaitForFrame(uint64_t timeout_us);

    /**
     * Updates the file descriptor sets with file descriptors used by the radio driver.
     *
     * @param[in,out]   aMainloopContext  A pointer to the mainloop context.
     *
     */
    void UpdateFdSet(void *aMainloopContext);

    /**
     * Performs radio driver processing.
     *
     * @param[in]   aMainloopContext  A pointer to the mainloop context.
     *
     */
    void Process(const void *aMainloopContext);

    /**
     * Returns the bus speed between the host and the radio.
     *
     * @returns   Bus speed in bits/second.
     *
     */
    uint32_t GetBusSpeed(void) const;

    /**
     * This method is called when RCP failure detected and resets internal states of the interface.
     *
     */
    otError HardwareReset(void);

    /**
     * Returns the RCP interface metrics.
     *
     * @returns The RCP interface metrics.
     *
     */
    const otRcpInterfaceMetrics *GetRcpInterfaceMetrics(void) const { return &mInterfaceMetrics; }

    /**
     * This methods registers the callback for RCP failure.
     *
     * @param[in] handler   The RCP failure handler.
     *
     */
    void RegisterRcpFailureHandler(esp_openthread_rcp_failure_handler handler) { mRcpFailureHandler = handler; }

    /**
     * This method is called when RCP is reset to recreate the connection with it.
     * Intentionally empty.
     *
     */
    otError ResetConnection(void) { return OT_ERROR_NONE; }

    /**
     * @brief   This method enable the spinel interface.
     *
     * @return
     *      - ESP_OK on success
     *      - ESP_ERR_INVALID_STATE if already initialized
     *      - ESP_ERR_NO_MEM if allocation has failed
     *      - ESP_FAIL on failure
     */
    esp_err_t Enable(const esp_openthread_spi_host_config_t &spi_config);

    /**
     * @brief  This method disable the spinel interface.
     *
     * @return
     *      - ESP_OK on success
     *      - ESP_FAIL on failure
     */
    esp_err_t Disable(void);

    /**
     * @brief  This method should be called after radio is initialized.
     *
     * @return
     *      - ESP_OK on success
     *      - ESP_FAIL on failure
     */
    esp_err_t AfterRadioInit(void);

private:
    static constexpr uint8_t kSPIFrameHeaderSize = 5;
    static constexpr uint16_t kSPIFrameSize = ot::Spinel::SpinelInterface::kMaxFrameSize + kSPIFrameHeaderSize;
    static constexpr uint8_t kSmallPacketSize = 32;
    static constexpr uint16_t kSPIDataEvent = 1;

    static void GpioIntrHandler(void *arg);
    esp_err_t ConductSPITransaction(bool reset, uint16_t tx_data_size, uint16_t rx_data_size);

    esp_openthread_spi_host_config_t m_spi_config;
    uint8_t m_tx_buffer[kSPIFrameSize];
    int m_event_fd;
    volatile uint16_t m_pending_data_len;

    ReceiveFrameCallback m_receiver_frame_callback;
    void *m_receiver_frame_context;
    RxFrameBuffer *m_receive_frame_buffer;
    bool m_has_pending_device_frame;

    spi_device_handle_t m_device;

    esp_openthread_rcp_failure_handler mRcpFailureHandler;

    otRcpInterfaceMetrics mInterfaceMetrics;
};

} // namespace openthread
} // namespace esp