#include <string.h>

#include "mcp2521.hpp"
#include "reg.hpp"

void MCP2521_SPI_Interface::reset() {
    spi_transaction_ext_t t = {
        .base = {
            .flags = SPI_TRANS_VARIABLE_CMD | SPI_TRANS_VARIABLE_ADDR,
            .cmd = MCP2521_OP_RESET,
            .addr = 8,
            .length = 0,
            .rxlength = 0,
            .tx_buffer = NULL,
            .rx_buffer = NULL
        },
        .command_bits = 8,
        .address_bits = 0,
        .dummy_bits = 0,
    };

    spi_device_transmit(this->spi_device_handle, (spi_transaction_t*)(&t));
}

void MCP2521_SPI_Interface::read_reg(uint8_t address, uint8_t *data, size_t length) {
    spi_transaction_ext_t t = {
        .base = {
            .flags = SPI_TRANS_VARIABLE_CMD | SPI_TRANS_VARIABLE_ADDR,
            .cmd = MCP2521_OP_READ,
            .addr = address,
            .length = 8 * length,
            .rxlength = 8 * length,
            .tx_buffer = &this->spi_tx_buffer,
            .rx_buffer = &this->spi_rx_buffer,
        },
        .command_bits = 8,
        .address_bits = 8,
        .dummy_bits = 0,
    };

    spi_device_transmit(this->spi_device_handle, (spi_transaction_t*)(&t));
    memcpy(data, this->spi_rx_buffer, length);
}

uint8_t MCP2521_SPI_Interface::read_reg(uint8_t address) {
    uint8_t data;
    read_reg(address, &data, 1);
    return data;
}