#include "platform.h"
#include "driver/console.h"
#include "driver/sigmadelta.h"
#include <stdio.h>

int platform_init (void)
{
  return PLATFORM_OK;
}


// *****************************************************************************
// GPIO subsection

int platform_gpio_exists( unsigned gpio ) { return GPIO_IS_VALID_GPIO(gpio); }
int platform_gpio_output_exists( unsigned gpio ) { return GPIO_IS_VALID_OUTPUT_GPIO(gpio); }


// ****************************************************************************
// UART

uint32_t platform_uart_setup( unsigned id, uint32_t baud, int databits, int parity, int stopbits )
{
  if (id == CONSOLE_UART)
  {
    ConsoleSetup_t cfg;
    cfg.bit_rate  = baud;
    switch (databits)
    {
      case 5: cfg.data_bits = CONSOLE_NUM_BITS_5; break;
      case 6: cfg.data_bits = CONSOLE_NUM_BITS_6; break;
      case 7: cfg.data_bits = CONSOLE_NUM_BITS_7; break;
      case 8: // fall-through
      default: cfg.data_bits = CONSOLE_NUM_BITS_8; break;
    }
    switch (parity)
    {
      case PLATFORM_UART_PARITY_EVEN: cfg.parity = CONSOLE_PARITY_EVEN; break;
      case PLATFORM_UART_PARITY_ODD:  cfg.parity = CONSOLE_PARITY_ODD; break;
      default: // fall-through
      case PLATFORM_UART_PARITY_NONE: cfg.parity = CONSOLE_PARITY_NONE; break;
    }
    switch (stopbits)
    {
      default: // fall-through
      case PLATFORM_UART_STOPBITS_1:
        cfg.stop_bits = CONSOLE_STOP_BITS_1; break;
      case PLATFORM_UART_STOPBITS_1_5:
        cfg.stop_bits = CONSOLE_STOP_BITS_1_5; break;
      case PLATFORM_UART_STOPBITS_2:
        cfg.stop_bits = CONSOLE_STOP_BITS_2; break;
    }
    cfg.auto_baud = false;
    console_setup (&cfg);
    return baud;
  }
  else
  {
    printf("UART1/UART2 not yet supported\n");
    return 0;
  }
}


void platform_uart_send( unsigned id, uint8_t data )
{
  if (id == CONSOLE_UART)
    putchar (data);
}

void platform_uart_flush( unsigned id )
{
  if (id == CONSOLE_UART)
    fflush (stdout);
}

// *****************************************************************************
// Sigma-Delta platform interface

static gpio_num_t platform_sigma_delta_channel2gpio[SIGMADELTA_CHANNEL_MAX];

int platform_sigma_delta_exists( unsigned channel ) {
  return (channel < SIGMADELTA_CHANNEL_MAX);
}

uint8_t platform_sigma_delta_setup( uint8_t channel, uint8_t gpio_num )
{
#if 0
  // signal generator can't be stopped this way
  // stop signal generator
  if (ESP_OK != sigmadelta_set_prescale( channel, 0 ))
    return 0;
#endif

  // note channel to gpio assignment
  platform_sigma_delta_channel2gpio[channel] = gpio_num;

  return ESP_OK == sigmadelta_set_pin( channel, gpio_num ) ? 1 : 0;
}

uint8_t platform_sigma_delta_close( uint8_t channel )
{
#if 0
  // Note: signal generator can't be stopped this way
  // stop signal generator
  if (ESP_OK != sigmadelta_set_prescale( channel, 0 ))
    return 0;
#endif

  gpio_set_level( platform_sigma_delta_channel2gpio[channel], 1 );
  gpio_config_t cfg;
  // force pin back to GPIO
  cfg.intr_type = GPIO_INTR_DISABLE;
  cfg.mode = GPIO_MODE_OUTPUT;  // essential to switch IO matrix to GPIO
  cfg.pull_down_en = GPIO_PULLDOWN_DISABLE;
  cfg.pull_up_en = GPIO_PULLUP_ENABLE;
  cfg.pin_bit_mask = 1 << platform_sigma_delta_channel2gpio[channel];
  if (ESP_OK != gpio_config( &cfg ))
    return 0;

  // and set it finally to input with pull-up enabled
  cfg.mode = GPIO_MODE_INPUT;

  return ESP_OK == gpio_config( &cfg ) ? 1 : 0;
}

#if 0
// PWM emulation not possible, code kept for future reference
uint8_t platform_sigma_delta_set_pwmduty( uint8_t channel, uint8_t duty )
{
  uint8_t target = 0, prescale = 0;

  target = duty > 128 ? 256 - duty : duty;
  prescale = target == 0 ? 0 : target-1;

  //freq = 80000 (khz) /256 /duty_target * (prescale+1)
  if (ESP_OK != sigmadelta_set_prescale( channel, prescale ))
    return 0;
  if (ESP_OK != sigmadelta_set_duty( channel, duty-128 ))
    return 0;

  return 1;
}
#endif

uint8_t platform_sigma_delta_set_prescale( uint8_t channel, uint8_t prescale )
{
  return ESP_OK == sigmadelta_set_prescale( channel, prescale ) ? 1 : 0;
}

uint8_t IRAM_ATTR platform_sigma_delta_set_duty( uint8_t channel, int8_t duty )
{
  return ESP_OK == sigmadelta_set_duty( channel, duty ) ? 1 : 0;
}

// *****************************************************************************
// I2C platform interface

#if 0
// platform functions for the IDF I2C driver
// they're currently deactivated because of https://github.com/espressif/esp-idf/issues/241
// long-term goal is to use these instead of the SW driver in the #else branch

#include "driver/i2c.h"
int platform_i2c_setup( unsigned id, uint8_t sda, uint8_t scl, uint32_t speed ) {
  i2c_config_t conf;
  conf.mode = I2C_MODE_MASTER;
  conf.sda_io_num = sda;
  conf.sda_pullup_en = GPIO_PULLUP_ENABLE;
  conf.scl_io_num = scl;
  conf.scl_pullup_en = GPIO_PULLUP_ENABLE;
  conf.master.clk_speed = speed;
  if (ESP_OK != i2c_param_config( id, &conf ))
    return 0;

  if (ESP_OK != i2c_driver_install( id, conf.mode, 0, 0, 0 ))
    return 0;

  return 1;
}

int platform_i2c_send_start( unsigned id ) {
  i2c_cmd_handle_t cmd = i2c_cmd_link_create();
  i2c_master_start( cmd );
  esp_err_t ret = i2c_master_cmd_begin( id, cmd, 1000 / portTICK_RATE_MS );
  i2c_cmd_link_delete( cmd );

  return ret == ESP_OK ? 1 : 0;
}

int platform_i2c_send_stop( unsigned id ) {
  i2c_cmd_handle_t cmd = i2c_cmd_link_create();
  i2c_master_stop( cmd );
  esp_err_t ret = i2c_master_cmd_begin( id, cmd, 1000 / portTICK_RATE_MS );
  i2c_cmd_link_delete( cmd );

  return ret == ESP_OK ? 1 : 0;
}

int platform_i2c_send_address( unsigned id, uint16_t address, int direction, int ack_check_en ) {
  i2c_cmd_handle_t cmd = i2c_cmd_link_create();

  direction = ( direction == PLATFORM_I2C_DIRECTION_TRANSMITTER ) ? 0 : 1;

  i2c_master_write_byte( cmd, (uint8_t) ((address << 1) | direction ), ack_check_en );

  esp_err_t ret = i2c_master_cmd_begin( id, cmd, 1000 / portTICK_RATE_MS );
  i2c_cmd_link_delete( cmd );

  // we return ack (1=acked).
  if (ret == ESP_FAIL)
    return 0;
  else if (ret == ESP_OK)
    return 1;
  else
    return -1;
}

int platform_i2c_send_byte( unsigned id, uint8_t data, int ack_check_en ) {
  i2c_cmd_handle_t cmd = i2c_cmd_link_create();
  i2c_master_write_byte( cmd, data, ack_check_en );

  esp_err_t ret = i2c_master_cmd_begin( id, cmd, 1000 / portTICK_RATE_MS );
  i2c_cmd_link_delete( cmd );

  // we return ack (1=acked).
  if (ret == ESP_FAIL)
    return 0;
  else if (ret == ESP_OK)
    return 1;
  else
    return -1;
}

int platform_i2c_recv_byte( unsigned id, int ack_val ){
  uint8_t data;
  i2c_cmd_handle_t cmd = i2c_cmd_link_create();
  i2c_master_read_byte( cmd, &data, ack_val > 0 ? 0 : 1 );

  esp_err_t ret = i2c_master_cmd_begin( id, cmd, 1000 / portTICK_RATE_MS );
  i2c_cmd_link_delete( cmd );

  return ret == ESP_OK ? data : -1;
}

#else

// platform functions for SW-based I2C driver
// they work around the issue with the IDF driver
// remove when functions for the IDF driver can be used instead

#include "driver/i2c_sw_master.h"
int platform_i2c_setup( unsigned id, uint8_t sda, uint8_t scl, uint32_t speed ){
  if (!platform_gpio_output_exists(sda) || !platform_gpio_output_exists(scl))
    return 0;

  if (speed != PLATFORM_I2C_SPEED_SLOW)
    return 0;

  i2c_sw_master_gpio_init(sda, scl);
  return 1;
}

int platform_i2c_send_start( unsigned id ){
  i2c_sw_master_start();
  return 1;
}

int platform_i2c_send_stop( unsigned id ){
  i2c_sw_master_stop();
  return 1;
}

int platform_i2c_send_address( unsigned id, uint16_t address, int direction, int ack_check_en ){
  // Convert enum codes to R/w bit value.
  // If TX == 0 and RX == 1, this test will be removed by the compiler
  if ( ! ( PLATFORM_I2C_DIRECTION_TRANSMITTER == 0 &&
           PLATFORM_I2C_DIRECTION_RECEIVER == 1 ) ) {
    direction = ( direction == PLATFORM_I2C_DIRECTION_TRANSMITTER ) ? 0 : 1;
  }

  i2c_sw_master_writeByte( (uint8_t) ((address << 1) | direction ));
  // Low-level returns nack (0=acked); we return ack (1=acked).
  return ! i2c_sw_master_getAck();
}

int platform_i2c_send_byte( unsigned id, uint8_t data, int ack_check_en ){
  i2c_sw_master_writeByte(data);
  // Low-level returns nack (0=acked); we return ack (1=acked).
  return ! i2c_sw_master_getAck();
}

int platform_i2c_recv_byte( unsigned id, int ack ){
  uint8_t r = i2c_sw_master_readByte();
  i2c_sw_master_setAck( !ack );
  return r;
}
#endif

int platform_i2c_exists( unsigned id ) { return id < I2C_NUM_MAX; }