text: // Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  
  //     http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  
  #ifndef __ESP_LOG_H__
  #define __ESP_LOG_H__
  
  #include <stdint.h>
  #include <stdarg.h>
  #include "sdkconfig.h"
  #if CONFIG_IDF_TARGET_ESP32
  #include "esp32/rom/ets_sys.h"
  #elif CONFIG_IDF_TARGET_ESP32S2
  #include "esp32s2/rom/ets_sys.h"
  #endif
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /**
   * @brief Log level
   *
   */
  typedef enum {
      ESP_LOG_NONE,       /*!< No log output */
      ESP_LOG_ERROR,      /*!< Critical errors, software module can not recover on its own */
      ESP_LOG_WARN,       /*!< Error conditions from which recovery measures have been taken */
      ESP_LOG_INFO,       /*!< Information messages which describe normal flow of events */
      ESP_LOG_DEBUG,      /*!< Extra information which is not necessary for normal use (values, pointers, sizes, etc). */
      ESP_LOG_VERBOSE     /*!< Bigger chunks of debugging information, or frequent messages which can potentially flood the output. */
  } esp_log_level_t;
  
  typedef int (*vprintf_like_t)(const char *, va_list);
  
  /**
   * @brief Set log level for given tag
   *
   * If logging for given component has already been enabled, changes previous setting.
   *
   * Note that this function can not raise log level above the level set using
   * CONFIG_LOG_DEFAULT_LEVEL setting in menuconfig.
   *
   * To raise log level above the default one for a given file, define
   * LOG_LOCAL_LEVEL to one of the ESP_LOG_* values, before including
   * esp_log.h in this file.
   *
   * @param tag Tag of the log entries to enable. Must be a non-NULL zero terminated string.
   *            Value "*" resets log level for all tags to the given value.
   *
   * @param level  Selects log level to enable. Only logs at this and lower verbosity
   * levels will be shown.
   */
  void esp_log_level_set(const char* tag, esp_log_level_t level);
  
  /**
   * @brief Set function used to output log entries
   *
   * By default, log output goes to UART0. This function can be used to redirect log
   * output to some other destination, such as file or network. Returns the original
   * log handler, which may be necessary to return output to the previous destination.
   *
   * @param func new Function used for output. Must have same signature as vprintf.
   *
   * @return func old Function used for output.
   */
  vprintf_like_t esp_log_set_vprintf(vprintf_like_t func);
  
  /**
   * @brief Function which returns timestamp to be used in log output
   *
   * This function is used in expansion of ESP_LOGx macros.
   * In the 2nd stage bootloader, and at early application startup stage
   * this function uses CPU cycle counter as time source. Later when
   * FreeRTOS scheduler start running, it switches to FreeRTOS tick count.
   *
   * For now, we ignore millisecond counter overflow.
   *
   * @return timestamp, in milliseconds
   */
  uint32_t esp_log_timestamp(void);
  
  /**
   * @brief Function which returns system timestamp to be used in log output
   *
   * This function is used in expansion of ESP_LOGx macros to print
   * the system time as "HH:MM:SS.sss". The system time is initialized to
   * 0 on startup, this can be set to the correct time with an SNTP sync,
   * or manually with standard POSIX time functions.
   *
   * Currently this will not get used in logging from binary blobs
   * (i.e WiFi & Bluetooth libraries), these will still print the RTOS tick time.
   *
   * @return timestamp, in "HH:MM:SS.sss"
   */
  char* esp_log_system_timestamp(void);
  
  /**
   * @brief Function which returns timestamp to be used in log output
   *
   * This function uses HW cycle counter and does not depend on OS,
   * so it can be safely used after application crash.
   *
   * @return timestamp, in milliseconds
   */
  uint32_t esp_log_early_timestamp(void);
  
  /**
   * @brief Write message into the log
   *
   * This function is not intended to be used directly. Instead, use one of
   * ESP_LOGE, ESP_LOGW, ESP_LOGI, ESP_LOGD, ESP_LOGV macros.
   *
   * This function or these macros should not be used from an interrupt.
   */
  void esp_log_write(esp_log_level_t level, const char* tag, const char* format, ...) __attribute__ ((format (printf, 3, 4)));
  
  /**
   * @brief Write message into the log, va_list variant
   * @see esp_log_write()
   *
   * This function is provided to ease integration toward other logging framework,
   * so that esp_log can be used as a log sink.
   */
  void esp_log_writev(esp_log_level_t level, const char* tag, const char* format, va_list args);
  
  /** @cond */
  
  #include "esp_log_internal.h"
  
  #ifndef LOG_LOCAL_LEVEL
  #ifndef BOOTLOADER_BUILD
  #define LOG_LOCAL_LEVEL  CONFIG_LOG_DEFAULT_LEVEL
  #else
  #define LOG_LOCAL_LEVEL  CONFIG_BOOTLOADER_LOG_LEVEL
  #endif
  #endif
  
  /** @endcond */
  
  /**
   * @brief Log a buffer of hex bytes at specified level, separated into 16 bytes each line.
   *
   * @param  tag      description tag
   * @param  buffer   Pointer to the buffer array
   * @param  buff_len length of buffer in bytes
   * @param  level    level of the log
   *
   */
  #define ESP_LOG_BUFFER_HEX_LEVEL( tag, buffer, buff_len, level ) \
      do {\
          if ( LOG_LOCAL_LEVEL >= (level) ) { \
              esp_log_buffer_hex_internal( tag, buffer, buff_len, level ); \
          } \
      } while(0)
  
  /**
   * @brief Log a buffer of characters at specified level, separated into 16 bytes each line. Buffer should contain only printable characters.
   *
   * @param  tag      description tag
   * @param  buffer   Pointer to the buffer array
   * @param  buff_len length of buffer in bytes
   * @param  level    level of the log
   *
   */
  #define ESP_LOG_BUFFER_CHAR_LEVEL( tag, buffer, buff_len, level ) \
      do {\
          if ( LOG_LOCAL_LEVEL >= (level) ) { \
              esp_log_buffer_char_internal( tag, buffer, buff_len, level ); \
          } \
      } while(0)
  
  /**
   * @brief Dump a buffer to the log at specified level.
   *
   * The dump log shows just like the one below:
   *
   *      W (195) log_example: 0x3ffb4280   45 53 50 33 32 20 69 73  20 67 72 65 61 74 2c 20  |ESP32 is great, |
   *      W (195) log_example: 0x3ffb4290   77 6f 72 6b 69 6e 67 20  61 6c 6f 6e 67 20 77 69  |working along wi|
   *      W (205) log_example: 0x3ffb42a0   74 68 20 74 68 65 20 49  44 46 2e 00              |th the IDF..|
   *
   * It is highly recommend to use terminals with over 102 text width.
   *
   * @param tag description tag
   * @param buffer Pointer to the buffer array
   * @param buff_len length of buffer in bytes
   * @param level level of the log
   */
  #define ESP_LOG_BUFFER_HEXDUMP( tag, buffer, buff_len, level ) \
      do { \
          if ( LOG_LOCAL_LEVEL >= (level) ) { \
              esp_log_buffer_hexdump_internal( tag, buffer, buff_len, level); \
          } \
      } while(0)
  
  /**
   * @brief Log a buffer of hex bytes at Info level
   *
   * @param  tag      description tag
   * @param  buffer   Pointer to the buffer array
   * @param  buff_len length of buffer in bytes
   *
   * @see ``esp_log_buffer_hex_level``
   *
   */
  #define ESP_LOG_BUFFER_HEX(tag, buffer, buff_len) \
      do { \
          if (LOG_LOCAL_LEVEL >= ESP_LOG_INFO) { \
              ESP_LOG_BUFFER_HEX_LEVEL( tag, buffer, buff_len, ESP_LOG_INFO ); \
          }\
      } while(0)
  
  /**
   * @brief Log a buffer of characters at Info level. Buffer should contain only printable characters.
   *
   * @param  tag      description tag
   * @param  buffer   Pointer to the buffer array
   * @param  buff_len length of buffer in bytes
   *
   * @see ``esp_log_buffer_char_level``
   *
   */
  #define ESP_LOG_BUFFER_CHAR(tag, buffer, buff_len) \
      do { \
          if (LOG_LOCAL_LEVEL >= ESP_LOG_INFO) { \
              ESP_LOG_BUFFER_CHAR_LEVEL( tag, buffer, buff_len, ESP_LOG_INFO ); \
          }\
      } while(0)
  
  /** @cond */
  
  //to be back compatible
  #define esp_log_buffer_hex      ESP_LOG_BUFFER_HEX
  #define esp_log_buffer_char     ESP_LOG_BUFFER_CHAR
  
  
  #if CONFIG_LOG_COLORS
  #define LOG_COLOR_BLACK   "30"
  #define LOG_COLOR_RED     "31"
  #define LOG_COLOR_GREEN   "32"
  #define LOG_COLOR_BROWN   "33"
  #define LOG_COLOR_BLUE    "34"
  #define LOG_COLOR_PURPLE  "35"
  #define LOG_COLOR_CYAN    "36"
  #define LOG_COLOR(COLOR)  "\033[0;" COLOR "m"
  #define LOG_BOLD(COLOR)   "\033[1;" COLOR "m"
  #define LOG_RESET_COLOR   "\033[0m"
  #define LOG_COLOR_E       LOG_COLOR(LOG_COLOR_RED)
  #define LOG_COLOR_W       LOG_COLOR(LOG_COLOR_BROWN)
  #define LOG_COLOR_I       LOG_COLOR(LOG_COLOR_GREEN)
  #define LOG_COLOR_D
  #define LOG_COLOR_V
  #else //CONFIG_LOG_COLORS
  #define LOG_COLOR_E
  #define LOG_COLOR_W
  #define LOG_COLOR_I
  #define LOG_COLOR_D
  #define LOG_COLOR_V
  #define LOG_RESET_COLOR
  #endif //CONFIG_LOG_COLORS
  
  #define LOG_FORMAT(letter, format)  LOG_COLOR_ ## letter #letter " (%d) %s: " format LOG_RESET_COLOR "\n"
  #define LOG_SYSTEM_TIME_FORMAT(letter, format)  LOG_COLOR_ ## letter #letter " (%s) %s: " format LOG_RESET_COLOR "\n"
  
  /** @endcond */
  
  /// macro to output logs in startup code, before heap allocator and syscalls have been initialized. log at ``ESP_LOG_ERROR`` level. @see ``printf``,``ESP_LOGE``
  #define ESP_EARLY_LOGE( tag, format, ... ) ESP_LOG_EARLY_IMPL(tag, format, ESP_LOG_ERROR,   E, ##__VA_ARGS__)
  /// macro to output logs in startup code at ``ESP_LOG_WARN`` level.  @see ``ESP_EARLY_LOGE``,``ESP_LOGE``, ``printf``
  #define ESP_EARLY_LOGW( tag, format, ... ) ESP_LOG_EARLY_IMPL(tag, format, ESP_LOG_WARN,    W, ##__VA_ARGS__)
  /// macro to output logs in startup code at ``ESP_LOG_INFO`` level.  @see ``ESP_EARLY_LOGE``,``ESP_LOGE``, ``printf``
  #define ESP_EARLY_LOGI( tag, format, ... ) ESP_LOG_EARLY_IMPL(tag, format, ESP_LOG_INFO,    I, ##__VA_ARGS__)
  /// macro to output logs in startup code at ``ESP_LOG_DEBUG`` level.  @see ``ESP_EARLY_LOGE``,``ESP_LOGE``, ``printf``
  #define ESP_EARLY_LOGD( tag, format, ... ) ESP_LOG_EARLY_IMPL(tag, format, ESP_LOG_DEBUG,   D, ##__VA_ARGS__)
  /// macro to output logs in startup code at ``ESP_LOG_VERBOSE`` level.  @see ``ESP_EARLY_LOGE``,``ESP_LOGE``, ``printf``
  #define ESP_EARLY_LOGV( tag, format, ... ) ESP_LOG_EARLY_IMPL(tag, format, ESP_LOG_VERBOSE, V, ##__VA_ARGS__)
  
  #define ESP_LOG_EARLY_IMPL(tag, format, log_level, log_tag_letter, ...) do {                         \
          if (LOG_LOCAL_LEVEL >= log_level) {                                                          \
              ets_printf(LOG_FORMAT(log_tag_letter, format), esp_log_timestamp(), tag, ##__VA_ARGS__); \
          }} while(0)
  
  #ifndef BOOTLOADER_BUILD
  #define ESP_LOGE( tag, format, ... ) ESP_LOG_LEVEL_LOCAL(ESP_LOG_ERROR,   tag, format, ##__VA_ARGS__)
  #define ESP_LOGW( tag, format, ... ) ESP_LOG_LEVEL_LOCAL(ESP_LOG_WARN,    tag, format, ##__VA_ARGS__)
  #define ESP_LOGI( tag, format, ... ) ESP_LOG_LEVEL_LOCAL(ESP_LOG_INFO,    tag, format, ##__VA_ARGS__)
  #define ESP_LOGD( tag, format, ... ) ESP_LOG_LEVEL_LOCAL(ESP_LOG_DEBUG,   tag, format, ##__VA_ARGS__)
  #define ESP_LOGV( tag, format, ... ) ESP_LOG_LEVEL_LOCAL(ESP_LOG_VERBOSE, tag, format, ##__VA_ARGS__)
  #else
  /**
   * macro to output logs at ESP_LOG_ERROR level.
   *
   * @param tag tag of the log, which can be used to change the log level by ``esp_log_level_set`` at runtime.
   *
   * @see ``printf``
   */
  #define ESP_LOGE( tag, format, ... )  ESP_EARLY_LOGE(tag, format, ##__VA_ARGS__)
  /// macro to output logs at ``ESP_LOG_WARN`` level.  @see ``ESP_LOGE``
  #define ESP_LOGW( tag, format, ... )  ESP_EARLY_LOGW(tag, format, ##__VA_ARGS__)
  /// macro to output logs at ``ESP_LOG_INFO`` level.  @see ``ESP_LOGE``
  #define ESP_LOGI( tag, format, ... )  ESP_EARLY_LOGI(tag, format, ##__VA_ARGS__)
  /// macro to output logs at ``ESP_LOG_DEBUG`` level.  @see ``ESP_LOGE``
  #define ESP_LOGD( tag, format, ... )  ESP_EARLY_LOGD(tag, format, ##__VA_ARGS__)
  /// macro to output logs at ``ESP_LOG_VERBOSE`` level.  @see ``ESP_LOGE``
  #define ESP_LOGV( tag, format, ... )  ESP_EARLY_LOGV(tag, format, ##__VA_ARGS__)
  #endif  // BOOTLOADER_BUILD
  
  /** runtime macro to output logs at a specified level.
   *
   * @param tag tag of the log, which can be used to change the log level by ``esp_log_level_set`` at runtime.
   * @param level level of the output log.
   * @param format format of the output log. see ``printf``
   * @param ... variables to be replaced into the log. see ``printf``
   *
   * @see ``printf``
   */
  #if CONFIG_LOG_TIMESTAMP_SOURCE_RTOS
  #define ESP_LOG_LEVEL(level, tag, format, ...) do {                     \
          if (level==ESP_LOG_ERROR )          { esp_log_write(ESP_LOG_ERROR,      tag, LOG_FORMAT(E, format), esp_log_timestamp(), tag, ##__VA_ARGS__); } \
          else if (level==ESP_LOG_WARN )      { esp_log_write(ESP_LOG_WARN,       tag, LOG_FORMAT(W, format), esp_log_timestamp(), tag, ##__VA_ARGS__); } \
          else if (level==ESP_LOG_DEBUG )     { esp_log_write(ESP_LOG_DEBUG,      tag, LOG_FORMAT(D, format), esp_log_timestamp(), tag, ##__VA_ARGS__); } \
          else if (level==ESP_LOG_VERBOSE )   { esp_log_write(ESP_LOG_VERBOSE,    tag, LOG_FORMAT(V, format), esp_log_timestamp(), tag, ##__VA_ARGS__); } \
          else                                { esp_log_write(ESP_LOG_INFO,       tag, LOG_FORMAT(I, format), esp_log_timestamp(), tag, ##__VA_ARGS__); } \
      } while(0)
  #elif CONFIG_LOG_TIMESTAMP_SOURCE_SYSTEM
  #define ESP_LOG_LEVEL(level, tag, format, ...) do {                     \
          if (level==ESP_LOG_ERROR )          { esp_log_write(ESP_LOG_ERROR,      tag, LOG_SYSTEM_TIME_FORMAT(E, format), esp_log_system_timestamp(), tag, ##__VA_ARGS__); } \
          else if (level==ESP_LOG_WARN )      { esp_log_write(ESP_LOG_WARN,       tag, LOG_SYSTEM_TIME_FORMAT(W, format), esp_log_system_timestamp(), tag, ##__VA_ARGS__); } \
          else if (level==ESP_LOG_DEBUG )     { esp_log_write(ESP_LOG_DEBUG,      tag, LOG_SYSTEM_TIME_FORMAT(D, format), esp_log_system_timestamp(), tag, ##__VA_ARGS__); } \
          else if (level==ESP_LOG_VERBOSE )   { esp_log_write(ESP_LOG_VERBOSE,    tag, LOG_SYSTEM_TIME_FORMAT(V, format), esp_log_system_timestamp(), tag, ##__VA_ARGS__); } \
          else                                { esp_log_write(ESP_LOG_INFO,       tag, LOG_SYSTEM_TIME_FORMAT(I, format), esp_log_system_timestamp(), tag, ##__VA_ARGS__); } \
      } while(0)
  #endif //CONFIG_LOG_TIMESTAMP_SOURCE_xxx
  
  /** runtime macro to output logs at a specified level. Also check the level with ``LOG_LOCAL_LEVEL``.
   *
   * @see ``printf``, ``ESP_LOG_LEVEL``
   */
  #define ESP_LOG_LEVEL_LOCAL(level, tag, format, ...) do {               \
          if ( LOG_LOCAL_LEVEL >= level ) ESP_LOG_LEVEL(level, tag, format, ##__VA_ARGS__); \
      } while(0)
  
  
  /**
   * @brief Macro to output logs when the cache is disabled. log at ``ESP_LOG_ERROR`` level.
   *
   * Similar to `ESP_EARLY_LOGE`, the log level cannot be changed by `esp_log_level_set`.
   *
   * Usage: `ESP_DRAM_LOGE(DRAM_STR("my_tag"), "format", or `ESP_DRAM_LOGE(TAG, "format", ...)`,
   * where TAG is a char* that points to a str in the DRAM.
   *
   * @note Placing log strings in DRAM reduces available DRAM, so only use when absolutely essential.
   *
   * @see ``ets_printf``,``ESP_LOGE``
   */
  #define ESP_DRAM_LOGE( tag, format, ... ) ESP_DRAM_LOG_IMPL(tag, format, ESP_LOG_ERROR,   E, ##__VA_ARGS__)
  /// macro to output logs when the cache is disabled at ``ESP_LOG_WARN`` level.  @see ``ESP_DRAM_LOGW``,``ESP_LOGW``, ``ets_printf``
  #define ESP_DRAM_LOGW( tag, format, ... ) ESP_DRAM_LOG_IMPL(tag, format, ESP_LOG_WARN,    W, ##__VA_ARGS__)
  /// macro to output logs when the cache is disabled at ``ESP_LOG_INFO`` level.  @see ``ESP_DRAM_LOGI``,``ESP_LOGI``, ``ets_printf``
  #define ESP_DRAM_LOGI( tag, format, ... ) ESP_DRAM_LOG_IMPL(tag, format, ESP_LOG_INFO,    I, ##__VA_ARGS__)
  /// macro to output logs when the cache is disabled at ``ESP_LOG_DEBUG`` level.  @see ``ESP_DRAM_LOGD``,``ESP_LOGD``, ``ets_printf``
  #define ESP_DRAM_LOGD( tag, format, ... ) ESP_DRAM_LOG_IMPL(tag, format, ESP_LOG_DEBUG,   D, ##__VA_ARGS__)
  /// macro to output logs when the cache is disabled at ``ESP_LOG_VERBOSE`` level.  @see ``ESP_DRAM_LOGV``,``ESP_LOGV``, ``ets_printf``
  #define ESP_DRAM_LOGV( tag, format, ... ) ESP_DRAM_LOG_IMPL(tag, format, ESP_LOG_VERBOSE, V, ##__VA_ARGS__)
  
  /** @cond */
  #define _ESP_LOG_DRAM_LOG_FORMAT(letter, format)  DRAM_STR(#letter " %s: " format "\n")
  
  #define ESP_DRAM_LOG_IMPL(tag, format, log_level, log_tag_letter, ...) do {                         \
          if (LOG_LOCAL_LEVEL >= log_level) {                                                          \
              ets_printf(_ESP_LOG_DRAM_LOG_FORMAT(log_tag_letter, format), tag, ##__VA_ARGS__); \
          }} while(0)
  /** @endcond */
  
  #ifdef __cplusplus
  }
  #endif
  
  
  #endif /* __ESP_LOG_H__ */
  