/**
 * Base on Malrin https://github.com/MarlinFirmware/Marlin
 * parser.h - Parser for a GCode line, providing a parameter interface.
 *            Codes like M149 control the way the GCode parser behaves,
 *            so settings for these codes are located in this class.
 */

#ifndef _PARSER_H_
#define _PARSER_H_

//#include "enum.h"
#include <stdint.h>
#include <stdlib.h>
#include "macros.h"

#define strtof strtod

/**
 * GCode parser
 *
 *  - Parse a single gcode line for its letter, code, subcode, and parameters
 *  - Provide accessors for parameters:
 *    - Parameter exists
 *    - Parameter has value
 *    - Parameter value in different units and types
 */
class GCodeParser {

private:
  static char *value_ptr;           // Set by seen, used to fetch the value
  static char *command_args;        // Args start here, for slow scan

public:

  // Command line state
  static char *command_ptr,               // The command, so it can be echoed
              *string_arg;                // string of command line

  static char command_letter;             // G, M, or T
  static int codenum;                     // 123

  #if defined(DEBUG_GCODE_PARSER)
    static void debug();
  #endif

  GCodeParser() {
  }

  // Reset is done before parsing
  static void reset();

  #define LETTER_BIT(N) ((N) - 'A')

  FORCE_INLINE static bool valid_signless(const char * const p) {
    return NUMERIC(p[0]) || (p[0] == '.' && NUMERIC(p[1])); // .?[0-9]
  }

  FORCE_INLINE static bool valid_float(const char * const p) {
    return valid_signless(p) || ((p[0] == '-' || p[0] == '+') && valid_signless(&p[1])); // [-+]?.?[0-9]
  }


  // Code is found in the string. If not found, value_ptr is unchanged.
  // This allows "if (seen('A')||seen('B'))" to use the last-found value.
  static bool seen(const char c) {
    char *p = strchr(command_args, c);
    const bool b = !!p;
    if (b) value_ptr = valid_float(&p[1]) ? &p[1] : (char*)NULL;
    return b;
  }

  static bool seen_any() { return *command_args == '\0'; }

  #define SEEN_TEST(L) !!strchr(command_args, L)

  // Seen any axis parameter
  static bool seen_axis() {
    return SEEN_TEST('X') || SEEN_TEST('Y') || SEEN_TEST('Z') || SEEN_TEST('E');
  }

  // Populate all fields by parsing a single line of GCode
  // This uses 54 bytes of SRAM to speed up seen/value
  static void parse(char * p);

  // The code value pointer was set
  FORCE_INLINE static bool has_value() { return value_ptr != NULL; }

  // Seen a parameter with a value
  inline static bool seenval(const char c) { return seen(c) && has_value(); }

  // Float removes 'E' to prevent scientific notation interpretation
  inline static float value_float() {
    if (value_ptr) {
      char *e = value_ptr;
      for (;;) {
        const char c = *e;
        if (c == '\0' || c == ' ') break;
        if (c == 'E' || c == 'e') {
          *e = '\0';
          const float ret = strtof(value_ptr, NULL);
          *e = c;
          return ret;
        }
        ++e;
      }
      return strtof(value_ptr, NULL);
    }
    return 0;
  }

  // Code value as a long or ulong
  inline static int32_t value_long() { return value_ptr ? strtol(value_ptr, NULL, 10) : 0L; }
  inline static uint32_t value_ulong() { return value_ptr ? strtoul(value_ptr, NULL, 10) : 0UL; }

  // Code value for use as time
  FORCE_INLINE static millis_t value_millis() { return value_ulong(); }
  FORCE_INLINE static millis_t value_millis_from_seconds() { return value_float() * 1000UL; }

  // Reduce to fewer bits
  FORCE_INLINE static int16_t value_int() { return (int16_t)value_long(); }
  FORCE_INLINE static uint16_t value_ushort() { return (uint16_t)value_long(); }
  inline static uint8_t value_byte() { return (uint8_t)constrain(value_long(), 0, 255); }

  // Bool is true with no value or non-zero
  inline static bool value_bool() { return !has_value() || !!value_byte(); }

  void unknown_command_error();

  // Provide simple value accessors with default option
  FORCE_INLINE static float    floatval(const char c, const float dval=0.0)   { return seenval(c) ? value_float()        : dval; }
  FORCE_INLINE static bool     boolval(const char c, const bool dval=false)   { return seenval(c) ? value_bool()         : (seen(c) ? true : dval); }
  FORCE_INLINE static uint8_t  byteval(const char c, const uint8_t dval=0)    { return seenval(c) ? value_byte()         : dval; }
  FORCE_INLINE static int16_t  intval(const char c, const int16_t dval=0)     { return seenval(c) ? value_int()          : dval; }
  FORCE_INLINE static uint16_t ushortval(const char c, const uint16_t dval=0) { return seenval(c) ? value_ushort()       : dval; }
  FORCE_INLINE static int32_t  longval(const char c, const int32_t dval=0)    { return seenval(c) ? value_long()         : dval; }
  FORCE_INLINE static uint32_t ulongval(const char c, const uint32_t dval=0)  { return seenval(c) ? value_ulong()        : dval; }
};

extern GCodeParser parser;

#endif // _PARSER_H_