#ifndef MACROS_H
#define MACROS_H

#include <avr/interrupt.h> //for cli() and sei()

#define  FORCE_INLINE __attribute__((always_inline)) inline
#define _UNUSED __attribute__((unused))

#ifndef CRITICAL_SECTION_START
  #define CRITICAL_SECTION_START  unsigned char _sreg = SREG; cli();
  #define CRITICAL_SECTION_END    SREG = _sreg;
#endif //CRITICAL_SECTION_START

// Macros to make a string from a macro
#define STRINGIFY_(M) #M
#define STRINGIFY(M) STRINGIFY_(M)

// Macros for bit masks
#undef _BV
#define _BV(n) (1<<(n))
#define TEST(n,b) (!!((n)&_BV(b)))
#define SET_BIT_TO(N,B,TF) do{ if (TF) SBI(N,B); else CBI(N,B); }while(0)

#ifndef SBI
  #define SBI(A,B) (A |= (1 << (B)))
#endif

#ifndef CBI
  #define CBI(A,B) (A &= ~(1 << (B)))
#endif

#define TBI(N,B) (N ^= _BV(B))


// Macros to chain up to 12 conditions
#define _DO_1(W,C,A)       (_##W##_1(A))
#define _DO_2(W,C,A,B)     (_##W##_1(A) C _##W##_1(B))
#define _DO_3(W,C,A,V...)  (_##W##_1(A) C _DO_2(W,C,V))
#define _DO_4(W,C,A,V...)  (_##W##_1(A) C _DO_3(W,C,V))
#define _DO_5(W,C,A,V...)  (_##W##_1(A) C _DO_4(W,C,V))
#define _DO_6(W,C,A,V...)  (_##W##_1(A) C _DO_5(W,C,V))
#define _DO_7(W,C,A,V...)  (_##W##_1(A) C _DO_6(W,C,V))
#define _DO_8(W,C,A,V...)  (_##W##_1(A) C _DO_7(W,C,V))
#define _DO_9(W,C,A,V...)  (_##W##_1(A) C _DO_8(W,C,V))
#define _DO_10(W,C,A,V...) (_##W##_1(A) C _DO_9(W,C,V))
#define _DO_11(W,C,A,V...) (_##W##_1(A) C _DO_10(W,C,V))
#define _DO_12(W,C,A,V...) (_##W##_1(A) C _DO_11(W,C,V))
#define __DO_N(W,C,N,V...) _DO_##N(W,C,V)
#define _DO_N(W,C,N,V...)  __DO_N(W,C,N,V)
#define DO(W,C,V...)       _DO_N(W,C,NUM_ARGS(V),V)

// Macros to support option testing
#define _CAT(a,V...) a##V
#define CAT(a,V...) _CAT(a,V)

#define _ISENA_     ~,1
#define _ISENA_1    ~,1
#define _ISENA_0x1  ~,1
#define _ISENA_true ~,1
#define _ISENA(V...)        IS_PROBE(V)

#define _ENA_1(O)           _ISENA(CAT(_IS,CAT(ENA_, O)))
#define _DIS_1(O)           NOT(_ENA_1(O))
#define ENABLED(V...)       DO(ENA,&&,V)
#define DISABLED(V...)      DO(DIS,&&,V)

#define TERN(O,A,B)         _TERN(_ENA_1(O),B,A)    // OPTION converted to '0' or '1'
#define TERN0(O,A)          _TERN(_ENA_1(O),0,A)    // OPTION converted to A or '0'
#define TERN1(O,A)          _TERN(_ENA_1(O),1,A)    // OPTION converted to A or '1'
#define TERN_(O,A)          _TERN(_ENA_1(O),,A)     // OPTION converted to A or '<nul>'
#define _TERN(E,V...)       __TERN(_CAT(T_,E),V)    // Prepend 'T_' to get 'T_0' or 'T_1'
#define __TERN(T,V...)      ___TERN(_CAT(_NO,T),V)  // Prepend '_NO' to get '_NOT_0' or '_NOT_1'
#define ___TERN(P,V...)     THIRD(P,V)              // If first argument has a comma, A. Else B.


// Use NUM_ARGS(__VA_ARGS__) to get the number of variadic arguments
#define _NUM_ARGS(_,Z,Y,X,W,V,U,T,S,R,Q,P,O,N,M,L,K,J,I,H,G,F,E,D,C,B,A,OUT,...) OUT
#define NUM_ARGS(V...) _NUM_ARGS(0,V,26,25,24,23,22,21,20,19,18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0)

//
// Primitives supporting precompiler REPEAT
//
#define FIRST(a,...)     a
#define SECOND(a,b,...)  b
#define THIRD(a,b,c,...) c

#define IS_PROBE(V...) SECOND(V, 0)     // Get the second item passed, or 0
#define NOT(x) IS_PROBE(_CAT(_NOT_, x)) // NOT('0') gets '1'. Anything else gets '0'.

#endif //MACROS_H
