/*
 * symmetry.c
 *
 * Symmetry
 *
 * (c) 2006-2010 Thomas White <taw@physics.org>
 *
 * Part of CrystFEL - crystallography with a FEL
 *
 */


#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdlib.h>
#include <stdio.h>
#include <math.h>

#include "utils.h"


#ifdef DEBUG
#define SYM_DEBUG STATUS
#else /* DEBUG */
#define SYM_DEBUG(...)
#endif /* DEBUG */


/* Check if a reflection is in the asymmetric unit cell */
static int check_cond(signed int h, signed int k, signed int l, const char *sym)
{
	if ( strcmp(sym, "1") == 0 )
		return ( 1 );
	if ( strcmp(sym, "-1") == 0 )
		return ( 1 );
	if ( strcmp(sym, "6") == 0 )
		return ( ((h>0) && (k>=0)) || ((h==0) && (k==0)) );
	if ( strcmp(sym, "6/m") == 0 )
		return ( (((h>0) && (k>=0)) || ((h==0) && (k==0))) && (l>=0) );
	if ( strcmp(sym, "6/mmm") == 0 )
		return ( (((h>0) && (k>=0)) || ((h==0) && (k==0))) && (l>=0)
		         && (h>=k) );

	/* TODO: Add more groups here */

	return 1;
}


/* Macros for checking the above conditions and returning if satisfied */
#define CHECK_COND(h, k, l, sym)                   \
	if ( check_cond((h), (k), (l), (sym)) ) {  \
		*hp = (h);  *kp = (k);  *lp = (l); \
		return;                            \
	}


int num_equivs(signed int h, signed int k, signed int l, const char *sym)
{
	/* 000 is always unique */
	if ( (h==0) && (k==0) && (l==0) ) return 1;

	if ( strcmp(sym, "1") == 0 ) return 1;

	if ( strcmp(sym, "-1") == 0 ) return 2;

	if ( strcmp(sym, "6") == 0 ) {
		if ( (h==0) && (k==0) ) return 2;  /* a */
		return 6;  /* b */
	}

	if ( strcmp(sym, "6/m") == 0 ) {
		if ( (h==0) && (k==0) ) return 2;  /* a */
		if ( l == 0 ) return 6;  /* b */
		return 12;  /* c */
	}

	if ( strcmp(sym, "6/mmm") == 0 ) {
		if ( (h==0) && (k==0) ) return 2;  /* a */
		if ( (l==0) && (h==k) ) return 6;  /* b */
		if ( (l==0) && (k==0) ) return 6;  /* c */
		if ( h == k ) return 12;  /* d */
		if ( k == 0 ) return 12;  /* e */
		if ( l == 0 ) return 12;  /* f */
		return 24;  /* g */
	}

	/* TODO: Add more groups here */

	return 1;
}


void get_equiv(signed int h, signed int k, signed int l,
               signed int *he, signed int *ke, signed int *le,
               const char *sym, int idx)
{
	signed int i = -h-k;

	if ( strcmp(sym, "1") == 0 ) {
		*he = h;   *ke = k;   *le = l;  return;
	}

	if ( strcmp(sym, "-1") == 0 ) {
		switch ( idx ) {
		case 0 : *he = h;   *ke = k;   *le = l;   return;
		case 1 : *he = -h;  *ke = -k;  *le = -l;  return;
		}
	}

	if ( strcmp(sym, "6") == 0 ) {
		/* a */
		if ( (h==0) && (k==0) ) {
			switch ( idx ) {
			case  0 : *he = 0;   *ke = 0;   *le = l;   return;
			case  1 : *he = 0;   *ke = 0;   *le = -l;  return;
			}
		}
		/* b */
		switch ( idx ) {
		case  0 : *he = h;   *ke = k;   *le = l;  return;
		case  1 : *he = i;   *ke = h;   *le = l;  return;
		case  2 : *he = k;   *ke = i;   *le = l;  return;
		case  3 : *he = -h;  *ke = -k;  *le = l;  return;
		case  4 : *he = -i;  *ke = -h;  *le = l;  return;
		case  5 : *he = -k;  *ke = -i;  *le = l;  return;
		}
	}

	if ( strcmp(sym, "6/m") == 0 ) {
		/* a */
		if ( (h==0) && (k==0) ) {
			switch ( idx ) {
			case  0 : *he = 0;   *ke = 0;   *le = l;   return;
			case  1 : *he = 0;   *ke = 0;   *le = -l;  return;
			}
		}
		/* b-c */
		switch ( idx ) {
		case  0 : *he = h;   *ke = k;   *le = l;   return;
		case  1 : *he = i;   *ke = h;   *le = l;   return;
		case  2 : *he = k;   *ke = i;   *le = l;   return;
		case  3 : *he = -h;  *ke = -k;  *le = l;   return;
		case  4 : *he = -i;  *ke = -h;  *le = l;   return;
		case  5 : *he = -k;  *ke = -i;  *le = l;   return;
		case  6 : *he = h;   *ke = k;   *le = -l;  return;
		case  7 : *he = i;   *ke = h;   *le = -l;  return;
		case  8 : *he = k;   *ke = i;   *le = -l;  return;
		case  9 : *he = -h;  *ke = -k;  *le = -l;  return;
		case 10 : *he = -i;  *ke = -h;  *le = -l;  return;
		case 11 : *he = -k;  *ke = -i;  *le = -l;  return;
		}
	}

	if ( strcmp(sym, "6/mmm") == 0 ) {
		/* a */
		if ( (h==0) && (k==0) ) {
			switch ( idx ) {
			case  0 : *he = 0;   *ke = 0;   *le = l;   return;
			case  1 : *he = 0;   *ke = 0;   *le = -l;  return;
			}
		}
		/* b-g */
		switch ( idx ) {
		case  0 : *he = h;   *ke = k;   *le = l;   return;
		case  1 : *he = i;   *ke = h;   *le = l;   return;
		case  2 : *he = k;   *ke = i;   *le = l;   return;
		case  3 : *he = -h;  *ke = -k;  *le = l;   return;
		case  4 : *he = -i;  *ke = -h;  *le = l;   return;
		case  5 : *he = -k;  *ke = -i;  *le = l;   return;
		case  6 : *he = k;   *ke = h;   *le = -l;  return;
		case  7 : *he = h;   *ke = i;   *le = -l;  return;
		case  8 : *he = i;   *ke = k;   *le = -l;  return;
		case  9 : *he = -k;  *ke = -h;  *le = -l;  return;
		case 10 : *he = -h;  *ke = -i;  *le = -l;  return;
		case 11 : *he = -i;  *ke = -k;  *le = -l;  return;
		case 12 : *he = -h;  *ke = -k;  *le = -l;  return;
		case 13 : *he = -i;  *ke = -h;  *le = -l;  return;
		case 14 : *he = -k;  *ke = -i;  *le = -l;  return;
		case 15 : *he = h;   *ke = k;   *le = -l;  return;
		case 16 : *he = i;   *ke = h;   *le = -l;  return;
		case 17 : *he = k;   *ke = i;   *le = -l;  return;
		case 18 : *he = -k;  *ke = -h;  *le = l;   return;
		case 19 : *he = -h;  *ke = -i;  *le = l;   return;
		case 20 : *he = -i;  *ke = -k;  *le = l;   return;
		case 21 : *he = k;   *ke = h;   *le = l;   return;
		case 22 : *he = h;   *ke = i;   *le = l;   return;
		case 23 : *he = i;   *ke = k;   *le = l;   return;
		}
	}

	/* TODO: Add more groups here */

	ERROR("Unrecognised symmetry '%s'\n", sym);
	abort();
}


void get_asymm(signed int h, signed int k, signed int l,
               signed int *hp, signed int *kp, signed int *lp,
               const char *sym)
{
	int nequiv = num_equivs(h, k, l, sym);
	int p;

	SYM_DEBUG("------ %i %i %i\n", h, k, l);
	for ( p=0; p<nequiv; p++ ) {
		signed int he, ke, le;
		get_equiv(h, k, l, &he, &ke, &le, sym, p);
		SYM_DEBUG("%i : %i %i %i\n", p, he, ke, le);
		CHECK_COND(he, ke, le, sym);
	}

	/* Should never reach here */
	ERROR("No match found in %s for %i %i %i\n", sym, h, k, l);
	abort();
}