/***********************************************************************
* pc_sort.c
*
*  Pointclound patch sorting.
*
*  Copyright (c) 2016 IGN
*
*  Author: M. Brédif
*
***********************************************************************/
#include "pc_api_internal.h"
#include <assert.h>
#include "sort_r/sort_r.h"

// NULL terminated array of PCDIMENSION pointers
typedef PCDIMENSION ** PCDIMENSION_LIST;

/**
* Comparators
*/

int
pc_compare_dim (const void *a, const void *b, void *arg)
{
	PCDIMENSION_LIST dim = (PCDIMENSION_LIST)arg;
	uint32_t byteoffset     = dim[0]->byteoffset;
	uint32_t interpretation = dim[0]->interpretation;
	double da = pc_double_from_ptr(a+byteoffset,interpretation);
	double db = pc_double_from_ptr(b+byteoffset,interpretation);
	int cmp = ((da > db) - (da < db));
	return ( cmp == 0 && dim[1]) ? pc_compare_dim(a,b,dim+1) : cmp;
}

int
pc_compare_pcb (const void *a, const void *b, const void *arg)
{
	PCBYTES *pcb = (PCBYTES *)arg;
	double da = pc_double_from_ptr(a,pcb->interpretation);
	double db = pc_double_from_ptr(b,pcb->interpretation);
	return ((da > db) - (da < db));
}


/**
* Sort
*/

PCPATCH_UNCOMPRESSED *
pc_patch_uncompressed_sort(const PCPATCH_UNCOMPRESSED *pu, PCDIMENSION_LIST dim)
{
	PCPATCH_UNCOMPRESSED *spu = pc_patch_uncompressed_make(pu->schema, pu->npoints);

	memcpy(spu->data, pu->data, pu->datasize);
	spu->npoints = pu->npoints;
	spu->bounds  = pu->bounds;
	spu->stats   = pc_stats_clone(pu->stats);

	sort_r(spu->data, spu->npoints, pu->schema->size, pc_compare_dim, dim);

	return spu;
}

PCDIMENSION_LIST pc_schema_get_dimensions_by_name(const PCSCHEMA *schema, const char ** name, int ndims)
{
	PCDIMENSION_LIST dim = pcalloc( (ndims+1) * sizeof(PCDIMENSION *));
	int i;
	for(i=0; i<ndims; ++i)
	{
		dim[i] = pc_schema_get_dimension_by_name(schema, name[i]);
		if ( ! dim[i] ) {
			pcerror("dimension \"%s\" does not exist", name[i]);
			return NULL;
		}
		assert(dim[i]->scale>0);
	}
	dim[ndims] = NULL;
	return dim;
}

PCPATCH *
pc_patch_sort(const PCPATCH *pa, const char ** name, int ndims)
{
	PCDIMENSION_LIST dim = pc_schema_get_dimensions_by_name(pa->schema, name, ndims);
	PCPATCH *pu = pc_patch_uncompress(pa);
	if ( !pu ) {
		pcfree(dim);
		pcerror("Patch uncompression failed");
		return NULL;
	}
	PCPATCH_UNCOMPRESSED *ps = pc_patch_uncompressed_sort((PCPATCH_UNCOMPRESSED *)pu, dim);

	pcfree(dim);
	if ( pu != pa )
		pc_patch_free(pu);
	return (PCPATCH *) ps;
}


/**
* IsSorted
*/

uint32_t
pc_patch_uncompressed_is_sorted(const PCPATCH_UNCOMPRESSED *pu, PCDIMENSION_LIST dim, char strict)
{
	size_t size = pu->schema->size;
	uint8_t *buf = pu->data, *last = pu->data+pu->datasize-size;
	while ( buf < last )
	{
		if( pc_compare_dim(buf,buf+size,dim) >= strict )
			return PC_FALSE;
		buf += size;
	}
	return PC_TRUE;
}

uint32_t
pc_bytes_uncompressed_is_sorted(const PCBYTES *pcb, char strict)
{
	assert(pcb->compression == PC_DIM_NONE);
	size_t size = pc_interpretation_size(pcb->interpretation);
	uint8_t *buf  = pcb->bytes;
	uint8_t *last = buf+pcb->size-size;
	while ( buf < last )
	{
		if( pc_compare_pcb(buf,buf+size,pcb) >= strict )
			return PC_FALSE;
		buf += size;
	}
	return PC_TRUE;
}


uint32_t
pc_bytes_sigbits_is_sorted(const PCBYTES *pcb, char strict)
{
	assert(pcb->compression == PC_DIM_SIGBITS);
	pcinfo("%s not implemented, decoding",__func__);
	PCBYTES dpcb = pc_bytes_decode(*pcb);
	uint32_t is_sorted = pc_bytes_uncompressed_is_sorted(&dpcb,strict);
	pc_bytes_free(dpcb);
	return is_sorted;
}

uint32_t
pc_bytes_zlib_is_sorted(const PCBYTES *pcb, char strict)
{
	assert(pcb->compression == PC_DIM_ZLIB);
	pcinfo("%s not implemented, decoding",__func__);
	PCBYTES dpcb = pc_bytes_decode(*pcb);
	uint32_t is_sorted = pc_bytes_uncompressed_is_sorted(&dpcb,strict);
	pc_bytes_free(dpcb);
	return is_sorted;
}


uint32_t
pc_bytes_run_length_is_sorted(const PCBYTES *pcb, char strict)
{
	assert(pcb->compression == PC_DIM_RLE);
	uint8_t run;
	size_t size = pc_interpretation_size(pcb->interpretation);
	const uint8_t *bytes_rle_curr_val = pcb->bytes + 1;
	const uint8_t *bytes_rle_next_val = pcb->bytes + 2 + size;
	const uint8_t *bytes_rle_end_val  = pcb->bytes + pcb->size - size;
	while( bytes_rle_next_val < bytes_rle_end_val )
	{
		run = bytes_rle_curr_val[-1];
		assert(run>0);
		if( pc_compare_pcb(bytes_rle_curr_val,bytes_rle_next_val,pcb) >= strict // value comparison
				|| (strict && run > 1) ) // run_length should be 1 if strict
			return PC_FALSE;
		bytes_rle_curr_val = bytes_rle_next_val;
		bytes_rle_next_val += 1 + size;
	}
	return PC_TRUE;
}


uint32_t
pc_patch_dimensional_is_sorted(const PCPATCH_DIMENSIONAL *pdl, PCDIMENSION_LIST dim, char strict)
{
	assert(pdl);
	assert(pdl->schema);

	// uncompress when checking multiple dimensions
	if(dim[1])
	{
		PCPATCH_UNCOMPRESSED *pu = pc_patch_uncompressed_from_dimensional(pdl);
		if ( !pu ) {
			pcerror("Patch uncompression failed");
			return PC_FAILURE - 1; // aliasing issue : PC_FALSE == PC_FAILURE...
		}
		uint32_t is_sorted = pc_patch_uncompressed_is_sorted(pu,dim,strict);
		pc_patch_free((PCPATCH *)pu);
		return is_sorted;
	}

	PCBYTES *pcb = pdl->bytes + dim[0]->position;
	switch ( pcb->compression )
	{
	case PC_DIM_RLE:
	{
		return pc_bytes_run_length_is_sorted(pcb,strict);
	}
	case PC_DIM_SIGBITS:
	{
		return pc_bytes_sigbits_is_sorted(pcb,strict);
	}
	case PC_DIM_ZLIB:
	{
		return pc_bytes_zlib_is_sorted(pcb,strict);
	}
	case PC_DIM_NONE:
	{
		return pc_bytes_uncompressed_is_sorted(pcb,strict);
	}
	default:
	{
		pcerror("%s: Uh oh", __func__);
	}
	}
	return PC_FAILURE - 1; // aliasing issue : PC_FALSE == PC_FAILURE...
}


uint32_t
pc_patch_lazperf_is_sorted(const PCPATCH_LAZPERF *pa, PCDIMENSION_LIST dim, char strict)
{
	PCPATCH_UNCOMPRESSED *pu = pc_patch_uncompressed_from_lazperf(pa);
	if ( !pu ) {
		pcerror("Patch uncompression failed");
		return PC_FAILURE - 1; // aliasing issue : PC_FALSE == PC_FAILURE...
	}
	uint32_t is_sorted = pc_patch_uncompressed_is_sorted(pu,dim,strict);
	pc_patch_free((PCPATCH*) pu);
	return is_sorted;
}

uint32_t
pc_patch_is_sorted(const PCPATCH *pa, const char **name, int ndims, char strict)
{
	int is_sorted = PC_FAILURE -1; // aliasing issue : PC_FALSE == PC_FAILURE...
	PCDIMENSION_LIST dim = pc_schema_get_dimensions_by_name(pa->schema, name, ndims);
	if ( ! dim ) return is_sorted;
	strict = (strict > 0); // ensure 0-1 value

	switch( pa->type )
	{
	case PC_NONE:
		is_sorted = pc_patch_uncompressed_is_sorted((PCPATCH_UNCOMPRESSED*)pa,dim,strict);
		break;
	case PC_DIMENSIONAL:
		is_sorted = pc_patch_dimensional_is_sorted((PCPATCH_DIMENSIONAL*)pa,dim,strict);
		break;
	case PC_LAZPERF:
		is_sorted = pc_patch_lazperf_is_sorted((PCPATCH_LAZPERF*)pa,dim,strict);
		break;
	default:
		pcerror("%s: unsupported compression %d requested", __func__, pa->type);
	}
	pcfree(dim);
	return is_sorted;
}