/***********************************************************************
* pc_filter.c
*
*  Pointclound patch filtering.
*
*  Copyright (c) 2013 OpenGeo
*
***********************************************************************/

#include "pc_api_internal.h"
#include <assert.h>
#include <float.h>


PCBITMAP *
pc_bitmap_new(uint32_t npoints)
{
	PCBITMAP *map = pcalloc(sizeof(PCBITMAP));
	map->map = pcalloc(sizeof(uint8_t)*npoints);
	map->npoints = npoints;
	map->nset = 0;
	return map;
}

void
pc_bitmap_free(PCBITMAP *map)
{
	if (map->map) pcfree(map->map);
	pcfree(map);
}

inline void
pc_bitmap_set(PCBITMAP *map, int i, int val)
{
	uint8_t curval = map->map[i];
	if ( val && (!curval) )
		map->nset++;
	if ( (!val) && curval )
		map->nset--;

	map->map[i] = (val!=0);
}

void
pc_bitmap_filter(PCBITMAP *map, PC_FILTERTYPE filter, int i, double d, double val1, double val2)
{
	switch ( filter )
	{
	case PC_GT:
		pc_bitmap_set(map, i, (d > val1 ? 1 : 0));
		break;
	case PC_LT:
		pc_bitmap_set(map, i, (d < val1 ? 1 : 0));
		break;
	case PC_EQUAL:
		pc_bitmap_set(map, i, (d == val1 ? 1 : 0));
		break;
	case PC_BETWEEN:
		pc_bitmap_set(map, i, (d > val1 && d < val2 ? 1 : 0));
		break;
	}
}

static PCBITMAP *
pc_patch_uncompressed_bitmap(const PCPATCH_UNCOMPRESSED *pa, uint32_t dimnum, PC_FILTERTYPE filter, double val1, double val2)
{
	PCPOINT pt;
	uint32_t i = 0;
	uint8_t *buf = pa->data;
	double d;
	size_t sz = pa->schema->size;
	PCBITMAP *map = pc_bitmap_new(pa->npoints);

	pt.readonly = PC_TRUE;
	pt.schema = pa->schema;

	while ( i < pa->npoints )
	{
		pt.data = buf;
		pc_point_get_double(&pt, pa->schema->dims[dimnum], &d);
		/* Apply the filter to the bitmap */
		pc_bitmap_filter(map, filter, i, d, val1, val2);
		/* Advance data pointer and counter */
		buf += sz;
		i++;
	}

	return map;
}


static PCPATCH_UNCOMPRESSED *
pc_patch_uncompressed_filter(const PCPATCH_UNCOMPRESSED *pu, const PCBITMAP *map)
{
	int i = 0;
	size_t sz = pu->schema->size;
	PCPATCH_UNCOMPRESSED *fpu = pc_patch_uncompressed_make(pu->schema, map->nset);
	uint8_t *buf = pu->data;
	uint8_t *fbuf = fpu->data;

	assert(map->npoints == pu->npoints);

	while ( i < pu->npoints )
	{
		if ( pc_bitmap_get(map, i) )
		{
			memcpy(fbuf, buf, sz);
			fbuf += sz;
		}
		buf += sz;
		i++;
	}

	fpu->maxpoints = fpu->npoints = map->nset;

	if ( PC_FAILURE == pc_patch_uncompressed_compute_extent(fpu) )
	{
		pcerror("%s: failed to compute patch extent", __func__);
		return NULL;
	}

	if ( PC_FAILURE == pc_patch_uncompressed_compute_stats(fpu) )
	{
		pcerror("%s: failed to compute patch stats", __func__);
		return NULL;
	}

	return fpu;
}



static PCBITMAP *
pc_patch_dimensional_bitmap(const PCPATCH_DIMENSIONAL *pdl, uint32_t dimnum, PC_FILTERTYPE filter, double val1, double val2)
{
	assert(dimnum < pdl->schema->ndims);
	double unscaled1 = pc_value_unscale_unoffset(val1, pdl->schema->dims[dimnum]);
	double unscaled2 = pc_value_unscale_unoffset(val2, pdl->schema->dims[dimnum]);

	return pc_bytes_bitmap(&(pdl->bytes[dimnum]), filter, unscaled1, unscaled2);
}

static PCPATCH_DIMENSIONAL *
pc_patch_dimensional_filter(const PCPATCH_DIMENSIONAL *pdl, const PCBITMAP *map)
{
	int i = 0;
	PCPATCH_DIMENSIONAL *fpdl = pc_patch_dimensional_clone(pdl);

    fpdl->stats = pc_stats_clone(pdl->stats);
	fpdl->npoints = map->nset;

	for ( i = 0; i < pdl->schema->ndims; i++ )
	{
		PCDIMENSION *dim;
        PCDOUBLESTAT stats;
        stats.min = FLT_MAX;
        stats.max = -1*FLT_MAX;
        stats.sum = 0;
		fpdl->bytes[i] = pc_bytes_filter(&(pdl->bytes[i]), map, &stats);


		/* Apply scale and offset */
		dim = pdl->schema->dims[i];
		stats.min = pc_value_scale_offset(stats.min, dim);
		stats.max = pc_value_scale_offset(stats.max, dim);
		stats.sum = pc_value_scale_offset(stats.sum, dim);

		/* Save the X/Y stats for use in bounds later */
		if ( i == pdl->schema->x_position )
		{
            fpdl->bounds.xmin = stats.min;
            fpdl->bounds.xmax = stats.max;
        }
		else if ( i == pdl->schema->y_position )
		{
            fpdl->bounds.ymin = stats.min;
            fpdl->bounds.ymax = stats.max;
        }

        pc_point_set_double_by_index(&(fpdl->stats->min), i, stats.min);
        pc_point_set_double_by_index(&(fpdl->stats->max), i, stats.max);
        pc_point_set_double_by_index(&(fpdl->stats->avg), i, stats.sum/fpdl->npoints);
	}

	return fpdl;
}

/* See if it's possible for the filter to have any results, given the stats */
static int
pc_patch_filter_has_results(const PCSTATS *stats, uint32_t dimnum, PC_FILTERTYPE filter, double val1, double val2)
{
    double min, max;
    pc_point_get_double_by_index(&(stats->min), dimnum, &min);
    pc_point_get_double_by_index(&(stats->max), dimnum, &max);
	switch ( filter )
	{
    	case PC_GT:
    	{
            if ( max < val1 ) return PC_FALSE;
    		break;
		}
    	case PC_LT:
    	{
            if ( min > val1 ) return PC_FALSE;
    		break;
		}
    	case PC_EQUAL:
    	{
            if ( min > val1 || max < val1 ) return PC_FALSE;
    		break;
		}
    	case PC_BETWEEN:
	    {
            if ( min > val2 || max < val1 ) return PC_FALSE;
    		break;
		}
	}
    return PC_TRUE;
}


PCPATCH *
pc_patch_filter(const PCPATCH *pa, uint32_t dimnum, PC_FILTERTYPE filter, double val1, double val2)
{
	if ( ! pa ) return NULL;
	PCPATCH *paout;

    /* If the stats say this filter returns an empty result, do that */
    if ( pa->stats && ! pc_patch_filter_has_results(pa->stats, dimnum, filter, val1, val2) )
    {
        /* Empty uncompressed patch to return */
        paout = (PCPATCH*)pc_patch_uncompressed_make(pa->schema, 0);
        return paout;
    }

	switch ( pa->type )
	{
	case PC_NONE:
	{
		PCBITMAP *map = pc_patch_uncompressed_bitmap((PCPATCH_UNCOMPRESSED*)pa, dimnum, filter, val1, val2);
		PCPATCH_UNCOMPRESSED *pu;
		if ( map->nset == 0 )
		{
			pc_bitmap_free(map);
			return (PCPATCH*)pc_patch_uncompressed_make(pa->schema, 0);
		}
		pu = pc_patch_uncompressed_filter((PCPATCH_UNCOMPRESSED*)pa, map);
		pc_bitmap_free(map);
		/* pc_patch_uncompressed_filter computes stats and bounds, so we're ready to return here */
		/* TODO, it could/should compute bounds and stats while filtering the points */
		paout = (PCPATCH*)pu;
		break;
	}
	case PC_GHT:
	{
        PCPATCH_GHT *pgh = pc_patch_ght_filter((PCPATCH_GHT*)pa, dimnum, filter, val1, val2);
		/* pc_patch_ght_filter computes the bounds itself */
		/* TODO: add stats computation to pc_patch_ght_filter */
		/* pc_patch_ght_filter is just re-using the input stats, which is wrong */
        paout = (PCPATCH*)pgh;
		break;
	}
	case PC_DIMENSIONAL:
	{
		PCBITMAP *map = pc_patch_dimensional_bitmap((PCPATCH_DIMENSIONAL*)pa, dimnum, filter, val1, val2);
		PCPATCH_DIMENSIONAL *pdl;
		if ( map->nset == 0 )
		{
			pc_bitmap_free(map);
			return (PCPATCH*)pc_patch_uncompressed_make(pa->schema, 0);
		}
		pdl = pc_patch_dimensional_filter((PCPATCH_DIMENSIONAL*)pa, map);
		pc_bitmap_free(map);
		/* pc_patch_dimensional_filter computes both stats and bounds, so we're done*/
		paout = (PCPATCH*)pdl;
		break;
	}
	default:
		pcerror("%s: failure", __func__);
		return NULL;
	}

	return paout;
}

PCPATCH *
pc_patch_filter_lt_by_name(const PCPATCH *pa, const char *name, double val)
{
	/* Error out if we can't find the name */
	PCDIMENSION *d = pc_schema_get_dimension_by_name(pa->schema, name);
	if ( ! d ) return NULL;

	return pc_patch_filter(pa, d->position, PC_LT, val, val);
}

PCPATCH *
pc_patch_filter_gt_by_name(const PCPATCH *pa, const char *name, double val)
{
	/* Error out if we can't find the name */
	PCDIMENSION *d = pc_schema_get_dimension_by_name(pa->schema, name);
	if ( ! d ) return NULL;

	return pc_patch_filter(pa, d->position, PC_GT, val, val);
}

PCPATCH *
pc_patch_filter_equal_by_name(const PCPATCH *pa, const char *name, double val)
{
	/* Error out if we can't find the name */
	PCDIMENSION *d = pc_schema_get_dimension_by_name(pa->schema, name);
	if ( ! d ) return NULL;

	return pc_patch_filter(pa, d->position, PC_EQUAL, val, val);
}

PCPATCH *
pc_patch_filter_between_by_name(const PCPATCH *pa, const char *name, double val1, double val2)
{
	/* Ensure val1 < val2 always */
	if ( val1 > val2 )
	{
		double tmp = val1;
		val1 = val2;
		val2 = tmp;
	}
	/* Error out if we can't find the name */
	PCDIMENSION *d = pc_schema_get_dimension_by_name(pa->schema, name);
	if ( ! d ) return NULL;

	return pc_patch_filter(pa, d->position, PC_BETWEEN, val1, val2);
}