#include <stdlib.h>
#include "global.h"

/* hash definitions (these should be prime numbers) ************* */
#define HASHSIZE 7307
#define HASHMOD  89

static CELL *values;
static struct Node *node_pool;
static int node_pool_count;
static CELL *value_pool;
static int value_pool_count;

#define NODE_INCR 32
#define VALUE_INCR 32

static struct Node **sorted_list;

struct Node
{
    CELL *values;
    struct Node *left;
    struct Node *right;
    struct Node *list;
    long count;
    double area;
};

static struct Node **hashtable;
static struct Node *node_list = NULL;
static int node_count = 0, total_count = 0;

int initialize_cell_stats(int n)
{
    int i;

    /* record nilfes first */
    nfiles = n;

    /* allocate a pool of value arrays */
    value_pool_count = 0;
    allocate_values();

    /* set Node pool to empty */
    node_pool_count = 0;


    /* empty the has table */
    hashtable = (struct Node **)G_malloc(HASHSIZE * sizeof(struct Node *));
    for (i = 0; i < HASHSIZE; i++)
	hashtable[i] = NULL;

    return 0;
}

int allocate_values(void)
{
    value_pool_count = VALUE_INCR;
    value_pool = (CELL *) G_calloc(nfiles * value_pool_count, sizeof(CELL));
    values = value_pool;

    return 0;
}

struct Node *NewNode(double area)
{
    struct Node *node;

    if (node_pool_count <= 0)
	node_pool = (struct Node *)G_calloc(node_pool_count =
					    NODE_INCR, sizeof(struct Node));
    node = &node_pool[--node_pool_count];
    node->count = 1;
    node->area = area;
    node->values = values;

    if (--value_pool_count <= 0)
	allocate_values();
    else
	values += nfiles;

    node->left = node->right = NULL;
    node->list = node_list;
    node_list = node;
    node_count++;

    return node;
}


/* Essentially, Rast_quant_add_rule() treats the ranges as half-open,
 *  i.e. the values range from low (inclusive) to high (exclusive).
 *  While half-open ranges are a common concept (e.g. floor() behaves
 *  the same way), the range of a GRASS raster is closed, i.e. both the
 *  low and high values are inclusive.
 *  Therefore the quantized max FP cell gets put in the nsteps+1'th bin
 *  and we need to manually place it back in the previous bin. */
void fix_max_fp_val(CELL *cell, int ncols)
{
    while (ncols-- > 0) {
	if (cell[ncols] > nsteps)
	    cell[ncols] = (CELL)nsteps;
	    /* { G_debug(5, ". resetting %d to %d", cell[ncols], nsteps); } */
    }
    return;
}


/* we can't compute hash on null values, so we change all
 *  nulls to max+1, set NULL_CELL to max+1, and later compare
 *  with NULL_CELL to chack for nulls */
void reset_null_vals(CELL *cell, int ncols)
{
    while (ncols-- > 0) {
	if (Rast_is_c_null_value(&cell[ncols]))
	    cell[ncols] = NULL_CELL;
    }
    return;
}


int update_cell_stats(CELL ** cell, int ncols, double area)
{
    register int i;
    register int hash;
    register struct Node *q, *p = NULL;
    register int dir = 0;

    while (ncols-- > 0) {
	/* copy this cell to an array, compute hash */

	hash = values[0] = cell[0][ncols];

	for (i = 1; i < nfiles; i++)
	    hash = hash * HASHMOD + (values[i] = cell[i][ncols]);

	if (hash < 0)
	    hash = -hash;

	hash %= HASHSIZE;

	/* look it up and update/insert */
	if ((q = hashtable[hash]) == NULL) {
	    hashtable[hash] = NewNode(area);
	}
	else {
	    while (1) {
		for (i = 0; i < nfiles; i++) {
		    if (values[i] < q->values[i]) {
			dir = -1;
			p = q->left;
			break;
		    }
		    if (values[i] > q->values[i]) {
			dir = 1;
			p = q->right;
			break;
		    }
		}

		if (i == nfiles) {	/* match */
		    q->count++;
		    q->area += area;
		    total_count++;
		    break;
		}
		else if (p == NULL) {
		    if (dir < 0)
			q->left = NewNode(area);
		    else
			q->right = NewNode(area);
		    break;
		}
		else
		    q = p;
	    }
	}
    }

    return 0;
}

int node_compare(const void *pp, const void *qq)
{
    struct Node *const *p = pp, *const *q = qq;
    register int i, x;
    register const CELL *a, *b;

    a = (*p)->values;
    b = (*q)->values;
    for (i = nfiles; --i >= 0;)
	if (x = (*a++ - *b++), x)
	    return x;
    return 0;
}

int sort_cell_stats(void)
{
    struct Node **q, *p;

    if (node_count <= 0)
	return 0;

    G_free(hashtable);		/* make a bit more room */
    sorted_list = (struct Node **)G_calloc(node_count, sizeof(struct Node *));
    for (q = sorted_list, p = node_list; p; p = p->list)
	*q++ = p;

    qsort(sorted_list, node_count, sizeof(struct Node *), node_compare);

    return 0;
}

int print_node_count(void)
{
    fprintf(stdout, "%d nodes\n", node_count);

    return 0;
}

int print_cell_stats(char *fmt, int with_percents, int with_counts,
		 int with_areas, int with_labels, char *fs)
{
    int i, n, nulls_found;
    struct Node *node;
    CELL tmp_cell, null_cell;
    DCELL dLow, dHigh;
    char str1[50], str2[50];

    if (no_nulls)
	total_count -= sorted_list[node_count - 1]->count;

    Rast_set_c_null_value(&null_cell, 1);
    if (node_count <= 0) {
	fprintf(stdout, "0");
	for (i = 1; i < nfiles; i++)
	    fprintf(stdout, "%s%s", fs, no_data_str);
	if (with_areas)
	    fprintf(stdout, "%s0.0", fs);
	if (with_counts)
	    fprintf(stdout, "%s0", fs);
	if (with_percents)
	    fprintf(stdout, "%s0.00%%", fs);
	if (with_labels)
	    fprintf(stdout, "%s%s", fs, Rast_get_c_cat(&null_cell, &labels[i]));
	fprintf(stdout, "\n");
    }
    else {
	for (n = 0; n < node_count; n++) {
	    node = sorted_list[n];

	    if (no_nulls || no_nulls_all) {
		nulls_found = 0;
		for (i = 0; i < nfiles; i++)
		    /*
		       if (node->values[i] || (!raw_output && is_fp[i]))
		       break;
		     */
		    if (node->values[i] == NULL_CELL)
			nulls_found++;

		if (nulls_found == nfiles)
		    continue;

		if (no_nulls && nulls_found)
		    continue;
	    }

	    for (i = 0; i < nfiles; i++) {
		if (node->values[i] == NULL_CELL) {
		    fprintf(stdout, "%s%s", i ? fs : "", no_data_str);
		    if (with_labels && !(raw_output && is_fp[i]))
			fprintf(stdout, "%s%s", fs,
				Rast_get_c_cat(&null_cell, &labels[i]));
		}
		else if (raw_output || !is_fp[i] || as_int) {
		    fprintf(stdout, "%s%ld", i ? fs : "",
			    (long)node->values[i]);
		    if (with_labels && !is_fp[i])
			fprintf(stdout, "%s%s", fs,
				Rast_get_c_cat((CELL*) &(node->values[i]),
					  &labels[i]));
		}
		else {		/* find out which floating point range to print */

		    if (cat_ranges)
			Rast_quant_get_ith_rule(&labels[i].q, node->values[i],
					     &dLow, &dHigh, &tmp_cell,
					     &tmp_cell);
		    else {
			dLow = (DMAX[i] - DMIN[i]) / nsteps *
			    (double)(node->values[i] - 1) + DMIN[i];
			dHigh = (DMAX[i] - DMIN[i]) / nsteps *
			    (double)node->values[i] + DMIN[i];
		    }
		    if (averaged) {
			/* print averaged values */
			sprintf(str1, "%10f", (dLow + dHigh) / 2.0);
			G_trim_decimal(str1);
			G_strip(str1);
			fprintf(stdout, "%s%s", i ? fs : "", str1);
		    }
		    else {
			/* print intervals */
			sprintf(str1, "%10f", dLow);
			sprintf(str2, "%10f", dHigh);
			G_trim_decimal(str1);
			G_trim_decimal(str2);
			G_strip(str1);
			G_strip(str2);
			fprintf(stdout, "%s%s-%s", i ? fs : "", str1, str2);
		    }
		    if (with_labels) {
			if (cat_ranges)
			    fprintf(stdout, "%s%s", fs,
				    labels[i].labels[node->values[i]]);
			else
			    fprintf(stdout, "%sfrom %s to %s", fs,
				    Rast_get_d_cat(&dLow, &labels[i]),
				    Rast_get_d_cat(&dHigh, &labels[i]));
		    }
		}

	    }
	    if (with_areas) {
		fprintf(stdout, "%s", fs);
		fprintf(stdout, fmt, node->area);
	    }
	    if (with_counts)
		fprintf(stdout, "%s%ld", fs, (long)node->count);
	    if (with_percents)
		fprintf(stdout, "%s%6.2f%%", fs,
			(double)100 * node->count / total_count);
	    fprintf(stdout, "\n");
	}
    }

    return 0;
}
