/*
    loader.c
    $Id: loader.c,v 1.2 2005/12/30 03:28:22 dmochiha Exp $
*/
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include "loader.h"
#include "dmatrix.h"

static char ws[] = " \t\n";
static char buf[BUFSIZ];
static char line[LINEBUFSIZ];

static int ntokens (char *line);
static int filelines (FILE *fp);
static int filetokens (FILE *fp);
static int isspaces (char *s);

double *
load_vector (char *file, int *dims) /* both column and row vectors ok */
{
	FILE *fp;
	double *vector;
	int i;

	/* open file */
	if ((fp = fopen(file, "r")) == NULL) {
		fprintf(stderr, "load_vector:: can't open %s.\n", file);
		return NULL;
	}
	*dims = filetokens(fp);
	if (!(*dims > 0)) {
		fprintf(stderr, "load_vector:: dimension invalid.\n");
		return NULL;
	}
	/* allocate vector */
	if ((vector = (double *)calloc(*dims, sizeof(double))) == NULL) {
		fprintf(stderr, "load_vector:: can't allocate vector.\n");
		return NULL;
	}
	/* read */
	i = 0;
	while (fscanf(fp, "%s", buf) != EOF)
	{
		vector[i] = atof(buf);
		i++;
	}

	fclose(fp);
	return vector;
}

double **
load_matrix (char *file, int *rows, int *cols)
{
	FILE *fp;
	int i, j;
	char *token;
	double **matrix;

	/* inspect dimensions */
	matrix_dimensions (file, rows, cols);
	if (!((*rows > 0) && (*cols > 0))) {
		fprintf(stderr, "load_matrix:: dimensions invalid.\n");
		return NULL;
	}
	
	/* open file */
	if ((fp = fopen(file, "r")) == NULL) {
		fprintf(stderr, "load_matrix:: can't open %s.\n", file);
		return NULL;
	}
	if ((matrix = dmatrix(*rows, *cols)) == NULL) {
		fprintf(stderr, "load_matrix:: can't allocate matrix.\n");
		return NULL;
	}
	i = 0;
	
	/* load data */
	while (fgets(line, sizeof(line), fp))
	{
		if (isspaces(line))
			continue;
		for (token = strtok(line, ws), j = 0; token;
		     token = strtok(NULL, ws), j++)
		{
			matrix[i][j] = atof(token);
		}
		i++;
	}

	fclose(fp);
	return matrix;
}

double **
load_matrix_transposed (char *file, int *rows, int *cols)
{
	FILE *fp;
	int i, j;
	char *token;
	double **matrix;

	/* inspect dimensions */
	matrix_dimensions (file, cols, rows);
	if (!((*rows > 0) && (*cols > 0))) {
		fprintf(stderr, "load_matrix:: dimensions invalid.\n");
		return NULL;
	}
	
	/* open file */
	if ((fp = fopen(file, "r")) == NULL) {
		fprintf(stderr, "load_matrix:: can't open %s.\n", file);
		return NULL;
	}
	if ((matrix = dmatrix(*rows, *cols)) == NULL) {
		fprintf(stderr, "load_matrix:: can't allocate matrix.\n");
		return NULL;
	}
	i = 0;
	
	/* load data */
	while (fgets(line, sizeof(line), fp))
	{
		if (isspaces(line))
			continue;
		for (token = strtok(line, ws), j = 0; token;
		     token = strtok(NULL, ws), j++)
		{
			matrix[j][i] = atof(token);
		}
		i++;
	}

	fclose(fp);
	return matrix;
}

void
matrix_dimensions (char *file, int *rows, int *cols)
{
	FILE *fp;
	int n, np = 0;
	
	if ((fp = fopen(file, "r")) == NULL) {
		fprintf(stderr, "matrix_dimensions:: can't open matrix %s.\n",
			file);
		return;
	}
	*rows = filelines(fp);
	
	while (fgets(line, sizeof(line), fp))
	{
		if (isspaces(line))
			continue;
		n = ntokens(line);
		if ((np > 0) && (n != np))
		{
			fprintf(stderr, "matrix_dimensions:: columns are not identical.\n");
			return;
		}
		np = n;
	}
	*cols = n;

	fclose(fp);
	return;
}

static int
ntokens (char *line)
{
	char *token;
	int n = 0;

	if ((token = strtok(line, ws)) == NULL)
		return 0;
	else
		n++;
	while (token = strtok(NULL, ws))
		n++;

	return n;
}

static int
filetokens (FILE *fp)
{
	int n = 0;

	while (fscanf(fp, "%s", buf) != EOF)
		n++;
	rewind(fp);
	return n;
}

static int
filelines (FILE *fp)
{
	int n = 0;

	while (fgets(line, sizeof(line), fp))
	{
		if (!isspaces(line))
			n++;
	}
	rewind(fp);
	return n;
}

static int
isspaces (char *s)  /* return 1 if s consists of only white spaces */
{
	char *c = s;
	while (*c)
	{
		if (!isspace(*c))
			return 0;
		c++;
	}
	return 1;
}