/* base class for various operations on bands
 *
 * Copyright: 1991, N. Dessipris, modification of im_bandary()
 *
 * Author: N. Dessipris
 * Written on: 17/04/1991
 * Modified on :
 * 16/3/94 JC
 *	- rewritten for partials
 *	- now in ANSI C
 *	- now works for any number of input images, except zero
 * 7/10/94 JC
 *	- new IM_NEW()
 * 16/4/07
 * 	- fall back to im_copy() for 1 input image
 * 17/1/09
 * 	- cleanups
 * 	- gtk-doc
 * 	- im_bandary() just calls this
 * 	- works for RAD coding too
 * 27/1/10
 * 	- formatalike inputs
 * 17/5/11
 * 	- sizealike inputs
 * 27/10/11
 * 	- rewrite as a class
 * 20/11/11
 * 	- from bandjoin
 * 15/12/17
 * 	- remove max images restriction
 */

/*

	This file is part of VIPS.

	VIPS is free software; you can redistribute it and/or modify
	it under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	02110-1301  USA

 */

/*

	These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk

 */

/*
#define VIPS_DEBUG
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <glib/gi18n-lib.h>

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

#include <vips/vips.h>
#include <vips/internal.h>
#include <vips/debug.h>

#include "bandary.h"

G_DEFINE_ABSTRACT_TYPE(VipsBandary, vips_bandary, VIPS_TYPE_CONVERSION);

static int
vips_bandary_stop(void *vseq, void *a, void *b)
{
	VipsBandarySequence *seq = (VipsBandarySequence *) vseq;

	if (seq->ir) {
		int i;

		for (i = 0; seq->ir[i]; i++)
			VIPS_UNREF(seq->ir[i]);
		VIPS_FREE(seq->ir);
	}

	VIPS_FREE(seq->p);
	VIPS_FREE(seq->pixels);

	VIPS_FREE(seq);

	return 0;
}

static void *
vips_bandary_start(VipsImage *out, void *a, void *b)
{
	VipsImage **in = (VipsImage **) a;
	VipsBandary *bandary = (VipsBandary *) b;

	VipsBandarySequence *seq;
	int i, n;

	if (!(seq = VIPS_NEW(NULL, VipsBandarySequence)))
		return NULL;

	seq->bandary = bandary;
	seq->ir = NULL;
	seq->p = NULL;
	seq->pixels = NULL;

	/* How many images?
	 */
	for (n = 0; in[n]; n++)
		;

	/* Allocate space for region array.
	 */
	if (!(seq->ir = VIPS_ARRAY(NULL, n + 1, VipsRegion *))) {
		vips_bandary_stop(seq, NULL, NULL);
		return NULL;
	}

	/* Create a set of regions.
	 */
	for (i = 0; i < n; i++)
		if (!(seq->ir[i] = vips_region_new(in[i]))) {
			vips_bandary_stop(seq, NULL, NULL);
			return NULL;
		}
	seq->ir[n] = NULL;

	/* Input pointers.
	 */
	if (!(seq->p = VIPS_ARRAY(NULL, n + 1, VipsPel *))) {
		vips_bandary_stop(seq, NULL, NULL);
		return NULL;
	}

	/* Pixel buffer. This is used as working space by some subclasses.
	 */
	if (!(seq->pixels = VIPS_ARRAY(NULL,
			  n * VIPS_IMAGE_SIZEOF_PEL(bandary->ready[0]), VipsPel))) {
		vips_bandary_stop(seq, NULL, NULL);
		return NULL;
	}

	return seq;
}

static int
vips_bandary_gen(VipsRegion *out_region,
	void *vseq, void *a, void *b, gboolean *stop)
{
	VipsBandarySequence *seq = (VipsBandarySequence *) vseq;
	VipsBandary *bandary = (VipsBandary *) b;
	VipsBandaryClass *class = VIPS_BANDARY_GET_CLASS(bandary);
	VipsRect *r = &out_region->valid;

	VipsPel *q;
	int y, i;

	if (vips_reorder_prepare_many(out_region->im, seq->ir, r))
		return -1;
	for (i = 0; i < bandary->n; i++)
		seq->p[i] = VIPS_REGION_ADDR(seq->ir[i], r->left, r->top);
	seq->p[i] = NULL;
	q = VIPS_REGION_ADDR(out_region, r->left, r->top);

	VIPS_GATE_START("vips_bandary_gen: work");

	for (y = 0; y < r->height; y++) {
		class->process_line(seq, q, seq->p, r->width);

		for (i = 0; i < bandary->n; i++)
			seq->p[i] += VIPS_REGION_LSKIP(seq->ir[i]);
		q += VIPS_REGION_LSKIP(out_region);
	}

	VIPS_GATE_STOP("vips_bandary_gen: work");

	return 0;
}

static int
vips_bandary_build(VipsObject *object)
{
	VipsObjectClass *object_class = VIPS_OBJECT_GET_CLASS(object);
	VipsBandaryClass *class = VIPS_BANDARY_GET_CLASS(object);
	VipsConversion *conversion = VIPS_CONVERSION(object);
	VipsBandary *bandary = VIPS_BANDARY(object);

	int i;
	VipsImage **decode;
	VipsImage **format;
	VipsImage **size;

	if (VIPS_OBJECT_CLASS(vips_bandary_parent_class)->build(object))
		return -1;

	if (bandary->n <= 0) {
		vips_error(object_class->nickname,
			"%s", _("no input images"));
		return -1;
	}

	decode = (VipsImage **) vips_object_local_array(object, bandary->n);
	format = (VipsImage **) vips_object_local_array(object, bandary->n);
	size = (VipsImage **) vips_object_local_array(object, bandary->n);

	for (i = 0; i < bandary->n; i++)
		if (vips_image_decode(bandary->in[i], &decode[i]))
			return -1;
	if (vips__formatalike_vec(decode, format, bandary->n) ||
		vips__sizealike_vec(format, size, bandary->n))
		return -1;
	bandary->ready = size;

	if (vips_image_pipeline_array(conversion->out,
			VIPS_DEMAND_STYLE_THINSTRIP, bandary->ready))
		return -1;

	conversion->out->Bands = bandary->out_bands;
	if (class->format_table)
		conversion->out->BandFmt =
			class->format_table[bandary->ready[0]->BandFmt];

	if (vips_image_generate(conversion->out,
			vips_bandary_start, vips_bandary_gen, vips_bandary_stop,
			bandary->ready, bandary))
		return -1;

	return 0;
}

static void
vips_bandary_class_init(VipsBandaryClass *class)
{
	GObjectClass *gobject_class = G_OBJECT_CLASS(class);
	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS(class);
	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS(class);

	VIPS_DEBUG_MSG("vips_bandary_class_init\n");

	gobject_class->set_property = vips_object_set_property;
	gobject_class->get_property = vips_object_get_property;

	vobject_class->nickname = "bandary";
	vobject_class->description = _("operations on image bands");
	vobject_class->build = vips_bandary_build;

	operation_class->flags = VIPS_OPERATION_SEQUENTIAL;
}

static void
vips_bandary_init(VipsBandary *bandary)
{
	bandary->out_bands = -1;
}

/* Call this before chaining up in _build() to make the operation fall back to
 * copy.
 */
int
vips_bandary_copy(VipsBandary *bandary)
{
	VipsObjectClass *object_class = VIPS_OBJECT_GET_CLASS(bandary);
	VipsConversion *conversion = VIPS_CONVERSION(bandary);

	if (!bandary->in) {
		vips_error(object_class->nickname,
			"%s", _("no input images"));
		return -1;
	}

	/* This isn't set by arith until build(), so we have to set
	 * again here.
	 *
	 * Should arith set out in _init()?
	 */
	g_object_set(bandary, "out", vips_image_new(), NULL);

	return vips_image_write(bandary->in[0], conversion->out);
}