/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU 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 General Public License for more details.
 *
 * You should have received a copy of the GNU 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.
 *
 * The Original Code is Copyright (C) 2007 Blender Foundation.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): Nathan Letwory.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/nodes/intern/node_util.c
 *  \ingroup nodes
 */

#include <ctype.h>
#include <limits.h>
#include <string.h>

#include "DNA_node_types.h"

#include "BLI_listbase.h"
#include "BLI_string.h"
#include "BLI_utildefines.h"

#include "BLT_translation.h"

#include "BKE_colortools.h"
#include "BKE_node.h"

#include "RNA_access.h"
#include "RNA_enum_types.h"

#include "MEM_guardedalloc.h"

#include "node_util.h"

/**** Storage Data ****/

void node_free_curves(bNode *node)
{
	curvemapping_free(node->storage);
}

void node_free_standard_storage(bNode *node)
{
	if (node->storage) {
		MEM_freeN(node->storage);
	}
}

void node_copy_curves(bNodeTree *UNUSED(dest_ntree), bNode *dest_node, bNode *src_node)
{
	dest_node->storage = curvemapping_copy(src_node->storage);
}

void node_copy_standard_storage(bNodeTree *UNUSED(dest_ntree), bNode *dest_node, bNode *src_node)
{
	dest_node->storage = MEM_dupallocN(src_node->storage);
}

void *node_initexec_curves(bNodeExecContext *UNUSED(context), bNode *node, bNodeInstanceKey UNUSED(key))
{
	curvemapping_initialize(node->storage);
	return NULL;  /* unused return */
}


/**** Labels ****/

void node_blend_label(bNodeTree *UNUSED(ntree), bNode *node, char *label, int maxlen)
{
	const char *name;
	RNA_enum_name(rna_enum_ramp_blend_items, node->custom1, &name);
	BLI_strncpy(label, IFACE_(name), maxlen);
}

void node_image_label(bNodeTree *UNUSED(ntree), bNode *node, char *label, int maxlen)
{
	/* if there is no loaded image, return an empty string, and let nodeLabel() fill in the proper type translation. */
	BLI_strncpy(label, (node->id) ? node->id->name + 2 : "", maxlen);
}

void node_math_label(bNodeTree *UNUSED(ntree), bNode *node, char *label, int maxlen)
{
	const char *name;
	RNA_enum_name(rna_enum_node_math_items, node->custom1, &name);
	BLI_strncpy(label, IFACE_(name), maxlen);
}

void node_vect_math_label(bNodeTree *UNUSED(ntree), bNode *node, char *label, int maxlen)
{
	const char *name;
	RNA_enum_name(rna_enum_node_vec_math_items, node->custom1, &name);
	BLI_strncpy(label, IFACE_(name), maxlen);
}

void node_filter_label(bNodeTree *UNUSED(ntree), bNode *node, char *label, int maxlen)
{
	const char *name;
	RNA_enum_name(rna_enum_node_filter_items, node->custom1, &name);
	BLI_strncpy(label, IFACE_(name), maxlen);
}


/*** Link Insertion ***/

/* test if two sockets are interchangeable */
static bool node_link_socket_match(bNodeSocket *a, bNodeSocket *b)
{
	/* tests if alphabetic prefix matches
	 * this allows for imperfect matches, such as numeric suffixes,
	 * like Color1/Color2
	 */
	int prefix_len = 0;
	char *ca = a->name, *cb = b->name;
	for (; *ca != '\0' && *cb != '\0'; ++ca, ++cb) {
		/* end of common prefix? */
		if (*ca != *cb) {
			/* prefix delimited by non-alphabetic char */
			if (isalpha(*ca) || isalpha(*cb))
				return false;
			break;
		}
		++prefix_len;
	}
	return prefix_len > 0;
}

static int node_count_links(bNodeTree *ntree, bNodeSocket *sock)
{
	bNodeLink *link;
	int count = 0;
	for (link = ntree->links.first; link; link = link->next) {
		if (link->fromsock == sock)
			++count;
		if (link->tosock == sock)
			++count;
	}
	return count;
}

/* find an eligible socket for linking */
static bNodeSocket *node_find_linkable_socket(bNodeTree *ntree, bNode *node, bNodeSocket *cur)
{
	/* link swapping: try to find a free slot with a matching name */
	
	bNodeSocket *first = cur->in_out == SOCK_IN ? node->inputs.first : node->outputs.first;
	bNodeSocket *sock;
	
	sock = cur->next ? cur->next : first; /* wrap around the list end */
	while (sock != cur) {
		if (!nodeSocketIsHidden(sock) && node_link_socket_match(sock, cur)) {
			int link_count = node_count_links(ntree, sock);
			/* take +1 into account since we would add a new link */
			if (link_count + 1 <= sock->limit)
				return sock; /* found a valid free socket we can swap to */
		}
		
		sock = sock->next ? sock->next : first; /* wrap around the list end */
	}
	return NULL;
}

void node_insert_link_default(bNodeTree *ntree, bNode *node, bNodeLink *link)
{
	bNodeSocket *sock = link->tosock;
	bNodeLink *tlink, *tlink_next;
	
	/* inputs can have one link only, outputs can have unlimited links */
	if (node != link->tonode)
		return;
	
	for (tlink = ntree->links.first; tlink; tlink = tlink_next) {
		bNodeSocket *new_sock;
		tlink_next = tlink->next;
		
		if (sock != tlink->tosock)
			continue;
		
		new_sock = node_find_linkable_socket(ntree, node, sock);
		if (new_sock && new_sock != sock) {
			/* redirect existing link */
			tlink->tosock = new_sock;
		}
		else if (!new_sock) {
			/* no possible replacement, remove tlink */
			nodeRemLink(ntree, tlink);
			tlink = NULL;
		}
	}
}


/**** Internal Links (mute and disconnect) ****/

/* common datatype priorities, works for compositor, shader and texture nodes alike
 * defines priority of datatype connection based on output type (to):
 *   < 0  : never connect these types
 *   >= 0 : priority of connection (higher values chosen first)
 */
static int node_datatype_priority(eNodeSocketDatatype from, eNodeSocketDatatype to)
{
	switch (to) {
		case SOCK_RGBA:
			switch (from) {
				case SOCK_RGBA:     return 4;
				case SOCK_FLOAT:    return 3;
				case SOCK_INT:      return 2;
				case SOCK_BOOLEAN:  return 1;
				default: return -1;
			}
		case SOCK_VECTOR:
			switch (from) {
				case SOCK_VECTOR:   return 4;
				case SOCK_FLOAT:    return 3;
				case SOCK_INT:      return 2;
				case SOCK_BOOLEAN:  return 1;
				default:            return -1;
			}
		case SOCK_FLOAT:
			switch (from) {
				case SOCK_FLOAT:    return 5;
				case SOCK_INT:      return 4;
				case SOCK_BOOLEAN:  return 3;
				case SOCK_RGBA:     return 2;
				case SOCK_VECTOR:   return 1;
				default:            return -1;
			}
		case SOCK_INT:
			switch (from) {
				case SOCK_INT:      return 5;
				case SOCK_FLOAT:    return 4;
				case SOCK_BOOLEAN:  return 3;
				case SOCK_RGBA:     return 2;
				case SOCK_VECTOR:   return 1;
				default:            return -1;
			}
		case SOCK_BOOLEAN:
			switch (from) {
				case SOCK_BOOLEAN:  return 5;
				case SOCK_INT:      return 4;
				case SOCK_FLOAT:    return 3;
				case SOCK_RGBA:     return 2;
				case SOCK_VECTOR:   return 1;
				default:            return -1;
			}
		case SOCK_SHADER:
			switch (from) {
				case SOCK_SHADER:   return 1;
				default:            return -1;
			}
		case SOCK_STRING:
			switch (from) {
				case SOCK_STRING:   return 1;
				default:            return -1;
			}
		default: return -1;
	}
}

/* select a suitable input socket for an output */
static bNodeSocket *select_internal_link_input(bNode *node, bNodeSocket *output)
{
	bNodeSocket *selected = NULL, *input;
	int i;
	int sel_priority = -1;
	bool sel_is_linked = false;
	
	for (input = node->inputs.first, i = 0; input; input = input->next, ++i) {
		int priority = node_datatype_priority(input->type, output->type);
		bool is_linked = (input->link != NULL);
		bool preferred;
		
		if (nodeSocketIsHidden(input) ||                /* ignore hidden sockets */
		    input->flag & SOCK_NO_INTERNAL_LINK ||      /* ignore if input is not allowed for internal connections */
		    priority < 0 ||                             /* ignore incompatible types */
		    priority < sel_priority)                    /* ignore if we already found a higher priority input */
		{
			continue;
		}
		
		/* determine if this input is preferred over the currently selected */
		preferred = (priority > sel_priority) ||    /* prefer higher datatype priority */
		            (is_linked && !sel_is_linked);  /* prefer linked over unlinked */
		
		if (preferred) {
			selected = input;
			sel_is_linked = is_linked;
			sel_priority = priority;
		}
	}
	
	return selected;
}

void node_update_internal_links_default(bNodeTree *ntree, bNode *node)
{
	bNodeLink *link;
	bNodeSocket *output, *input;
	
	/* sanity check */
	if (!ntree)
		return;
	
	/* use link pointer as a tag for handled sockets (for outputs is unused anyway) */
	for (output = node->outputs.first; output; output = output->next)
		output->link = NULL;
	
	for (link = ntree->links.first; link; link = link->next) {
		if (nodeLinkIsHidden(link))
			continue;
		
		output = link->fromsock;
		if (link->fromnode != node || output->link)
			continue;
		if (nodeSocketIsHidden(output) || output->flag & SOCK_NO_INTERNAL_LINK)
			continue;
		output->link = link; /* not really used, just for tagging handled sockets */
		
		/* look for suitable input */
		input = select_internal_link_input(node, output);
		
		if (input) {
			bNodeLink *ilink = MEM_callocN(sizeof(bNodeLink), "internal node link");
			ilink->fromnode = node;
			ilink->fromsock = input;
			ilink->tonode = node;
			ilink->tosock = output;
			/* internal link is always valid */
			ilink->flag |= NODE_LINK_VALID;
			BLI_addtail(&node->internal_links, ilink);
		}
	}
	
	/* clean up */
	for (output = node->outputs.first; output; output = output->next)
		output->link = NULL;
}


/**** Default value RNA access ****/

float node_socket_get_float(bNodeTree *ntree, bNode *UNUSED(node), bNodeSocket *sock)
{
	PointerRNA ptr;
	RNA_pointer_create((ID *)ntree, &RNA_NodeSocket, sock, &ptr);
	return RNA_float_get(&ptr, "default_value");
}

void node_socket_set_float(bNodeTree *ntree, bNode *UNUSED(node), bNodeSocket *sock, float value)
{
	PointerRNA ptr;
	RNA_pointer_create((ID *)ntree, &RNA_NodeSocket, sock, &ptr);
	RNA_float_set(&ptr, "default_value", value);
}

void node_socket_get_color(bNodeTree *ntree, bNode *UNUSED(node), bNodeSocket *sock, float *value)
{
	PointerRNA ptr;
	RNA_pointer_create((ID *)ntree, &RNA_NodeSocket, sock, &ptr);
	RNA_float_get_array(&ptr, "default_value", value);
}

void node_socket_set_color(bNodeTree *ntree, bNode *UNUSED(node), bNodeSocket *sock, const float *value)
{
	PointerRNA ptr;
	RNA_pointer_create((ID *)ntree, &RNA_NodeSocket, sock, &ptr);
	RNA_float_set_array(&ptr, "default_value", value);
}

void node_socket_get_vector(bNodeTree *ntree, bNode *UNUSED(node), bNodeSocket *sock, float *value)
{
	PointerRNA ptr;
	RNA_pointer_create((ID *)ntree, &RNA_NodeSocket, sock, &ptr);
	RNA_float_get_array(&ptr, "default_value", value);
}

void node_socket_set_vector(bNodeTree *ntree, bNode *UNUSED(node), bNodeSocket *sock, const float *value)
{
	PointerRNA ptr;
	RNA_pointer_create((ID *)ntree, &RNA_NodeSocket, sock, &ptr);
	RNA_float_set_array(&ptr, "default_value", value);
}
