/*
 * 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) 2016 Blender Foundation.
 * All rights reserved.
 */

/** \file
 * \ingroup depsgraph
 */

#include "intern/builder/deg_builder.h"

#include <cstring>

#include "DNA_anim_types.h"
#include "DNA_layer_types.h"
#include "DNA_ID.h"
#include "DNA_object_types.h"

#include "BLI_utildefines.h"
#include "BLI_ghash.h"
#include "BLI_stack.h"

extern "C" {
#include "BKE_animsys.h"
}

#include "intern/depsgraph.h"
#include "intern/depsgraph_tag.h"
#include "intern/depsgraph_type.h"
#include "intern/eval/deg_eval_copy_on_write.h"
#include "intern/node/deg_node.h"
#include "intern/node/deg_node_id.h"
#include "intern/node/deg_node_component.h"
#include "intern/node/deg_node_operation.h"

#include "DEG_depsgraph.h"

namespace DEG {

/*******************************************************************************
 * Base class for builders.
 */

namespace {

struct VisibilityCheckData {
	eEvaluationMode eval_mode;
	bool is_visibility_animated;
};

void visibility_animated_check_cb(ID * /*id*/, FCurve *fcu, void *user_data)
{
	VisibilityCheckData *data =
	        reinterpret_cast<VisibilityCheckData *>(user_data);
	if (data->is_visibility_animated) {
		return;
	}
	if (data->eval_mode == DAG_EVAL_VIEWPORT) {
		if (STREQ(fcu->rna_path, "hide_viewport")) {
			data->is_visibility_animated = true;
		}
	}
	else if (data->eval_mode == DAG_EVAL_RENDER) {
		if (STREQ(fcu->rna_path, "hide_render")) {
			data->is_visibility_animated = true;
		}
	}
}

bool is_object_visibility_animated(const Depsgraph *graph, Object *object)
{
	AnimData *anim_data = BKE_animdata_from_id(&object->id);
	if (anim_data == NULL) {
		return false;
	}
	VisibilityCheckData data;
	data.eval_mode = graph->mode;
	data.is_visibility_animated = false;
	BKE_fcurves_id_cb(&object->id, visibility_animated_check_cb, &data);
	return data.is_visibility_animated;
}

}  // namespace

bool deg_check_base_available_for_build(const Depsgraph *graph, Base *base)
{
	const int base_flag = (graph->mode == DAG_EVAL_VIEWPORT) ?
	        BASE_ENABLED_VIEWPORT : BASE_ENABLED_RENDER;
	if (base->flag & base_flag) {
		return true;
	}
	if (is_object_visibility_animated(graph, base->object)) {
		return true;
	}
	return false;
}

DepsgraphBuilder::DepsgraphBuilder(Main *bmain, Depsgraph *graph)
        : bmain_(bmain),
          graph_(graph) {
}

bool DepsgraphBuilder::need_pull_base_into_graph(Base *base)
{
	return deg_check_base_available_for_build(graph_, base);
}

/*******************************************************************************
 * Builder finalizer.
 */

namespace {

void deg_graph_build_flush_visibility(Depsgraph *graph)
{
	enum {
		DEG_NODE_VISITED = (1 << 0),
	};

	BLI_Stack *stack = BLI_stack_new(sizeof(OperationNode *),
	                                 "DEG flush layers stack");
	for (IDNode *id_node : graph->id_nodes) {
		GHASH_FOREACH_BEGIN(ComponentNode *, comp_node, id_node->components)
		{
			comp_node->affects_directly_visible |= id_node->is_directly_visible;
		}
		GHASH_FOREACH_END();
	}
	for (OperationNode *op_node : graph->operations) {
		op_node->custom_flags = 0;
		op_node->num_links_pending = 0;
		for (Relation *rel : op_node->outlinks) {
			if ((rel->from->type == NodeType::OPERATION) &&
			    (rel->flag & RELATION_FLAG_CYCLIC) == 0)
			{
				++op_node->num_links_pending;
			}
		}
		if (op_node->num_links_pending == 0) {
			BLI_stack_push(stack, &op_node);
			op_node->custom_flags |= DEG_NODE_VISITED;
		}
	}
	while (!BLI_stack_is_empty(stack)) {
		OperationNode *op_node;
		BLI_stack_pop(stack, &op_node);
		/* Flush layers to parents. */
		for (Relation *rel : op_node->inlinks) {
			if (rel->from->type == NodeType::OPERATION) {
				OperationNode *op_from = (OperationNode *)rel->from;
				op_from->owner->affects_directly_visible |=
				        op_node->owner->affects_directly_visible;
			}
		}
		/* Schedule parent nodes. */
		for (Relation *rel : op_node->inlinks) {
			if (rel->from->type == NodeType::OPERATION) {
				OperationNode *op_from = (OperationNode *)rel->from;
				if ((rel->flag & RELATION_FLAG_CYCLIC) == 0) {
					BLI_assert(op_from->num_links_pending > 0);
					--op_from->num_links_pending;
				}
				if ((op_from->num_links_pending == 0) &&
				    (op_from->custom_flags & DEG_NODE_VISITED) == 0)
				{
					BLI_stack_push(stack, &op_from);
					op_from->custom_flags |= DEG_NODE_VISITED;
				}
			}
		}
	}
	BLI_stack_free(stack);
}

}  // namespace

void deg_graph_build_finalize(Main *bmain, Depsgraph *graph)
{
	/* Make sure dependencies of visible ID datablocks are visible. */
	deg_graph_build_flush_visibility(graph);
	/* Re-tag IDs for update if it was tagged before the relations
	 * update tag. */
	for (IDNode *id_node : graph->id_nodes) {
		ID *id = id_node->id_orig;
		id_node->finalize_build(graph);
		int flag = 0;
		/* Tag rebuild if special evaluation flags changed. */
		if (id_node->eval_flags != id_node->previous_eval_flags) {
			flag |= ID_RECALC_TRANSFORM | ID_RECALC_GEOMETRY;
		}
		/* Tag rebuild if the custom data mask changed. */
		if (id_node->customdata_masks != id_node->previous_customdata_masks) {
			flag |= ID_RECALC_GEOMETRY;
		}
		if (!deg_copy_on_write_is_expanded(id_node->id_cow)) {
			flag |= ID_RECALC_COPY_ON_WRITE;
			/* This means ID is being added to the dependency graph first
			 * time, which is similar to "ob-visible-change" */
			if (GS(id->name) == ID_OB) {
				flag |= ID_RECALC_TRANSFORM | ID_RECALC_GEOMETRY;
			}
		}
		if (flag != 0) {
			graph_id_tag_update(bmain,
			                    graph,
			                    id_node->id_orig,
			                    flag,
			                    DEG_UPDATE_SOURCE_RELATIONS);
		}
	}
}

}  // namespace DEG