/*************************************************************************/
/*  animation_cache.cpp                                                  */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                      https://godotengine.org                          */
/*************************************************************************/
/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
/*                                                                       */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the       */
/* "Software"), to deal in the Software without restriction, including   */
/* without limitation the rights to use, copy, modify, merge, publish,   */
/* distribute, sublicense, and/or sell copies of the Software, and to    */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions:                                             */
/*                                                                       */
/* The above copyright notice and this permission notice shall be        */
/* included in all copies or substantial portions of the Software.       */
/*                                                                       */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
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/*************************************************************************/

#include "animation_cache.h"

void AnimationCache::_node_exit_tree(Node *p_node) {
	//it is one shot, so it disconnects upon arrival

	ERR_FAIL_COND(!connected_nodes.has(p_node));

	connected_nodes.erase(p_node);

	for (int i = 0; i < path_cache.size(); i++) {
		if (path_cache[i].node != p_node) {
			continue;
		}

		path_cache.write[i].valid = false; //invalidate path cache
	}
}

void AnimationCache::_animation_changed() {
	_clear_cache();
}

void AnimationCache::_clear_cache() {
	while (connected_nodes.size()) {
		connected_nodes.front()->get()->disconnect("tree_exiting", callable_mp(this, &AnimationCache::_node_exit_tree));
		connected_nodes.erase(connected_nodes.front());
	}
	path_cache.clear();
	cache_valid = false;
	cache_dirty = true;
}

void AnimationCache::_update_cache() {
	cache_valid = false;

	ERR_FAIL_COND(!root);
	ERR_FAIL_COND(!root->is_inside_tree());
	ERR_FAIL_COND(animation.is_null());

	for (int i = 0; i < animation->get_track_count(); i++) {
		NodePath np = animation->track_get_path(i);

		Node *node = root->get_node(np);
		if (!node) {
			path_cache.push_back(Path());
			ERR_CONTINUE_MSG(!node, "Invalid track path in animation '" + np + "'.");
		}

		Path path;

		Ref<Resource> res;

		if (animation->track_get_type(i) == Animation::TYPE_TRANSFORM3D) {
			if (np.get_subname_count() > 1) {
				path_cache.push_back(Path());
				ERR_CONTINUE_MSG(animation->track_get_type(i) == Animation::TYPE_TRANSFORM3D, "Transform tracks can't have a subpath '" + np + "'.");
			}

			Node3D *sp = Object::cast_to<Node3D>(node);

			if (!sp) {
				path_cache.push_back(Path());
				ERR_CONTINUE_MSG(!sp, "Transform track not of type Node3D '" + np + "'.");
			}

			if (np.get_subname_count() == 1) {
				StringName property = np.get_subname(0);
				String ps = property;

				Skeleton3D *sk = Object::cast_to<Skeleton3D>(node);
				if (!sk) {
					path_cache.push_back(Path());
					ERR_CONTINUE_MSG(!sk, "Property defined in Transform track, but not a Skeleton! '" + np + "'.");
				}

				int idx = sk->find_bone(ps);
				if (idx == -1) {
					path_cache.push_back(Path());
					ERR_CONTINUE_MSG(idx == -1, "Property defined in Transform track, but not a Skeleton Bone! '" + np + "'.");
				}

				path.bone_idx = idx;
				path.skeleton = sk;
			}

			path.spatial = sp;

		} else {
			if (np.get_subname_count() > 0) {
				RES res2;
				Vector<StringName> leftover_subpath;

				// We don't want to cache the last resource unless it is a method call
				bool is_method = animation->track_get_type(i) == Animation::TYPE_METHOD;
				root->get_node_and_resource(np, res2, leftover_subpath, is_method);

				if (res2.is_valid()) {
					path.resource = res2;
				} else {
					path.node = node;
				}
				path.object = res2.is_valid() ? res2.ptr() : (Object *)node;
				path.subpath = leftover_subpath;

			} else {
				path.node = node;
				path.object = node;
				path.subpath = np.get_subnames();
			}
		}

		if (animation->track_get_type(i) == Animation::TYPE_VALUE) {
			if (np.get_subname_count() == 0) {
				path_cache.push_back(Path());
				ERR_CONTINUE_MSG(np.get_subname_count() == 0, "Value Track lacks property: " + np + ".");
			}

		} else if (animation->track_get_type(i) == Animation::TYPE_METHOD) {
			if (path.subpath.size() != 0) { // Trying to call a method of a non-resource

				path_cache.push_back(Path());
				ERR_CONTINUE_MSG(path.subpath.size() != 0, "Method Track has property: " + np + ".");
			}
		}

		path.valid = true;

		path_cache.push_back(path);

		if (!connected_nodes.has(path.node)) {
			connected_nodes.insert(path.node);
			path.node->connect("tree_exiting", callable_mp(this, &AnimationCache::_node_exit_tree), Node::make_binds(path.node), CONNECT_ONESHOT);
		}
	}

	cache_dirty = false;
	cache_valid = true;
}

void AnimationCache::set_track_transform(int p_idx, const Transform3D &p_transform) {
	if (cache_dirty) {
		_update_cache();
	}

	ERR_FAIL_COND(!cache_valid);
	ERR_FAIL_INDEX(p_idx, path_cache.size());
	Path &p = path_cache.write[p_idx];
	if (!p.valid) {
		return;
	}

	ERR_FAIL_COND(!p.node);
	ERR_FAIL_COND(!p.spatial);

	if (p.skeleton) {
		p.skeleton->set_bone_pose(p.bone_idx, p_transform);
	} else {
		p.spatial->set_transform(p_transform);
	}
}

void AnimationCache::set_track_value(int p_idx, const Variant &p_value) {
	if (cache_dirty) {
		_update_cache();
	}

	ERR_FAIL_COND(!cache_valid);
	ERR_FAIL_INDEX(p_idx, path_cache.size());
	Path &p = path_cache.write[p_idx];
	if (!p.valid) {
		return;
	}

	ERR_FAIL_COND(!p.object);
	p.object->set_indexed(p.subpath, p_value);
}

void AnimationCache::call_track(int p_idx, const StringName &p_method, const Variant **p_args, int p_argcount, Callable::CallError &r_error) {
	if (cache_dirty) {
		_update_cache();
	}

	ERR_FAIL_COND(!cache_valid);
	ERR_FAIL_INDEX(p_idx, path_cache.size());
	Path &p = path_cache.write[p_idx];
	if (!p.valid) {
		return;
	}

	ERR_FAIL_COND(!p.object);
	p.object->call(p_method, p_args, p_argcount, r_error);
}

void AnimationCache::set_all(float p_time, float p_delta) {
	if (cache_dirty) {
		_update_cache();
	}

	ERR_FAIL_COND(!cache_valid);

	int tc = animation->get_track_count();
	for (int i = 0; i < tc; i++) {
		switch (animation->track_get_type(i)) {
			case Animation::TYPE_TRANSFORM3D: {
				Vector3 loc, scale;
				Quat rot;
				animation->transform_track_interpolate(i, p_time, &loc, &rot, &scale);
				Transform3D tr(Basis(rot), loc);
				tr.basis.scale(scale);

				set_track_transform(i, tr);

			} break;
			case Animation::TYPE_VALUE: {
				if (animation->value_track_get_update_mode(i) == Animation::UPDATE_CONTINUOUS || (animation->value_track_get_update_mode(i) == Animation::UPDATE_DISCRETE && p_delta == 0)) {
					Variant v = animation->value_track_interpolate(i, p_time);
					set_track_value(i, v);
				} else {
					List<int> indices;
					animation->value_track_get_key_indices(i, p_time, p_delta, &indices);

					for (List<int>::Element *E = indices.front(); E; E = E->next()) {
						Variant v = animation->track_get_key_value(i, E->get());
						set_track_value(i, v);
					}
				}

			} break;
			case Animation::TYPE_METHOD: {
				List<int> indices;
				animation->method_track_get_key_indices(i, p_time, p_delta, &indices);

				for (List<int>::Element *E = indices.front(); E; E = E->next()) {
					Vector<Variant> args = animation->method_track_get_params(i, E->get());
					StringName name = animation->method_track_get_name(i, E->get());
					Callable::CallError err;

					if (!args.size()) {
						call_track(i, name, nullptr, 0, err);
					} else {
						Vector<const Variant *> argptrs;
						argptrs.resize(args.size());
						for (int j = 0; j < args.size(); j++) {
							argptrs.write[j] = &args.write[j];
						}

						call_track(i, name, (const Variant **)&argptrs[0], args.size(), err);
					}
				}

			} break;
			default: {
			}
		}
	}
}

void AnimationCache::set_animation(const Ref<Animation> &p_animation) {
	_clear_cache();

	if (animation.is_valid()) {
		animation->disconnect("changed", callable_mp(this, &AnimationCache::_animation_changed));
	}

	animation = p_animation;

	if (animation.is_valid()) {
		animation->connect("changed", callable_mp(this, &AnimationCache::_animation_changed));
	}
}

void AnimationCache::_bind_methods() {
}

void AnimationCache::set_root(Node *p_root) {
	_clear_cache();
	root = p_root;
}

AnimationCache::AnimationCache() {
}