/*************************************************************************/
/*  resource_importer_obj.cpp                                            */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2017 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  */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
/*************************************************************************/
#include "resource_importer_obj.h"

#include "io/resource_saver.h"
#include "os/file_access.h"
#include "scene/3d/mesh_instance.h"
#include "scene/3d/spatial.h"
#include "scene/resources/mesh.h"
#include "scene/resources/surface_tool.h"

uint32_t EditorOBJImporter::get_import_flags() const {

	return IMPORT_SCENE;
}
void EditorOBJImporter::get_extensions(List<String> *r_extensions) const {

	r_extensions->push_back("obj");
}

Error EditorOBJImporter::_parse_material_library(const String &p_path, Map<String, Ref<SpatialMaterial> > &material_map, List<String> *r_missing_deps) {

	FileAccessRef f = FileAccess::open(p_path, FileAccess::READ);
	ERR_FAIL_COND_V(!f, ERR_CANT_OPEN);

	Ref<SpatialMaterial> current;
	String current_name;
	String base_path = p_path.get_base_dir();
	while (true) {

		String l = f->get_line().strip_edges();

		if (l.begins_with("newmtl ")) {
			//vertex

			current_name = l.replace("newmtl", "").strip_edges();
			current.instance();
			material_map[current_name] = current;
		} else if (l.begins_with("Ka ")) {
			//uv
			print_line("Warning: Ambient light for material '" + current_name + "' is ignored in PBR");

		} else if (l.begins_with("Kd ")) {
			//normal
			ERR_FAIL_COND_V(current.is_null(), ERR_FILE_CORRUPT);
			Vector<String> v = l.split(" ", false);
			ERR_FAIL_COND_V(v.size() < 4, ERR_INVALID_DATA);
			Color c = current->get_albedo();
			c.r = v[1].to_float();
			c.g = v[2].to_float();
			c.b = v[3].to_float();
			current->set_albedo(c);
		} else if (l.begins_with("Ks ")) {
			//normal
			ERR_FAIL_COND_V(current.is_null(), ERR_FILE_CORRUPT);
			Vector<String> v = l.split(" ", false);
			ERR_FAIL_COND_V(v.size() < 4, ERR_INVALID_DATA);
			float r = v[1].to_float();
			float g = v[2].to_float();
			float b = v[3].to_float();
			float metalness = MAX(r, MAX(g, b));
			current->set_metallic(metalness);
		} else if (l.begins_with("Ns ")) {
			//normal
			ERR_FAIL_COND_V(current.is_null(), ERR_FILE_CORRUPT);
			Vector<String> v = l.split(" ", false);
			ERR_FAIL_COND_V(v.size() != 2, ERR_INVALID_DATA);
			float s = v[1].to_float();
			current->set_metallic((1000.0 - s) / 1000.0);
		} else if (l.begins_with("d ")) {
			//normal
			ERR_FAIL_COND_V(current.is_null(), ERR_FILE_CORRUPT);
			Vector<String> v = l.split(" ", false);
			ERR_FAIL_COND_V(v.size() != 2, ERR_INVALID_DATA);
			float d = v[1].to_float();
			Color c = current->get_albedo();
			c.a = d;
			current->set_albedo(c);
			if (c.a < 0.99) {
				current->set_feature(SpatialMaterial::FEATURE_TRANSPARENT, true);
			}
		} else if (l.begins_with("Tr ")) {
			//normal
			ERR_FAIL_COND_V(current.is_null(), ERR_FILE_CORRUPT);
			Vector<String> v = l.split(" ", false);
			ERR_FAIL_COND_V(v.size() != 2, ERR_INVALID_DATA);
			float d = v[1].to_float();
			Color c = current->get_albedo();
			c.a = 1.0 - d;
			current->set_albedo(c);
			if (c.a < 0.99) {
				current->set_feature(SpatialMaterial::FEATURE_TRANSPARENT, true);
			}

		} else if (l.begins_with("map_Ka ")) {
			//uv
			print_line("Warning: Ambient light texture for material '" + current_name + "' is ignored in PBR");

		} else if (l.begins_with("map_Kd ")) {
			//normal
			ERR_FAIL_COND_V(current.is_null(), ERR_FILE_CORRUPT);

			String p = l.replace("map_Kd", "").replace("\\", "/").strip_edges();
			String path = base_path.plus_file(p);

			Ref<Texture> texture = ResourceLoader::load(path);

			if (texture.is_valid()) {
				current->set_texture(SpatialMaterial::TEXTURE_ALBEDO, texture);
			} else {
				r_missing_deps->push_back(path);
			}

		} else if (l.begins_with("map_Ks ")) {
			//normal
			ERR_FAIL_COND_V(current.is_null(), ERR_FILE_CORRUPT);

			String p = l.replace("map_Ks", "").replace("\\", "/").strip_edges();
			String path = base_path.plus_file(p);

			Ref<Texture> texture = ResourceLoader::load(path);

			if (texture.is_valid()) {
				current->set_texture(SpatialMaterial::TEXTURE_METALLIC, texture);
			} else {
				r_missing_deps->push_back(path);
			}

		} else if (l.begins_with("map_Ns ")) {
			//normal
			ERR_FAIL_COND_V(current.is_null(), ERR_FILE_CORRUPT);

			String p = l.replace("map_Ns", "").replace("\\", "/").strip_edges();
			String path = base_path.plus_file(p);

			Ref<Texture> texture = ResourceLoader::load(path);

			if (texture.is_valid()) {
				current->set_texture(SpatialMaterial::TEXTURE_ROUGHNESS, texture);
			} else {
				r_missing_deps->push_back(path);
			}
		} else if (l.begins_with("map_bump ")) {
			//normal
			ERR_FAIL_COND_V(current.is_null(), ERR_FILE_CORRUPT);

			String p = l.replace("map_bump", "").replace("\\", "/").strip_edges();
			String path = base_path.plus_file(p);

			Ref<Texture> texture = ResourceLoader::load(path);

			if (texture.is_valid()) {
				current->set_feature(SpatialMaterial::FEATURE_NORMAL_MAPPING, true);
				current->set_texture(SpatialMaterial::TEXTURE_NORMAL, texture);
			} else {
				r_missing_deps->push_back(path);
			}
		} else if (f->eof_reached()) {
			break;
		}
	}

	return OK;
}

Node *EditorOBJImporter::import_scene(const String &p_path, uint32_t p_flags, int p_bake_fps, List<String> *r_missing_deps, Error *r_err) {

	FileAccessRef f = FileAccess::open(p_path, FileAccess::READ);

	if (r_err) {
		*r_err = ERR_CANT_OPEN;
	}

	ERR_FAIL_COND_V(!f, NULL);

	if (r_err) {
		*r_err = OK;
	}

	Spatial *scene = memnew(Spatial);

	Ref<ArrayMesh> mesh;
	mesh.instance();

	Map<String, Ref<Material> > name_map;

	bool generate_tangents = p_flags & IMPORT_GENERATE_TANGENT_ARRAYS;
	bool flip_faces = false;
	//bool flip_faces = p_options["force/flip_faces"];
	//bool force_smooth = p_options["force/smooth_shading"];
	//bool weld_vertices = p_options["force/weld_vertices"];
	//float weld_tolerance = p_options["force/weld_tolerance"];

	Vector<Vector3> vertices;
	Vector<Vector3> normals;
	Vector<Vector2> uvs;
	String name;

	Map<String, Map<String, Ref<SpatialMaterial> > > material_map;

	Ref<SurfaceTool> surf_tool = memnew(SurfaceTool);
	surf_tool->begin(Mesh::PRIMITIVE_TRIANGLES);

	String current_material_library;
	String current_material;
	String current_group;

	while (true) {

		String l = f->get_line().strip_edges();

		if (l.begins_with("v ")) {
			//vertex
			Vector<String> v = l.split(" ", false);
			ERR_FAIL_COND_V(v.size() < 4, NULL);
			Vector3 vtx;
			vtx.x = v[1].to_float();
			vtx.y = v[2].to_float();
			vtx.z = v[3].to_float();
			vertices.push_back(vtx);
		} else if (l.begins_with("vt ")) {
			//uv
			Vector<String> v = l.split(" ", false);
			ERR_FAIL_COND_V(v.size() < 3, NULL);
			Vector2 uv;
			uv.x = v[1].to_float();
			uv.y = 1.0 - v[2].to_float();
			uvs.push_back(uv);

		} else if (l.begins_with("vn ")) {
			//normal
			Vector<String> v = l.split(" ", false);
			ERR_FAIL_COND_V(v.size() < 4, NULL);
			Vector3 nrm;
			nrm.x = v[1].to_float();
			nrm.y = v[2].to_float();
			nrm.z = v[3].to_float();
			normals.push_back(nrm);
		} else if (l.begins_with("f ")) {
			//vertex

			Vector<String> v = l.split(" ", false);
			ERR_FAIL_COND_V(v.size() < 4, NULL);

			//not very fast, could be sped up

			Vector<String> face[3];
			face[0] = v[1].split("/");
			face[1] = v[2].split("/");
			ERR_FAIL_COND_V(face[0].size() == 0, NULL);
			ERR_FAIL_COND_V(face[0].size() != face[1].size(), NULL);
			for (int i = 2; i < v.size() - 1; i++) {

				face[2] = v[i + 1].split("/");
				ERR_FAIL_COND_V(face[0].size() != face[2].size(), NULL);
				for (int j = 0; j < 3; j++) {

					int idx = j;

					if (!flip_faces && idx < 2) {
						idx = 1 ^ idx;
					}

					if (face[idx].size() == 3) {
						int norm = face[idx][2].to_int() - 1;
						if (norm < 0)
							norm += normals.size() + 1;
						ERR_FAIL_INDEX_V(norm, normals.size(), NULL);
						surf_tool->add_normal(normals[norm]);
					}

					if (face[idx].size() >= 2 && face[idx][1] != String()) {
						int uv = face[idx][1].to_int() - 1;
						if (uv < 0)
							uv += uvs.size() + 1;
						ERR_FAIL_INDEX_V(uv, uvs.size(), NULL);
						surf_tool->add_uv(uvs[uv]);
					}

					int vtx = face[idx][0].to_int() - 1;
					if (vtx < 0)
						vtx += vertices.size() + 1;
					ERR_FAIL_INDEX_V(vtx, vertices.size(), NULL);

					Vector3 vertex = vertices[vtx];
					//if (weld_vertices)
					//	vertex.snap(Vector3(weld_tolerance, weld_tolerance, weld_tolerance));
					surf_tool->add_vertex(vertex);
				}

				face[1] = face[2];
			}
		} else if (l.begins_with("s ")) { //smoothing
			String what = l.substr(2, l.length()).strip_edges();
			if (what == "off")
				surf_tool->add_smooth_group(false);
			else
				surf_tool->add_smooth_group(true);
		} else if (l.begins_with("g ") || l.begins_with("usemtl ") || (l.begins_with("o ") || f->eof_reached())) { //commit group to mesh

			if (surf_tool->get_vertex_array().size()) {
				//another group going on, commit it
				if (normals.size() == 0) {
					surf_tool->generate_normals();
				}

				if (generate_tangents && uvs.size()) {
					surf_tool->generate_tangents();
				}

				surf_tool->index();

				print_line("current material library " + current_material_library + " has " + itos(material_map.has(current_material_library)));
				print_line("current material " + current_material + " has " + itos(material_map.has(current_material_library) && material_map[current_material_library].has(current_material)));

				if (material_map.has(current_material_library) && material_map[current_material_library].has(current_material)) {
					surf_tool->set_material(material_map[current_material_library][current_material]);
				}

				mesh = surf_tool->commit(mesh);

				if (current_material != String()) {
					mesh->surface_set_name(mesh->get_surface_count() - 1, current_material.get_basename());
				} else if (current_group != String()) {
					mesh->surface_set_name(mesh->get_surface_count() - 1, current_group);
				}

				print_line("Added surface :" + mesh->surface_get_name(mesh->get_surface_count() - 1));
				surf_tool->clear();
				surf_tool->begin(Mesh::PRIMITIVE_TRIANGLES);
			}

			if (l.begins_with("o ") || f->eof_reached()) {

				MeshInstance *mi = memnew(MeshInstance);
				mi->set_name(name);
				mi->set_mesh(mesh);

				scene->add_child(mi);
				mi->set_owner(scene);

				mesh.instance();
				current_group = "";
				current_material = "";
			}

			if (f->eof_reached()) {
				break;
			}

			if (l.begins_with("o ")) {
				name = l.substr(2, l.length()).strip_edges();
			}

			if (l.begins_with("usemtl ")) {

				current_material = l.replace("usemtl", "").strip_edges();
			}

			if (l.begins_with("g ")) {

				current_group = l.substr(2, l.length()).strip_edges();
			}

		} else if (l.begins_with("mtllib ")) { //parse material

			current_material_library = l.replace("mtllib", "").strip_edges();
			if (!material_map.has(current_material_library)) {
				Map<String, Ref<SpatialMaterial> > lib;
				Error err = _parse_material_library(current_material_library, lib, r_missing_deps);
				if (err == ERR_CANT_OPEN) {
					String dir = p_path.get_base_dir();
					err = _parse_material_library(dir.plus_file(current_material_library), lib, r_missing_deps);
				}
				if (err == OK) {
					material_map[current_material_library] = lib;
				}
			}
		}
	}

	/*
	TODO, check existing materials and merge?
	//re-apply materials if exist
	for(int i=0;i<mesh->get_surface_count();i++) {

		String n = mesh->surface_get_name(i);
		if (name_map.has(n))
			mesh->surface_set_material(i,name_map[n]);
	}
*/

	return scene;
}
Ref<Animation> EditorOBJImporter::import_animation(const String &p_path, uint32_t p_flags) {

	return Ref<Animation>();
}
EditorOBJImporter::EditorOBJImporter() {
}
