#include "resource_importer_obj.h"

#include "io/resource_saver.h"
#include "scene/resources/mesh.h"
#include "scene/resources/surface_tool.h"
#include "scene/resources/surface_tool.h"
#include "os/file_access.h"

String ResourceImporterOBJ::get_importer_name() const {

	return "obj_mesh";
}

String ResourceImporterOBJ::get_visible_name() const{

	return "OBJ As Mesh";
}
void ResourceImporterOBJ::get_recognized_extensions(List<String> *p_extensions) const{

	p_extensions->push_back("obj");
}
String ResourceImporterOBJ::get_save_extension() const {
	return "msh";
}

String ResourceImporterOBJ::get_resource_type() const{

	return "Mesh";
}

bool ResourceImporterOBJ::get_option_visibility(const String& p_option,const Map<StringName,Variant>& p_options) const {

	return true;
}

int ResourceImporterOBJ::get_preset_count() const {
	return 0;
}
String ResourceImporterOBJ::get_preset_name(int p_idx) const {

	return String();
}


void ResourceImporterOBJ::get_import_options(List<ImportOption> *r_options,int p_preset) const {

	r_options->push_back(ImportOption(PropertyInfo(Variant::BOOL,"generate/tangents"),true));
	r_options->push_back(ImportOption(PropertyInfo(Variant::BOOL,"generate/normals"),true));
	//not for nowp
	//r_options->push_back(ImportOption(PropertyInfo(Variant::BOOL,"import/materials")));
	//r_options->push_back(ImportOption(PropertyInfo(Variant::BOOL,"import/textures")));
	r_options->push_back(ImportOption(PropertyInfo(Variant::BOOL,"force/flip_faces"),false));
	r_options->push_back(ImportOption(PropertyInfo(Variant::BOOL,"force/smooth_shading"),true));
	r_options->push_back(ImportOption(PropertyInfo(Variant::BOOL,"force/weld_vertices"),true));
	r_options->push_back(ImportOption(PropertyInfo(Variant::REAL,"force/weld_tolerance",PROPERTY_HINT_RANGE,"0.00001,16,0.00001"),0.0001));
	//r_options->push_back(PropertyInfo(Variant::INT,"compress/bitrate",PROPERTY_HINT_ENUM,"64,96,128,192"));

}



Error ResourceImporterOBJ::import(const String& p_source_file, const String& p_save_path, const Map<StringName,Variant>& p_options, List<String>* r_platform_variants, List<String> *r_gen_files) {

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

	Ref<Mesh> mesh = Ref<Mesh>( memnew( Mesh ) );
	Map<String,Ref<Material> > name_map;



	bool generate_normals=p_options["generate/normals"];
	bool generate_tangents=p_options["generate/tangents"];
	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;

	Ref<SurfaceTool> surf_tool = memnew( SurfaceTool) ;
	surf_tool->begin(Mesh::PRIMITIVE_TRIANGLES);
	if (force_smooth)
		surf_tool->add_smooth_group(true);
	int has_index_data=false;

	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,ERR_INVALID_DATA);
			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,ERR_INVALID_DATA);
			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,ERR_INVALID_DATA);
			Vector3 nrm;
			nrm.x=v[1].to_float();
			nrm.y=v[2].to_float();
			nrm.z=v[3].to_float();
			normals.push_back(nrm);
		} if (l.begins_with("f ")) {
				//vertex

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

			//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,ERR_PARSE_ERROR);
			ERR_FAIL_COND_V(face[0].size()!=face[1].size(),ERR_PARSE_ERROR);
			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(),ERR_PARSE_ERROR);
				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;
						ERR_FAIL_INDEX_V(norm,normals.size(),ERR_PARSE_ERROR);
						surf_tool->add_normal(normals[norm]);
					}

					if (face[idx].size()>=2 && face[idx][1]!=String()) {

						int uv = face[idx][1].to_int()-1;
						ERR_FAIL_INDEX_V(uv,uvs.size(),ERR_PARSE_ERROR);
						surf_tool->add_uv(uvs[uv]);
					}

					int vtx = face[idx][0].to_int()-1;
					ERR_FAIL_INDEX_V(vtx,vertices.size(),ERR_PARSE_ERROR);

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

				face[1]=face[2];
			}
		} else if (l.begins_with("s ") && !force_smooth) { //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("o ") || f->eof_reached()) { //new surface or done

			if (has_index_data) {
				//new object/surface
				if (generate_normals || force_smooth)
					surf_tool->generate_normals();
				if (uvs.size() && (normals.size() || generate_normals) && generate_tangents)
					surf_tool->generate_tangents();

				surf_tool->index();
				mesh = surf_tool->commit(mesh);
				if (name=="")
					name=vformat(TTR("Surface %d"),mesh->get_surface_count()-1);
				mesh->surface_set_name(mesh->get_surface_count()-1,name);
				name="";
				surf_tool->clear();
				surf_tool->begin(Mesh::PRIMITIVE_TRIANGLES);
				if (force_smooth)
					surf_tool->add_smooth_group(true);

				has_index_data=false;

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

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

/*
	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]);
	}
*/

	Error err = ResourceSaver::save(p_save_path+".msh",mesh);

	return err;

}

ResourceImporterOBJ::ResourceImporterOBJ()
{

}
