#include <string>

#include <glm/glm.hpp>
#include <rapidjson/document.h>
#include <rapidjson/schema.h>
#include <rapidjson/stringbuffer.h>
#include "aixlog.hpp"

#include "entity.h"
#include "mesh.h"
#include "util.h"
#include "scene_loader.h"


// forward declarations
bool parseFile(rapidjson::Document& doc, const char* data_dir, const char* file_name);
bool validateScene(rapidjson::Document& schema_doc, rapidjson::Document& scene_doc,
		const char* scene_file);


// interface

bool
slLoadFile(
		const char* data_dir,
		const char* scene_file,
		const char* schema_file,
		Entity* entity_array,
		uint& entity_count,
		uint max_entities)
{
	if (entity_array == nullptr) {
		LOG(ERROR) << "entity array not initialized\n";
		return false;
	}

	LOG(INFO) << "Loading scene file: " << scene_file << "\n";
	rapidjson::Document doc, schema_doc;
	bool retDoc = parseFile(doc, data_dir, scene_file);
	bool retSchema = parseFile(schema_doc, data_dir, schema_file);

	if (!retDoc || !retSchema || !validateScene(schema_doc, doc, scene_file))
		return false;

	// camera
	const rapidjson::Value& cam = doc["camera"];


	// hex grid

	// entities
	const rapidjson::Value& e = doc["entities"];
	if (e.Size() > max_entities) {
		LOG(ERROR) << "entity count: " << e.Size() << ", was more than max_entities: "
			<< max_entities << "\n";
		return false;
	}

	for (uint i = 0; i < e.Size(); i++) {
		meMeshGroup mg;
		std::string model_path;
		model_path.append(data_dir).append("/").append(e[i]["model_file"].GetString());

		if (meLoadFromFile(model_path.c_str(), mg)) {
			Entity& e = entity_array[entity_count];
			e.mesh_group = mg;
			//
			e.scale = glm::vec3(10,10,10);
			e.translation = glm::vec3(640, 500, 0);
			//
		} else {
			LOG(ERROR) << "Error loading mesh file\n";
			return false;
		}

		entity_count++;
	}

	// lights

	return true;
}

bool
parseFile(rapidjson::Document& doc, const char* data_dir, const char* file_name)
{
	bool ret = true;
	std::string file_path;
	file_path.append(data_dir).append("/").append(file_name);
	char* contents = utilDumpTextFile(file_path.c_str());

	if (contents == nullptr) {
		LOG(ERROR) << "Error reading file: " << file_name << "\n";
		ret = false;
	}

	if (doc.Parse(contents).HasParseError() || !doc.IsObject()) {
		LOG(ERROR) << "Error parrsing scene file: " << file_name << "\n";
		ret = false;
	}

	utilSafeFree(contents);

	return ret;
}

bool
validateScene(rapidjson::Document& schema_doc, rapidjson::Document& scene_doc, const char* scene_file)
{
	rapidjson::SchemaDocument schema(schema_doc);
	rapidjson::SchemaValidator validator(schema);

	if (!scene_doc.Accept(validator)) {
		LOG(ERROR) << "Error validating scene file: " << scene_file << "\n";
		rapidjson::StringBuffer sb;
		validator.GetInvalidSchemaPointer().StringifyUriFragment(sb);
		LOG(ERROR) << "Invalid schema: " << sb.GetString() << "\n";
		LOG(ERROR) << "Invalid keyword:" << validator.GetInvalidSchemaKeyword() << "\n";
		sb.Clear();
		validator.GetInvalidDocumentPointer().StringifyUriFragment(sb);
		LOG(ERROR) << "Invalid Document: " << sb.GetString() << "\n";
		return false;
	}
	
	LOG(INFO) << "scene file: " << scene_file << " passed schema validation\n";

	return true;
}