#include "game.hpp"

#include "camera.hpp"
#include "components.hpp"
#include "ecs.hpp"
#include "entities.hpp"
#include "event.hpp"
#include "font.hpp"
#include "game-settings.hpp"
#include "game-type-defs.hpp"
#include "helpers.hpp"
#include "imgui.h"
#include "level-types.hpp"
#include "level.hpp"
#include "physics.hpp"
#include "player-input.hpp"
#include "plugins.hpp"
#include "project.hpp"
#include "scene.hpp"
#include "static-ui.hpp"
#include "thread-pool.hpp"
#include "window.hpp"
#include "pk.h"

#include <BulletCollision/CollisionShapes/btConvexHullShape.h>
#include <BulletCollision/NarrowPhaseCollision/btRaycastCallback.h>
#include <GLFW/glfw3.h>
#include <cstring>
#include <iomanip>
#include <ostream>
#include <fstream>
#include <thread>

const long readLineLength = 128;
char readLine[readLineLength];
struct InstMapping {
	InstanceHandle origHandle = InstanceHandle_MAX;
	EntityHandle newEntHandle;
	InstanceHandle newInstHandle;
	InstPos newInstance{};
};
pk_arr_t<InstMapping> loadFileInstanceMappings{};

const char *levelName = "demo-level";

const char *PKE_FILE_BEGIN = ":PKFB:";
const char *PKE_FILE_END = ":PKFE:";
const char *PKE_FILE_VERSION = ":0:";
const char *PKE_FILE_OBJ_END = "";
const char *PKE_FILE_OBJ_INSTANCE = "Instance:";
const char *PKE_FILE_OBJ_CAMERA = "Camera:";

const char *PKE_FILE_INSTANCE_HANDLE = "Inst::InstHandle: ";
const char *PKE_FILE_INSTANCE_ENTITY_HANDLE = "EntityHandle: ";
const char *PKE_FILE_INSTANCE_ENTITY_TYPE_CODE = "EntityTypeCode: ";
const char *PKE_FILE_INSTANCE_UUID = "UUID: ";
const char *PKE_FILE_INSTANCE_POS_POS = "InstPos::Pos: ";
const char *PKE_FILE_INSTANCE_POS_ROT = "InstPos::Rot: ";
const char *PKE_FILE_INSTANCE_POS_SCALE = "InstPos::Scale: ";
const char *PKE_FILE_INSTANCE_PHYSICS_MASS = "InstPos::Mass: ";
const char *PKE_FILE_INSTANCE_PHYSICS_COLLISION_LAYER = "InstPos::CollisionLayer: ";
const char *PKE_FILE_INSTANCE_PHYSICS_COLLISION_MASK = "InstPos::CollisionMask: ";
const char *PKE_FILE_INSTANCE_COLLISION_CALLBACK_SIGNATURE = "Inst::CollisionCallbackSignature: ";

const char PKE_FILE_INSTANCE_SPECIAL_ENTITY_TYPE_CODE_CAMERA = 'C';

const char *PKE_FILE_CAMERA_POS = "Cam::Pos: ";
const char *PKE_FILE_CAMERA_ROT = "Cam::Rot: ";
const char *PKE_FILE_CAMERA_TARGET = "Cam::Target: ";
const char *PKE_FILE_CAMERA_TYPE = "Cam::Type: ";
const char *PKE_FILE_CAMERA_UUID = "Cam::UUID: ";
const char *PKE_FILE_CAMERA_ORIENTATION = "Cam::Orientation: ";
const char *PKE_FILE_CAMERA_INSTANCE_HANDLE = "Cam::InstanceHandle: ";
const char *PKE_FILE_CAMERA_TARGET_INSTANCE_HANDLE = "Cam::TargetInstanceHandle: ";
const char *PKE_FILE_CAMERA_IS_PRIMARY = "Cam::IsPrimary: ";

void SerializeCamera(std::ostream &stream, const PkeCamera &cam) {
	NULL_CHAR_ARR(handleStr, 23);
	PkeCamera c{};
	if (cam.uuid != pk_uuid_zed && cam.uuid != pk_uuid_max) {
		stream << PKE_FILE_CAMERA_UUID << cam.uuid << std::endl;
	}
	if (cam.type != c.type) {
		stream << PKE_FILE_CAMERA_TYPE << int(static_cast<PkeCameraType_T>(cam.type)) << std::endl;
	}
	if (cam.view != c.view) {
		stream << PKE_FILE_CAMERA_ORIENTATION << int(static_cast<PkeCameraView_T>(cam.view)) << std::endl;
	}
	if (cam.phys.instHandle != InstanceHandle_MAX) {
		snprintf(handleStr, 22, "0x%08X 0x%08X", cam.phys.instHandle.bucketIndex, cam.phys.instHandle.itemIndex);
		stream << PKE_FILE_CAMERA_INSTANCE_HANDLE << handleStr << std::endl;
	}
	if (cam.phys.targetInstHandle != InstanceHandle_MAX) {
		snprintf(handleStr, 22, "0x%08X 0x%08X", cam.phys.targetInstHandle.bucketIndex, cam.phys.targetInstHandle.itemIndex);
		stream << PKE_FILE_CAMERA_TARGET_INSTANCE_HANDLE << handleStr << std::endl;
	}
	if (cam.isPrimary != c.isPrimary) {
		stream << PKE_FILE_CAMERA_IS_PRIMARY << cam.isPrimary << std::endl;
	}
}

void SerializeInstance(std::ostream &stream, const CompInstance &comp) {
	NULL_CHAR_ARR(handleStr, 23);
	EntityType *et = nullptr;
	if (comp.grBindsHandle != GrBindsHandle_MAX) {
		et = EntityType_FindByEntityHandle(ECS_GetGrBinds(comp.grBindsHandle)->entHandle);
	}
	CompInstance c{};
	InstPos baseInst{};
	baseInst.posRot = btTransform{};
	baseInst.posRot.setIdentity();
	baseInst.scale = btVector3(1, 1, 1);
	baseInst.mass = 1;
	if (comp.entHandle != InstanceHandle_MAX) {
		snprintf(handleStr, 22, "0x%08X 0x%08X", comp.entHandle.bucketIndex, comp.entHandle.itemIndex);
		stream << PKE_FILE_INSTANCE_ENTITY_HANDLE << handleStr << std::endl;
	}
	if (comp.instanceHandle != InstanceHandle_MAX) {
		snprintf(handleStr, 22, "0x%08X 0x%08X", comp.instanceHandle.bucketIndex, comp.instanceHandle.itemIndex);
		stream << PKE_FILE_INSTANCE_HANDLE << handleStr << std::endl;
	}
	if (comp.uuid != pk_uuid_zed && comp.uuid != pk_uuid_max) {
		stream << PKE_FILE_INSTANCE_UUID << comp.uuid << std::endl;
	}
	if (et != nullptr) {
		stream << PKE_FILE_INSTANCE_ENTITY_TYPE_CODE << et->entityTypeCode.val << std::endl;
	} else if (PkeCamera_Get(comp.entHandle)) {
		stream << PKE_FILE_INSTANCE_ENTITY_TYPE_CODE << PKE_FILE_INSTANCE_SPECIAL_ENTITY_TYPE_CODE_CAMERA << std::endl;
	}

	btTransform trans;
	comp.bt.motionState->getWorldTransform(trans);
	btVector3 scale = comp.bt.rigidBody->getCollisionShape()->getLocalScaling();
	btScalar mass = comp.bt.rigidBody->getMass();
	PhysicsCollision collisionLayer{static_cast<PhysicsCollision_T>(comp.bt.rigidBody->getBroadphaseProxy()->m_collisionFilterGroup)};
	PhysicsCollision collisionMask{static_cast<PhysicsCollision_T>(comp.bt.rigidBody->getBroadphaseProxy()->m_collisionFilterMask)};
	if (trans != baseInst.posRot) {
		btVector3 pos = trans.getOrigin();
		btQuaternion rot = trans.getRotation();
		stream << PKE_FILE_INSTANCE_POS_POS << "["
			<< std::setw(10) << pos[0] << ","
			<< std::setw(10) << pos[1] << ","
			<< std::setw(10) << pos[2] << "]" << std::endl
			<< PKE_FILE_INSTANCE_POS_ROT << "["
			<< std::setw(10) << rot[0] << ","
			<< std::setw(10) << rot[1] << ","
			<< std::setw(10) << rot[2] << ","
			<< std::setw(10) << rot[3] << "]" << std::endl;
	}
	if (scale != baseInst.scale)
		stream << PKE_FILE_INSTANCE_POS_SCALE << "["
			<< std::setw(10) << scale[0] << ","
			<< std::setw(10) << scale[1] << ","
			<< std::setw(10) << scale[2] << "]" << std::endl;
	if (mass != baseInst.mass) {
		stream << PKE_FILE_INSTANCE_PHYSICS_MASS << mass << std::endl;
	}
	if (collisionLayer != c.physicsLayer) {
		stream << PKE_FILE_INSTANCE_PHYSICS_COLLISION_LAYER << static_cast<PhysicsCollision_T>(collisionLayer) << std::endl;
	}
	if (collisionMask != c.physicsMask) {
		stream << PKE_FILE_INSTANCE_PHYSICS_COLLISION_MASK << static_cast<PhysicsCollision_T>(collisionMask) << std::endl;
	}
	if (comp.collisionCallback.name[0] != '\0') {
		stream << PKE_FILE_INSTANCE_COLLISION_CALLBACK_SIGNATURE << comp.collisionCallback.name << std::endl;
	}
}

bool FindFirstInstanceHandle(void *handle, void *mapping) {
	InstMapping *inst_mapping = reinterpret_cast<InstMapping *>(mapping);
	return inst_mapping->origHandle == *reinterpret_cast<InstanceHandle *>(handle);
}
void DeserializeCamera(pke_scene *scene, std::istream &stream) {
	PkeCamera cam{};
	InstanceHandle instanceHandle = InstanceHandle_MAX;
	InstanceHandle targetInstanceHandle = InstanceHandle_MAX;
	while (stream.getline(readLine, readLineLength)) {
		if (strcmp(readLine, PKE_FILE_OBJ_END) == 0) {

			int64_t instanceIndex = -1, targetInstanceIndex = -1;

			instanceIndex = pk_arr_find_first_index(&loadFileInstanceMappings, &instanceHandle, FindFirstInstanceHandle);

			if (targetInstanceHandle != InstanceHandle_MAX) {
				targetInstanceIndex = pk_arr_find_first_index(&loadFileInstanceMappings, &targetInstanceHandle, FindFirstInstanceHandle);
			}

			InstPos instPos;
			if (instanceIndex == -1) {
				instPos.mass = 1.f;
				instPos.posRot.setIdentity();
				instPos.scale = btVector3(1.f, 1.f, 1.f);
				fprintf(stdout, "[DeserializeCamera] Failed to find instance mapping. Is this an outdated parse?\n");
			} else {
				instPos = loadFileInstanceMappings[instanceIndex].newInstance;
			}
			auto &rCam = PkeCamera_Register(cam.uuid, instPos);
			rCam.type = cam.type;
			rCam.view = cam.view;
			rCam.isPrimary = cam.isPrimary;
			rCam.phys.targetInstHandle = targetInstanceHandle;
			pke_scene_register_camera(scene->scene_handle, rCam.camHandle);
			if (targetInstanceIndex > -1) {
				PkeCamera_TargetInstance(rCam.camHandle, ECS_GetInstance(loadFileInstanceMappings[targetInstanceIndex].newInstHandle));
			}
			if (rCam.isPrimary == true) {
				ActiveCamera = &rCam;
			}
			return;
		}
		if (strncmp(readLine, PKE_FILE_CAMERA_UUID, strlen(PKE_FILE_CAMERA_TYPE)) == 0) {
			uint64_t prefixLen = strlen(PKE_FILE_CAMERA_UUID);
			(readLine + prefixLen) >> cam.uuid;
			continue;
		}
		if (strncmp(readLine, PKE_FILE_CAMERA_TYPE, strlen(PKE_FILE_CAMERA_TYPE)) == 0) {
			uint64_t prefixLen = strlen(PKE_FILE_CAMERA_TYPE);
			PkeCameraType_T handle_t;
			STR2NUM_ERROR result = str2num(handle_t, readLine + prefixLen);
			assert(result == STR2NUM_ERROR::SUCCESS);
			cam.type = PkeCameraType{handle_t};
			continue;
		}
		if (strncmp(readLine, PKE_FILE_CAMERA_ORIENTATION, strlen(PKE_FILE_CAMERA_ORIENTATION)) == 0) {
			uint64_t prefixLen = strlen(PKE_FILE_CAMERA_ORIENTATION);
			PkeCameraView_T handle_t;
			STR2NUM_ERROR result = str2num(handle_t, readLine + prefixLen);
			assert(result == STR2NUM_ERROR::SUCCESS);
			cam.view = PkeCameraView{handle_t};
			continue;
		}
		if (strstr(readLine, PKE_FILE_CAMERA_INSTANCE_HANDLE)) {
			uint64_t prefixLen = strlen(PKE_FILE_CAMERA_INSTANCE_HANDLE);
			readLine[prefixLen + 10] = '\0';
			STR2NUM_ERROR result1 = str2num(instanceHandle.bucketIndex, readLine + prefixLen);
			STR2NUM_ERROR result2 = str2num(instanceHandle.itemIndex, readLine + prefixLen + 11);
			assert(result1 == STR2NUM_ERROR::SUCCESS);
			assert(result2 == STR2NUM_ERROR::SUCCESS);
			// TODO add to global list
			continue;
		}
		if (strstr(readLine, PKE_FILE_CAMERA_TARGET_INSTANCE_HANDLE)) {
			uint64_t prefixLen = strlen(PKE_FILE_CAMERA_TARGET_INSTANCE_HANDLE);
			readLine[prefixLen + 10] = '\0';
			STR2NUM_ERROR result1 = str2num(targetInstanceHandle.bucketIndex, readLine + prefixLen);
			STR2NUM_ERROR result2 = str2num(targetInstanceHandle.itemIndex, readLine + prefixLen + 11);
			assert(result1 == STR2NUM_ERROR::SUCCESS);
			assert(result2 == STR2NUM_ERROR::SUCCESS);
			// TODO find and set
			continue;
		}
		if (strncmp(readLine, PKE_FILE_CAMERA_IS_PRIMARY, strlen(PKE_FILE_CAMERA_IS_PRIMARY)) == 0) {
			uint64_t prefixLen = strlen(PKE_FILE_CAMERA_IS_PRIMARY);
			uint8_t isPrimary;
			STR2NUM_ERROR result = str2num(isPrimary, readLine + prefixLen);
			assert(result == STR2NUM_ERROR::SUCCESS);
			cam.isPrimary = bool(isPrimary);
			continue;
		}
	}
}

void DeserializeInstance(Entity_Base *parentEntity, std::istream &stream) {
	CompInstance comp{};
	InstMapping mapping {
		.origHandle = InstanceHandle_MAX,
		.newEntHandle = EntityHandle_MAX,
		.newInstHandle = InstanceHandle_MAX,
		.newInstance = {
			.posRot = {},
			.scale = btVector3(1.f, 1.f, 1.f),
			.mass = 1.f,
		},
	};
	mapping.newInstance.posRot.setIdentity();
	comp.collisionCallback.name[0] = '\0';
	NULL_CHAR_ARR(entTypeCode, 21);
	while (stream.getline(readLine, readLineLength)) {
		if (strstr(PKE_FILE_OBJ_END, readLine)) {
			EntityType *etPtr = nullptr;
			Entity_Base *entity = nullptr;
			bool skipEntCreate = false;
			if (strlen(entTypeCode) > 1) {
				etPtr = EntityType_FindByTypeCode(entTypeCode);
				if (etPtr == nullptr) {
					fprintf(stdout, "[Game::DeserializeInstance] Unknown EntityTypeCode: \"%s\"\n", entTypeCode);
					break;
				}
			} else if (strlen(entTypeCode) == 1) {
				// handle internally
				if (entTypeCode[0] == PKE_FILE_INSTANCE_SPECIAL_ENTITY_TYPE_CODE_CAMERA) {
					skipEntCreate = true;
				}
			} else {
				fprintf(stdout, "[Game::DeserializeInstance] Failed to create instance from save file. No EntTypeCode present.\n");
				break;
			}

			if (skipEntCreate == false) {
				if (etPtr != nullptr && etPtr->createInstanceCallback.func != nullptr) {
					/* TODO 2025-03-27 JCB
					 * We have not yet defined what the appropriate callback signature
					 *  for creating an entity instance is.
					 * What should be passed as arguments? What would need to be passed
					 *  that couldn't be accessed globally?
					 * Consider changing this callback to trigger after creating a
					 *  generic instance, rather than *creating* it.
					 */
					// typedef Entity_Base *CreateInst();
					// entity = reinterpret_cast<CreateInst*>(etPtr->createInstanceCallback.func)();
					fprintf(stderr, "[%s] Attempted to call EntityType::createInstanceCallback and we have not yet defined a valid function signature", __FILE__);
				} else {
					entity = EntityType_CreateGenericInstance(etPtr, parentEntity, &comp, &mapping.newInstance);
					fprintf(stdout ,"[Game::DeserializeInstance] Debug: entTypeCode '%s' does not have a registered callback func to handle instance creation.\n", entTypeCode);
				}
				mapping.newEntHandle = entity->handle;
			}
			if (mapping.newEntHandle != EntityHandle_MAX) {
				// TODO this is messy
				pk_arr_t<CompInstance *> instances{};
				ECS_GetInstances(entity, instances);
				assert(instances.next > 0);
				mapping.newInstHandle = instances[0]->instanceHandle;
			}
			pk_arr_append(&loadFileInstanceMappings, &mapping);
			break;
		}
		if (strstr(readLine, PKE_FILE_INSTANCE_ENTITY_HANDLE)) {
			uint64_t prefixLen = strlen(PKE_FILE_INSTANCE_ENTITY_HANDLE);
			readLine[prefixLen + 10] = '\0';
			STR2NUM_ERROR result1 = str2num(comp.entHandle.bucketIndex, readLine + prefixLen);
			STR2NUM_ERROR result2 = str2num(comp.entHandle.itemIndex, readLine + prefixLen + 11);
			assert(result1 == STR2NUM_ERROR::SUCCESS);
			assert(result2 == STR2NUM_ERROR::SUCCESS);
			continue;
		}
		if (strstr(readLine, PKE_FILE_INSTANCE_HANDLE)) {
			uint64_t prefixLen = strlen(PKE_FILE_INSTANCE_HANDLE);
			readLine[prefixLen + 10] = '\0';
			STR2NUM_ERROR result1 = str2num(mapping.origHandle.bucketIndex, readLine + prefixLen);
			STR2NUM_ERROR result2 = str2num(mapping.origHandle.itemIndex, readLine + prefixLen + 11);
			assert(result1 == STR2NUM_ERROR::SUCCESS);
			assert(result2 == STR2NUM_ERROR::SUCCESS);
			continue;
		}
		if (strstr(readLine, PKE_FILE_INSTANCE_UUID)) {
			uint64_t prefixLen = strlen(PKE_FILE_INSTANCE_UUID);
			(readLine + prefixLen) >> comp.uuid ;
			continue;
		}
		if (strstr(readLine, PKE_FILE_INSTANCE_ENTITY_TYPE_CODE)) {
			uint64_t prefixLen = strlen(PKE_FILE_INSTANCE_ENTITY_TYPE_CODE);
			strncpy(entTypeCode, readLine + prefixLen, 21);
			continue;
		}
		if (strstr(readLine, PKE_FILE_INSTANCE_POS_POS)) {
			uint64_t prefixLen = strlen(PKE_FILE_INSTANCE_POS_POS);
			char *startingChar = strchr(readLine + prefixLen, '[') + 1;
			assert(startingChar != nullptr);
			char *pEnd = nullptr;
			long index = 0;
			btVector3 pos;
			do {
				assert(index < 3);
				STR2NUM_ERROR result = str2num(pos[index], startingChar, pEnd);
				assert(result == STR2NUM_ERROR::SUCCESS);
				startingChar = pEnd + 1;
				++index;
			} while (*pEnd != ']');
			mapping.newInstance.posRot.setOrigin(pos);
			continue;
		}
		if (strstr(readLine, PKE_FILE_INSTANCE_POS_ROT)) {
			uint64_t prefixLen = strlen(PKE_FILE_INSTANCE_POS_ROT);
			char *startingChar = strchr(readLine + prefixLen, '[') + 1;
			assert(startingChar != nullptr);
			char *pEnd = nullptr;
			long index = 0;
			btQuaternion rot;
			do {
				assert(index < 4);
				STR2NUM_ERROR result = str2num(rot[index], startingChar, pEnd);
				assert(result == STR2NUM_ERROR::SUCCESS);
				startingChar = pEnd + 1;
				++index;
			} while (*pEnd != ']');
			mapping.newInstance.posRot.setRotation(rot);
			continue;
		}
		if (strstr(readLine, PKE_FILE_INSTANCE_POS_SCALE)) {
			uint64_t prefixLen = strlen(PKE_FILE_INSTANCE_POS_SCALE);
			char *startingChar = strchr(readLine + prefixLen, '[') + 1;
			assert(startingChar != nullptr);
			char *pEnd = nullptr;
			long index = 0;
			do {
				assert(index < 3);
				STR2NUM_ERROR result = str2num(mapping.newInstance.scale[index], startingChar, pEnd);
				assert(result == STR2NUM_ERROR::SUCCESS);
				startingChar = pEnd + 1;
				++index;
			} while (*pEnd != ']');
			continue;
		}
		if (strstr(readLine, PKE_FILE_INSTANCE_PHYSICS_MASS)) {
			uint64_t prefixLen = strlen(PKE_FILE_INSTANCE_PHYSICS_MASS);
			STR2NUM_ERROR result = str2num(mapping.newInstance.mass, readLine + prefixLen);
			assert(result == STR2NUM_ERROR::SUCCESS);
			continue;
		}
		if (strstr(readLine, PKE_FILE_INSTANCE_PHYSICS_COLLISION_LAYER)) {
			uint64_t prefixLen = strlen(PKE_FILE_INSTANCE_PHYSICS_COLLISION_LAYER);
			PhysicsCollision_T val = static_cast<PhysicsCollision_T>(comp.physicsLayer);
			STR2NUM_ERROR result = str2num(val, readLine + prefixLen);
			comp.physicsLayer = PhysicsCollision{val};
			assert(result == STR2NUM_ERROR::SUCCESS);
			continue;
		}
		if (strstr(readLine, PKE_FILE_INSTANCE_PHYSICS_COLLISION_MASK)) {
			uint64_t prefixLen = strlen(PKE_FILE_INSTANCE_PHYSICS_COLLISION_MASK);
			PhysicsCollision_T val = static_cast<PhysicsCollision_T>(comp.physicsMask);
			STR2NUM_ERROR result = str2num(val, readLine + prefixLen);
			comp.physicsMask = PhysicsCollision{val};
			assert(result == STR2NUM_ERROR::SUCCESS);
			continue;
		}
		if (strstr(readLine, PKE_FILE_INSTANCE_COLLISION_CALLBACK_SIGNATURE)) {
			uint64_t prefixLen = strlen(PKE_FILE_INSTANCE_COLLISION_CALLBACK_SIGNATURE);
			strncpy(comp.collisionCallback.name, readLine + prefixLen, 16);
			continue;
		}
	}
}

void Game_SaveSceneFile(const char *sceneFilePath) {
	std::ostringstream stream{};
	bool failed = false;

	try {
		stream << PKE_FILE_BEGIN << std::endl;
		stream << PKE_FILE_VERSION << std::endl;
		stream << "" << std::endl;

		pk_handle_bucket_index_T instanceBucketCount = ECS_GetInstances_BucketCount();
		for (pk_handle_bucket_index_T b = 0; b < instanceBucketCount; ++b) {
			pk_handle_item_index_T count;
			auto *instances = ECS_GetInstances(b, count);
			for (pk_handle_item_index_T i = 0; i < count; ++i) {
				const auto &instance = instances[i];
				if (instance.entHandle == EntityHandle_MAX)
					continue;
				stream << PKE_FILE_OBJ_INSTANCE << std::endl;
				SerializeInstance(stream, instance);
				stream << PKE_FILE_OBJ_END << std::endl;
			}
		}

		pk_handle_bucket_index_T cameraBucketCount = PkeCamera_GetBucketCount();
		for (pk_handle_bucket_index_T b = 0; b < cameraBucketCount; ++b) {
			pk_handle_item_index_T count;
			auto *cameras = PkeCamera_GetCameras(b, count);
			for (pk_handle_item_index_T i = 0; i < count; ++i) {
				const auto &cam = cameras[i];
				if (cam.handle == CameraHandle_MAX)
					continue;
				stream << PKE_FILE_OBJ_CAMERA << std::endl;
				SerializeCamera(stream, cam);
				stream << PKE_FILE_OBJ_END << std::endl;
			}
		}

		stream << PKE_FILE_END << std::endl;
	} catch (std::exception &e) {
		fprintf(stderr, "[%s][Game_SaveSceneFile] Failed to serialize scene file: %s\n", __FILE__, e.what());
		failed = false;
	} catch (...) {
		fprintf(stderr, "[%s][Game_SaveSceneFile] Failed to serialize scene file, uncaught exception.\n", __FILE__);
		failed = false;
	}

	if (failed == false) {
		std::ofstream f(sceneFilePath);
		if (!f.is_open()) {
			failed = true;
		} else {
			f << stream.str();
		}
		f.flush();
		f.close();
	}

	if (failed) {
		NULL_CHAR_ARR(errFileName, 256);
		strncpy(errFileName, sceneFilePath, 256);
		strncpy(errFileName + strlen(sceneFilePath), ".err", 256 - strlen(sceneFilePath));
		std::ofstream errF(sceneFilePath);
		if (errF.is_open()) {
			errF << stream.str();
			errF.flush();
			errF.close();
			fprintf(stderr, "Failed to save scene file '%s', partial output saved to '%s'\n", sceneFilePath, errFileName);
		} else {
			fprintf(stderr, "Failed to save scene file '%s' and also failed to write failed output\n", sceneFilePath);
		}
	}
}

void Game_LoadSceneFile(const char *sceneFilePath) {
	std::ifstream f(sceneFilePath);
	if (!f.is_open()) {
		fprintf(stderr, "Failed to load requested scene file: '%s'\n", sceneFilePath);
		return;
	}
	// TODO scene name is in the file?
	pke_scene *scn = pke_scene_get_by_name(sceneFilePath);
	if (scn == nullptr) {
		scn = pke_scene_create(sceneFilePath);
	}

	memset(readLine, '\0', readLineLength);

	while (f.getline(readLine, readLineLength)) {
		if (strcmp(PKE_FILE_OBJ_INSTANCE, readLine) == 0) {
			DeserializeInstance(scn, f);
			continue;
		}
		if (strcmp(PKE_FILE_OBJ_CAMERA, readLine) == 0) {
			DeserializeCamera(scn, f);
			continue;
		}
	}

	f.close();
	pk_arr_clear(&loadFileInstanceMappings);
}

const int64_t consoleBufferCount = 30;
const int64_t consoleLineLength = 128;
char consoleBuffer[consoleBufferCount][consoleLineLength];
int64_t consoleBufferIndex = 0;
void Game_RecordImGui() {
	static bool scrollToBottom = true;
	if (!ImGui::Begin("Console", &pkeSettings.editorSettings.isShowingConsole)) {
		ImGui::End();
		return;
	}
	ImVec2 region = ImGui::GetContentRegionAvail();
	region.y -= 27;
	if (ImGui::BeginListBox("##ConsoleHistory", region)) {
		for (int64_t i = consoleBufferIndex + 1; i < consoleBufferCount; ++i) {
			ImGui::Text("%s", consoleBuffer[i]);
		}
		for (int64_t i = 0; i < consoleBufferIndex; ++i) {
			ImGui::Text("%s", consoleBuffer[i]);
		}
		if (scrollToBottom) ImGui::SetScrollHereY(1);
		scrollToBottom = false;
		ImGui::EndListBox();
	}
	ImGui::Separator();
	if (ImGui::InputText("##ConsoleInput", consoleBuffer[consoleBufferIndex], consoleLineLength, ImGuiInputTextFlags_EnterReturnsTrue)) {
		// TODO parse and execute.
		scrollToBottom = true;
		consoleBufferIndex = (consoleBufferIndex + 1) % consoleBufferCount;
		memset(consoleBuffer[consoleBufferIndex], '\0', consoleLineLength);
	}
	auto focusedFlags = (ImGuiFocusedFlags_ChildWindows);
	if (ImGui::IsWindowFocused(focusedFlags) && !ImGui::IsAnyItemFocused() && !ImGui::IsAnyItemHovered() && !ImGui::IsMouseClicked(ImGuiMouseButton_Left) && !ImGui::IsMouseClicked(ImGuiMouseButton_Left, true)) {
		ImGui::SetKeyboardFocusHere(-1);
	}
	ImGui::End();
}

void Game_Tick(double delta) {
	pk_bucket_reset(pkeSettings.mem.bkt);

	if (pkeSettings.rt.nextLevel != LevelHandle_MAX) {
		// TODO async this
		PkeLevel *lvl = PkeLevel_Get(pkeSettings.rt.activeLevel);
		for (uint32_t i = 0; i < lvl->scene_instances.next; ++i) {
			// TODO can't instantiate a scene that hasn't been loaded yet
			/*
			struct pke_scene *scene = pke_scene_get_by_handle(lvl->scene_instances[i].scene_handle);
			if (scene != nullptr) {
				Game_LoadSceneFile(scene->name);
			}
			*/
		}
		pkeSettings.rt.activeLevel = pkeSettings.rt.nextLevel;
		pkeSettings.rt.nextLevel = LevelHandle_MAX;
	}
	if (pkeSettings.rt.previousLevel != LevelHandle_MAX) {
		PkeLevel_Remove(pkeSettings.rt.previousLevel);
		pkeSettings.rt.previousLevel = LevelHandle_MAX;
	}

	/*
	 * ECS_Tick_Early() gets called first because it updates the public
	 *  `EntitiesToBeRemoved` for all other ticks to use.
	 */
	ECS_Tick_Early(delta);

	EntityType_Tick(delta);
	ECS_Tick(delta);
	PkeInput_Tick(delta);
	pke_ui_tick(delta);
	FontType_Tick(delta);

	for (long i = 0; i < LoadedPkePlugins.next; ++i) {
		if (LoadedPkePlugins[i].OnTick != nullptr) {
			LoadedPkePlugins[i].OnTick(delta);
		}
	}

	PkeCamera_Tick(delta);

	EntityType_Tick_Late(delta);
	ECS_Tick_Late(delta);
}

void Game_Main(PKEWindowProperties windowProps, const char *executablePath) {
	pkeSettings.executablePath = executablePath;
	fprintf(stdout, "Game_Main Entering\n");
	try {
		pk_ev_init();
		PkeThreads_Init();
		AM_Init();
		ECS_Init();
		Physics_Init();
		PkeCamera_Init();
		PkeLevel_Init();
		pke_scene_master_init();
		Game_Init();
		CreateWindow(windowProps);
		EntityType_Init();
		PkeInput_Init();
		pke_ui_init();
		pke_ui_init_bindings();
		FontType_Init();
		PkeProject_Load(pkeSettings.args.projectPath);
		if (pkeSettings.args.pluginPath != nullptr) {
			PkePlugin_Load(pkeSettings.args.pluginPath);
		}
		for (long i = 0; i < LoadedPkePlugins.next; ++i) {
			if (LoadedPkePlugins[i].OnInit != nullptr) {
				LoadedPkePlugins[i].OnInit();
			}
		}

		//
		// at this point, everything is loaded or initialized.
		//

		// if we were passed only a scene name, create a faux level.
		if (!pkeSettings.args.levelName && pkeSettings.args.sceneName) {
			pkeSettings.rt.nextLevel = PkeLevel_Create("faux-level")->levelHandle;
			PkeLevel *lvl = PkeLevel_Get(pkeSettings.rt.nextLevel);
			scene_instance si{};
			si.scene_handle = pke_scene_get_by_name(pkeSettings.args.sceneName)->scene_handle;
			pk_arr_append_t(&lvl->scene_instances, si);
		}

		// TODO remove me: temp stuff for testing
		pk_cstr test_text = cstring_to_pk_cstr("012\n3456789\tThe quick\r\nbrown fox jumped over the lazy dog.");
		// pk_cstr test_text = cstring_to_pk_cstr("%+-*0123456789$");
		// pk_cstr test_text = cstring_to_pk_cstr("$#");
		// pk_cstr test_text = cstring_to_pk_cstr("$");
		pk_cstr test_text2 = cstring_to_pk_cstr("+0123456\n789\tThe quick brown fox jumped over the lazy dog.");
		FontTypeIndex font_type_count;
		FontRenderSettings fr_set;
		fr_set.char_scale = 9 * 7.0;
		fr_set.line_height_scale = 1.0;
		fr_set.char_spacing_scale = 1.0;
		fr_set.surface_area_size.x = 1920 - (1920 / 4.0);
		fr_set.surface_area_size.y = 1080 - (1080 / 3.0);
		fr_set.surface_area_pos.x = 1920 / 4.0;
		fr_set.surface_area_pos.y = 1080 / 3.0;
		fr_set.surface_area_type_flags = FONT_RENDER_SURFACE_AREA_TYPE_FLAGS_NONE;
		if ((FontType_GetFonts(font_type_count)); font_type_count != FontTypeIndex{0}) {
			FontType_AddStringRender(FontTypeIndex{0}, pk_cstr_to_pk_str(&test_text), &fr_set);
		}
		if ((FontType_GetFonts(font_type_count)); font_type_count > FontTypeIndex{1}) {
			fr_set.surface_area_pos.y *= 2;
			fr_set.surface_area_size.y = 1080 - fr_set.surface_area_pos.y;
			FontType_AddStringRender(FontTypeIndex{1}, pk_cstr_to_pk_str(&test_text2), &fr_set);
		}

		// TODO remove me: temp stuff for testing
		pke_ui_box *ui_box = pke_ui_box_new_root();
		ui_box->flags = PKE_UI_BOX_FLAG_POSITION_TYPE_DYNAMIC;
		ui_box->pos_top_left_x = 0.1;
		ui_box->pos_top_left_y = 0.1;
		ui_box->max_width = 0.8;
		ui_box->max_height = 0.8;

		// TODO remove me: temp stuff for testing
		pke_ui_box *c_ui_box = pke_ui_box_new_child(ui_box);
		c_ui_box->flags = PKE_UI_BOX_FLAG_POSITION_TYPE_STATIC;
		c_ui_box->pos_top_left_x = 20;
		c_ui_box->pos_top_left_y = 20;
		c_ui_box->max_width = 3000;
		c_ui_box->max_height = 3000;

		GameTimePoint lastTimePoint = pkeSettings.steadyClock.now();
		double deltaTillNextRender = pkeSettings.deltaPerFrame;
		GameTimePoint lastLogTimePoint = pkeSettings.steadyClock.now();
		int64_t tickCount = 0;
		int64_t renderCount = 0;

		int64_t nsAhead = 0.0;

		while (pkeSettings.isGameRunning) {

			glfwPollEvents();

			int64_t nsAheadHolder = 0.0;
			if (nsAhead > 0) {
				nsAheadHolder = nsAhead;
				std::this_thread::sleep_for(GameTimeDuration(nsAhead));
				nsAhead = 0;
			}
			if (vidMode.refreshRate != pkeSettings.targetFPS) {
				pkeSettings.targetFPS = vidMode.refreshRate;
				pkeSettings.deltaPerFrame = 1 / double(pkeSettings.targetFPS);
			}

			GameTimePoint currentTimePoint = pkeSettings.steadyClock.now();
			double deltaThisTick = ((currentTimePoint - lastTimePoint).count() - nsAheadHolder) / NANO_DENOM_DOUBLE;
			deltaThisTick = std::min(deltaThisTick, pkeSettings.minimumDeltaPerFrame);
			lastTimePoint = currentTimePoint;

			deltaTillNextRender -= deltaThisTick;
			bool shouldRender = pkeSettings.graphicsSettings.isFramerateUnlocked
				|| pkeSettings.graphicsSettings.isWaitingForVsync
				|| deltaTillNextRender <= 0.0;

			if (shouldRender == false && (deltaTillNextRender > 0.0 && deltaTillNextRender - (deltaThisTick * 2.0) <= 0.0)) {
				/*
				 * We are ahead of the render schedule
				 * && the current tick's speed would put us behind schedule next tick.
				 *  Simulate the extra time we are ahead and prepare to sleep the difference
				 *  before the next tick.
				 */
				nsAhead = std::floor(deltaTillNextRender * NANO_DENOM_DOUBLE);
				deltaThisTick += deltaTillNextRender;
				shouldRender = true;
			}

			tickCount += 1;
			Game_Tick(deltaThisTick);

			pkeSettings.rt.was_framebuffer_resized = false;
			if (shouldRender) {
				Render();
				renderCount += 1;
				double msBehind = deltaTillNextRender * -1000;
				int64_t behindCount = 0;
				while (deltaTillNextRender < pkeSettings.deltaPerFrame) {
					behindCount += 1;
					deltaTillNextRender += pkeSettings.deltaPerFrame;
				}
				if (behindCount > 2) {
					fprintf(stderr, "[PKE::main] late render - simulated ahead: %fms - delta behind: %fms - missed frames:%ld\n", nsAheadHolder / (NANO_DENOM_DOUBLE / 1000), msBehind, behindCount - 1);
					fflush(stderr);
				}
			}

			if ((currentTimePoint - lastLogTimePoint).count() > std::chrono::nanoseconds::period::den) {
				lastLogTimePoint = currentTimePoint;
				fprintf(stdout, "TPS: ~%ld - actual:%ld - presents:%ld\n", int64_t(1 / deltaThisTick), tickCount, renderCount);
				fflush(stdout);
				tickCount = 0;
				renderCount = 0;
			}

			pkeSettings.isGameRunning = !glfwWindowShouldClose(window);
		}

		vkDeviceWaitIdle(vkDevice);

	} catch (const std::exception &exc) {
		fprintf(stderr, "Game_Main EXCEPTION: %s\n", exc.what());
	} catch (const char *err) {
		fprintf(stderr, "Game_Main UNHANDLED EXCEPTION: %s\n", err);
	} catch (...) {
		fprintf(stderr, "Game_Main UNHANDLED EXCEPTION\n");
	}
	fprintf(stdout, "Game_Main SHUTDOWN INITIATED\n");
#ifndef NDEBUG
	pk_memory_debug_print();
#endif
	for (long i = 0; i < LoadedPkePlugins.next; ++i) {
		if (LoadedPkePlugins[i].OnTeardown) {
			LoadedPkePlugins[i].OnTeardown();
		}
	}
	Game_Teardown();
	Event_Teardown();
	EntityType_Teardown();
	FontType_Teardown();
	pke_ui_teardown();
	PkeInput_Teardown();
	pke_scene_master_teardown();
	PkeLevel_Teardown();
	PkeCamera_Teardown();
	Physics_Teardown();
	ECS_Teardown();
	DestroyWindow();
	AM_DebugPrint();
	AM_Teardown();
	PkeThreads_Teardown();
	pk_ev_teardown();
	pk_memory_debug_print();
	fprintf(stdout, "Game_Main Exiting\n");
}

void Game_Init() {
	pkeSettings.mem.bkt = pk_bucket_create("game-transient", 1UL << 26, true);

	for (uint64_t i = 0; i < consoleBufferCount; ++i) {
		memset(consoleBuffer[i], '\0', consoleLineLength);
	}
}

void Game_Teardown() { }