#include "EditorCore.hpp"

#include "App.hpp"
#include "AppConfig.hpp"
#include "EditorAccessories.hpp"
#include "EditorAttachmentImpl.hpp"
#include "EditorCommandPalette.hpp"
#include "EditorNotification.hpp"
#include "EditorUtils.hpp"
#include "GameObject.hpp"
#include "Level.hpp"
#include "Macros.hpp"
#include "Mesh.hpp"
#include "Player.hpp"
#include "SceneThings.hpp"
#include "ScopeGuard.hpp"
#include "VertexIndex.hpp"
#include "YCombinator.hpp"

#define GLFW_INCLUDE_NONE
#include <GLFW/glfw3.h>

#include <ImGuizmo.h>
#include <imgui.h>
#include <misc/cpp/imgui_stdlib.h>
#include <cstddef>
#include <cstdint>
#include <cstdlib>
#include <functional>
#include <limits>
#include <memory>
#include <string>
#include <string_view>
#include <utility>

using namespace std::literals;

void EditorInspector::SelectTarget(TargetType type, void* object) {
	selectedItt = type;
	selectedItPtr = object;
	renaming = false;
	renamingScratchBuffer.clear();
}

EditorContentBrowser::EditorContentBrowser(EditorInspector* inspector)
	: mInspector{ inspector } {
}

EditorContentBrowser::~EditorContentBrowser() {
}

void EditorContentBrowser::Show(bool* open) {
	ImGuiWindowFlags windowFlags;
	if (mDocked) {
		// Center window horizontally, align bottom  vertically
		auto& viewportSize = ImGui::GetMainViewport()->Size;
		ImGui::SetNextWindowPos(ImVec2(viewportSize.x / 2, viewportSize.y), ImGuiCond_Always, ImVec2(0.5f, 1.0f));
		ImGui::SetNextWindowSizeRelScreen(0.8f, mBrowserHeight);
		windowFlags = ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoCollapse;
	} else {
		windowFlags = 0;
	}
	ImGui::Begin("Content Browser", open, windowFlags);

	ImGui::Splitter(true, kSplitterThickness, &mSplitterLeft, &mSplitterRight, kLeftPaneMinWidth, kRightPaneMinWidth);

	ImGui::BeginChild("LeftPane", ImVec2(mSplitterLeft - kPadding, 0.0f));
	{
		if (ImGui::Selectable("Settings", mPane == P_Settings)) {
			mPane = P_Settings;
		}
		if (ImGui::Selectable("Ires", mPane == P_Ires)) {
			mPane = P_Ires;
		}
	}
	ImGui::EndChild();

	ImGui::SameLine(0.0f, kPadding + kSplitterThickness + kPadding);
	ImGui::BeginChild("RightPane"); // Fill remaining space
	switch (mPane) {
		case P_Settings: {
			ImGui::Checkbox("Docked", &mDocked);
			ImGui::SliderFloat("Height", &mBrowserHeight, 0.1f, 1.0f);
		} break;

		case P_Ires: {
			auto itt = mInspector->selectedItt;
			auto itPtr = mInspector->selectedItPtr;
			bool isIttIres = itt == EditorInspector::ITT_Ires;

			if (ImGui::Button("New")) {
				ImGui::OpenPopup("New Ires");
			}
			if (ImGui::BeginPopup("New Ires")) {
				for (int i = 0; i < IresObject::KD_COUNT; ++i) {
					auto kind = static_cast<IresObject::Kind>(i);
					if (ImGui::MenuItem(IresObject::ToString(kind).data())) {
						auto ires = IresObject::Create(kind);
						auto [DISCARD, success] = IresManager::instance->Add(ires.get());
						if (success) {
							(void)ires.release();
						}
					}
				}
				ImGui::EndPopup();
			}

			ImGui::SameLine();
			if (ImGui::Button("Refresh list") ||
				ImGui::IsKeyPressed(ImGuiKey_F5))
			{
				// TODO
			}

			ImGui::SameLine();
			if (ImGui::Button("Save", !isIttIres)) {
				auto ires = static_cast<IresObject*>(itPtr);
				IresManager::instance->Save(ires);
			}

			ImGui::SameLine();
			if (ImGui::Button("Reload", !isIttIres)) {
				auto ires = static_cast<IresObject*>(itPtr);
				IresManager::instance->Reload(ires);
			}

			ImGui::SameLine();
			if (ImGui::Button("Rename", !isIttIres) ||
				(isIttIres && ImGui::IsKeyPressed(ImGuiKey_F2, false)))
			{
				auto ires = static_cast<IresObject*>(itPtr);
				mInspector->renaming = true;
				mInspector->renamingScratchBuffer = ires->GetName();
			}

			ImGui::SameLine();
			if (ImGui::Button("Delete", !isIttIres) ||
				(isIttIres && ImGui::IsKeyPressed(ImGuiKey_Delete, false)))
			{
				ImGui::OpenPopup("Delete Ires");
			}
			bool openedDummy = true;
			if (ImGui::BeginPopupModal("Delete Ires", &openedDummy, ImGuiWindowFlags_AlwaysAutoResize | ImGuiWindowFlags_NoResize)) {
				if (ImGui::Button("Confirm")) {
					auto ires = static_cast<IresObject*>(itPtr);
					IresManager::instance->Delete(ires);
				}
				ImGui::SameLine();
				if (ImGui::Button("Cancel")) {
					ImGui::CloseCurrentPopup();
				}
				ImGui::EndPopup();
			}

			auto& objects = IresManager::instance->GetObjects();
			for (auto it = objects.begin(); it != objects.end(); ++it) {
				auto ires = it->second.Get();
				auto& name = ires->GetName();

				bool selected = itPtr == ires;

				ImGuiSelectableFlags flags = 0;
				// When renaming, disable all other entries
				if (mInspector->renaming && !selected) {
					flags |= ImGuiSelectableFlags_Disabled;
				}

				if (mInspector->renaming && selected) {
					// State: being renamed

					ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, { 0, 0 });
					ImGui::PushStyleVar(ImGuiStyleVar_FrameBorderSize, 0);
					ImGui::SetKeyboardFocusHere();
					if (ImGui::InputText("##Rename", &mInspector->renamingScratchBuffer, ImGuiInputTextFlags_AutoSelectAll | ImGuiInputTextFlags_EnterReturnsTrue)) {
						// Confirm
						ires->SetName(std::move(mInspector->renamingScratchBuffer));
						mInspector->renaming = false;
					}
					ImGui::PopStyleVar(2);

					if (ImGui::IsKeyPressed(ImGuiKey_Escape)) {
						// Cancel
						mInspector->renaming = false;
					}
				} else {
					// State: normal

					if (ImGui::Selectable(name.c_str(), selected, flags)) {
						mInspector->SelectTarget(EditorInspector::ITT_Ires, ires);
					}
					if (ImGui::BeginDragDropSource()) {
						auto kindName = IresObject::ToString(ires->GetKind());
						// Reason: intentionally using pointer as payload
						ImGui::SetDragDropPayload(kindName.data(), &ires, sizeof(ires)); // NOLINT(bugprone-sizeof-expression)
						ImGui::Text("%s '%s'", kindName.data(), name.c_str());
						ImGui::EndDragDropSource();
					}
				}
			}
		} break;
	}
	ImGui::EndChild();

	ImGui::End();
}

namespace ProjectBrussel_UNITY_ID {
void PushKeyCodeRecorder(App* app, int* writeKey, bool* writeKeyStatus) {
	app->PushKeyCaptureCallback([=](int key, int action) {
		// Allow the user to cancel by pressing Esc
		if (key == GLFW_KEY_ESCAPE) {
			return true;
		}

		if (action == GLFW_PRESS) {
			*writeKey = key;
			*writeKeyStatus = writeKeyStatus;
			return true;
		}
		return false;
	});
}

struct GobjTreeNodeShowInfo {
	EditorInstance* in_editor;
	GameObject* out_openPopup = nullptr;
};

void GobjTreeNode(GobjTreeNodeShowInfo& showInfo, GameObject* object) {
	auto& inspector = showInfo.in_editor->GetInspector();

	auto attachment = object->GetEditorAttachment();
	if (!attachment) {
		attachment = EaGameObject::Create(object).release();
		object->SetEditorAttachment(attachment); // NOTE: takes ownership
	}

	ImGuiTreeNodeFlags flags =
		ImGuiTreeNodeFlags_DefaultOpen |
		ImGuiTreeNodeFlags_OpenOnDoubleClick |
		ImGuiTreeNodeFlags_OpenOnArrow |
		ImGuiTreeNodeFlags_SpanAvailWidth |
		ImGuiTreeNodeFlags_NoTreePushOnOpen;
	if (inspector.selectedItPtr == object) {
		flags |= ImGuiTreeNodeFlags_Selected;
	}

	ImGui::PushID(reinterpret_cast<uintptr_t>(object));
	// BEGIN tree node

	bool opened = ImGui::TreeNodeEx(attachment->name.c_str(), flags);
	if (ImGui::IsItemClicked(ImGuiMouseButton_Left)) {
		inspector.SelectTarget(EditorInspector::ITT_GameObject, object);
	}
	if (ImGui::IsMouseReleased(ImGuiMouseButton_Right) &&
		ImGui::IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByPopup))
	{
		showInfo.out_openPopup = object;
	}

	if (opened) {
		ImGui::Indent();
		for (auto& child : object->GetChildren()) {
			GobjTreeNode(showInfo, child);
		}
		ImGui::Unindent();
	}

	// END tree node
	ImGui::PopID();
};

#define GAMEOBJECT_CONSTRUCTOR(ClassName) [](GameWorld* world) -> GameObject* { return new ClassName(world); }
struct CreatableGameObject {
	GameObject* (*factory)(GameWorld*);
	const char* name;
	GameObject::Kind kind;
} creatableGameObjects[] = {
	{
		.factory = GAMEOBJECT_CONSTRUCTOR(GameObject),
		.name = "GameObject",
		.kind = GameObject::KD_Generic,
	},
	{
		.factory = GAMEOBJECT_CONSTRUCTOR(SimpleGeometryObject),
		.name = "Simple Geometry",
		.kind = GameObject::KD_SimpleGeometry,
	},
	{
		.factory = GAMEOBJECT_CONSTRUCTOR(BuildingObject),
		.name = "Building",
		.kind = GameObject::KD_Building,
	},
	{
		.factory = GAMEOBJECT_CONSTRUCTOR(LevelWrapperObject),
		.name = "Level Wrapper",
		.kind = GameObject::KD_LevelWrapper,
	},
};
#undef GAMEOBJECT_CONSTRUCTOR
} // namespace ProjectBrussel_UNITY_ID

EditorInstance::EditorInstance(App* app, GameWorld* world)
	: mApp{ app }
	, mWorld{ world }
	, mEdContentBrowser(&mEdInspector) {}

EditorInstance::~EditorInstance() {
}

void EditorInstance::Show() {
	using namespace ProjectBrussel_UNITY_ID;
	using namespace Tags;

	if (!mWorld) {
		return;
	}

	auto& io = ImGui::GetIO();

	ImGui::BeginMainMenuBar();
	if (ImGui::BeginMenu("View")) {
		ImGui::MenuItem("ImGui Demo", nullptr, &mWindowVisible_ImGuiDemo);
		ImGui::MenuItem("Command Palette", "Ctrl+Shift+P", &mWindowVisible_CommandPalette);
		ImGui::MenuItem("Inspector", nullptr, &mWindowVisible_Inspector);
		ImGui::MenuItem("Content Browser", "Ctrl+Space", &mWindowVisible_ContentBrowser);
		ImGui::MenuItem("World Structure", nullptr, &mWindowVisible_WorldStructure);
		ImGui::MenuItem("World Properties", nullptr, &mWindowVisible_WorldProperties);
		ImGui::EndMenu();
	}
	ImGui::EndMainMenuBar();

	if (mWindowVisible_ImGuiDemo) {
		ImGui::ShowDemoWindow(&mWindowVisible_ImGuiDemo);
	}

	if (io.KeyCtrl && io.KeyShift && ImGui::IsKeyPressed(GLFW_KEY_P, false)) {
		mWindowVisible_CommandPalette = !mWindowVisible_CommandPalette;
	}
	if (mWindowVisible_CommandPalette) {
		mEdCommandPalette.Show(&mWindowVisible_CommandPalette);
	}

	if (io.KeyCtrl && ImGui::IsKeyPressed(GLFW_KEY_SPACE, false)) {
		mWindowVisible_ContentBrowser = !mWindowVisible_ContentBrowser;
	}
	if (mWindowVisible_ContentBrowser) {
		mEdContentBrowser.Show(&mWindowVisible_ContentBrowser);
	}

	if (mWindowVisible_Inspector) {
		ImGui::Begin("Inspector");
		switch (mEdInspector.selectedItt) {
			case EditorInspector::ITT_GameObject: {
				ShowInspector(static_cast<GameObject*>(mEdInspector.selectedItPtr));
			} break;

			case EditorInspector::ITT_Ires: {
				auto ires = static_cast<IresObject*>(mEdInspector.selectedItPtr);
				ShowInspector(ires);
			} break;

			case EditorInspector::ITT_None: break;
		}
		ImGui::End();
	}

	if (mWindowVisible_WorldProperties) {
		ImGui::Begin("World properties");
		ShowWorldProperties();
		ImGui::End();
	}

	if (mWindowVisible_WorldStructure) {
		ImGui::Begin("World structure");
		{
			GobjTreeNodeShowInfo showInfo{
				.in_editor = this,
			};
			GobjTreeNode(showInfo, &mWorld->GetRoot());

			if (showInfo.out_openPopup) {
				mPopupCurrent_GameObject = showInfo.out_openPopup;

				ImGui::OpenPopup("GameObject Popup");
				ImGui::SetNextWindowPos(ImGui::GetMousePos());
			}
			if (ImGui::BeginPopup("GameObject Popup")) {
				// Target no longer selected during popup open
				if (!mPopupCurrent_GameObject) {
					ImGui::CloseCurrentPopup();
				}

				if (ImGui::BeginMenu("Add child")) {
					for (size_t i = 0; i < std::size(creatableGameObjects); ++i) {
						auto& info = creatableGameObjects[i];
						if (ImGui::MenuItem(info.name)) {
							auto object = info.factory(mWorld);
							mPopupCurrent_GameObject->AddChild(object);
						}
					}
					ImGui::EndMenu();
				}
				ImGui::Separator();
				if (ImGui::MenuItem("Remove")) {
					// TODO
				}
				ImGui::EndPopup();
			}
		}
		ImGui::End();
	}

	ShowSpriteViewer();

	ImGui::ShowNotifications();
}

void EditorInstance::ShowWorldProperties() {
	if (mApp->IsGameRunning()) {
		if (ImGui::Button("Pause")) {
			mApp->SetGameRunning(false);
		}
		if (ImGui::IsItemHovered()) {
			ImGui::SetTooltip("The game is currently running. Click to pause.");
		}
	} else {
		if (ImGui::Button("Play")) {
			mApp->SetGameRunning(true);
		}
		if (ImGui::IsItemHovered()) {
			ImGui::SetTooltip("The game is currently paused. Click to run.");
		}
	}
}

// TOOD move resource-specific and gameobject-specific inspector code into attachments mechanism

void EditorInstance::ShowInspector(IresObject* ires) {
	ires->ShowEditor(*this);
}

void EditorInstance::ShowInspector(GameObject* object) {
	using namespace Tags;
	using namespace ProjectBrussel_UNITY_ID;

	auto ShowFields = [&]() {
		auto pos = object->GetPos();
		if (ImGui::InputFloat3("Position", &pos.x)) {
			object->SetPos(pos);
		}

		auto quat = object->GetRotation();
		if (ImGui::InputFloat4("Rotation", &quat.x)) {
			object->SetRotation(quat);
		}
	};

	auto type = object->GetKind();
	switch (type) {
		case GameObject::KD_Player: {
			ShowFields();
			ImGui::Separator();

			auto player = static_cast<Player*>(object);
			auto ea = static_cast<EaPlayer*>(player->GetEditorAttachment());
			auto& kb = player->keybinds;

			ImGui::Text("Player #%d", player->GetId());

			ImGui::TextUnformatted("Spritesheet: ");
			ImGui::SameLine();
			IresObject::ShowReferenceSafe(*this, ea->confSprite.Get());
			if (ImGui::BeginDragDropTarget()) {
				if (auto payload = ImGui::AcceptDragDropPayload(IresObject::ToString(IresObject::KD_Spritesheet).data())) {
					auto spritesheet = *static_cast<IresSpritesheet* const*>(payload->Data);
					ea->confSprite.Attach(spritesheet);
					player->sprite.SetDefinition(spritesheet->GetInstance());
				}
				ImGui::EndDragDropTarget();
			}

			ImGui::TextUnformatted("Material: ");
			ImGui::SameLine();
			IresObject::ShowReferenceSafe(*this, ea->confMaterial.Get());
			if (ImGui::BeginDragDropTarget()) {
				if (auto payload = ImGui::AcceptDragDropPayload(IresObject::ToString(IresObject::KD_Material).data())) {
					auto material = *static_cast<IresMaterial* const*>(payload->Data);
					ea->confMaterial.Attach(material);
					player->SetMaterial(material->GetInstance());
				}
				ImGui::EndDragDropTarget();
			}

			if (ImGui::Button("Load config")) {
				bool success = player->LoadFromFile();
				if (success) {
					ImGui::AddNotification(ImGuiToast(ImGuiToastType_Success, "Successfully loaded player config"));
				}
			}
			ImGui::SameLine();
			if (ImGui::Button("Save config")) {
				bool success = player->SaveToFile();
				if (success) {
					ImGui::AddNotification(ImGuiToast(ImGuiToastType_Success, "Successfully saved player config"));
				}
			}

			ImGui::Text("Move left (%s)", ImGui::GetKeyNameGlfw(kb.keyLeft));
			ImGui::SameLine();
			if (ImGui::Button("Change##Move left")) {
				PushKeyCodeRecorder(mApp, &kb.keyLeft, &kb.pressedLeft);
			}

			ImGui::Text("Move right (%s)", ImGui::GetKeyNameGlfw(kb.keyRight));
			ImGui::SameLine();
			if (ImGui::Button("Change##Move right")) {
				PushKeyCodeRecorder(mApp, &kb.keyRight, &kb.pressedRight);
			}

			ImGui::Text("Jump (%s)", ImGui::GetKeyNameGlfw(kb.keyJump));
			ImGui::SameLine();
			if (ImGui::Button("Change##Jump")) {
				PushKeyCodeRecorder(mApp, &kb.keyJump, &kb.pressedJump);
			}

			ImGui::Text("Attack (%s)", ImGui::GetKeyNameGlfw(kb.keyAttack));
			ImGui::SameLine();
			if (ImGui::Button("Change##Attack")) {
				PushKeyCodeRecorder(mApp, &kb.keyAttack, &kb.pressedAttack);
			}
		} break;

		case GameObject::KD_SimpleGeometry: {
			ShowFields();
			ImGui::Separator();

			auto sg = static_cast<SimpleGeometryObject*>(object);
			// TODO
		} break;

		case GameObject::KD_Building: {
			ShowFields();
			ImGui::Separator();

			auto b = static_cast<BuildingObject*>(object);
			// TODO
		} break;

		case GameObject::KD_LevelWrapper: {
			ShowFields();
			ImGui::Separator();

			auto lwo = static_cast<LevelWrapperObject*>(object);
			// TODO
		} break;

		default: {
			ShowFields();
		} break;
	}
}

void EditorInstance::OpenSpriteViewer(SpriteDefinition* sprite) {
	mSpriteView_Instance.Attach(sprite);
	mSpriteView_Frame = 0;
	mSpriteView_OpenNextFrame = true;
}

void EditorInstance::ShowSpriteViewer() {
	if (mSpriteView_Instance == nullptr) return;
	if (!mSpriteView_Instance->IsValid()) return;

	if (mSpriteView_OpenNextFrame) {
		mSpriteView_OpenNextFrame = false;
		ImGui::OpenPopup("Sprite Viewer");
	}

	bool windowOpen = true;
	if (ImGui::BeginPopupModal("Sprite Viewer", &windowOpen)) {
		auto atlas = mSpriteView_Instance->GetAtlas();
		auto atlasSize = atlas->GetInfo().size;
		auto& frames = mSpriteView_Instance->GetFrames();

		int frameCount = mSpriteView_Instance->GetFrames().size();
		if (ImGui::Button("<")) {
			--mSpriteView_Frame;
		}
		ImGui::SameLine();
		ImGui::Text("%d/%d", mSpriteView_Frame + 1, frameCount);
		ImGui::SameLine();
		if (ImGui::Button(">")) {
			++mSpriteView_Frame;
		}
		// Scrolling down (negative value) should advance, so invert the sign
		mSpriteView_Frame += -std::round(ImGui::GetIO().MouseWheel);
		// Clamp mSpriteView_Frame to range [0, frameCount)
		if (mSpriteView_Frame < 0) {
			mSpriteView_Frame = frameCount - 1;
		} else if (mSpriteView_Frame >= frameCount) {
			mSpriteView_Frame = 0;
		}

		auto& currFrame = frames[mSpriteView_Frame];
		auto boundingBox = mSpriteView_Instance->GetBoundingBox();
		ImGui::Text("Frame size: (%d, %d)", boundingBox.x, boundingBox.y);
		ImGui::Text("Frame location: (%f, %f) to (%f, %f)", currFrame.u0, currFrame.v0, currFrame.u1, currFrame.v1);
		ImGui::Image(
			(ImTextureID)(uintptr_t)atlas->GetHandle(),
			Utils::FitImage(atlasSize),
			ImVec2(currFrame.u0, currFrame.v0),
			ImVec2(currFrame.u1, currFrame.v1));

		ImGui::EndPopup();
	}
}