#include "UserInterface.h"
#include <algorithm>
#include <iostream>
#include <string>

// NOTE: to use filesystem, you must also include the fs library such
// as via the `-lstdc++fs` linker option -- see b3view.pro
// #include <filesystem>  // requires C++17
#include <experimental/filesystem> // requires C++14 such as gcc 8.2.1

#include "Debug.h"
#include "Engine.h"
#include "Utility.h"

using namespace irr;
using namespace irr::core;
using namespace irr::gui;

using std::string;
using std::wstring;
using namespace std;

// C++14: namespace filesystem = std::experimental::filesystem;
// namespace fs = std::filesystem;  // doesn't work (not a namespace in gcc's C++17)
// using namespace std::filesystem;  // doesn't work (not a namespace in gcc's C++17)
namespace fs = std::experimental::filesystem;

// PRIVATE
void UserInterface::setupUserInterface()
{
    // Menu
    menu = m_Gui->addMenu();
    menu->addItem(L"File", UIE_FILEMENU, true, true);
    menu->addItem(L"View", UIE_VIEWMENU, true, true);

    // File Menu
    fileMenu = menu->getSubMenu(0);
    fileMenu->addItem(L"Load", UIC_FILE_LOAD);
    fileMenu->addItem(L"LoadTexture", UIC_FILE_LOAD_TEXTURE);
    fileMenu->addItem(L"Quit", UIC_FILE_QUIT);

    // View Menu
    viewMenu = menu->getSubMenu(1);
    INDEX_VIEW_WIREFRAME_MESH = viewMenu->addItem(L"Wireframe Mesh", UIC_VIEW_WIREFRAME, true, false, this->m_WireframeDisplay, true);
    INDEX_VIEW_LIGHTING = viewMenu->addItem(L"Lighting", UIC_VIEW_LIGHTING, true, false, this->m_Lighting, true);
    INDEX_VIEW_TEXTURE_INTERPOLATION = viewMenu->addItem(L"Texture Interpolation", UIC_VIEW_TEXTURE_INTERPOLATION, true, false, this->m_TextureInterpolation, true);

    // Playback Control Window
    dimension2d<u32> windowSize = m_Engine->m_Driver->getScreenSize();
    playbackWindow = m_Gui->addWindow(
        rect<s32>(vector2d<s32>(windowSize.Width - 4 - 160, 28), dimension2d<s32>(160, 300)), false, L"Playback", nullptr, UIE_PLAYBACKWINDOW);
    playbackWindow->getCloseButton()->setVisible(false);
    s32 spacing_x = 4;
    spacing_y = 4;
    s32 size_x = playbackWindow->getClientRect().getWidth() - 8;
    s32 size_y = 24;
    s32 y = 24;
    playbackStartStopButton = m_Gui->addButton(
        rect<s32>(vector2d<s32>(spacing_x, y), dimension2d<s32>(size_x, size_y)),
        playbackWindow,
        UIE_PLAYBACKSTARTSTOPBUTTON,
        L"Start/Stop",
        nullptr);
    y += size_y + spacing_y;
    playbackIncreaseButton = m_Gui->addButton(
        rect<s32>(vector2d<s32>(spacing_x, y), dimension2d<s32>(size_x, size_y)),
        playbackWindow,
        UIE_PLAYBACKINCREASEBUTTON,
        L"Faster",
        nullptr);
    y += size_y + spacing_y;
    playbackDecreaseButton = m_Gui->addButton(
        rect<s32>(vector2d<s32>(spacing_x, y), dimension2d<s32>(size_x, size_y)),
        playbackWindow,
        UIE_PLAYBACKDECREASEBUTTON,
        L"Slower",
        nullptr);

    y += size_y + spacing_y;
    playbackSetFrameEditBox = m_Gui->addEditBox(
        L"",
        rect<s32>(vector2d<s32>(spacing_x, y), dimension2d<s32>(size_x, size_y)),
        true,
        playbackWindow,
        UIE_PLAYBACKSETFRAMEEDITBOX);

    y += size_y + spacing_y;
    texturePathStaticText = m_Gui->addStaticText(
        L"Texture Path:",
        rect<s32>(vector2d<s32>(spacing_x, y), dimension2d<s32>(size_x, size_y)),
        true,
        true,
        playbackWindow,
        UIE_TEXTUREPATHSTATICTEXT,
        false);
    y += size_y + spacing_y;
    texturePathEditBox = m_Gui->addEditBox(
        L"",
        rect<s32>(vector2d<s32>(spacing_x, y), dimension2d<s32>(size_x, size_y)),
        true,
        playbackWindow,
        UIE_TEXTUREPATHEDITBOX);

    // Set Font for UI Elements
    m_GuiFontFace = new CGUITTFace();
    // irrString defines stringc as string<c8>
    // if (QFile(fontPath).exists()) {
    if (!Utility::isFile(m_Engine->m_FontPath)) {
        m_Engine->m_FontPath = L"C:\\Windows\\Fonts\\calibrib.ttf";
    }
    if (!Utility::isFile(m_Engine->m_FontPath)) {
        m_Engine->m_FontPath = L"C:\\Windows\\Fonts\\arialbd.ttf";
    }
    if (!Utility::isFile(m_Engine->m_FontPath)) {
        m_Engine->m_FontPath = L"/usr/share/fonts/liberation/LiberationSans-Bold.ttf";
    }
    if (!Utility::isFile(m_Engine->m_FontPath)) {
        m_Engine->m_FontPath = L"/usr/share/fonts/gnu-free/FreeSansBold.ttf";
    }
    if (!Utility::isFile(m_Engine->m_FontPath)) {
        m_Engine->m_FontPath = L"/usr/share/fonts/dejavu/DejaVuSans-Bold.ttf";
    }
    if (!Utility::isFile(m_Engine->m_FontPath)) {
        m_Engine->m_FontPath = L"/usr/share/fonts/google-droid/DroidSans-Bold.ttf";
    }

    if (m_GuiFontFace->load(m_Engine->m_FontPath.c_str())) { // actually takes `const io::path &`
        m_GuiFont = new CGUITTFont(m_Gui);
        m_GuiFont->attach(m_GuiFontFace, 14);
        m_Gui->getSkin()->setFont(m_GuiFont);
    } else {
        std::wcerr << L"WARNING: Missing '" << m_Engine->m_FontPath << L"'" << endl;
        delete m_GuiFontFace;
        m_GuiFontFace = nullptr;
        if (m_GuiFont != nullptr) {
            std::wcerr << L"WARNING: Keeping old font loaded." << endl;
        }
    }
    //}
}

void UserInterface::displayLoadFileDialog()
{
    m_Gui->addFileOpenDialog(L"Select file to load", true, nullptr, UIE_LOADFILEDIALOG);
}

void UserInterface::displayLoadTextureDialog()
{
    m_Gui->addFileOpenDialog(L"Select file to load", true, nullptr, UIE_LOADTEXTUREDIALOG);
}

void UserInterface::handleMenuItemPressed(IGUIContextMenu* menu)
{
    s32 selected = menu->getSelectedItem();
    if (selected > -1) {
        s32 id = menu->getItemCommandId(static_cast<u32>(selected));

        switch (id) {
        case UIC_FILE_LOAD:
            displayLoadFileDialog();
            break;

        case UIC_FILE_LOAD_TEXTURE:
            displayLoadTextureDialog();
            break;

        case UIC_FILE_QUIT:
            m_Engine->m_RunEngine = false;
            break;

        case UIC_VIEW_WIREFRAME:
            m_WireframeDisplay = viewMenu->isItemChecked(INDEX_VIEW_WIREFRAME_MESH);
            m_Engine->setMeshDisplayMode(m_WireframeDisplay, m_Lighting, m_TextureInterpolation);
            break;

        case UIC_VIEW_LIGHTING:
            m_Lighting = viewMenu->isItemChecked(INDEX_VIEW_LIGHTING);
            m_Engine->setMeshDisplayMode(m_WireframeDisplay, m_Lighting, m_TextureInterpolation);
            break;

        case UIC_VIEW_TEXTURE_INTERPOLATION:
            m_TextureInterpolation = viewMenu->isItemChecked(INDEX_VIEW_TEXTURE_INTERPOLATION);
            m_Engine->setMeshDisplayMode(m_WireframeDisplay, m_Lighting, m_TextureInterpolation);
            break;
        }
    }
}

void UserInterface::snapWidgets()
{
    dimension2d<u32> screenSize = m_Engine->m_Driver->getScreenSize();
    rect<s32> newRect;
    //newRect.LowerRightCorner.X = static_cast<s32>(size.Width);
    //newRect.LowerRightCorner.Y = static_cast<s32>(size.Height);
    rect<s32> prevRect = playbackWindow->getRelativePosition();
    newRect.UpperLeftCorner.X = static_cast<s32>(screenSize.Width) - prevRect.getWidth() - spacing_y;
    //debug() << "screen size: " << screenSize.Width << "x" << screenSize.Height;
    //debug() << "  prevRect: "
    //        << prevRect.UpperLeftCorner.X << "," << prevRect.UpperLeftCorner.Y << ","
    //        << prevRect.LowerRightCorner.X << "," << prevRect.LowerRightCorner.Y
    //        << " size=(" << prevRect.getWidth() << "," <<prevRect.getHeight() << ")" << endl;
    newRect.UpperLeftCorner.Y = prevRect.UpperLeftCorner.Y;
    newRect.LowerRightCorner.X = newRect.UpperLeftCorner.X + prevRect.getWidth();
    newRect.LowerRightCorner.Y = newRect.UpperLeftCorner.Y + prevRect.getHeight();
    playbackWindow->setRelativePosition(newRect);
    m_WindowSize.Width = m_Engine->m_Driver->getScreenSize().Width;
    m_WindowSize.Height = m_Engine->m_Driver->getScreenSize().Height;
}

// PUBLIC
UserInterface::UserInterface(Engine* engine)
{
    INDEX_VIEW_TEXTURE_INTERPOLATION = 0;
    INDEX_VIEW_WIREFRAME_MESH = 0;
    INDEX_VIEW_LIGHTING = 0;
    this->playbackStartStopButton = nullptr;

    m_Engine = engine;
    m_Gui = engine->getGUIEnvironment();

    m_WireframeDisplay = false;
    m_Lighting = true;
    m_TextureInterpolation = true;
    playbackWindow = nullptr;

    setupUserInterface();
}

UserInterface::~UserInterface()
{
    delete m_GuiFont;
    delete m_GuiFontFace;
}

IGUIEnvironment* UserInterface::getGUIEnvironment() const
{
    return m_Gui;
}

void UserInterface::drawStatusLine() const
{
}

bool UserInterface::loadNextTexture(int direction)
{
    bool ret = false;
    this->m_Engine->m_NextPath = L"";
    std::wstring basePath = L".";
    if (this->m_Engine->m_PreviousPath.length() > 0) {
        std::wstring lastName = Utility::basename(this->m_Engine->m_PreviousPath);
        std::wstring lastDirPath = Utility::parentOfPath(this->m_Engine->m_PreviousPath);
        std::wstring parentPath = Utility::parentOfPath(lastDirPath);
        std::wstring dirSeparator = Utility::delimiter(this->m_Engine->m_PreviousPath);
        std::wstring texturesPath = parentPath + dirSeparator + L"textures";
        std::wstring tryTexPath = texturesPath + dirSeparator + Utility::withoutExtension(lastName) + L".png";
        if (direction == 0 && Utility::isFile(tryTexPath)) {
            this->m_Engine->m_NextPath = tryTexPath;
            this->m_Engine->loadTexture(this->m_Engine->m_NextPath);
        } else {
            tryTexPath = lastDirPath + dirSeparator + Utility::withoutExtension(lastName) + L".png";
            if (direction == 0 && Utility::isFile(tryTexPath)) {
                this->m_Engine->m_NextPath = tryTexPath;
                ret = this->m_Engine->loadTexture(this->m_Engine->m_NextPath);
            } else {
                std::wstring path = texturesPath;

                if (!fs::is_directory(fs::status(path)))
                    path = lastDirPath; // cycle textures in model's directory instead

                fs::directory_iterator end_itr; // default construction yields past-the-end

                std::wstring nextPath = L"";
                std::wstring retroPath = L"";
                std::wstring lastPath = L"";

                bool found = false;
                bool force = false;
                wstring tryPath;
                if (fs::is_directory(fs::status(path))) {
                    if (this->m_Engine->m_PrevTexturePath.length() == 0) {
                        if (this->m_Engine->m_PreviousPath.length() > 0) {
                            //debug() << "tryPath..." << endl;
                            tryPath = texturesPath + dirSeparator + Utility::withoutExtension(Utility::basename(this->m_Engine->m_PreviousPath)) + L".png";
                            // debug() << "tryPath 1a " << Utility::toString(tryPath) << "..." << endl;
                            tryPath = Utility::toWstring(Utility::toString(tryPath));
                            // debug() << "tryPath 1b " << Utility::toString(tryPath) << "..." << endl;
                            // tryPath = texturesPath + dirSeparator + Utility::basename(this->m_Engine->m_PreviousPath) + L".png";
                            if (!Utility::isFile(tryPath)) {
                                //asdf
                                tryPath = texturesPath + dirSeparator + Utility::withoutExtension(Utility::basename(this->m_Engine->m_PreviousPath)) + L".jpg";
                                // debug() << "tryPath 2a " << Utility::toString(tryPath) << "..." << endl;
                                tryPath = Utility::toWstring(Utility::toString(tryPath));
                                // tryPath = Utility::toWstring(Utility::toString(L"debug1")); // ../iconv/loop.c:457: internal_utf8_loop_single: Assertion `inptr - (state->__count & 7)' failed.
                                // debug() << "tryPath 2b " << Utility::toString(tryPath) << "..." << endl;
                                // tryPath = texturesPath + dirSeparator + Utility::basename(this->m_Engine->m_PreviousPath) + L".jpg";
                                if (Utility::isFile(tryPath)) {
                                    nextPath = tryPath;
                                    found = true;
                                    force = true;
                                }
                            } else {
                                nextPath = tryPath;
                                found = true;
                                force = true;
                            }
                        }
                    }
                    //debug() << "tryPath: " << Utility::toString(tryPath) << endl;
                    //debug() << "nextPath: " << Utility::toString(nextPath) << endl;
                    for (const auto& itr : fs::directory_iterator(path)) {
                        std::wstring ext = Utility::extensionOf(itr.path().wstring()); // no dot!
                        if (!is_directory(itr.status())
                            && std::find(m_Engine->textureExtensions.begin(), m_Engine->textureExtensions.end(), ext) != m_Engine->textureExtensions.end()) {
                            // cycle through files (go to next after m_PrevTexturePath
                            // if any previously loaded, otherwise first)
                            if (nextPath.length() == 0)
                                nextPath = itr.path().wstring();
                            lastPath = itr.path().wstring();
                            if (found && direction > 0) {
                                if (!force)
                                    nextPath = itr.path().wstring();
                                break;
                            }
                            if (itr.path().wstring() == this->m_Engine->m_PrevTexturePath)
                                found = true;
                            if (!found)
                                retroPath = itr.path().wstring();
                        }
                    }
                    if (retroPath.length() == 0)
                        retroPath = lastPath; // previous is last if at beginning
                    if (direction < 0)
                        nextPath = retroPath;
                    if (nextPath.length() > 0) {
                        ret = this->m_Engine->loadTexture(nextPath);
                    }
                }
            }
        }
    } else
        debug() << "Can't cycle texture since no file was opened" << endl;
    return ret;
}

// IEventReceiver
bool UserInterface::OnEvent(const SEvent& event)
{
    // Events arriving here should be destined for us
    if (event.EventType == EET_USER_EVENT) {
        if (event.UserEvent.UserData1 == UEI_WINDOWSIZECHANGED) {
            if ((m_WindowSize.Width != m_Engine->m_Driver->getScreenSize().Width) || (m_WindowSize.Height != m_Engine->m_Driver->getScreenSize().Height)) {
                snapWidgets();
            }
        }
        return true;
    } else if (event.EventType == EET_KEY_INPUT_EVENT) {
        if (event.KeyInput.PressedDown && !m_Engine->KeyIsDown[event.KeyInput.Key]) {
            if (event.KeyInput.Key == irr::KEY_F5) {
                m_Engine->reloadMesh();
            } else if (event.KeyInput.Key == irr::KEY_KEY_T) {
                loadNextTexture(1);
            } else if (event.KeyInput.Key == irr::KEY_KEY_E) {
                loadNextTexture(-1);
            } else if (event.KeyInput.Key == irr::KEY_KEY_R) {
                m_Engine->reloadTexture();
            } else if (event.KeyInput.Key == irr::KEY_KEY_Z) {
                m_Engine->setZUp(true);
            } else if (event.KeyInput.Key == irr::KEY_KEY_Y) {
                m_Engine->setZUp(false);
            } else if (event.KeyInput.Key == irr::KEY_KEY_X) {
                // IGUIContextMenu* textureInterpolationElement = dynamic_cast<IGUIContextMenu*>(viewMenu->getElementFromId(UIC_VIEW_TEXTURE_INTERPOLATION));
                //m_TextureInterpolation = textureInterpolationElement->isItemChecked(UIC_VIEW_TEXTURE_INTERPOLATION);
                m_TextureInterpolation = m_TextureInterpolation ? false : true;
                //doesn't work: m_TextureInterpolation = viewMenu->isItemChecked(UIC_VIEW_TEXTURE_INTERPOLATION);
                m_Engine->setMeshDisplayMode(m_WireframeDisplay, m_Lighting, m_TextureInterpolation);
                viewMenu->setItemChecked(INDEX_VIEW_TEXTURE_INTERPOLATION, m_TextureInterpolation);
            } else if (event.KeyInput.Char == L'+' || event.KeyInput.Char == L'=') {
                m_Engine->setAnimationFPS(m_Engine->animationFPS() + 5);
            } else if (event.KeyInput.Char == L'-') {
                if (m_Engine->animationFPS() > 0) {
                    m_Engine->setAnimationFPS(m_Engine->animationFPS() - 5);
                }
            } else if (event.KeyInput.Char == L' ') {
                m_Engine->toggleAnimation();
            } else if (event.KeyInput.Key == irr::KEY_LEFT) {
                if (this->m_Engine->m_LoadedMesh != nullptr) {
                    if (m_Engine->isPlaying)
                        m_Engine->toggleAnimation();
                    this->m_Engine->m_LoadedMesh->setCurrentFrame(round(this->m_Engine->m_LoadedMesh->getFrameNr()) - 1);
                    this->playbackSetFrameEditBox->setText(Utility::toWstring(this->m_Engine->m_LoadedMesh->getFrameNr()).c_str());
                }
            } else if (event.KeyInput.Key == irr::KEY_RIGHT) {
                if (this->m_Engine->m_LoadedMesh != nullptr) {
                    if (m_Engine->isPlaying)
                        m_Engine->toggleAnimation();
                    this->m_Engine->m_LoadedMesh->setCurrentFrame(round(this->m_Engine->m_LoadedMesh->getFrameNr()) + 1);
                    this->playbackSetFrameEditBox->setText(Utility::toWstring(this->m_Engine->m_LoadedMesh->getFrameNr()).c_str());
                }
            }
            // std::wcerr << "Char: " << event.KeyInput.Char << endl;
        }
        m_Engine->KeyIsDown[event.KeyInput.Key] = event.KeyInput.PressedDown;

        return true;
    } else if (event.EventType == EET_MOUSE_INPUT_EVENT) {
        // TODO: improve this copypasta
        switch (event.MouseInput.Event) {
        case EMIE_LMOUSE_LEFT_UP:
            if (m_Engine->LMouseState == 2) {
                m_Engine->LMouseState = 3;
            }
            break;

        case EMIE_LMOUSE_PRESSED_DOWN:
            if (m_Engine->LMouseState == 0) {
                m_Engine->LMouseState = 1;
            }
            break;

        case EMIE_RMOUSE_LEFT_UP:
            if (m_Engine->RMouseState == 2) {
                m_Engine->RMouseState = 3;
            }
            break;

        case EMIE_RMOUSE_PRESSED_DOWN:
            if (m_Engine->RMouseState == 0) {
                m_Engine->RMouseState = 1;
            }
            break;
        }
    } else if (!(event.EventType == EET_GUI_EVENT))
        return false;

    const SEvent::SGUIEvent* ge = &(event.GUIEvent);

    switch (ge->Caller->getID()) {
    case UIE_FILEMENU:
    case UIE_VIEWMENU:
        // call handler for all menu related actions
        handleMenuItemPressed(static_cast<IGUIContextMenu*>(ge->Caller));
        break;

    case UIE_LOADFILEDIALOG:
        if (ge->EventType == EGET_FILE_SELECTED) {
            IGUIFileOpenDialog* fileOpenDialog = static_cast<IGUIFileOpenDialog*>(ge->Caller);
            m_Engine->loadMesh(fileOpenDialog->getFileName());
        }
        break;

    case UIE_LOADTEXTUREDIALOG:
        if (ge->EventType == EGET_FILE_SELECTED) {
            IGUIFileOpenDialog* fileOpenDialog = static_cast<IGUIFileOpenDialog*>(ge->Caller);
            m_Engine->loadTexture(fileOpenDialog->getFileName());
        }
        break;

    case UIE_PLAYBACKSTARTSTOPBUTTON:
        if (ge->EventType == EGET_BUTTON_CLICKED) {
            this->m_Engine->toggleAnimation();
        }
        break;

    case UIE_PLAYBACKINCREASEBUTTON:
        if (ge->EventType == EGET_BUTTON_CLICKED) {
            this->m_Engine->setAnimationFPS(this->m_Engine->animationFPS() + 5);
        }
        break;

    case UIE_PLAYBACKDECREASEBUTTON:
        if (ge->EventType == EGET_BUTTON_CLICKED) {
            if (this->m_Engine->animationFPS() >= 5) {
                this->m_Engine->setAnimationFPS(this->m_Engine->animationFPS() - 5);
            }
        }
        break;
    case UIE_PLAYBACKSETFRAMEEDITBOX:
        if (ge->EventType == EGET_EDITBOX_ENTER) {
            if (this->m_Engine->m_LoadedMesh != nullptr) {
                this->m_Engine->m_LoadedMesh->setCurrentFrame(Utility::toF32(this->playbackSetFrameEditBox->getText()));
            }
        }
        break;

    default:
        break;
    }

    return true;
}