/*
    This file is part of Magnum.

    Copyright © 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018
              Vladimír Vondruš <mosra@centrum.cz>
    Copyright © 2016 Jonathan Hale <squareys@googlemail.com>

    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
    to deal in the Software without restriction, including without limitation
    the rights to use, copy, modify, merge, publish, distribute, sublicense,
    and/or sell copies of the Software, and to permit persons to whom the
    Software is furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included
    in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    DEALINGS IN THE SOFTWARE.
*/

#include "GlfwApplication.h"

#include <cstring>
#include <tuple>
#include <Corrade/Utility/String.h>
#include <Corrade/Utility/Unicode.h>

#include "Magnum/Platform/ScreenedApplication.hpp"

#ifdef MAGNUM_TARGET_GL
#include "Magnum/GL/Version.h"
#include "Magnum/Platform/GLContext.h"
#endif

namespace Magnum { namespace Platform {

#ifdef GLFW_TRUE
/* The docs say that it's the same, verify that just in case */
static_assert(GLFW_TRUE == true && GLFW_FALSE == false, "GLFW does not have sane bool values");
#endif

GlfwApplication::GlfwApplication(const Arguments& arguments): GlfwApplication{arguments, Configuration{}} {}

GlfwApplication::GlfwApplication(const Arguments& arguments, const Configuration& configuration): GlfwApplication{arguments, NoCreate} {
    create(configuration);
}

#ifdef MAGNUM_TARGET_GL
GlfwApplication::GlfwApplication(const Arguments& arguments, const Configuration& configuration, const GLConfiguration& glConfiguration): GlfwApplication{arguments, NoCreate} {
    create(configuration, glConfiguration);
}
#endif

GlfwApplication::GlfwApplication(const Arguments& arguments, NoCreateT):
    _flags{Flag::Redraw}
    #ifdef MAGNUM_TARGET_GL
    , _context{new GLContext{NoCreate, arguments.argc, arguments.argv}}
    #endif
{
    /* Init GLFW */
    glfwSetErrorCallback([](int, const char* const description) {
        Error{} << description;
    });

    if(!glfwInit()) {
        Error() << "Could not initialize GLFW";
        std::exit(8);
    }

    #ifndef MAGNUM_TARGET_GL
    static_cast<void>(arguments);
    #endif
}

void GlfwApplication::create() {
    create(Configuration{});
}

void GlfwApplication::create(const Configuration& configuration) {
    if(!tryCreate(configuration)) std::exit(1);
}

#ifdef MAGNUM_TARGET_GL
void GlfwApplication::create(const Configuration& configuration, const GLConfiguration& glConfiguration) {
    if(!tryCreate(configuration, glConfiguration)) std::exit(1);
}
#endif

bool GlfwApplication::tryCreate(const Configuration& configuration) {
    #ifdef MAGNUM_TARGET_GL
    #ifdef GLFW_NO_API
    if(!(configuration.windowFlags() & Configuration::WindowFlag::Contextless))
    #endif
    {
        return tryCreate(configuration, GLConfiguration{});
    }
    #endif

    CORRADE_ASSERT(!_window, "Platform::GlfwApplication::tryCreate(): window already created", false);

    /* Window flags */
    GLFWmonitor* monitor = nullptr; /* Needed for setting fullscreen */
    if (configuration.windowFlags() >= Configuration::WindowFlag::Fullscreen) {
        monitor = glfwGetPrimaryMonitor();
        glfwWindowHint(GLFW_AUTO_ICONIFY, configuration.windowFlags() >= Configuration::WindowFlag::AutoIconify);
    } else {
        const Configuration::WindowFlags& flags = configuration.windowFlags();
        glfwWindowHint(GLFW_RESIZABLE, flags >= Configuration::WindowFlag::Resizable);
        glfwWindowHint(GLFW_VISIBLE, !(flags >= Configuration::WindowFlag::Hidden));
        #ifdef GLFW_MAXIMIZED
        glfwWindowHint(GLFW_MAXIMIZED, flags >= Configuration::WindowFlag::Maximized);
        #endif
        glfwWindowHint(GLFW_FLOATING, flags >= Configuration::WindowFlag::Floating);
    }
    glfwWindowHint(GLFW_FOCUSED, configuration.windowFlags() >= Configuration::WindowFlag::Focused);

    #ifdef GLFW_NO_API
    /* Disable implicit GL context creation */
    glfwWindowHint(GLFW_CONTEXT_CREATION_API, GLFW_NO_API);
    #endif

    /* Create the window */
    _window = glfwCreateWindow(configuration.size().x(), configuration.size().y(), configuration.title().c_str(), monitor, nullptr);
    if(!_window) {
        Error() << "Platform::GlfwApplication::tryCreate(): cannot create window";
        glfwTerminate();
        return false;
    }

    /* Proceed with configuring other stuff that couldn't be done with window
       hints */
    if(configuration.windowFlags() >= Configuration::WindowFlag::Minimized)
        glfwIconifyWindow(_window);
    glfwSetInputMode(_window, GLFW_CURSOR, Int(configuration.cursorMode()));

    /* Set callbacks */
    setupCallbacks();

    return true;
}

namespace {

GlfwApplication::InputEvent::Modifiers currentGlfwModifiers(GLFWwindow* window) {
    static_assert(GLFW_PRESS == true && GLFW_RELEASE == false,
        "GLFW press and release constants do not correspond to bool values");

    GlfwApplication::InputEvent::Modifiers mods;
    if(glfwGetKey(window, GLFW_KEY_LEFT_SHIFT) ||
       glfwGetKey(window, GLFW_KEY_RIGHT_SHIFT))
        mods |= GlfwApplication::InputEvent::Modifier::Shift;
    if(glfwGetKey(window, GLFW_KEY_LEFT_CONTROL) ||
       glfwGetKey(window, GLFW_KEY_RIGHT_CONTROL))
        mods |= GlfwApplication::InputEvent::Modifier::Ctrl;
    if(glfwGetKey(window, GLFW_KEY_LEFT_ALT) ||
       glfwGetKey(window, GLFW_KEY_RIGHT_ALT))
        mods |= GlfwApplication::InputEvent::Modifier::Alt;
    if(glfwGetKey(window, GLFW_KEY_LEFT_SUPER) ||
       glfwGetKey(window, GLFW_KEY_RIGHT_SUPER))
        mods |= GlfwApplication::InputEvent::Modifier::Super;

    return mods;
}

}

#ifdef MAGNUM_TARGET_GL
bool GlfwApplication::tryCreate(const Configuration& configuration, const GLConfiguration&
    #ifndef MAGNUM_BUILD_DEPRECATED
    glConfiguration
    #else
    _glConfiguration
    #endif
) {
    #ifdef MAGNUM_BUILD_DEPRECATED
    GLConfiguration glConfiguration{_glConfiguration};
    CORRADE_IGNORE_DEPRECATED_PUSH
    if(configuration.flags() && !glConfiguration.flags())
        glConfiguration.setFlags(configuration.flags());
    if(configuration.version() != GL::Version::None && glConfiguration.version() == GL::Version::None)
        glConfiguration.setVersion(configuration.version());
    if(configuration.sampleCount() && !glConfiguration.sampleCount())
        glConfiguration.setSampleCount(configuration.sampleCount());
    if(configuration.isSRGBCapable() && !glConfiguration.isSRGBCapable())
        glConfiguration.setSRGBCapable(configuration.isSRGBCapable());
    CORRADE_IGNORE_DEPRECATED_POP
    #endif

    CORRADE_ASSERT(!_window && _context->version() == GL::Version::None, "Platform::GlfwApplication::tryCreate(): window with OpenGL context already created", false);

    /* Window flags */
    GLFWmonitor* monitor = nullptr; /* Needed for setting fullscreen */
    if (configuration.windowFlags() >= Configuration::WindowFlag::Fullscreen) {
        monitor = glfwGetPrimaryMonitor();
        glfwWindowHint(GLFW_AUTO_ICONIFY, configuration.windowFlags() >= Configuration::WindowFlag::AutoIconify);
    } else {
        const Configuration::WindowFlags& flags = configuration.windowFlags();
        glfwWindowHint(GLFW_RESIZABLE, flags >= Configuration::WindowFlag::Resizable);
        glfwWindowHint(GLFW_VISIBLE, !(flags >= Configuration::WindowFlag::Hidden));
        #ifdef GLFW_MAXIMIZED
        glfwWindowHint(GLFW_MAXIMIZED, flags >= Configuration::WindowFlag::Maximized);
        #endif
        glfwWindowHint(GLFW_FLOATING, flags >= Configuration::WindowFlag::Floating);
    }
    glfwWindowHint(GLFW_FOCUSED, configuration.windowFlags() >= Configuration::WindowFlag::Focused);

    /* Framebuffer setup */
    glfwWindowHint(GLFW_RED_BITS, glConfiguration.colorBufferSize().r());
    glfwWindowHint(GLFW_GREEN_BITS, glConfiguration.colorBufferSize().g());
    glfwWindowHint(GLFW_BLUE_BITS, glConfiguration.colorBufferSize().b());
    glfwWindowHint(GLFW_ALPHA_BITS, glConfiguration.colorBufferSize().a());
    glfwWindowHint(GLFW_DEPTH_BITS, glConfiguration.depthBufferSize());
    glfwWindowHint(GLFW_STENCIL_BITS, glConfiguration.stencilBufferSize());
    glfwWindowHint(GLFW_SAMPLES, glConfiguration.sampleCount());
    glfwWindowHint(GLFW_SRGB_CAPABLE, glConfiguration.isSRGBCapable());

    const GLConfiguration::Flags& flags = glConfiguration.flags();
    #ifdef GLFW_CONTEXT_NO_ERROR
    glfwWindowHint(GLFW_CONTEXT_NO_ERROR, flags >= GLConfiguration::Flag::NoError);
    #endif
    glfwWindowHint(GLFW_OPENGL_DEBUG_CONTEXT, flags >= GLConfiguration::Flag::Debug);
    glfwWindowHint(GLFW_STEREO, flags >= GLConfiguration::Flag::Stereo);

    /* Set context version, if requested */
    if(glConfiguration.version() != GL::Version::None) {
        Int major, minor;
        std::tie(major, minor) = version(glConfiguration.version());
        glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, major);
        glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, minor);
        #ifndef MAGNUM_TARGET_GLES
        if(glConfiguration.version() >= GL::Version::GL320) {
            glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
            glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, true);
        }
        #else
        glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);
        #endif

    /* Request usable version otherwise */
    } else {
        #ifndef MAGNUM_TARGET_GLES
        /* First try to create core context. This is needed mainly on macOS and
           Mesa, as support for recent OpenGL versions isn't implemented in
           compatibility contexts (which are the default). Unlike SDL2, GLFW
           requires at least version 3.2 to be able to request a core profile. */
        glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
        glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
        glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
        glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, true);
        #else
        /* For ES the major context version is compile-time constant */
        #ifdef MAGNUM_TARGET_GLES3
        glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
        #elif defined(MAGNUM_TARGET_GLES2)
        glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
        #else
        #error unsupported OpenGL ES version
        #endif
        glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
        glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);
        #endif
    }

    /* Create window. Hide it by default so we don't have distracting window
       blinking in case we have to destroy it again right away. If the creation
       succeeds, make the context current so we can query GL_VENDOR below. */
    glfwWindowHint(GLFW_VISIBLE, false);
    if((_window = glfwCreateWindow(configuration.size().x(), configuration.size().y(), configuration.title().c_str(), monitor, nullptr)))
        glfwMakeContextCurrent(_window);

    #ifndef MAGNUM_TARGET_GLES
   /* Fall back to (forward compatible) GL 2.1, if version is not
       user-specified and either core context creation fails or we are on
       binary NVidia/AMD drivers on Linux/Windows or Intel Windows drivers.
       Instead of creating forward-compatible context with highest available
       version, they force the version to the one specified, which is
       completely useless behavior. */
    #ifndef CORRADE_TARGET_APPLE
    constexpr static const char nvidiaVendorString[] = "NVIDIA Corporation";
    #ifdef CORRADE_TARGET_WINDOWS
    constexpr static const char intelVendorString[] = "Intel";
    #endif
    constexpr static const char amdVendorString[] = "ATI Technologies Inc.";
    const char* vendorString;
    #endif
    if(glConfiguration.version() == GL::Version::None && (!_window
        #ifndef CORRADE_TARGET_APPLE
        /* Sorry about the UGLY code, HOPEFULLY THERE WON'T BE MORE WORKAROUNDS */
        || (vendorString = reinterpret_cast<const char*>(glGetString(GL_VENDOR)),
        (std::strncmp(vendorString, nvidiaVendorString, sizeof(nvidiaVendorString)) == 0 ||
         #ifdef CORRADE_TARGET_WINDOWS
         std::strncmp(vendorString, intelVendorString, sizeof(intelVendorString)) == 0 ||
         #endif
         std::strncmp(vendorString, amdVendorString, sizeof(amdVendorString)) == 0)
         && !_context->isDriverWorkaroundDisabled("no-forward-compatible-core-context"))
         #endif
    )) {
        /* Don't print any warning when doing the workaround, because the bug
           will be there probably forever */
        if(!_window) Warning{}
            << "Platform::GlfwApplication::tryCreate(): cannot create a window with core OpenGL context, falling back to compatibility context";
        else glfwDestroyWindow(_window);

        glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
        glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 1);
        glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_ANY_PROFILE);
        glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, false);

        _window = glfwCreateWindow(configuration.size().x(), configuration.size().y(), configuration.title().c_str(), monitor, nullptr);
    }
    #endif

    if(!_window) {
        Error() << "Platform::GlfwApplication::tryCreate(): cannot create a window with OpenGL context";
        return false;
    }

    /* Proceed with configuring other stuff that couldn't be done with window
       hints */
    if(configuration.windowFlags() >= Configuration::WindowFlag::Minimized)
        glfwIconifyWindow(_window);
    glfwSetInputMode(_window, GLFW_CURSOR, Int(configuration.cursorMode()));

    /* Set callbacks */
    setupCallbacks();

    /* Make the final context current */
    glfwMakeContextCurrent(_window);

    /* Destroy everything when the Magnum context creation fails */
    if(!_context->tryCreate()) {
        glfwDestroyWindow(_window);
        _window = nullptr;
    }

    /* Show the window once we are sure that everything is okay */
    if(!(configuration.windowFlags() & Configuration::WindowFlag::Hidden))
        glfwShowWindow(_window);

    /* Return true if the initialization succeeds */
    return true;
}
#endif

void GlfwApplication::setupCallbacks() {
    glfwSetWindowUserPointer(_window, this);
    glfwSetWindowRefreshCallback(_window, [](GLFWwindow* const window){
        /* Properly redraw after the window is restored from minimized state */
        static_cast<GlfwApplication*>(glfwGetWindowUserPointer(window))->drawEvent();
    });
    glfwSetFramebufferSizeCallback(_window, [](GLFWwindow* const window, const int w, const int h) {
        ViewportEvent e{{w, h}};
        static_cast<GlfwApplication*>(glfwGetWindowUserPointer(window))->viewportEvent(e);
    });
    glfwSetKeyCallback(_window, [](GLFWwindow* const window, const int key, int, const int action, const int mods) {
        const auto instance = static_cast<GlfwApplication*>(glfwGetWindowUserPointer(window));

        KeyEvent e(static_cast<KeyEvent::Key>(key), {static_cast<InputEvent::Modifier>(mods)}, action == GLFW_REPEAT);

        if(action == GLFW_PRESS) {
            instance->keyPressEvent(e);
        } else if(action == GLFW_RELEASE) {
            instance->keyReleaseEvent(e);
        } else if(action == GLFW_REPEAT) {
            instance->keyPressEvent(e);
        }
    });
    glfwSetMouseButtonCallback(_window, [](GLFWwindow* const window, const int button, const int action, const int mods) {
        const auto instance = static_cast<GlfwApplication*>(glfwGetWindowUserPointer(window));

        double x, y;
        glfwGetCursorPos(window, &x, &y);
        MouseEvent e(static_cast<MouseEvent::Button>(button), {Int(x), Int(y)}, {static_cast<InputEvent::Modifier>(mods)});

        if(action == GLFW_PRESS) {
            instance->mousePressEvent(e);
        } else if(action == GLFW_RELEASE) {
            instance->mouseReleaseEvent(e);
        } /* we don't handle GLFW_REPEAT */
    });
    glfwSetCursorPosCallback(_window, [](GLFWwindow* const window, const double x, const double y) {
        MouseMoveEvent e{window, Vector2i{Int(x), Int(y)}};
        static_cast<GlfwApplication*>(glfwGetWindowUserPointer(window))->mouseMoveEvent(e);
    });
    glfwSetScrollCallback(_window, [](GLFWwindow* window, double xoffset, double yoffset) {
        const auto instance = static_cast<GlfwApplication*>(glfwGetWindowUserPointer(window));

        MouseScrollEvent e(window, Vector2{Float(xoffset), Float(yoffset)});
        instance->mouseScrollEvent(e);

        #ifdef MAGNUM_BUILD_DEPRECATED
        if(yoffset != 0.0) {
            #ifdef __GNUC__
            #pragma GCC diagnostic push
            #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
            #endif
            MouseEvent e1((yoffset > 0.0) ? MouseEvent::Button::WheelUp : MouseEvent::Button::WheelDown, {}, currentGlfwModifiers(window));
            #ifdef __GNUC__
            #pragma GCC diagnostic pop
            #endif
            instance->mousePressEvent(e1);
        }
        #endif
    });
    glfwSetCharCallback(_window, [](GLFWwindow* window, unsigned int codepoint) {
        const auto instance = static_cast<GlfwApplication*>(glfwGetWindowUserPointer(window));

        if(!(instance->_flags & Flag::TextInputActive)) return;

        char utf8[4];
        const std::size_t size = Utility::Unicode::utf8(codepoint, utf8);
        TextInputEvent e{{utf8, size}};
        instance->textInputEvent(e);
    });
}

GlfwApplication::~GlfwApplication() {
    glfwDestroyWindow(_window);
    glfwTerminate();
}

Vector2i GlfwApplication::windowSize() const {
    Vector2i size;
    glfwGetWindowSize(_window, &size.x(), &size.y());
    return size;
}

void GlfwApplication::setSwapInterval(const Int interval) {
    glfwSwapInterval(interval);
}

int GlfwApplication::exec() {
    CORRADE_ASSERT(_window, "Platform::GlfwApplication::exec(): no window opened", {});

    while(!glfwWindowShouldClose(_window)) {
        if(_flags & Flag::Redraw) {
            _flags &= ~Flag::Redraw;
            drawEvent();
        }
        glfwPollEvents();
    }
    return 0;
}

auto GlfwApplication::MouseMoveEvent::buttons() -> Buttons {
    if(!_buttons) {
        _buttons = Buttons{};
        for(const Int button: {GLFW_MOUSE_BUTTON_LEFT,
                               GLFW_MOUSE_BUTTON_MIDDLE,
                               GLFW_MOUSE_BUTTON_RIGHT}) {
            if(glfwGetMouseButton(_window, button) == GLFW_PRESS)
                *_buttons |= Button(1 << button);
        }
    }

    return *_buttons;
}

auto GlfwApplication::MouseMoveEvent::modifiers() -> Modifiers {
    if(!_modifiers) _modifiers = currentGlfwModifiers(_window);
    return *_modifiers;
}

Vector2i GlfwApplication::MouseScrollEvent::position() {
    if(!_position) {
        Vector2d position;
        glfwGetCursorPos(_window, &position.x(), &position.y());
        _position = Vector2i{position};
    }

    return *_position;
}

auto GlfwApplication::MouseScrollEvent::modifiers() -> Modifiers {
    if(!_modifiers) _modifiers = currentGlfwModifiers(_window);
    return *_modifiers;
}

void GlfwApplication::viewportEvent(ViewportEvent& event) {
    #ifdef MAGNUM_BUILD_DEPRECATED
    CORRADE_IGNORE_DEPRECATED_PUSH
    viewportEvent(event.windowSize());
    CORRADE_IGNORE_DEPRECATED_POP
    #else
    static_cast<void>(event);
    #endif
}

#ifdef MAGNUM_BUILD_DEPRECATED
void GlfwApplication::viewportEvent(const Vector2i&) {}
#endif

void GlfwApplication::keyPressEvent(KeyEvent&) {}
void GlfwApplication::keyReleaseEvent(KeyEvent&) {}
void GlfwApplication::mousePressEvent(MouseEvent&) {}
void GlfwApplication::mouseReleaseEvent(MouseEvent&) {}
void GlfwApplication::mouseMoveEvent(MouseMoveEvent&) {}
void GlfwApplication::mouseScrollEvent(MouseScrollEvent&) {}
void GlfwApplication::textInputEvent(TextInputEvent&) {}

#ifdef MAGNUM_TARGET_GL
GlfwApplication::GLConfiguration::GLConfiguration():
    _colorBufferSize{8, 8, 8, 0}, _depthBufferSize{24}, _stencilBufferSize{0},
    _sampleCount{0}, _version{GL::Version::None} {}

GlfwApplication::GLConfiguration::~GLConfiguration() = default;
#endif

GlfwApplication::Configuration::Configuration():
    _title{"Magnum GLFW Application"},
    _size{800, 600},
    _windowFlags{WindowFlag::Focused},
    _cursorMode{CursorMode::Normal}
    #if defined(MAGNUM_BUILD_DEPRECATED) && defined(MAGNUM_TARGET_GL)
    , _sampleCount{0}, _version{GL::Version::None}
    #endif
    {}

GlfwApplication::Configuration::~Configuration() = default;

#if defined(DOXYGEN_GENERATING_OUTPUT) || GLFW_VERSION_MAJOR*100 + GLFW_VERSION_MINOR >= 302
std::string GlfwApplication::KeyEvent::keyName(const Key key) {
    /* It can return null, so beware */
    return Utility::String::fromArray(glfwGetKeyName(int(key), 0));
}

std::string GlfwApplication::KeyEvent::keyName() const {
    return keyName(_key);
}
#endif

template class BasicScreen<GlfwApplication>;
template class BasicScreenedApplication<GlfwApplication>;

}}