//========================================================================
// GLFW 3.2 - www.glfw.org
//------------------------------------------------------------------------
// Copyright (c) 2002-2006 Marcus Geelnard
// Copyright (c) 2006-2016 Camilla Berglund <elmindreda@glfw.org>
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would
//    be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not
//    be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source
//    distribution.
//
//========================================================================

#include "internal.h"

#include <assert.h>
#include <float.h>
#include <stdlib.h>

// Internal key state used for sticky keys
#define _GLFW_STICK 3


//////////////////////////////////////////////////////////////////////////
//////                         GLFW event API                       //////
//////////////////////////////////////////////////////////////////////////

void _glfwInputKey(_GLFWwindow* window, int key, int scancode, int action, int mods)
{
    if (key >= 0 && key <= GLFW_KEY_LAST)
    {
        GLFWbool repeated = GLFW_FALSE;

        if (action == GLFW_RELEASE && window->keys[key] == GLFW_RELEASE)
            return;

        if (action == GLFW_PRESS && window->keys[key] == GLFW_PRESS)
            repeated = GLFW_TRUE;

        if (action == GLFW_RELEASE && window->stickyKeys)
            window->keys[key] = _GLFW_STICK;
        else
            window->keys[key] = (char) action;

        if (repeated)
            action = GLFW_REPEAT;
    }

    if (window->callbacks.key)
        window->callbacks.key((GLFWwindow*) window, key, scancode, action, mods);
}

void _glfwInputChar(_GLFWwindow* window, unsigned int codepoint, int mods, GLFWbool plain)
{
    if (codepoint < 32 || (codepoint > 126 && codepoint < 160))
        return;

    if (window->callbacks.charmods)
        window->callbacks.charmods((GLFWwindow*) window, codepoint, mods);

    if (plain)
    {
        if (window->callbacks.character)
            window->callbacks.character((GLFWwindow*) window, codepoint);
    }
}

void _glfwInputScroll(_GLFWwindow* window, double xoffset, double yoffset)
{
    if (window->callbacks.scroll)
        window->callbacks.scroll((GLFWwindow*) window, xoffset, yoffset);
}

void _glfwInputMouseClick(_GLFWwindow* window, int button, int action, int mods)
{
    if (button < 0 || button > GLFW_MOUSE_BUTTON_LAST)
        return;

    // Register mouse button action
    if (action == GLFW_RELEASE && window->stickyMouseButtons)
        window->mouseButtons[button] = _GLFW_STICK;
    else
        window->mouseButtons[button] = (char) action;

    if (window->callbacks.mouseButton)
        window->callbacks.mouseButton((GLFWwindow*) window, button, action, mods);
}

void _glfwInputCursorPos(_GLFWwindow* window, double xpos, double ypos)
{
    if (window->virtualCursorPosX == xpos && window->virtualCursorPosY == ypos)
        return;

    window->virtualCursorPosX = xpos;
    window->virtualCursorPosY = ypos;

    if (window->callbacks.cursorPos)
        window->callbacks.cursorPos((GLFWwindow*) window, xpos, ypos);
}

void _glfwInputCursorEnter(_GLFWwindow* window, GLFWbool entered)
{
    if (window->callbacks.cursorEnter)
        window->callbacks.cursorEnter((GLFWwindow*) window, entered);
}

void _glfwInputDrop(_GLFWwindow* window, int count, const char** paths)
{
    if (window->callbacks.drop)
        window->callbacks.drop((GLFWwindow*) window, count, paths);
}

void _glfwInputJoystickChange(int joy, int event)
{
    if (_glfw.callbacks.joystick)
        _glfw.callbacks.joystick(joy, event);
}


//////////////////////////////////////////////////////////////////////////
//////                       GLFW internal API                      //////
//////////////////////////////////////////////////////////////////////////

GLFWbool _glfwIsPrintable(int key)
{
    return (key >= GLFW_KEY_APOSTROPHE && key <= GLFW_KEY_WORLD_2) ||
           (key >= GLFW_KEY_KP_0 && key <= GLFW_KEY_KP_ADD) ||
           key == GLFW_KEY_KP_EQUAL;
}


//////////////////////////////////////////////////////////////////////////
//////                        GLFW public API                       //////
//////////////////////////////////////////////////////////////////////////

GLFWAPI int glfwGetInputMode(GLFWwindow* handle, int mode)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(0);

    switch (mode)
    {
        case GLFW_CURSOR:
            return window->cursorMode;
        case GLFW_STICKY_KEYS:
            return window->stickyKeys;
        case GLFW_STICKY_MOUSE_BUTTONS:
            return window->stickyMouseButtons;
        default:
            _glfwInputError(GLFW_INVALID_ENUM, "Invalid input mode %i", mode);
            return 0;
    }
}

GLFWAPI void glfwSetInputMode(GLFWwindow* handle, int mode, int value)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT();

    switch (mode)
    {
        case GLFW_CURSOR:
        {
            if (value != GLFW_CURSOR_NORMAL &&
                value != GLFW_CURSOR_HIDDEN &&
                value != GLFW_CURSOR_DISABLED)
            {
                _glfwInputError(GLFW_INVALID_ENUM,
                                "Invalid cursor mode %i",
                                value);
                return;
            }

            if (window->cursorMode == value)
                return;

            window->cursorMode = value;

            _glfwPlatformGetCursorPos(window,
                                      &window->virtualCursorPosX,
                                      &window->virtualCursorPosY);

            if (_glfwPlatformWindowFocused(window))
                _glfwPlatformSetCursorMode(window, value);

            return;
        }

        case GLFW_STICKY_KEYS:
        {
            if (window->stickyKeys == value)
                return;

            if (!value)
            {
                int i;

                // Release all sticky keys
                for (i = 0;  i <= GLFW_KEY_LAST;  i++)
                {
                    if (window->keys[i] == _GLFW_STICK)
                        window->keys[i] = GLFW_RELEASE;
                }
            }

            window->stickyKeys = value ? GLFW_TRUE : GLFW_FALSE;
            return;
        }

        case GLFW_STICKY_MOUSE_BUTTONS:
        {
            if (window->stickyMouseButtons == value)
                return;

            if (!value)
            {
                int i;

                // Release all sticky mouse buttons
                for (i = 0;  i <= GLFW_MOUSE_BUTTON_LAST;  i++)
                {
                    if (window->mouseButtons[i] == _GLFW_STICK)
                        window->mouseButtons[i] = GLFW_RELEASE;
                }
            }

            window->stickyMouseButtons = value ? GLFW_TRUE : GLFW_FALSE;
            return;
        }
    }

    _glfwInputError(GLFW_INVALID_ENUM, "Invalid input mode %i", mode);
}

GLFWAPI const char* glfwGetKeyName(int key, int scancode)
{
    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    return _glfwPlatformGetKeyName(key, scancode);
}

GLFWAPI int glfwGetKey(GLFWwindow* handle, int key)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(GLFW_RELEASE);

    if (key < GLFW_KEY_SPACE || key > GLFW_KEY_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid key %i", key);
        return GLFW_RELEASE;
    }

    if (window->keys[key] == _GLFW_STICK)
    {
        // Sticky mode: release key now
        window->keys[key] = GLFW_RELEASE;
        return GLFW_PRESS;
    }

    return (int) window->keys[key];
}

GLFWAPI int glfwGetMouseButton(GLFWwindow* handle, int button)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(GLFW_RELEASE);

    if (button < GLFW_MOUSE_BUTTON_1 || button > GLFW_MOUSE_BUTTON_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid mouse button %i", button);
        return GLFW_RELEASE;
    }

    if (window->mouseButtons[button] == _GLFW_STICK)
    {
        // Sticky mode: release mouse button now
        window->mouseButtons[button] = GLFW_RELEASE;
        return GLFW_PRESS;
    }

    return (int) window->mouseButtons[button];
}

GLFWAPI void glfwGetCursorPos(GLFWwindow* handle, double* xpos, double* ypos)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    if (xpos)
        *xpos = 0;
    if (ypos)
        *ypos = 0;

    _GLFW_REQUIRE_INIT();

    if (window->cursorMode == GLFW_CURSOR_DISABLED)
    {
        if (xpos)
            *xpos = window->virtualCursorPosX;
        if (ypos)
            *ypos = window->virtualCursorPosY;
    }
    else
        _glfwPlatformGetCursorPos(window, xpos, ypos);
}

GLFWAPI void glfwSetCursorPos(GLFWwindow* handle, double xpos, double ypos)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT();

    if (xpos != xpos || xpos < -DBL_MAX || xpos > DBL_MAX ||
        ypos != ypos || ypos < -DBL_MAX || ypos > DBL_MAX)
    {
        _glfwInputError(GLFW_INVALID_VALUE,
                        "Invalid cursor position %f %f",
                        xpos, ypos);
        return;
    }

    if (!_glfwPlatformWindowFocused(window))
        return;

    if (window->cursorMode == GLFW_CURSOR_DISABLED)
    {
        // Only update the accumulated position if the cursor is disabled
        window->virtualCursorPosX = xpos;
        window->virtualCursorPosY = ypos;
    }
    else
    {
        // Update system cursor position
        _glfwPlatformSetCursorPos(window, xpos, ypos);
    }
}

GLFWAPI GLFWcursor* glfwCreateCursor(const GLFWimage* image, int xhot, int yhot)
{
    _GLFWcursor* cursor;

    assert(image != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    cursor = calloc(1, sizeof(_GLFWcursor));
    cursor->next = _glfw.cursorListHead;
    _glfw.cursorListHead = cursor;

    if (!_glfwPlatformCreateCursor(cursor, image, xhot, yhot))
    {
        glfwDestroyCursor((GLFWcursor*) cursor);
        return NULL;
    }

    return (GLFWcursor*) cursor;
}

GLFWAPI GLFWcursor* glfwCreateStandardCursor(int shape)
{
    _GLFWcursor* cursor;

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    if (shape != GLFW_ARROW_CURSOR &&
        shape != GLFW_IBEAM_CURSOR &&
        shape != GLFW_CROSSHAIR_CURSOR &&
        shape != GLFW_HAND_CURSOR &&
        shape != GLFW_HRESIZE_CURSOR &&
        shape != GLFW_VRESIZE_CURSOR)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid standard cursor %i", shape);
        return NULL;
    }

    cursor = calloc(1, sizeof(_GLFWcursor));
    cursor->next = _glfw.cursorListHead;
    _glfw.cursorListHead = cursor;

    if (!_glfwPlatformCreateStandardCursor(cursor, shape))
    {
        glfwDestroyCursor((GLFWcursor*) cursor);
        return NULL;
    }

    return (GLFWcursor*) cursor;
}

GLFWAPI void glfwDestroyCursor(GLFWcursor* handle)
{
    _GLFWcursor* cursor = (_GLFWcursor*) handle;

    _GLFW_REQUIRE_INIT();

    if (cursor == NULL)
        return;

    // Make sure the cursor is not being used by any window
    {
        _GLFWwindow* window;

        for (window = _glfw.windowListHead;  window;  window = window->next)
        {
            if (window->cursor == cursor)
                glfwSetCursor((GLFWwindow*) window, NULL);
        }
    }

    _glfwPlatformDestroyCursor(cursor);

    // Unlink cursor from global linked list
    {
        _GLFWcursor** prev = &_glfw.cursorListHead;

        while (*prev != cursor)
            prev = &((*prev)->next);

        *prev = cursor->next;
    }

    free(cursor);
}

GLFWAPI void glfwSetCursor(GLFWwindow* windowHandle, GLFWcursor* cursorHandle)
{
    _GLFWwindow* window = (_GLFWwindow*) windowHandle;
    _GLFWcursor* cursor = (_GLFWcursor*) cursorHandle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT();

    window->cursor = cursor;

    _glfwPlatformSetCursor(window, cursor);
}

GLFWAPI GLFWkeyfun glfwSetKeyCallback(GLFWwindow* handle, GLFWkeyfun cbfun)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(window->callbacks.key, cbfun);
    return cbfun;
}

GLFWAPI GLFWcharfun glfwSetCharCallback(GLFWwindow* handle, GLFWcharfun cbfun)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(window->callbacks.character, cbfun);
    return cbfun;
}

GLFWAPI GLFWcharmodsfun glfwSetCharModsCallback(GLFWwindow* handle, GLFWcharmodsfun cbfun)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(window->callbacks.charmods, cbfun);
    return cbfun;
}

GLFWAPI GLFWmousebuttonfun glfwSetMouseButtonCallback(GLFWwindow* handle,
                                                      GLFWmousebuttonfun cbfun)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(window->callbacks.mouseButton, cbfun);
    return cbfun;
}

GLFWAPI GLFWcursorposfun glfwSetCursorPosCallback(GLFWwindow* handle,
                                                  GLFWcursorposfun cbfun)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(window->callbacks.cursorPos, cbfun);
    return cbfun;
}

GLFWAPI GLFWcursorenterfun glfwSetCursorEnterCallback(GLFWwindow* handle,
                                                      GLFWcursorenterfun cbfun)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(window->callbacks.cursorEnter, cbfun);
    return cbfun;
}

GLFWAPI GLFWscrollfun glfwSetScrollCallback(GLFWwindow* handle,
                                            GLFWscrollfun cbfun)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(window->callbacks.scroll, cbfun);
    return cbfun;
}

GLFWAPI GLFWdropfun glfwSetDropCallback(GLFWwindow* handle, GLFWdropfun cbfun)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(window->callbacks.drop, cbfun);
    return cbfun;
}

GLFWAPI int glfwJoystickPresent(int joy)
{
    _GLFW_REQUIRE_INIT_OR_RETURN(0);

    if (joy < 0 || joy > GLFW_JOYSTICK_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid joystick %i", joy);
        return 0;
    }

    return _glfwPlatformJoystickPresent(joy);
}

GLFWAPI const float* glfwGetJoystickAxes(int joy, int* count)
{
    assert(count != NULL);
    *count = 0;

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    if (joy < 0 || joy > GLFW_JOYSTICK_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid joystick %i", joy);
        return NULL;
    }

    return _glfwPlatformGetJoystickAxes(joy, count);
}

GLFWAPI const unsigned char* glfwGetJoystickButtons(int joy, int* count)
{
    assert(count != NULL);
    *count = 0;

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    if (joy < 0 || joy > GLFW_JOYSTICK_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid joystick %i", joy);
        return NULL;
    }

    return _glfwPlatformGetJoystickButtons(joy, count);
}

GLFWAPI const char* glfwGetJoystickName(int joy)
{
    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    if (joy < 0 || joy > GLFW_JOYSTICK_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid joystick %i", joy);
        return NULL;
    }

    return _glfwPlatformGetJoystickName(joy);
}

GLFWAPI GLFWjoystickfun glfwSetJoystickCallback(GLFWjoystickfun cbfun)
{
    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(_glfw.callbacks.joystick, cbfun);
    return cbfun;
}

GLFWAPI void glfwSetClipboardString(GLFWwindow* handle, const char* string)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);
    assert(string != NULL);

    _GLFW_REQUIRE_INIT();
    _glfwPlatformSetClipboardString(window, string);
}

GLFWAPI const char* glfwGetClipboardString(GLFWwindow* handle)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    return _glfwPlatformGetClipboardString(window);
}

GLFWAPI double glfwGetTime(void)
{
    _GLFW_REQUIRE_INIT_OR_RETURN(0.0);
    return (double) (_glfwPlatformGetTimerValue() - _glfw.timerOffset) /
        _glfwPlatformGetTimerFrequency();
}

GLFWAPI void glfwSetTime(double time)
{
    _GLFW_REQUIRE_INIT();

    if (time != time || time < 0.0 || time > 18446744073.0)
    {
        _glfwInputError(GLFW_INVALID_VALUE, "Invalid time %f", time);
        return;
    }

    _glfw.timerOffset = _glfwPlatformGetTimerValue() -
        (uint64_t) (time * _glfwPlatformGetTimerFrequency());
}

GLFWAPI uint64_t glfwGetTimerValue(void)
{
    _GLFW_REQUIRE_INIT_OR_RETURN(0);
    return _glfwPlatformGetTimerValue();
}

GLFWAPI uint64_t glfwGetTimerFrequency(void)
{
    _GLFW_REQUIRE_INIT_OR_RETURN(0);
    return _glfwPlatformGetTimerFrequency();
}