/* Copyright 2020 Jaakko Keränen <jaakko.keranen@iki.fi>

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */

#include "window.h"

#include "labelwidget.h"
#include "inputwidget.h"
#include "documentwidget.h"
#include "sidebarwidget.h"
#include "lookupwidget.h"
#include "embedded.h"
#include "command.h"
#include "paint.h"
#include "util.h"
#include "keys.h"
#include "../app.h"
#include "../visited.h"
#include "../gmcerts.h"
#include "../gmutil.h"
#if defined (iPlatformMsys)
#   include "../win32.h"
#endif
#if defined (iPlatformApple) && !defined (iPlatformIOS)
#   include "macos.h"
#endif

#include <the_Foundation/file.h>
#include <the_Foundation/path.h>
#include <SDL_hints.h>
#include <SDL_timer.h>
#include <SDL_syswm.h>

#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"

static iWindow *theWindow_ = NULL;

#if defined (iPlatformApple)
static float initialUiScale_ = 1.0f;
#else
static float initialUiScale_ = 1.1f;
#endif

iDefineTypeConstructionArgs(Window, (iRect rect), rect)

static iBool handleRootCommands_(iWidget *root, const char *cmd) {
    iUnused(root);
    if (equal_Command(cmd, "menu.open")) {
        iWidget *button = pointer_Command(cmd);
        iWidget *menu = findChild_Widget(button, "menu");
        iAssert(menu);
        if (!isVisible_Widget(menu)) {
            openMenu_Widget(menu, init_I2(0, button->rect.size.y));
        }
        else {
            closeMenu_Widget(menu);
        }
        return iTrue;
    }
    else if (equal_Command(cmd, "focus.set")) {
        setFocus_Widget(findWidget_App(cstr_Rangecc(range_Command(cmd, "id"))));
        return iTrue;
    }
    else if (handleCommand_App(cmd)) {
        return iTrue;
    }
    return iFalse;
}

#if defined (iPlatformApple)
#  define iHaveNativeMenus
#endif

#if !defined (iHaveNativeMenus)
/* TODO: Submenus wouldn't hurt here. */
static const iMenuItem navMenuItems[] = {
    { "New Tab", 't', KMOD_PRIMARY, "tabs.new" },
    { "Open Location...", SDLK_l, KMOD_PRIMARY, "navigate.focus" },
    { "---", 0, 0, NULL },
    { "Save to Downloads", SDLK_s, KMOD_PRIMARY, "document.save" },
    { "---", 0, 0, NULL },
    { "Copy Source Text", SDLK_c, KMOD_PRIMARY, "copy" },
    { "Bookmark This Page", SDLK_d, KMOD_PRIMARY, "bookmark.add" },
    { "---", 0, 0, NULL },
    { "Toggle Sidebar", SDLK_l, KMOD_PRIMARY | KMOD_SHIFT, "sidebar.toggle" },
    { "Zoom In", SDLK_EQUALS, KMOD_PRIMARY, "zoom.delta arg:10" },
    { "Zoom Out", SDLK_MINUS, KMOD_PRIMARY, "zoom.delta arg:-10" },
    { "Reset Zoom", SDLK_0, KMOD_PRIMARY, "zoom.set arg:100" },
    { "---", 0, 0, NULL },
    { "Preferences...", SDLK_COMMA, KMOD_PRIMARY, "preferences" },
    { "Help", SDLK_F1, 0, "!open url:about:help" },
    { "Release Notes", 0, 0, "!open url:about:version" },
    { "---", 0, 0, NULL },
    { "Quit Lagrange", 'q', KMOD_PRIMARY, "quit" }
};
#endif

#if defined (iHaveNativeMenus)
/* Using native menus. */
static const iMenuItem fileMenuItems[] = {
    { "New Tab", SDLK_t, KMOD_PRIMARY, "tabs.new" },
    { "Open Location...", SDLK_l, KMOD_PRIMARY, "navigate.focus" },
    { "---", 0, 0, NULL },
    { "Save to Downloads", SDLK_s, KMOD_PRIMARY, "document.save" },
};

static const iMenuItem editMenuItems[] = {
    { "Copy Source Text", SDLK_c, KMOD_PRIMARY, "copy" },
    { "Copy Link to Page", SDLK_c, KMOD_PRIMARY | KMOD_SHIFT, "document.copylink" },
    { "---", 0, 0, NULL },
    { "Find", SDLK_f, KMOD_PRIMARY, "focus.set id:find.input" },
    { "---", 0, 0, NULL },
    { "Bookmark This Page...", SDLK_d, KMOD_PRIMARY, "bookmark.add" },
};

static const iMenuItem identityMenuItems[] = {
    { "New Identity...", SDLK_n, KMOD_PRIMARY | KMOD_SHIFT, "ident.new" },
};

static const iMenuItem viewMenuItems[] = {
    { "Show Bookmarks", '1', KMOD_PRIMARY, "sidebar.mode arg:0 toggle:1" },
    { "Show History", '2', KMOD_PRIMARY, "sidebar.mode arg:1 toggle:1" },
    { "Show Identities", '3', KMOD_PRIMARY, "sidebar.mode arg:2 toggle:1" },
    { "Show Page Outline", '4', KMOD_PRIMARY, "sidebar.mode arg:3 toggle:1" },
    { "Toggle Sidebar", SDLK_l, KMOD_PRIMARY | KMOD_SHIFT, "sidebar.toggle" },
    { "---", 0, 0, NULL },
    { "Go Back", SDLK_LEFTBRACKET, KMOD_PRIMARY, "navigate.back" },
    { "Go Forward", SDLK_RIGHTBRACKET, KMOD_PRIMARY, "navigate.forward" },
    { "Reload Page", reload_KeyShortcut, "navigate.reload" },
    { "---", 0, 0, NULL },
    { "Zoom In", SDLK_EQUALS, KMOD_PRIMARY, "zoom.delta arg:10" },
    { "Zoom Out", SDLK_MINUS, KMOD_PRIMARY, "zoom.delta arg:-10" },
    { "Reset Zoom", SDLK_0, KMOD_PRIMARY, "zoom.set arg:100" },
    { "---", 0, 0, NULL },
    { "Wrap Preformatted", 0, 0, "forcewrap.toggle" }
};

static const iMenuItem helpMenuItems[] = {
    { "Help", 0, 0, "!open url:about:help" },
    { "Release Notes", 0, 0, "!open url:about:version" },
};
#endif

static const iMenuItem identityButtonMenuItems[] = {
    { "No Active Identity", 0, 0, "ident.showactive" },
    { "---", 0, 0, NULL },
#if !defined (iHaveNativeMenus)
    { "New Identity...", SDLK_n, KMOD_PRIMARY | KMOD_SHIFT, "ident.new" },
    { "---", 0, 0, NULL },
    { "Show Identities", '3', KMOD_PRIMARY, "sidebar.mode arg:2 show:1" },
#else
    { "New Identity...", 0, 0, "ident.new" },
    { "---", 0, 0, NULL },
    { "Show Identities", 0, 0, "sidebar.mode arg:2 show:1" },
#endif
};

static const char *reloadCStr_ = "\U0001f503";
static const char *stopCStr_   = uiTextCaution_ColorEscape "\U0001f310";

static void updateNavBarIdentity_(iWidget *navBar) {
    const iGmIdentity *ident =
        identityForUrl_GmCerts(certs_App(), url_DocumentWidget(document_App()));
    iWidget *button = findChild_Widget(navBar, "navbar.ident");
    setFlags_Widget(button, selected_WidgetFlag, ident != NULL);
    /* Update menu. */
    iLabelWidget *idItem = child_Widget(findChild_Widget(button, "menu"), 0);
    setTextCStr_LabelWidget(
        idItem,
        ident ? format_CStr(uiTextAction_ColorEscape "%s",
                            cstrCollect_String(subject_TlsCertificate(ident->cert)))
              : "No Active Identity");
    setFlags_Widget(as_Widget(idItem), disabled_WidgetFlag, !ident);
}

static iBool handleNavBarCommands_(iWidget *navBar, const char *cmd) {
    if (equal_Command(cmd, "window.resized")) {
        const iBool isNarrow = width_Rect(bounds_Widget(navBar)) / gap_UI < 140;
        if (isNarrow ^ ((flags_Widget(navBar) & tight_WidgetFlag) != 0)) {
            setFlags_Widget(navBar, tight_WidgetFlag, isNarrow);
            iForEach(ObjectList, i, navBar->children) {
                iWidget *child = as_Widget(i.object);
                setFlags_Widget(
                    child, tight_WidgetFlag, isNarrow || !cmp_String(id_Widget(child), "lock"));
                if (isInstance_Object(i.object, &Class_LabelWidget)) {
                    iLabelWidget *label = i.object;
                    updateSize_LabelWidget(label);
                }
            }
        }
        arrange_Widget(navBar);
        refresh_Widget(navBar);
        postCommand_Widget(navBar, "layout.changed id:navbar");
        return iFalse;
    }
    else if (equal_Command(cmd, "navigate.focus")) {
        iWidget *url = findChild_Widget(navBar, "url");
        if (focus_Widget() != url) {
            setFocus_Widget(findChild_Widget(navBar, "url"));
        }
        else {
            selectAll_InputWidget((iInputWidget *) url);
        }
        return iTrue;
    }
    else if (equal_Command(cmd, "input.edited")) {
        iAnyObject *url = findChild_Widget(navBar, "url");
        if (pointer_Command(cmd) == url) {
            submit_LookupWidget(findWidget_App("lookup"), text_InputWidget(url));
            return iTrue;
        }
    }
    else if (startsWith_CStr(cmd, "input.ended id:url ")) {
        iInputWidget *url = findChild_Widget(navBar, "url");
        if (isEmpty_String(text_InputWidget(url))) {
            /* User entered nothing; restore the current URL. */
            setText_InputWidget(url, url_DocumentWidget(document_App()));
            return iTrue;
        }
        if (arg_Command(cmd) && argLabel_Command(cmd, "enter") &&
            !isFocused_Widget(findWidget_App("lookup"))) {
            postCommandf_App(
                "open url:%s",
                cstr_String(absoluteUrl_String(&iStringLiteral(""), text_InputWidget(url))));
            return iTrue;
        }
    }
    else if (startsWith_CStr(cmd, "document.")) {
        /* React to the current document only. */
        if (document_Command(cmd) == document_App()) {
            iLabelWidget *reloadButton = findChild_Widget(navBar, "reload");
            if (equal_Command(cmd, "document.changed")) {
                iInputWidget *url = findWidget_App("url");
                const iString *urlStr = collect_String(suffix_Command(cmd, "url"));
                setText_InputWidget(url, urlStr);
                updateTextCStr_LabelWidget(reloadButton, reloadCStr_);
                updateNavBarIdentity_(navBar);
                return iFalse;
            }
            else if (equal_Command(cmd, "document.request.cancelled")) {
                updateTextCStr_LabelWidget(reloadButton, reloadCStr_);
                return iFalse;
            }
            else if (equal_Command(cmd, "document.request.started")) {
                iInputWidget *url = findChild_Widget(navBar, "url");
                setTextCStr_InputWidget(url, suffixPtr_Command(cmd, "url"));
                updateTextCStr_LabelWidget(reloadButton, stopCStr_);
                return iFalse;
            }
        }
    }
    else if (equal_Command(cmd, "tabs.changed")) {
        /* Update navbar according to the current tab. */
        iDocumentWidget *doc = document_App();
        if (doc) {
            setText_InputWidget(findChild_Widget(navBar, "url"), url_DocumentWidget(doc));
            updateTextCStr_LabelWidget(findChild_Widget(navBar, "reload"),
                                       isRequestOngoing_DocumentWidget(doc) ? stopCStr_ : reloadCStr_);
            updateNavBarIdentity_(navBar);
        }
    }
    else if (equal_Command(cmd, "mouse.clicked") && arg_Command(cmd)) {
        iWidget *widget = pointer_Command(cmd);
        iWidget *menu = findWidget_App("doctabs.menu");
        if (isTabButton_Widget(widget) && !isVisible_Widget(menu)) {
            iWidget *tabs = findWidget_App("doctabs");
            showTabPage_Widget(tabs,
                               tabPage_Widget(tabs, childIndex_Widget(widget->parent, widget)));
            openMenu_Widget(menu, coord_Command(cmd));
        }
    }
    else if (equal_Command(cmd, "navigate.reload")) {
        iDocumentWidget *doc = document_Command(cmd);
        if (isRequestOngoing_DocumentWidget(doc)) {
            postCommand_App("document.stop");
        }
        else {
            postCommand_App("document.reload");
        }
        return iTrue;
    }
    return iFalse;
}

static iBool handleSearchBarCommands_(iWidget *searchBar, const char *cmd) {
    if (equal_Command(cmd, "input.ended") &&
        equal_Rangecc(range_Command(cmd, "id"), "find.input")) {
        iInputWidget *input = findChild_Widget(searchBar, "find.input");
        if (arg_Command(cmd) && argLabel_Command(cmd, "enter") && isVisible_Widget(input)) {
            postCommand_App("find.next");
            /* Keep focus when pressing Enter. */
            if (!isEmpty_String(text_InputWidget(input))) {
                postCommand_App("focus.set id:find.input");
            }
        }
        else {
            postCommand_App("find.clearmark");
        }
        return iTrue;
    }
    else if (equal_Command(cmd, "focus.gained")) {
        if (pointer_Command(cmd) == findChild_Widget(searchBar, "find.input")) {
            if (!isVisible_Widget(searchBar)) {
                setFlags_Widget(searchBar, hidden_WidgetFlag, iFalse);
                arrange_Widget(get_Window()->root);
                refresh_App();
            }
        }
    }
    else if (equal_Command(cmd, "find.close")) {
        if (isVisible_Widget(searchBar)) {
            setFlags_Widget(searchBar, hidden_WidgetFlag, iTrue);
            arrange_Widget(searchBar->parent);
            if (isFocused_Widget(findChild_Widget(searchBar, "find.input"))) {
                setFocus_Widget(NULL);
            }
            refresh_Widget(searchBar->parent);
        }
        return iTrue;
    }
    return iFalse;
}

static void setupUserInterface_Window(iWindow *d) {
    /* Children of root cover the entire window. */
    setFlags_Widget(d->root, resizeChildren_WidgetFlag, iTrue);
    setCommandHandler_Widget(d->root, handleRootCommands_);

    iWidget *div = makeVDiv_Widget();
    setId_Widget(div, "navdiv");
    addChild_Widget(d->root, iClob(div));

    /* Navigation bar. */ {
        iWidget *navBar = new_Widget();
        setId_Widget(navBar, "navbar");
        /*setPadding_Widget(navBar, gap_UI / 2, 0, gap_UI / 2, 0);*/
        setPadding_Widget(navBar, gap_UI, gap_UI / 2, gap_UI, gap_UI / 2);
        setFlags_Widget(navBar,
                        arrangeHeight_WidgetFlag | resizeChildren_WidgetFlag |
                            arrangeHorizontal_WidgetFlag,
                        iTrue);
        addChild_Widget(div, iClob(navBar));
        setBackgroundColor_Widget(navBar, uiBackground_ColorId);
        setCommandHandler_Widget(navBar, handleNavBarCommands_);
        addChild_Widget(navBar, iClob(newIcon_LabelWidget("\U0001f870", 0, 0, "navigate.back")));
        addChild_Widget(navBar, iClob(newIcon_LabelWidget("\U0001f872", 0, 0, "navigate.forward")));
        iLabelWidget *idMenu = makeMenuButton_LabelWidget(
            "\U0001f464", identityButtonMenuItems, iElemCount(identityButtonMenuItems));
        setAlignVisually_LabelWidget(idMenu, iTrue);
        addChild_Widget(navBar, iClob(idMenu));
        setId_Widget(as_Widget(idMenu), "navbar.ident");
        iLabelWidget *lock =
            addChildFlags_Widget(navBar,
                                 iClob(newIcon_LabelWidget("\U0001f513", 0, 0, "server.showcert")),
                                 frameless_WidgetFlag | tight_WidgetFlag);
        setId_Widget(as_Widget(lock), "navbar.lock");
        setFont_LabelWidget(lock, defaultSymbols_FontId);
        updateTextCStr_LabelWidget(lock, "\U0001f512");
        /* URL input field. */ {
            iInputWidget *url = new_InputWidget(0);
            setSelectAllOnFocus_InputWidget(url, iTrue);
            setId_Widget(as_Widget(url), "url");
            setNotifyEdits_InputWidget(url, iTrue);
            setTextCStr_InputWidget(url, "gemini://");
            addChildFlags_Widget(navBar, iClob(url), expand_WidgetFlag);
            /* Download progress indicator is inside the input field, but hidden normally. */
            setPadding_Widget(as_Widget(url),0, 0, gap_UI * 1, 0);
            iLabelWidget *progress = new_LabelWidget(uiTextCaution_ColorEscape "00.000 MB", 0, 0, NULL);
            setId_Widget(as_Widget(progress), "document.progress");
            setAlignVisually_LabelWidget(progress, iTrue);
            shrink_Rect(&as_Widget(progress)->rect, init_I2(0, gap_UI));
            addChildFlags_Widget(as_Widget(url),
                                 iClob(progress),
                                 moveToParentRightEdge_WidgetFlag);
            setBackgroundColor_Widget(as_Widget(progress), uiBackground_ColorId);
        }
        setId_Widget(addChild_Widget(
                         navBar, iClob(newIcon_LabelWidget(reloadCStr_, 0, 0, "navigate.reload"))),
                     "reload");
        addChild_Widget(navBar,
                        iClob(newIcon_LabelWidget(
                            "\U0001f3e0", SDLK_h, KMOD_PRIMARY | KMOD_SHIFT, "navigate.home")));
#if !defined (iHaveNativeMenus)
        iLabelWidget *navMenu =
            makeMenuButton_LabelWidget("\U0001d362", navMenuItems, iElemCount(navMenuItems));
        setAlignVisually_LabelWidget(navMenu, iTrue);
        addChild_Widget(navBar, iClob(navMenu));
#else
        insertMenuItems_MacOS("File", 1, fileMenuItems, iElemCount(fileMenuItems));
        insertMenuItems_MacOS("Edit", 2, editMenuItems, iElemCount(editMenuItems));
        insertMenuItems_MacOS("View", 3, viewMenuItems, iElemCount(viewMenuItems));
        insertMenuItems_MacOS("Identity", 4, identityMenuItems, iElemCount(identityMenuItems));
        insertMenuItems_MacOS("Help", 6, helpMenuItems, iElemCount(helpMenuItems));
#endif
    }
    /* Tab bar. */ {
        iWidget *tabBar = makeTabs_Widget(div);
        setId_Widget(tabBar, "doctabs");
        setFlags_Widget(tabBar, expand_WidgetFlag, iTrue);
        setBackgroundColor_Widget(tabBar, uiBackground_ColorId);
        appendTabPage_Widget(tabBar, iClob(new_DocumentWidget()), "Document", 0, 0);
        iWidget *buttons = findChild_Widget(tabBar, "tabs.buttons");
        setFlags_Widget(buttons, collapse_WidgetFlag | hidden_WidgetFlag, iTrue);
        setId_Widget(
            addChild_Widget(buttons, iClob(newIcon_LabelWidget("\u2795", 0, 0, "tabs.new"))),
            "newtab");
    }
    /* Side bar. */ {
        iWidget *content = findChild_Widget(d->root, "tabs.content");
        iSidebarWidget *sidebar = new_SidebarWidget();
        addChildPos_Widget(content, iClob(sidebar), front_WidgetAddPos);
    }
    /* Lookup results. */ {
        iLookupWidget *lookup = new_LookupWidget();
        addChildFlags_Widget(div, iClob(lookup), fixedPosition_WidgetFlag | hidden_WidgetFlag);
    }
    /* Search bar. */ {
        iWidget *searchBar = new_Widget();
        setId_Widget(searchBar, "search");
        setFlags_Widget(searchBar,
                        hidden_WidgetFlag | collapse_WidgetFlag | arrangeHeight_WidgetFlag |
                            resizeChildren_WidgetFlag | arrangeHorizontal_WidgetFlag,
                        iTrue);
        addChild_Widget(div, iClob(searchBar));
        setBackgroundColor_Widget(searchBar, uiBackground_ColorId);
        setCommandHandler_Widget(searchBar, handleSearchBarCommands_);
        addChildFlags_Widget(
            searchBar, iClob(new_LabelWidget("\U0001f50d Text", 0, 0, NULL)), frameless_WidgetFlag);
        iInputWidget *input = new_InputWidget(0);
        setId_Widget(addChildFlags_Widget(searchBar, iClob(input), expand_WidgetFlag),
                     "find.input");
        addChild_Widget(searchBar, iClob(newIcon_LabelWidget("  \u2b9f  ", 'g', KMOD_PRIMARY, "find.next")));
        addChild_Widget(searchBar, iClob(newIcon_LabelWidget("  \u2b9d  ", 'g', KMOD_PRIMARY | KMOD_SHIFT, "find.prev")));
        addChild_Widget(searchBar, iClob(newIcon_LabelWidget("\u2a2f", SDLK_ESCAPE, 0, "find.close")));
    }
    iWidget *tabsMenu = makeMenu_Widget(d->root,
                                        (iMenuItem[]){
                                            { "Close Tab", 0, 0, "tabs.close" },
                                            { "Duplicate Tab", 0, 0, "tabs.new duplicate:1" },
                                            { "---", 0, 0, NULL },
                                            { "Close Other Tabs", 0, 0, "tabs.close toleft:1 toright:1" },
                                            { "Close Tabs To Left", 0, 0, "tabs.close toleft:1" },
                                            { "Close Tabs To Right", 0, 0, "tabs.close toright:1" },
                                        },
                                        6);
    setId_Widget(tabsMenu, "doctabs.menu");
    /* Global keyboard shortcuts. */ {
        addAction_Widget(d->root, prevTab_KeyShortcut, "tabs.prev");
        addAction_Widget(d->root, nextTab_KeyShortcut, "tabs.next");
#if !defined (iHaveNativeMenus)
        addAction_Widget(d->root, 'l', KMOD_PRIMARY, "navigate.focus");
        addAction_Widget(d->root, 'f', KMOD_PRIMARY, "focus.set id:find.input");
        addAction_Widget(d->root, '1', KMOD_PRIMARY, "sidebar.mode arg:0 toggle:1");
        addAction_Widget(d->root, '2', KMOD_PRIMARY, "sidebar.mode arg:1 toggle:1");
        addAction_Widget(d->root, '3', KMOD_PRIMARY, "sidebar.mode arg:2 toggle:1");
        addAction_Widget(d->root, '4', KMOD_PRIMARY, "sidebar.mode arg:3 toggle:1");
#endif
    }
}

static void updateRootSize_Window_(iWindow *d) {
    iInt2 *size = &d->root->rect.size;
    const iInt2 oldSize = *size;
    SDL_GetRendererOutputSize(d->render, &size->x, &size->y);
    if (!isEqual_I2(oldSize, *size)) {
        arrange_Widget(d->root);
        postCommandf_App("window.resized width:%d height:%d", size->x, size->y);
        postRefresh_App();
    }
}

static float pixelRatio_Window_(const iWindow *d) {
#if defined (iPlatformMsys)
    iUnused(d);
    return desktopDPI_Win32();
#else
    int dx, x;
    SDL_GetRendererOutputSize(d->render, &dx, NULL);
    SDL_GetWindowSize(d->win, &x, NULL);
    return (float) dx / (float) x;
#endif
}

static void drawBlank_Window_(iWindow *d) {
    const iColor bg = get_Color(uiBackground_ColorId);
    SDL_SetRenderDrawColor(d->render, bg.r, bg.g, bg.b, 255);
    SDL_RenderClear(d->render);
    SDL_RenderPresent(d->render);
}

iBool create_Window_(iWindow *d, iRect rect, uint32_t flags) {
    flags |= SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI;
    if (SDL_CreateWindowAndRenderer(
            width_Rect(rect), height_Rect(rect), flags, &d->win, &d->render)) {
        return iFalse;
    }
    return iTrue;
}

void init_Window(iWindow *d, iRect rect) {
    theWindow_ = d;
    iZap(d->cursors);
    d->initialPos = rect.pos;
    d->lastRect = rect;
    d->pendingCursor = NULL;
    d->isDrawFrozen = iTrue;
    uint32_t flags = 0;
#if defined (iPlatformApple)
    SDL_SetHint(SDL_HINT_RENDER_DRIVER, shouldDefaultToMetalRenderer_MacOS() ? "metal" : "opengl");
#else
    flags |= SDL_WINDOW_OPENGL;
#endif
    SDL_SetHint(SDL_HINT_RENDER_VSYNC, "1");
    /* First try SDL's default renderer that should be the best option. */
    if (forceSoftwareRender_App() || !create_Window_(d, rect, flags)) {
        /* No luck, maybe software only? This should always work as long as there is a display. */
        SDL_SetHint(SDL_HINT_RENDER_DRIVER, "software");
        if (!create_Window_(d, rect, 0)) {
            fprintf(stderr, "Error when creating window: %s\n", SDL_GetError());
            exit(-2);
        }
    }
    if (left_Rect(rect) >= 0 || top_Rect(rect) >= 0) {
        SDL_SetWindowPosition(d->win, left_Rect(rect), top_Rect(rect));
    }
    const iInt2 minSize = init_I2(400, 250);
    SDL_SetWindowMinimumSize(d->win, minSize.x, minSize.y);
    SDL_SetWindowTitle(d->win, "Lagrange");
    /* Some info. */ {
        SDL_RendererInfo info;
        SDL_GetRendererInfo(d->render, &info);
        printf("[window] renderer: %s%s\n", info.name,
               info.flags & SDL_RENDERER_ACCELERATED ? " (accelerated)" : "");
#if !defined (NDEBUG)
        printf("[window] max texture size: %d x %d\n",
               info.max_texture_width,
               info.max_texture_height);
        for (size_t i = 0; i < info.num_texture_formats; ++i) {
            printf("[window] supported texture format: %s\n", SDL_GetPixelFormatName(
                       info.texture_formats[i]));
        }
#endif
    }
    drawBlank_Window_(d);
    d->uiScale = initialUiScale_;
    d->pixelRatio = pixelRatio_Window_(d);
    setPixelRatio_Metrics(d->pixelRatio * d->uiScale);
#if defined (iPlatformMsys)
    SDL_SetWindowMinimumSize(d->win, minSize.x * d->pixelRatio, minSize.y * d->pixelRatio);
    useExecutableIconResource_SDLWindow(d->win);
#endif
#if defined (iPlatformLinux)
    /* Load the window icon. */ {
        int w, h, num;
        const iBlock *icon = &imageLagrange64_Embedded;
        stbi_uc *pixels = stbi_load_from_memory(constData_Block(icon),
                                                size_Block(icon),
                                                &w,
                                                &h,
                                                &num,
                                                STBI_rgb_alpha);
        SDL_Surface *surf =
            SDL_CreateRGBSurfaceWithFormatFrom(pixels, w, h, 32, 4 * w, SDL_PIXELFORMAT_RGBA32);
        SDL_SetWindowIcon(d->win, surf);
        SDL_FreeSurface(surf);
        stbi_image_free(pixels);
    }
#endif
    d->root = new_Widget();
    d->presentTime = 0.0;
    d->frameTime = SDL_GetTicks();
    setId_Widget(d->root, "root");
    init_Text(d->render);
    setupUserInterface_Window(d);
    updateRootSize_Window_(d);
}

void deinit_Window(iWindow *d) {
    if (theWindow_ == d) {
        theWindow_ = NULL;
    }
    iForIndices(i, d->cursors) {
        if (d->cursors[i]) {
            SDL_FreeCursor(d->cursors[i]);
        }
    }
    iReleasePtr(&d->root);
    deinit_Text();
    SDL_DestroyRenderer(d->render);
    SDL_DestroyWindow(d->win);
}

SDL_Renderer *renderer_Window(const iWindow *d) {
    return d->render;
}

static iBool isMaximized_Window_(const iWindow *d) {
#if !defined (iPlatformApple)
    return (SDL_GetWindowFlags(d->win) & (SDL_WINDOW_MINIMIZED | SDL_WINDOW_MAXIMIZED)) != 0;
#else
    iUnused(d);
    return iFalse; /* There is fullscreen mode but that is not handled at the moment. */
#endif
}

static iBool handleWindowEvent_Window_(iWindow *d, const SDL_WindowEvent *ev) {
    switch (ev->event) {
#if defined (LAGRANGE_ENABLE_WINDOWPOS_FIX)
        case SDL_WINDOWEVENT_EXPOSED:
            if (d->initialPos.x >= 0) {
                int bx, by;
                SDL_GetWindowBordersSize(d->win, &by, &bx, NULL, NULL);
                SDL_SetWindowPosition(d->win, d->initialPos.x + bx, d->initialPos.y + by);
                d->initialPos = init1_I2(-1);
            }
            return iFalse;
#endif
        case SDL_WINDOWEVENT_MOVED: {
            if (!isMaximized_Window_(d) && !d->isDrawFrozen) {
                d->lastRect.pos = init_I2(ev->data1, ev->data2);
                iInt2 border = zero_I2();
#if !defined (iPlatformApple)
                SDL_GetWindowBordersSize(d->win, &border.y, &border.x, NULL, NULL);
#endif
                d->lastRect.pos = max_I2(zero_I2(), sub_I2(d->lastRect.pos, border));
            }
            return iTrue;
        }
        case SDL_WINDOWEVENT_RESIZED:
        case SDL_WINDOWEVENT_SIZE_CHANGED:
            if (!isMaximized_Window_(d) && !d->isDrawFrozen) {
                d->lastRect.size = init_I2(ev->data1, ev->data2);
            }
            updateRootSize_Window_(d);
            return iTrue;
        case SDL_WINDOWEVENT_LEAVE:
            unhover_Widget();
            return iTrue;
        default:
            break;
    }
    return iFalse;
}

static void applyCursor_Window_(iWindow *d) {
    if (d->pendingCursor) {
        SDL_SetCursor(d->pendingCursor);
        d->pendingCursor = NULL;
    }
}

iBool processEvent_Window(iWindow *d, const SDL_Event *ev) {
    switch (ev->type) {
        case SDL_WINDOWEVENT: {
            return handleWindowEvent_Window_(d, &ev->window);
        }
        case SDL_RENDER_TARGETS_RESET:
        case SDL_RENDER_DEVICE_RESET: {
            resetFonts_Text();
            postCommand_App("theme.changed"); /* forces UI invalidation */
            break;
        }
        default: {
            SDL_Event event = *ev;
            if (event.type == SDL_USEREVENT && isCommand_UserEvent(ev, "window.unfreeze")) {
                d->isDrawFrozen = iFalse;
                postRefresh_App();
                return iTrue;
            }
            /* Map mouse pointer coordinate to our coordinate system. */
            if (event.type == SDL_MOUSEMOTION) {
                setCursor_Window(d, SDL_SYSTEM_CURSOR_ARROW); /* default cursor */
                const iInt2 pos = coord_Window(d, event.motion.x, event.motion.y);
                event.motion.x = pos.x;
                event.motion.y = pos.y;
            }
            else if (event.type == SDL_MOUSEBUTTONUP || event.type == SDL_MOUSEBUTTONDOWN) {
                const iInt2 pos = coord_Window(d, event.button.x, event.button.y);
                event.button.x = pos.x;
                event.button.y = pos.y;
            }
            iWidget *widget = d->root;
            if (event.type == SDL_MOUSEMOTION || event.type == SDL_MOUSEWHEEL ||
                event.type == SDL_MOUSEBUTTONUP || event.type == SDL_MOUSEBUTTONDOWN) {
                if (mouseGrab_Widget()) {
                    widget = mouseGrab_Widget();
                }
            }
            iWidget *oldHover = hover_Widget();
            /* As a special case, clicking the middle mouse button can be used for pasting
               from the clipboard. */
            if (event.type == SDL_MOUSEBUTTONDOWN && event.button.button == SDL_BUTTON_MIDDLE) {
                SDL_Event paste;
                iZap(paste);
                paste.type           = SDL_KEYDOWN;
                paste.key.keysym.sym = SDLK_v;
                paste.key.keysym.mod = KMOD_PRIMARY;
                paste.key.state      = SDL_PRESSED;
                paste.key.timestamp  = SDL_GetTicks();
                dispatchEvent_Widget(widget, &paste);
            }
            /* Dispatch the event to the tree of widgets. */
            iBool wasUsed = dispatchEvent_Widget(widget, &event);
            if (oldHover != hover_Widget()) {
                postRefresh_App();
            }
            if (event.type == SDL_MOUSEMOTION) {
                applyCursor_Window_(d);
            }
            return wasUsed;
        }
    }
    return iFalse;
}

void draw_Window(iWindow *d) {
    if (d->isDrawFrozen) {
        return;
    }
//#if !defined (NDEBUG)
//    printf("draw %d\n", d->frameTime); fflush(stdout);
//#endif
    /* Clear the window. */
    SDL_SetRenderDrawColor(d->render, 0, 0, 0, 255);
    SDL_RenderClear(d->render);
    /* Draw widgets. */
    d->frameTime = SDL_GetTicks();
    draw_Widget(d->root);
#if 0
    /* Text cache debugging. */ {
        SDL_Texture *cache = glyphCache_Text();
        SDL_Rect rect = { d->root->rect.size.x - 640, 0, 640, 5 * 640 };
        SDL_SetRenderDrawColor(d->render, 0, 0, 0, 255);
        SDL_RenderFillRect(d->render, &rect);
        SDL_RenderCopy(d->render, glyphCache_Text(), NULL, &rect);
    }
#endif
    SDL_RenderPresent(d->render);
}

void resize_Window(iWindow *d, int w, int h) {
    SDL_SetWindowSize(d->win, w, h);
    updateRootSize_Window_(d);
}

void setTitle_Window(iWindow *d, const iString *title) {
    SDL_SetWindowTitle(d->win, cstr_String(title));
}

void setUiScale_Window(iWindow *d, float uiScale) {
    uiScale = iClamp(uiScale, 0.5f, 4.0f);
    if (d) {
        d->uiScale = uiScale;
#if 0
        deinit_Text();
        setPixelRatio_Metrics(d->pixelRatio * d->uiScale);
        init_Text(d->render);
        postCommand_App("metrics.changed");
        /* TODO: Dynamic UI metrics change. Widgets need to update themselves. */
#endif
    }
    else {
        initialUiScale_ = uiScale;
    }
}

void setFreezeDraw_Window(iWindow *d, iBool freezeDraw) {
    d->isDrawFrozen = freezeDraw;
}

void setCursor_Window(iWindow *d, int cursor) {
    if (!d->cursors[cursor]) {
        d->cursors[cursor] = SDL_CreateSystemCursor(cursor);
    }
    d->pendingCursor = d->cursors[cursor];
}

iInt2 rootSize_Window(const iWindow *d) {
    return d->root->rect.size;
}

iInt2 coord_Window(const iWindow *d, int x, int y) {
#if defined (iPlatformMsys)
    /* On Windows, surface coordinates are in pixels. */
    return init_I2(x, y);
#else
    /* Coordinates are in points. */
    return mulf_I2(init_I2(x, y), d->pixelRatio);
#endif
}

iInt2 mouseCoord_Window(const iWindow *d) {
    int x, y;
    SDL_GetMouseState(&x, &y);
    return coord_Window(d, x, y);
}

float uiScale_Window(const iWindow *d) {
    return d->uiScale;
}

uint32_t frameTime_Window(const iWindow *d) {
    return d->frameTime;
}

iWindow *get_Window(void) {
    return theWindow_;
}