/*
 * https://st.suckless.org/
 *
 * MIT/X Consortium License
 *
 * © 2014-2022 Hiltjo Posthuma <hiltjo at codemadness dot org>
 * © 2018 Devin J. Pohly <djpohly at gmail dot com>
 * © 2014-2017 Quentin Rameau <quinq at fifth dot space>
 * © 2009-2012 Aurélien APTEL <aurelien dot aptel at gmail dot com>
 * © 2008-2017 Anselm R Garbe <garbeam at gmail dot com>
 * © 2012-2017 Roberto E. Vargas Caballero <k0ga at shike2 dot com>
 * © 2012-2016 Christoph Lohmann <20h at r-36 dot net>
 * © 2013 Eon S. Jeon <esjeon at hyunmu dot am>
 * © 2013 Alexander Sedov <alex0player at gmail dot com>
 * © 2013 Mark Edgar <medgar123 at gmail dot com>
 * © 2013-2014 Eric Pruitt <eric.pruitt at gmail dot com>
 * © 2013 Michael Forney <mforney at mforney dot org>
 * © 2013-2014 Markus Teich <markus dot teich at stusta dot mhn dot de>
 * © 2014-2015 Laslo Hunhold <dev at frign dot de>
 *
 * 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.
 */

/* ChangeLog for Xfe
 * - upgraded to st 0.9.2
 * - added the _XOPEN_SOURCE directive to remove a compilation warning
 * - changed default foreground and background colors in config.h
 * - scale the font size by dpi/72 in xloadfonts(). Added the getdpi()
 *   function, found on the web (author ???)
 * - add of an extern "C" instruction to x.h, to compile with C++
 * - replaced the main() function with a st() function,
 *   to allow st to be called within a program
 * - removed the usage() function
 * - removed unused selclean() function
 * - changed terminal name to "Xfe"
 */

#include <errno.h>
#include <math.h>
#include <limits.h>
#include <locale.h>
#include <signal.h>
#include <sys/select.h>
#include <time.h>
#include <unistd.h>
#include <libgen.h>
#include <X11/Xatom.h>
#include <X11/Xlib.h>
#include <X11/cursorfont.h>
#include <X11/keysym.h>
#include <X11/Xft/Xft.h>
#include <X11/XKBlib.h>

char* argv0;
#include "arg.h"
#include "st.h"
#include "win.h"

/* types used in config.h */
typedef struct
{
    uint	mod;
    KeySym	keysym;
    void (*func)(const Arg*);
    const Arg	arg;
} Shortcut;

typedef struct
{
    uint	mod;
    uint	button;
    void (*func)(const Arg*);
    const Arg	arg;
    uint	release;
} MouseShortcut;

typedef struct
{
    KeySym	k;
    uint	mask;
    char*	s;
    /* three-valued logic variables: 0 indifferent, 1 on, -1 off */
    signed char appkey;         /* application keypad */
    signed char appcursor;      /* application cursor */
} Key;

/* X modifiers */
#define XK_ANY_MOD    UINT_MAX
#define XK_NO_MOD     0
#define XK_SWITCH_MOD (1 << 13 | 1 << 14)

/* function definitions used in config.h */
static void clipcopy(const Arg*);
static void clippaste(const Arg*);
static void numlock(const Arg*);
static void selpaste(const Arg*);
static void zoom(const Arg*);
static void zoomabs(const Arg*);
static void zoomreset(const Arg*);
static void ttysend(const Arg*);

/* config.h for applying patches and the configuration. */
#include "config.h"

/* XEMBED messages */
#define XEMBED_FOCUS_IN  4
#define XEMBED_FOCUS_OUT 5

/* macros */
#define IS_SET(flag)            ((win.mode & (flag)) != 0)
#define TRUERED(x)              (((x) & 0xff0000) >> 8)
#define TRUEGREEN(x)            (((x) & 0xff00))
#define TRUEBLUE(x)             (((x) & 0xff) << 8)

typedef XftDraw* Draw;
typedef XftColor Color;
typedef XftGlyphFontSpec GlyphFontSpec;

/* Purely graphic info */
typedef struct
{
    int tw, th; /* tty width and height */
    int w, h;   /* window width and height */
    int ch;     /* char height */
    int cw;     /* char width  */
    int mode;   /* window state/mode flags */
    int cursor; /* cursor style */
} TermWindow;

typedef struct
{
    Display*		dpy;
    Colormap		cmap;
    Window		win;
    Drawable		buf;
    GlyphFontSpec*	specbuf; /* font spec buffer used for rendering */
    Atom		xembed, wmdeletewin, netwmname, netwmiconname, netwmpid;
    struct
    {
        XIM		xim;
        XIC		xic;
        XPoint		spot;
        XVaNestedList	spotlist;
    } ime;
    Draw			draw;
    Visual*			vis;
    XSetWindowAttributes	attrs;
    int				scr;
    int				isfixed;        /* is fixed geometry? */
    int				l, t;           /* left and top offset */
    int				gm;             /* geometry mask */
} XWindow;

typedef struct
{
    Atom		xtarget;
    char*		primary, * clipboard;
    struct timespec	tclick1;
    struct timespec	tclick2;
} XSelection;

/* Font structure */
#define Font Font_
typedef struct
{
    int		height;
    int		width;
    int		ascent;
    int		descent;
    int		badslant;
    int		badweight;
    short	lbearing;
    short	rbearing;
    XftFont*	match;
    FcFontSet*	set;
    FcPattern*	pattern;
} Font;

/* Drawing Context */
typedef struct
{
    Color*	col;
    size_t	collen;
    Font	font, bfont, ifont, ibfont;
    GC		gc;
} DC;

static inline ushort sixd_to_16bit(int);
static int xmakeglyphfontspecs(XftGlyphFontSpec*, const Glyph*, int, int, int);
static void xdrawglyphfontspecs(const XftGlyphFontSpec*, Glyph, int, int, int);
static void xdrawglyph(Glyph, int, int);
static void xclear(int, int, int, int);
static int xgeommasktogravity(int);
static int ximopen(Display*);
static void ximinstantiate(Display*, XPointer, XPointer);
static void ximdestroy(XIM, XPointer, XPointer);
static int xicdestroy(XIC, XPointer, XPointer);
static void xinit(int, int);
static void cresize(int, int);
static void xresize(int, int);
static void xhints(void);
static int xloadcolor(int, const char*, Color*);
static void getdpi(int*, int*);
static int xloadfont(Font*, FcPattern*);
static void xloadfonts(const char*, double);
static void xunloadfont(Font*);
static void xunloadfonts(void);
static void xsetenv(void);
static void xseturgency(int);
static int evcol(XEvent*);
static int evrow(XEvent*);

static void expose(XEvent*);
static void visibility(XEvent*);
static void unmap(XEvent*);
static void kpress(XEvent*);
static void cmessage(XEvent*);
static void resize(XEvent*);
static void focus(XEvent*);
static uint buttonmask(uint);
static int mouseaction(XEvent*, uint);
static void brelease(XEvent*);
static void bpress(XEvent*);
static void bmotion(XEvent*);
static void propnotify(XEvent*);
static void selnotify(XEvent*);
static void selrequest(XEvent*);
static void setsel(char*, Time);
static void mousesel(XEvent*, int);
static void mousereport(XEvent*);
static char*kmap(KeySym, uint);
static int match(uint, uint);

static void run(void);

static void (*handler[LASTEvent])(XEvent*) =
{
    [KeyPress] = kpress,
    [ClientMessage] = cmessage,
    [ConfigureNotify] = resize,
    [VisibilityNotify] = visibility,
    [UnmapNotify] = unmap,
    [Expose] = expose,
    [FocusIn] = focus,
    [FocusOut] = focus,
    [MotionNotify] = bmotion,
    [ButtonPress] = bpress,
    [ButtonRelease] = brelease,
/*
 * Uncomment if you want the selection to disappear when you select something
 * different in another window.
 */
/*	[SelectionClear] = selclear_, */
    [SelectionNotify] = selnotify,
/*
 * PropertyNotify is only turned on when there is some INCR transfer happening
 * for the selection retrieval.
 */
    [PropertyNotify] = propnotify,
    [SelectionRequest] = selrequest,
};

/* Globals */
static DC dc;
static XWindow xw;
static XSelection xsel;
static TermWindow win;

/* Font Ring Cache */
enum
{
    FRC_NORMAL,
    FRC_ITALIC,
    FRC_BOLD,
    FRC_ITALICBOLD
};

typedef struct
{
    XftFont*	font;
    int		flags;
    Rune	unicodep;
} Fontcache;

/* Fontcache is an array now. A new font will be appended to the array. */
static Fontcache* frc = NULL;
static int frclen = 0;
static int frccap = 0;
static char* usedfont = NULL;
static double usedfontsize = 0;
static double defaultfontsize = 0;

static char* opt_class = NULL;
static char** opt_cmd = NULL;
static char* opt_embed = NULL;
static char* opt_font = NULL;
static char* opt_io = NULL;
static char* opt_line = NULL;
static char* opt_name = NULL;
static char* opt_title = NULL;

static uint buttons; /* bit field of pressed buttons */

void
clipcopy(const Arg* dummy)
{
    Atom clipboard;

    free(xsel.clipboard);
    xsel.clipboard = NULL;

    if (xsel.primary != NULL)
    {
        xsel.clipboard = xstrdup(xsel.primary);
        clipboard = XInternAtom(xw.dpy, "CLIPBOARD", 0);
        XSetSelectionOwner(xw.dpy, clipboard, xw.win, CurrentTime);
    }
}

void
clippaste(const Arg* dummy)
{
    Atom clipboard;

    clipboard = XInternAtom(xw.dpy, "CLIPBOARD", 0);
    XConvertSelection(xw.dpy, clipboard, xsel.xtarget, clipboard,
                      xw.win, CurrentTime);
}

void
selpaste(const Arg* dummy)
{
    XConvertSelection(xw.dpy, XA_PRIMARY, xsel.xtarget, XA_PRIMARY,
                      xw.win, CurrentTime);
}

void
numlock(const Arg* dummy)
{
    win.mode ^= MODE_NUMLOCK;
}

void
zoom(const Arg* arg)
{
    Arg larg;

    larg.f = usedfontsize + arg->f;
    zoomabs(&larg);
}

void
zoomabs(const Arg* arg)
{
    xunloadfonts();
    xloadfonts(usedfont, arg->f);
    cresize(0, 0);
    redraw();
    xhints();
}

void
zoomreset(const Arg* arg)
{
    Arg larg;

    if (defaultfontsize > 0)
    {
        larg.f = defaultfontsize;
        zoomabs(&larg);
    }
}

void
ttysend(const Arg* arg)
{
    ttywrite(arg->s, strlen(arg->s), 1);
}

int
evcol(XEvent* e)
{
    int x = e->xbutton.x - borderpx;

    LIMIT(x, 0, win.tw - 1);
    return x / win.cw;
}

int
evrow(XEvent* e)
{
    int y = e->xbutton.y - borderpx;

    LIMIT(y, 0, win.th - 1);
    return y / win.ch;
}

void
mousesel(XEvent* e, int done)
{
    int type, seltype = SEL_REGULAR;
    uint state = e->xbutton.state & ~(Button1Mask | forcemousemod);

    for (type = 1; type < LEN(selmasks); ++type)
    {
        if (match(selmasks[type], state))
        {
            seltype = type;
            break;
        }
    }
    selextend(evcol(e), evrow(e), seltype, done);
    if (done)
    {
        setsel(getsel(), e->xbutton.time);
    }
}

void
mousereport(XEvent* e)
{
    int len, btn, code;
    int x = evcol(e), y = evrow(e);
    int state = e->xbutton.state;
    char buf[40];
    static int ox, oy;

    if (e->type == MotionNotify)
    {
        if (x == ox && y == oy)
        {
            return;
        }
        if (!IS_SET(MODE_MOUSEMOTION) && !IS_SET(MODE_MOUSEMANY))
        {
            return;
        }
        /* MODE_MOUSEMOTION: no reporting if no button is pressed */
        if (IS_SET(MODE_MOUSEMOTION) && buttons == 0)
        {
            return;
        }
        /* Set btn to lowest-numbered pressed button, or 12 if no
         * buttons are pressed. */
        for (btn = 1; btn <= 11 && !(buttons & (1 << (btn - 1))); btn++)
        {
            ;
        }
        code = 32;
    }
    else
    {
        btn = e->xbutton.button;
        /* Only buttons 1 through 11 can be encoded */
        if (btn < 1 || btn > 11)
        {
            return;
        }
        if (e->type == ButtonRelease)
        {
            /* MODE_MOUSEX10: no button release reporting */
            if (IS_SET(MODE_MOUSEX10))
            {
                return;
            }
            /* Don't send release events for the scroll wheel */
            if (btn == 4 || btn == 5)
            {
                return;
            }
        }
        code = 0;
    }

    ox = x;
    oy = y;

    /* Encode btn into code. If no button is pressed for a motion event in
     * MODE_MOUSEMANY, then encode it as a release. */
    if ((!IS_SET(MODE_MOUSESGR) && e->type == ButtonRelease) || btn == 12)
    {
        code += 3;
    }
    else if (btn >= 8)
    {
        code += 128 + btn - 8;
    }
    else if (btn >= 4)
    {
        code += 64 + btn - 4;
    }
    else
    {
        code += btn - 1;
    }

    if (!IS_SET(MODE_MOUSEX10))
    {
        code += ((state & ShiftMask) ?  4 : 0)
                + ((state & Mod1Mask) ?  8 : 0)/* meta key: alt */
                + ((state & ControlMask) ? 16 : 0);
    }

    if (IS_SET(MODE_MOUSESGR))
    {
        len = snprintf(buf, sizeof(buf), "\033[<%d;%d;%d%c",
                       code, x + 1, y + 1,
                       e->type == ButtonRelease ? 'm' : 'M');
    }
    else if (x < 223 && y < 223)
    {
        len = snprintf(buf, sizeof(buf), "\033[M%c%c%c",
                       32 + code, 32 + x + 1, 32 + y + 1);
    }
    else
    {
        return;
    }

    ttywrite(buf, len, 0);
}

uint
buttonmask(uint button)
{
    return button == Button1 ? Button1Mask
             : button == Button2 ? Button2Mask
             : button == Button3 ? Button3Mask
             : button == Button4 ? Button4Mask
             : button == Button5 ? Button5Mask
             : 0;
}

int
mouseaction(XEvent* e, uint release)
{
    MouseShortcut* ms;

    /* ignore Button<N>mask for Button<N> - it's set on release */
    uint state = e->xbutton.state & ~buttonmask(e->xbutton.button);

    for (ms = mshortcuts; ms < mshortcuts + LEN(mshortcuts); ms++)
    {
        if (ms->release == release &&
            ms->button == e->xbutton.button &&
            (match(ms->mod, state) ||  /* exact or forced */
             match(ms->mod, state & ~forcemousemod)))
        {
            ms->func(&(ms->arg));
            return 1;
        }
    }

    return 0;
}

void
bpress(XEvent* e)
{
    int btn = e->xbutton.button;
    struct timespec now;
    int snap;

    if (1 <= btn && btn <= 11)
    {
        buttons |= 1 << (btn - 1);
    }

    if (IS_SET(MODE_MOUSE) && !(e->xbutton.state & forcemousemod))
    {
        mousereport(e);
        return;
    }

    if (mouseaction(e, 0))
    {
        return;
    }

    if (btn == Button1)
    {
        /*
         * If the user clicks below predefined timeouts specific
         * snapping behaviour is exposed.
         */
        clock_gettime(CLOCK_MONOTONIC, &now);
        if (TIMEDIFF(now, xsel.tclick2) <= tripleclicktimeout)
        {
            snap = SNAP_LINE;
        }
        else if (TIMEDIFF(now, xsel.tclick1) <= doubleclicktimeout)
        {
            snap = SNAP_WORD;
        }
        else
        {
            snap = 0;
        }
        xsel.tclick2 = xsel.tclick1;
        xsel.tclick1 = now;

        selstart(evcol(e), evrow(e), snap);
    }
}

void
propnotify(XEvent* e)
{
    XPropertyEvent* xpev;
    Atom clipboard = XInternAtom(xw.dpy, "CLIPBOARD", 0);

    xpev = &e->xproperty;
    if (xpev->state == PropertyNewValue &&
        (xpev->atom == XA_PRIMARY ||
         xpev->atom == clipboard))
    {
        selnotify(e);
    }
}

void
selnotify(XEvent* e)
{
    ulong nitems, ofs, rem;
    int format;
    uchar* data, * last, * repl;
    Atom type, incratom, property = None;

    incratom = XInternAtom(xw.dpy, "INCR", 0);

    ofs = 0;
    if (e->type == SelectionNotify)
    {
        property = e->xselection.property;
    }
    else if (e->type == PropertyNotify)
    {
        property = e->xproperty.atom;
    }

    if (property == None)
    {
        return;
    }

    do
    {
        if (XGetWindowProperty(xw.dpy, xw.win, property, ofs,
                               BUFSIZ / 4, False, AnyPropertyType,
                               &type, &format, &nitems, &rem,
                               &data))
        {
            fprintf(stderr, "Clipboard allocation failed\n");
            return;
        }

        if (e->type == PropertyNotify && nitems == 0 && rem == 0)
        {
            /*
             * If there is some PropertyNotify with no data, then
             * this is the signal of the selection owner that all
             * data has been transferred. We won't need to receive
             * PropertyNotify events anymore.
             */
            MODBIT(xw.attrs.event_mask, 0, PropertyChangeMask);
            XChangeWindowAttributes(xw.dpy, xw.win, CWEventMask,
                                    &xw.attrs);
        }

        if (type == incratom)
        {
            /*
             * Activate the PropertyNotify events so we receive
             * when the selection owner does send us the next
             * chunk of data.
             */
            MODBIT(xw.attrs.event_mask, 1, PropertyChangeMask);
            XChangeWindowAttributes(xw.dpy, xw.win, CWEventMask,
                                    &xw.attrs);

            /*
             * Deleting the property is the transfer start signal.
             */
            XDeleteProperty(xw.dpy, xw.win, (int)property);
            continue;
        }

        /*
         * As seen in getsel:
         * Line endings are inconsistent in the terminal and GUI world
         * copy and pasting. When receiving some selection data,
         * replace all '\n' with '\r'.
         * FIXME: Fix the computer world.
         */
        repl = data;
        last = data + nitems * format / 8;
        while ((repl = memchr(repl, '\n', last - repl)))
        {
            *repl++ = '\r';
        }

        if (IS_SET(MODE_BRCKTPASTE) && ofs == 0)
        {
            ttywrite("\033[200~", 6, 0);
        }
        ttywrite((char*)data, nitems * format / 8, 1);
        if (IS_SET(MODE_BRCKTPASTE) && rem == 0)
        {
            ttywrite("\033[201~", 6, 0);
        }
        XFree(data);
        /* number of 32-bit chunks returned */
        ofs += nitems * format / 32;
    }
    while (rem > 0);

    /*
     * Deleting the property again tells the selection owner to send the
     * next data chunk in the property.
     */
    XDeleteProperty(xw.dpy, xw.win, (int)property);
}

void
xclipcopy(void)
{
    clipcopy(NULL);
}

void
selclear_(XEvent* e)
{
    selclear();
}

void
selrequest(XEvent* e)
{
    XSelectionRequestEvent* xsre;
    XSelectionEvent xev;
    Atom xa_targets, string, clipboard;
    char* seltext;

    xsre = (XSelectionRequestEvent*)e;
    xev.type = SelectionNotify;
    xev.requestor = xsre->requestor;
    xev.selection = xsre->selection;
    xev.target = xsre->target;
    xev.time = xsre->time;
    if (xsre->property == None)
    {
        xsre->property = xsre->target;
    }

    /* reject */
    xev.property = None;

    xa_targets = XInternAtom(xw.dpy, "TARGETS", 0);
    if (xsre->target == xa_targets)
    {
        /* respond with the supported type */
        string = xsel.xtarget;
        XChangeProperty(xsre->display, xsre->requestor, xsre->property,
                        XA_ATOM, 32, PropModeReplace,
                        (uchar*)&string, 1);
        xev.property = xsre->property;
    }
    else if (xsre->target == xsel.xtarget || xsre->target == XA_STRING)
    {
        /*
         * xith XA_STRING non ascii characters may be incorrect in the
         * requestor. It is not our problem, use utf8.
         */
        clipboard = XInternAtom(xw.dpy, "CLIPBOARD", 0);
        if (xsre->selection == XA_PRIMARY)
        {
            seltext = xsel.primary;
        }
        else if (xsre->selection == clipboard)
        {
            seltext = xsel.clipboard;
        }
        else
        {
            fprintf(stderr,
                    "Unhandled clipboard selection 0x%lx\n",
                    xsre->selection);
            return;
        }
        if (seltext != NULL)
        {
            XChangeProperty(xsre->display, xsre->requestor,
                            xsre->property, xsre->target,
                            8, PropModeReplace,
                            (uchar*)seltext, strlen(seltext));
            xev.property = xsre->property;
        }
    }

    /* all done, send a notification to the listener */
    if (!XSendEvent(xsre->display, xsre->requestor, 1, 0, (XEvent*)&xev))
    {
        fprintf(stderr, "Error sending SelectionNotify event\n");
    }
}

void
setsel(char* str, Time t)
{
    if (!str)
    {
        return;
    }

    free(xsel.primary);
    xsel.primary = str;

    XSetSelectionOwner(xw.dpy, XA_PRIMARY, xw.win, t);
    if (XGetSelectionOwner(xw.dpy, XA_PRIMARY) != xw.win)
    {
        selclear();
    }
}

void
xsetsel(char* str)
{
    setsel(str, CurrentTime);
}

void
brelease(XEvent* e)
{
    int btn = e->xbutton.button;

    if (1 <= btn && btn <= 11)
    {
        buttons &= ~(1 << (btn - 1));
    }

    if (IS_SET(MODE_MOUSE) && !(e->xbutton.state & forcemousemod))
    {
        mousereport(e);
        return;
    }

    if (mouseaction(e, 1))
    {
        return;
    }
    if (btn == Button1)
    {
        mousesel(e, 1);
    }
}

void
bmotion(XEvent* e)
{
    if (IS_SET(MODE_MOUSE) && !(e->xbutton.state & forcemousemod))
    {
        mousereport(e);
        return;
    }

    mousesel(e, 0);
}

void
cresize(int width, int height)
{
    int col, row;

    if (width != 0)
    {
        win.w = width;
    }
    if (height != 0)
    {
        win.h = height;
    }

    col = (win.w - 2 * borderpx) / win.cw;
    row = (win.h - 2 * borderpx) / win.ch;
    col = MAX(1, col);
    row = MAX(1, row);

    tresize(col, row);
    xresize(col, row);
    ttyresize(win.tw, win.th);
}

void
xresize(int col, int row)
{
    win.tw = col * win.cw;
    win.th = row * win.ch;

    XFreePixmap(xw.dpy, xw.buf);
    xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h,
                           DefaultDepth(xw.dpy, xw.scr));
    XftDrawChange(xw.draw, xw.buf);
    xclear(0, 0, win.w, win.h);

    /* resize to new width */
    xw.specbuf = xrealloc(xw.specbuf, col * sizeof(GlyphFontSpec));
}

ushort
sixd_to_16bit(int x)
{
    return x == 0 ? 0 : 0x3737 + 0x2828 * x;
}

int
xloadcolor(int i, const char* name, Color* ncolor)
{
    XRenderColor color = { .alpha = 0xffff };

    if (!name)
    {
        if (BETWEEN(i, 16, 255))        /* 256 color */
        {
            if (i < 6 * 6 * 6 + 16)     /* same colors as xterm */
            {
                color.red = sixd_to_16bit(((i - 16) / 36) % 6);
                color.green = sixd_to_16bit(((i - 16) / 6) % 6);
                color.blue = sixd_to_16bit(((i - 16) / 1) % 6);
            }
            else /* greyscale */
            {
                color.red = 0x0808 + 0x0a0a * (i - (6 * 6 * 6 + 16));
                color.green = color.blue = color.red;
            }
            return XftColorAllocValue(xw.dpy, xw.vis,
                                      xw.cmap, &color, ncolor);
        }
        else
        {
            name = colorname[i];
        }
    }

    return XftColorAllocName(xw.dpy, xw.vis, xw.cmap, name, ncolor);
}

void
xloadcols(void)
{
    int i;
    static int loaded;
    Color* cp;

    if (loaded)
    {
        for (cp = dc.col; cp < &dc.col[dc.collen]; ++cp)
        {
            XftColorFree(xw.dpy, xw.vis, xw.cmap, cp);
        }
    }
    else
    {
        dc.collen = MAX(LEN(colorname), 256);
        dc.col = xmalloc(dc.collen * sizeof(Color));
    }

    for (i = 0; i < dc.collen; i++)
    {
        if (!xloadcolor(i, NULL, &dc.col[i]))
        {
            if (colorname[i])
            {
                die("could not allocate color '%s'\n", colorname[i]);
            }
            else
            {
                die("could not allocate color %d\n", i);
            }
        }
    }
    loaded = 1;
}

int
xgetcolor(int x, unsigned char* r, unsigned char* g, unsigned char* b)
{
    if (!BETWEEN(x, 0, dc.collen - 1))
    {
        return 1;
    }

    *r = dc.col[x].color.red >> 8;
    *g = dc.col[x].color.green >> 8;
    *b = dc.col[x].color.blue >> 8;

    return 0;
}

int
xsetcolorname(int x, const char* name)
{
    Color ncolor;

    if (!BETWEEN(x, 0, dc.collen - 1))
    {
        return 1;
    }

    if (!xloadcolor(x, name, &ncolor))
    {
        return 1;
    }

    XftColorFree(xw.dpy, xw.vis, xw.cmap, &dc.col[x]);
    dc.col[x] = ncolor;

    return 0;
}

/*
 * Absolute coordinates.
 */
void
xclear(int x1, int y1, int x2, int y2)
{
    XftDrawRect(xw.draw,
                &dc.col[IS_SET(MODE_REVERSE)? defaultfg : defaultbg],
                x1, y1, x2 - x1, y2 - y1);
}

void
xhints(void)
{
    XClassHint class = { opt_name ? opt_name : termname,
                         opt_class ? opt_class : termname };
    XWMHints wm = { .flags = InputHint, .input = 1 };
    XSizeHints* sizeh;

    sizeh = XAllocSizeHints();

    sizeh->flags = PSize | PResizeInc | PBaseSize | PMinSize;
    sizeh->height = win.h;
    sizeh->width = win.w;
    sizeh->height_inc = win.ch;
    sizeh->width_inc = win.cw;
    sizeh->base_height = 2 * borderpx;
    sizeh->base_width = 2 * borderpx;
    sizeh->min_height = win.ch + 2 * borderpx;
    sizeh->min_width = win.cw + 2 * borderpx;
    if (xw.isfixed)
    {
        sizeh->flags |= PMaxSize;
        sizeh->min_width = sizeh->max_width = win.w;
        sizeh->min_height = sizeh->max_height = win.h;
    }
    if (xw.gm & (XValue | YValue))
    {
        sizeh->flags |= USPosition | PWinGravity;
        sizeh->x = xw.l;
        sizeh->y = xw.t;
        sizeh->win_gravity = xgeommasktogravity(xw.gm);
    }

    XSetWMProperties(xw.dpy, xw.win, NULL, NULL, NULL, 0, sizeh, &wm,
                     &class);
    XFree(sizeh);
}

int
xgeommasktogravity(int mask)
{
    switch (mask & (XNegative | YNegative))
    {
    case 0:
        return NorthWestGravity;
    case XNegative:
        return NorthEastGravity;
    case YNegative:
        return SouthWestGravity;
    }

    return SouthEastGravity;
}

int
xloadfont(Font* f, FcPattern* pattern)
{
    FcPattern* configured;
    FcPattern* match;
    FcResult result;
    XGlyphInfo extents;
    int wantattr, haveattr;

    /*
     * Manually configure instead of calling XftMatchFont
     * so that we can use the configured pattern for
     * "missing glyph" lookups.
     */
    configured = FcPatternDuplicate(pattern);
    if (!configured)
    {
        return 1;
    }

    FcConfigSubstitute(NULL, configured, FcMatchPattern);
    XftDefaultSubstitute(xw.dpy, xw.scr, configured);

    match = FcFontMatch(NULL, configured, &result);
    if (!match)
    {
        FcPatternDestroy(configured);
        return 1;
    }

    if (!(f->match = XftFontOpenPattern(xw.dpy, match)))
    {
        FcPatternDestroy(configured);
        FcPatternDestroy(match);
        return 1;
    }

    if ((XftPatternGetInteger(pattern, "slant", 0, &wantattr) ==
         XftResultMatch))
    {
        /*
         * Check if xft was unable to find a font with the appropriate
         * slant but gave us one anyway. Try to mitigate.
         */
        if ((XftPatternGetInteger(f->match->pattern, "slant", 0,
                                  &haveattr) != XftResultMatch) || haveattr < wantattr)
        {
            f->badslant = 1;
            fputs("font slant does not match\n", stderr);
        }
    }

    if ((XftPatternGetInteger(pattern, "weight", 0, &wantattr) ==
         XftResultMatch))
    {
        if ((XftPatternGetInteger(f->match->pattern, "weight", 0,
                                  &haveattr) != XftResultMatch) || haveattr != wantattr)
        {
            f->badweight = 1;
            fputs("font weight does not match\n", stderr);
        }
    }

    XftTextExtentsUtf8(xw.dpy, f->match,
                       (const FcChar8*)ascii_printable,
                       strlen(ascii_printable), &extents);

    f->set = NULL;
    f->pattern = configured;

    f->ascent = f->match->ascent;
    f->descent = f->match->descent;
    f->lbearing = 0;
    f->rbearing = f->match->max_advance_width;

    f->height = f->ascent + f->descent;
    f->width = DIVCEIL(extents.xOff, strlen(ascii_printable));

    return 0;
}

/* Get dots per inch */
void
getdpi(int* x, int* y)
{
    double xres, yres;
    Display* dpy;
    char* displayname = NULL;
    int scr = 0; /* Screen number */

    if ((NULL == x) || (NULL == y))
    {
        return;
    }

    dpy = XOpenDisplay(displayname);

    /*
     * there are 2.54 centimeters to an inch; so there are 25.4 millimeters.
     *
     *     dpi = N pixels / (M millimeters / (25.4 millimeters / 1 inch))
     *         = N pixels / (M inch / 25.4)
     *         = N * 25.4 pixels / M inch
     */
    xres = ((((double)DisplayWidth(dpy, scr)) * 25.4) /
            ((double)DisplayWidthMM(dpy, scr)));
    yres = ((((double)DisplayHeight(dpy, scr)) * 25.4) /
            ((double)DisplayHeightMM(dpy, scr)));

    *x = (int)(xres + 0.5);
    *y = (int)(yres + 0.5);

    XCloseDisplay(dpy);
}

void
xloadfonts(const char* fontstr, double fontsize)
{
    FcPattern* pattern;
    double fontval;
    int dpix, dpiy;

    double floor(double);

    if (fontstr[0] == '-')
    {
        pattern = XftXlfdParse(fontstr, False, False);
    }
    else
    {
        pattern = FcNameParse((const FcChar8*)fontstr);
    }

    if (!pattern)
    {
        die("can't open font %s\n", fontstr);
    }

    /* Scale the font size by dpix/72 */
    getdpi(&dpix, &dpiy);
    FcPatternGetDouble(pattern, FC_PIXEL_SIZE, 0, &fontval);
    FcPatternDel(pattern, FC_PIXEL_SIZE);
    FcPatternAddDouble(pattern, FC_PIXEL_SIZE, floor(fontval * dpix / 72.0));

    if (fontsize > 1)
    {
        FcPatternDel(pattern, FC_PIXEL_SIZE);
        FcPatternDel(pattern, FC_SIZE);
        FcPatternAddDouble(pattern, FC_PIXEL_SIZE, (double)fontsize);
        usedfontsize = fontsize;
    }
    else
    {
        if (FcPatternGetDouble(pattern, FC_PIXEL_SIZE, 0, &fontval) ==
            FcResultMatch)
        {
            usedfontsize = fontval;
        }
        else if (FcPatternGetDouble(pattern, FC_SIZE, 0, &fontval) ==
                 FcResultMatch)
        {
            usedfontsize = -1;
        }
        else
        {
            /*
             * Default font size is 12, if none given. This is to
             * have a known usedfontsize value.
             */
            FcPatternAddDouble(pattern, FC_PIXEL_SIZE, 12);
            usedfontsize = 12;
        }
        defaultfontsize = usedfontsize;
    }

    if (xloadfont(&dc.font, pattern))
    {
        die("can't open font %s\n", fontstr);
    }

    if (usedfontsize < 0)
    {
        FcPatternGetDouble(dc.font.match->pattern,
                           FC_PIXEL_SIZE, 0, &fontval);
        usedfontsize = fontval;
        if (fontsize == 0)
        {
            defaultfontsize = fontval;
        }
    }

    /* Setting character width and height. */
    win.cw = ceilf(dc.font.width * cwscale);
    win.ch = ceilf(dc.font.height * chscale);

    FcPatternDel(pattern, FC_SLANT);
    FcPatternAddInteger(pattern, FC_SLANT, FC_SLANT_ITALIC);
    if (xloadfont(&dc.ifont, pattern))
    {
        die("can't open font %s\n", fontstr);
    }

    FcPatternDel(pattern, FC_WEIGHT);
    FcPatternAddInteger(pattern, FC_WEIGHT, FC_WEIGHT_BOLD);
    if (xloadfont(&dc.ibfont, pattern))
    {
        die("can't open font %s\n", fontstr);
    }

    FcPatternDel(pattern, FC_SLANT);
    FcPatternAddInteger(pattern, FC_SLANT, FC_SLANT_ROMAN);
    if (xloadfont(&dc.bfont, pattern))
    {
        die("can't open font %s\n", fontstr);
    }

    FcPatternDestroy(pattern);
}

void
xunloadfont(Font* f)
{
    XftFontClose(xw.dpy, f->match);
    FcPatternDestroy(f->pattern);
    if (f->set)
    {
        FcFontSetDestroy(f->set);
    }
}

void
xunloadfonts(void)
{
    /* Free the loaded fonts in the font cache.  */
    while (frclen > 0)
    {
        XftFontClose(xw.dpy, frc[--frclen].font);
    }

    xunloadfont(&dc.font);
    xunloadfont(&dc.bfont);
    xunloadfont(&dc.ifont);
    xunloadfont(&dc.ibfont);
}

int
ximopen(Display* dpy)
{
    XIMCallback imdestroy = { .client_data = NULL, .callback = ximdestroy };
    XICCallback icdestroy = { .client_data = NULL, .callback = xicdestroy };

    xw.ime.xim = XOpenIM(xw.dpy, NULL, NULL, NULL);
    if (xw.ime.xim == NULL)
    {
        return 0;
    }

    if (XSetIMValues(xw.ime.xim, XNDestroyCallback, &imdestroy, NULL))
    {
        fprintf(stderr, "XSetIMValues: "
                        "Could not set XNDestroyCallback.\n");
    }

    xw.ime.spotlist = XVaCreateNestedList(0, XNSpotLocation, &xw.ime.spot,
                                          NULL);

    if (xw.ime.xic == NULL)
    {
        xw.ime.xic = XCreateIC(xw.ime.xim, XNInputStyle,
                               XIMPreeditNothing | XIMStatusNothing,
                               XNClientWindow, xw.win,
                               XNDestroyCallback, &icdestroy,
                               NULL);
    }
    if (xw.ime.xic == NULL)
    {
        fprintf(stderr, "XCreateIC: Could not create input context.\n");
    }

    return 1;
}

void
ximinstantiate(Display* dpy, XPointer client, XPointer call)
{
    if (ximopen(dpy))
    {
        XUnregisterIMInstantiateCallback(xw.dpy, NULL, NULL, NULL,
                                         ximinstantiate, NULL);
    }
}

void
ximdestroy(XIM xim, XPointer client, XPointer call)
{
    xw.ime.xim = NULL;
    XRegisterIMInstantiateCallback(xw.dpy, NULL, NULL, NULL,
                                   ximinstantiate, NULL);
    XFree(xw.ime.spotlist);
}

int
xicdestroy(XIC xim, XPointer client, XPointer call)
{
    xw.ime.xic = NULL;
    return 1;
}

void
xinit(int cols, int rows)
{
    XGCValues gcvalues;
    Cursor cursor;
    Window parent;
    pid_t thispid = getpid();
    XColor xmousefg, xmousebg;

    if (!(xw.dpy = XOpenDisplay(NULL)))
    {
        die("can't open display\n");
    }
    xw.scr = XDefaultScreen(xw.dpy);
    xw.vis = XDefaultVisual(xw.dpy, xw.scr);

    /* font */
    if (!FcInit())
    {
        die("could not init fontconfig.\n");
    }

    usedfont = (opt_font == NULL)? font : opt_font;
    xloadfonts(usedfont, 0);

    /* colors */
    xw.cmap = XDefaultColormap(xw.dpy, xw.scr);
    xloadcols();

    /* adjust fixed window geometry */
    win.w = 2 * borderpx + cols * win.cw;
    win.h = 2 * borderpx + rows * win.ch;
    if (xw.gm & XNegative)
    {
        xw.l += DisplayWidth(xw.dpy, xw.scr) - win.w - 2;
    }
    if (xw.gm & YNegative)
    {
        xw.t += DisplayHeight(xw.dpy, xw.scr) - win.h - 2;
    }

    /* Events */
    xw.attrs.background_pixel = dc.col[defaultbg].pixel;
    xw.attrs.border_pixel = dc.col[defaultbg].pixel;
    xw.attrs.bit_gravity = NorthWestGravity;
    xw.attrs.event_mask = FocusChangeMask | KeyPressMask | KeyReleaseMask
                          | ExposureMask | VisibilityChangeMask | StructureNotifyMask
                          | ButtonMotionMask | ButtonPressMask | ButtonReleaseMask;
    xw.attrs.colormap = xw.cmap;

    if (!(opt_embed && (parent = strtol(opt_embed, NULL, 0))))
    {
        parent = XRootWindow(xw.dpy, xw.scr);
    }
    xw.win = XCreateWindow(xw.dpy, parent, xw.l, xw.t,
                           win.w, win.h, 0, XDefaultDepth(xw.dpy, xw.scr), InputOutput,
                           xw.vis, CWBackPixel | CWBorderPixel | CWBitGravity
                           | CWEventMask | CWColormap, &xw.attrs);

    memset(&gcvalues, 0, sizeof(gcvalues));
    gcvalues.graphics_exposures = False;
    dc.gc = XCreateGC(xw.dpy, parent, GCGraphicsExposures,
                      &gcvalues);
    xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h,
                           DefaultDepth(xw.dpy, xw.scr));
    XSetForeground(xw.dpy, dc.gc, dc.col[defaultbg].pixel);
    XFillRectangle(xw.dpy, xw.buf, dc.gc, 0, 0, win.w, win.h);

    /* font spec buffer */
    xw.specbuf = xmalloc(cols * sizeof(GlyphFontSpec));

    /* Xft rendering context */
    xw.draw = XftDrawCreate(xw.dpy, xw.buf, xw.vis, xw.cmap);

    /* input methods */
    if (!ximopen(xw.dpy))
    {
        XRegisterIMInstantiateCallback(xw.dpy, NULL, NULL, NULL,
                                       ximinstantiate, NULL);
    }

    /* white cursor, black outline */
    cursor = XCreateFontCursor(xw.dpy, mouseshape);
    XDefineCursor(xw.dpy, xw.win, cursor);

    if (XParseColor(xw.dpy, xw.cmap, colorname[mousefg], &xmousefg) == 0)
    {
        xmousefg.red = 0xffff;
        xmousefg.green = 0xffff;
        xmousefg.blue = 0xffff;
    }

    if (XParseColor(xw.dpy, xw.cmap, colorname[mousebg], &xmousebg) == 0)
    {
        xmousebg.red = 0x0000;
        xmousebg.green = 0x0000;
        xmousebg.blue = 0x0000;
    }

    XRecolorCursor(xw.dpy, cursor, &xmousefg, &xmousebg);

    xw.xembed = XInternAtom(xw.dpy, "_XEMBED", False);
    xw.wmdeletewin = XInternAtom(xw.dpy, "WM_DELETE_WINDOW", False);
    xw.netwmname = XInternAtom(xw.dpy, "_NET_WM_NAME", False);
    xw.netwmiconname = XInternAtom(xw.dpy, "_NET_WM_ICON_NAME", False);
    XSetWMProtocols(xw.dpy, xw.win, &xw.wmdeletewin, 1);

    xw.netwmpid = XInternAtom(xw.dpy, "_NET_WM_PID", False);
    XChangeProperty(xw.dpy, xw.win, xw.netwmpid, XA_CARDINAL, 32,
                    PropModeReplace, (uchar*)&thispid, 1);

    win.mode = MODE_NUMLOCK;
    resettitle();
    xhints();
    XMapWindow(xw.dpy, xw.win);
    XSync(xw.dpy, False);

    clock_gettime(CLOCK_MONOTONIC, &xsel.tclick1);
    clock_gettime(CLOCK_MONOTONIC, &xsel.tclick2);
    xsel.primary = NULL;
    xsel.clipboard = NULL;
    xsel.xtarget = XInternAtom(xw.dpy, "UTF8_STRING", 0);
    if (xsel.xtarget == None)
    {
        xsel.xtarget = XA_STRING;
    }
}

int
xmakeglyphfontspecs(XftGlyphFontSpec* specs, const Glyph* glyphs, int len, int x, int y)
{
    float winx = borderpx + x * win.cw, winy = borderpx + y * win.ch, xp, yp;
    ushort mode, prevmode = USHRT_MAX;
    Font* font = &dc.font;
    int frcflags = FRC_NORMAL;
    float runewidth = win.cw;
    Rune rune;
    FT_UInt glyphidx;
    FcResult fcres;
    FcPattern* fcpattern, * fontpattern;
    FcFontSet* fcsets[] = { NULL };
    FcCharSet* fccharset;
    int i, f, numspecs = 0;

    for (i = 0, xp = winx, yp = winy + font->ascent; i < len; ++i)
    {
        /* Fetch rune and mode for current glyph. */
        rune = glyphs[i].u;
        mode = glyphs[i].mode;

        /* Skip dummy wide-character spacing. */
        if (mode == ATTR_WDUMMY)
        {
            continue;
        }

        /* Determine font for glyph if different from previous glyph. */
        if (prevmode != mode)
        {
            prevmode = mode;
            font = &dc.font;
            frcflags = FRC_NORMAL;
            runewidth = win.cw * ((mode & ATTR_WIDE) ? 2.0f : 1.0f);
            if ((mode & ATTR_ITALIC) && (mode & ATTR_BOLD))
            {
                font = &dc.ibfont;
                frcflags = FRC_ITALICBOLD;
            }
            else if (mode & ATTR_ITALIC)
            {
                font = &dc.ifont;
                frcflags = FRC_ITALIC;
            }
            else if (mode & ATTR_BOLD)
            {
                font = &dc.bfont;
                frcflags = FRC_BOLD;
            }
            yp = winy + font->ascent;
        }

        /* Lookup character index with default font. */
        glyphidx = XftCharIndex(xw.dpy, font->match, rune);
        if (glyphidx)
        {
            specs[numspecs].font = font->match;
            specs[numspecs].glyph = glyphidx;
            specs[numspecs].x = (short)xp;
            specs[numspecs].y = (short)yp;
            xp += runewidth;
            numspecs++;
            continue;
        }

        /* Fallback on font cache, search the font cache for match. */
        for (f = 0; f < frclen; f++)
        {
            glyphidx = XftCharIndex(xw.dpy, frc[f].font, rune);
            /* Everything correct. */
            if (glyphidx && frc[f].flags == frcflags)
            {
                break;
            }
            /* We got a default font for a not found glyph. */
            if (!glyphidx && frc[f].flags == frcflags
                && frc[f].unicodep == rune)
            {
                break;
            }
        }

        /* Nothing was found. Use fontconfig to find matching font. */
        if (f >= frclen)
        {
            if (!font->set)
            {
                font->set = FcFontSort(0, font->pattern,
                                       1, 0, &fcres);
            }
            fcsets[0] = font->set;

            /*
             * Nothing was found in the cache. Now use
             * some dozen of Fontconfig calls to get the
             * font for one single character.
             *
             * Xft and fontconfig are design failures.
             */
            fcpattern = FcPatternDuplicate(font->pattern);
            fccharset = FcCharSetCreate();

            FcCharSetAddChar(fccharset, rune);
            FcPatternAddCharSet(fcpattern, FC_CHARSET,
                                fccharset);
            FcPatternAddBool(fcpattern, FC_SCALABLE, 1);

            FcConfigSubstitute(0, fcpattern,
                               FcMatchPattern);
            FcDefaultSubstitute(fcpattern);

            fontpattern = FcFontSetMatch(0, fcsets, 1,
                                         fcpattern, &fcres);

            /* Allocate memory for the new cache entry. */
            if (frclen >= frccap)
            {
                frccap += 16;
                frc = xrealloc(frc, frccap * sizeof(Fontcache));
            }

            frc[frclen].font = XftFontOpenPattern(xw.dpy,
                                                  fontpattern);
            if (!frc[frclen].font)
            {
                die("XftFontOpenPattern failed seeking fallback font: %s\n",
                    strerror(errno));
            }
            frc[frclen].flags = frcflags;
            frc[frclen].unicodep = rune;

            glyphidx = XftCharIndex(xw.dpy, frc[frclen].font, rune);

            f = frclen;
            frclen++;

            FcPatternDestroy(fcpattern);
            FcCharSetDestroy(fccharset);
        }

        specs[numspecs].font = frc[f].font;
        specs[numspecs].glyph = glyphidx;
        specs[numspecs].x = (short)xp;
        specs[numspecs].y = (short)yp;
        xp += runewidth;
        numspecs++;
    }

    return numspecs;
}

void
xdrawglyphfontspecs(const XftGlyphFontSpec* specs, Glyph base, int len, int x, int y)
{
    int charlen = len * ((base.mode & ATTR_WIDE) ? 2 : 1);
    int winx = borderpx + x * win.cw, winy = borderpx + y * win.ch,
        width = charlen * win.cw;
    Color* fg, * bg, * temp, revfg, revbg, truefg, truebg;
    XRenderColor colfg, colbg;
    XRectangle r;

    /* Fallback on color display for attributes not supported by the font */
    if (base.mode & ATTR_ITALIC && base.mode & ATTR_BOLD)
    {
        if (dc.ibfont.badslant || dc.ibfont.badweight)
        {
            base.fg = defaultattr;
        }
    }
    else if ((base.mode & ATTR_ITALIC && dc.ifont.badslant) ||
             (base.mode & ATTR_BOLD && dc.bfont.badweight))
    {
        base.fg = defaultattr;
    }

    if (IS_TRUECOL(base.fg))
    {
        colfg.alpha = 0xffff;
        colfg.red = TRUERED(base.fg);
        colfg.green = TRUEGREEN(base.fg);
        colfg.blue = TRUEBLUE(base.fg);
        XftColorAllocValue(xw.dpy, xw.vis, xw.cmap, &colfg, &truefg);
        fg = &truefg;
    }
    else
    {
        fg = &dc.col[base.fg];
    }

    if (IS_TRUECOL(base.bg))
    {
        colbg.alpha = 0xffff;
        colbg.green = TRUEGREEN(base.bg);
        colbg.red = TRUERED(base.bg);
        colbg.blue = TRUEBLUE(base.bg);
        XftColorAllocValue(xw.dpy, xw.vis, xw.cmap, &colbg, &truebg);
        bg = &truebg;
    }
    else
    {
        bg = &dc.col[base.bg];
    }

    /* Change basic system colors [0-7] to bright system colors [8-15] */
    if ((base.mode & ATTR_BOLD_FAINT) == ATTR_BOLD && BETWEEN(base.fg, 0, 7))
    {
        fg = &dc.col[base.fg + 8];
    }

    if (IS_SET(MODE_REVERSE))
    {
        if (fg == &dc.col[defaultfg])
        {
            fg = &dc.col[defaultbg];
        }
        else
        {
            colfg.red = ~fg->color.red;
            colfg.green = ~fg->color.green;
            colfg.blue = ~fg->color.blue;
            colfg.alpha = fg->color.alpha;
            XftColorAllocValue(xw.dpy, xw.vis, xw.cmap, &colfg,
                               &revfg);
            fg = &revfg;
        }

        if (bg == &dc.col[defaultbg])
        {
            bg = &dc.col[defaultfg];
        }
        else
        {
            colbg.red = ~bg->color.red;
            colbg.green = ~bg->color.green;
            colbg.blue = ~bg->color.blue;
            colbg.alpha = bg->color.alpha;
            XftColorAllocValue(xw.dpy, xw.vis, xw.cmap, &colbg,
                               &revbg);
            bg = &revbg;
        }
    }

    if ((base.mode & ATTR_BOLD_FAINT) == ATTR_FAINT)
    {
        colfg.red = fg->color.red / 2;
        colfg.green = fg->color.green / 2;
        colfg.blue = fg->color.blue / 2;
        colfg.alpha = fg->color.alpha;
        XftColorAllocValue(xw.dpy, xw.vis, xw.cmap, &colfg, &revfg);
        fg = &revfg;
    }

    if (base.mode & ATTR_REVERSE)
    {
        temp = fg;
        fg = bg;
        bg = temp;
    }

    if (base.mode & ATTR_BLINK && win.mode & MODE_BLINK)
    {
        fg = bg;
    }

    if (base.mode & ATTR_INVISIBLE)
    {
        fg = bg;
    }

    /* Intelligent cleaning up of the borders. */
    if (x == 0)
    {
        xclear(0, (y == 0)? 0 : winy, borderpx,
               winy + win.ch +
               ((winy + win.ch >= borderpx + win.th)? win.h : 0));
    }
    if (winx + width >= borderpx + win.tw)
    {
        xclear(winx + width, (y == 0)? 0 : winy, win.w,
               ((winy + win.ch >= borderpx + win.th)? win.h : (winy + win.ch)));
    }
    if (y == 0)
    {
        xclear(winx, 0, winx + width, borderpx);
    }
    if (winy + win.ch >= borderpx + win.th)
    {
        xclear(winx, winy + win.ch, winx + width, win.h);
    }

    /* Clean up the region we want to draw to. */
    XftDrawRect(xw.draw, bg, winx, winy, width, win.ch);

    /* Set the clip region because Xft is sometimes dirty. */
    r.x = 0;
    r.y = 0;
    r.height = win.ch;
    r.width = width;
    XftDrawSetClipRectangles(xw.draw, winx, winy, &r, 1);

    /* Render the glyphs. */
    XftDrawGlyphFontSpec(xw.draw, fg, specs, len);

    /* Render underline and strikethrough. */
    if (base.mode & ATTR_UNDERLINE)
    {
        XftDrawRect(xw.draw, fg, winx, winy + dc.font.ascent * chscale + 1,
                    width, 1);
    }

    if (base.mode & ATTR_STRUCK)
    {
        XftDrawRect(xw.draw, fg, winx, winy + 2 * dc.font.ascent * chscale / 3,
                    width, 1);
    }

    /* Reset clip to none. */
    XftDrawSetClip(xw.draw, 0);
}

void
xdrawglyph(Glyph g, int x, int y)
{
    int numspecs;
    XftGlyphFontSpec spec;

    numspecs = xmakeglyphfontspecs(&spec, &g, 1, x, y);
    xdrawglyphfontspecs(&spec, g, numspecs, x, y);
}

void
xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og)
{
    Color drawcol;

    /* remove the old cursor */
    if (selected(ox, oy))
    {
        og.mode ^= ATTR_REVERSE;
    }
    xdrawglyph(og, ox, oy);

    if (IS_SET(MODE_HIDE))
    {
        return;
    }

    /*
     * Select the right color for the right mode.
     */
    g.mode &= ATTR_BOLD | ATTR_ITALIC | ATTR_UNDERLINE | ATTR_STRUCK | ATTR_WIDE;

    if (IS_SET(MODE_REVERSE))
    {
        g.mode |= ATTR_REVERSE;
        g.bg = defaultfg;
        if (selected(cx, cy))
        {
            drawcol = dc.col[defaultcs];
            g.fg = defaultrcs;
        }
        else
        {
            drawcol = dc.col[defaultrcs];
            g.fg = defaultcs;
        }
    }
    else
    {
        if (selected(cx, cy))
        {
            g.fg = defaultfg;
            g.bg = defaultrcs;
        }
        else
        {
            g.fg = defaultbg;
            g.bg = defaultcs;
        }
        drawcol = dc.col[g.bg];
    }

    /* draw the new one */
    if (IS_SET(MODE_FOCUSED))
    {
        switch (win.cursor)
        {
        case 7:                 /* st extension */
            g.u = 0x2603;       /* snowman (U+2603) */
        /* FALLTHROUGH */
        case 0:                 /* Blinking Block */
        case 1:                 /* Blinking Block (Default) */
        case 2:                 /* Steady Block */
            xdrawglyph(g, cx, cy);
            break;
        case 3: /* Blinking Underline */
        case 4: /* Steady Underline */
            XftDrawRect(xw.draw, &drawcol,
                        borderpx + cx * win.cw,
                        borderpx + (cy + 1) * win.ch - \
                        cursorthickness,
                        win.cw, cursorthickness);
            break;
        case 5: /* Blinking bar */
        case 6: /* Steady bar */
            XftDrawRect(xw.draw, &drawcol,
                        borderpx + cx * win.cw,
                        borderpx + cy * win.ch,
                        cursorthickness, win.ch);
            break;
        }
    }
    else
    {
        XftDrawRect(xw.draw, &drawcol,
                    borderpx + cx * win.cw,
                    borderpx + cy * win.ch,
                    win.cw - 1, 1);
        XftDrawRect(xw.draw, &drawcol,
                    borderpx + cx * win.cw,
                    borderpx + cy * win.ch,
                    1, win.ch - 1);
        XftDrawRect(xw.draw, &drawcol,
                    borderpx + (cx + 1) * win.cw - 1,
                    borderpx + cy * win.ch,
                    1, win.ch - 1);
        XftDrawRect(xw.draw, &drawcol,
                    borderpx + cx * win.cw,
                    borderpx + (cy + 1) * win.ch - 1,
                    win.cw, 1);
    }
}

void
xsetenv(void)
{
    char buf[sizeof(long) * 8 + 1];

    snprintf(buf, sizeof(buf), "%lu", xw.win);
    setenv("WINDOWID", buf, 1);
}

void
xseticontitle(char* p)
{
    XTextProperty prop;

    DEFAULT(p, opt_title);

    if (p[0] == '\0')
    {
        p = opt_title;
    }

    if (Xutf8TextListToTextProperty(xw.dpy, &p, 1, XUTF8StringStyle,
                                    &prop) != Success)
    {
        return;
    }
    XSetWMIconName(xw.dpy, xw.win, &prop);
    XSetTextProperty(xw.dpy, xw.win, &prop, xw.netwmiconname);
    XFree(prop.value);
}

void
xsettitle(char* p)
{
    XTextProperty prop;

    DEFAULT(p, opt_title);

    if (p[0] == '\0')
    {
        p = opt_title;
    }

    if (Xutf8TextListToTextProperty(xw.dpy, &p, 1, XUTF8StringStyle,
                                    &prop) != Success)
    {
        return;
    }
    XSetWMName(xw.dpy, xw.win, &prop);
    XSetTextProperty(xw.dpy, xw.win, &prop, xw.netwmname);
    XFree(prop.value);
}

int
xstartdraw(void)
{
    return IS_SET(MODE_VISIBLE);
}

void
xdrawline(Line line, int x1, int y1, int x2)
{
    int i, x, ox, numspecs;
    Glyph base, new;
    XftGlyphFontSpec* specs = xw.specbuf;

    numspecs = xmakeglyphfontspecs(specs, &line[x1], x2 - x1, x1, y1);
    i = ox = 0;
    for (x = x1; x < x2 && i < numspecs; x++)
    {
        new = line[x];
        if (new.mode == ATTR_WDUMMY)
        {
            continue;
        }
        if (selected(x, y1))
        {
            new.mode ^= ATTR_REVERSE;
        }
        if (i > 0 && ATTRCMP(base, new))
        {
            xdrawglyphfontspecs(specs, base, i, ox, y1);
            specs += i;
            numspecs -= i;
            i = 0;
        }
        if (i == 0)
        {
            ox = x;
            base = new;
        }
        i++;
    }
    if (i > 0)
    {
        xdrawglyphfontspecs(specs, base, i, ox, y1);
    }
}

void
xfinishdraw(void)
{
    XCopyArea(xw.dpy, xw.buf, xw.win, dc.gc, 0, 0, win.w,
              win.h, 0, 0);
    XSetForeground(xw.dpy, dc.gc,
                   dc.col[IS_SET(MODE_REVERSE)?
                          defaultfg : defaultbg].pixel);
}

void
xximspot(int x, int y)
{
    if (xw.ime.xic == NULL)
    {
        return;
    }

    xw.ime.spot.x = borderpx + x * win.cw;
    xw.ime.spot.y = borderpx + (y + 1) * win.ch;

    XSetICValues(xw.ime.xic, XNPreeditAttributes, xw.ime.spotlist, NULL);
}

void
expose(XEvent* ev)
{
    redraw();
}

void
visibility(XEvent* ev)
{
    XVisibilityEvent* e = &ev->xvisibility;

    MODBIT(win.mode, e->state != VisibilityFullyObscured, MODE_VISIBLE);
}

void
unmap(XEvent* ev)
{
    win.mode &= ~MODE_VISIBLE;
}

void
xsetpointermotion(int set)
{
    MODBIT(xw.attrs.event_mask, set, PointerMotionMask);
    XChangeWindowAttributes(xw.dpy, xw.win, CWEventMask, &xw.attrs);
}

void
xsetmode(int set, unsigned int flags)
{
    int mode = win.mode;

    MODBIT(win.mode, set, flags);
    if ((win.mode & MODE_REVERSE) != (mode & MODE_REVERSE))
    {
        redraw();
    }
}

int
xsetcursor(int cursor)
{
    if (!BETWEEN(cursor, 0, 7)) /* 7: st extension */
    {
        return 1;
    }
    win.cursor = cursor;
    return 0;
}

void
xseturgency(int add)
{
    XWMHints* h = XGetWMHints(xw.dpy, xw.win);

    MODBIT(h->flags, add, XUrgencyHint);
    XSetWMHints(xw.dpy, xw.win, h);
    XFree(h);
}

void
xbell(void)
{
    if (!(IS_SET(MODE_FOCUSED)))
    {
        xseturgency(1);
    }
    if (bellvolume)
    {
        XkbBell(xw.dpy, xw.win, bellvolume, (Atom)NULL);
    }
}

void
focus(XEvent* ev)
{
    XFocusChangeEvent* e = &ev->xfocus;

    if (e->mode == NotifyGrab)
    {
        return;
    }

    if (ev->type == FocusIn)
    {
        if (xw.ime.xic)
        {
            XSetICFocus(xw.ime.xic);
        }
        win.mode |= MODE_FOCUSED;
        xseturgency(0);
        if (IS_SET(MODE_FOCUS))
        {
            ttywrite("\033[I", 3, 0);
        }
    }
    else
    {
        if (xw.ime.xic)
        {
            XUnsetICFocus(xw.ime.xic);
        }
        win.mode &= ~MODE_FOCUSED;
        if (IS_SET(MODE_FOCUS))
        {
            ttywrite("\033[O", 3, 0);
        }
    }
}

int
match(uint mask, uint state)
{
    return mask == XK_ANY_MOD || mask == (state & ~ignoremod);
}

char*
kmap(KeySym k, uint state)
{
    Key* kp;
    int i;

    /* Check for mapped keys out of X11 function keys. */
    for (i = 0; i < LEN(mappedkeys); i++)
    {
        if (mappedkeys[i] == k)
        {
            break;
        }
    }
    if (i == LEN(mappedkeys))
    {
        if ((k & 0xFFFF) < 0xFD00)
        {
            return NULL;
        }
    }

    for (kp = key; kp < key + LEN(key); kp++)
    {
        if (kp->k != k)
        {
            continue;
        }

        if (!match(kp->mask, state))
        {
            continue;
        }

        if (IS_SET(MODE_APPKEYPAD) ? kp->appkey < 0 : kp->appkey > 0)
        {
            continue;
        }
        if (IS_SET(MODE_NUMLOCK) && kp->appkey == 2)
        {
            continue;
        }

        if (IS_SET(MODE_APPCURSOR) ? kp->appcursor < 0 : kp->appcursor > 0)
        {
            continue;
        }

        return kp->s;
    }

    return NULL;
}

void
kpress(XEvent* ev)
{
    XKeyEvent* e = &ev->xkey;
    KeySym ksym = NoSymbol;
    char buf[64], * customkey;
    int len;
    Rune c;
    Status status;
    Shortcut* bp;

    if (IS_SET(MODE_KBDLOCK))
    {
        return;
    }

    if (xw.ime.xic)
    {
        len = XmbLookupString(xw.ime.xic, e, buf, sizeof buf, &ksym, &status);
        if (status == XBufferOverflow)
        {
            return;
        }
    }
    else
    {
        len = XLookupString(e, buf, sizeof buf, &ksym, NULL);
    }
    /* 1. shortcuts */
    for (bp = shortcuts; bp < shortcuts + LEN(shortcuts); bp++)
    {
        if (ksym == bp->keysym && match(bp->mod, e->state))
        {
            bp->func(&(bp->arg));
            return;
        }
    }

    /* 2. custom keys from config.h */
    if ((customkey = kmap(ksym, e->state)))
    {
        ttywrite(customkey, strlen(customkey), 1);
        return;
    }

    /* 3. composed string from input method */
    if (len == 0)
    {
        return;
    }
    if (len == 1 && e->state & Mod1Mask)
    {
        if (IS_SET(MODE_8BIT))
        {
            if (*buf < 0177)
            {
                c = *buf | 0x80;
                len = utf8encode(c, buf);
            }
        }
        else
        {
            buf[1] = buf[0];
            buf[0] = '\033';
            len = 2;
        }
    }
    ttywrite(buf, len, 1);
}

void
cmessage(XEvent* e)
{
    /*
     * See xembed specs
     *  http://standards.freedesktop.org/xembed-spec/xembed-spec-latest.html
     */
    if (e->xclient.message_type == xw.xembed && e->xclient.format == 32)
    {
        if (e->xclient.data.l[1] == XEMBED_FOCUS_IN)
        {
            win.mode |= MODE_FOCUSED;
            xseturgency(0);
        }
        else if (e->xclient.data.l[1] == XEMBED_FOCUS_OUT)
        {
            win.mode &= ~MODE_FOCUSED;
        }
    }
    else if (e->xclient.data.l[0] == xw.wmdeletewin)
    {
        ttyhangup();
        exit(0);
    }
}

void
resize(XEvent* e)
{
    if (e->xconfigure.width == win.w && e->xconfigure.height == win.h)
    {
        return;
    }

    cresize(e->xconfigure.width, e->xconfigure.height);
}

void
run(void)
{
    XEvent ev;
    int w = win.w, h = win.h;
    fd_set rfd;
    int xfd = XConnectionNumber(xw.dpy), ttyfd, xev, drawing;
    struct timespec seltv, * tv, now, lastblink, trigger;
    double timeout;

    /* Waiting for window mapping */
    do
    {
        XNextEvent(xw.dpy, &ev);
        /*
         * This XFilterEvent call is required because of XOpenIM. It
         * does filter out the key event and some client message for
         * the input method too.
         */
        if (XFilterEvent(&ev, None))
        {
            continue;
        }
        if (ev.type == ConfigureNotify)
        {
            w = ev.xconfigure.width;
            h = ev.xconfigure.height;
        }
    }
    while (ev.type != MapNotify);

    ttyfd = ttynew(opt_line, shell, opt_io, opt_cmd);
    cresize(w, h);

    for (timeout = -1, drawing = 0, lastblink = (struct timespec){ 0 };;)
    {
        FD_ZERO(&rfd);
        FD_SET(ttyfd, &rfd);
        FD_SET(xfd, &rfd);

        if (XPending(xw.dpy))
        {
            timeout = 0;  /* existing events might not set xfd */
        }
        seltv.tv_sec = timeout / 1E3;
        seltv.tv_nsec = 1E6 * (timeout - 1E3 * seltv.tv_sec);
        tv = timeout >= 0 ? &seltv : NULL;

        if (pselect(MAX(xfd, ttyfd) + 1, &rfd, NULL, NULL, tv, NULL) < 0)
        {
            if (errno == EINTR)
            {
                continue;
            }
            die("select failed: %s\n", strerror(errno));
        }
        clock_gettime(CLOCK_MONOTONIC, &now);

        if (FD_ISSET(ttyfd, &rfd))
        {
            ttyread();
        }

        xev = 0;
        while (XPending(xw.dpy))
        {
            xev = 1;
            XNextEvent(xw.dpy, &ev);
            if (XFilterEvent(&ev, None))
            {
                continue;
            }
            if (handler[ev.type])
            {
                (handler[ev.type])(&ev);
            }
        }

        /*
         * To reduce flicker and tearing, when new content or event
         * triggers drawing, we first wait a bit to ensure we got
         * everything, and if nothing new arrives - we draw.
         * We start with trying to wait minlatency ms. If more content
         * arrives sooner, we retry with shorter and shorter periods,
         * and eventually draw even without idle after maxlatency ms.
         * Typically this results in low latency while interacting,
         * maximum latency intervals during `cat huge.txt`, and perfect
         * sync with periodic updates from animations/key-repeats/etc.
         */
        if (FD_ISSET(ttyfd, &rfd) || xev)
        {
            if (!drawing)
            {
                trigger = now;
                drawing = 1;
            }
            timeout = (maxlatency - TIMEDIFF(now, trigger)) \
                      / maxlatency * minlatency;
            if (timeout > 0)
            {
                continue;  /* we have time, try to find idle */
            }
        }

        /* idle detected or maxlatency exhausted -> draw */
        timeout = -1;
        if (blinktimeout && tattrset(ATTR_BLINK))
        {
            timeout = blinktimeout - TIMEDIFF(now, lastblink);
            if (timeout <= 0)
            {
                if (-timeout > blinktimeout) /* start visible */
                {
                    win.mode |= MODE_BLINK;
                }
                win.mode ^= MODE_BLINK;
                tsetdirtattr(ATTR_BLINK);
                lastblink = now;
                timeout = blinktimeout;
            }
        }

        draw();
        XFlush(xw.dpy);
        drawing = 0;
    }
}

int
st(int argc, char* argv[])
{
    xw.l = xw.t = 0;
    xw.isfixed = False;
    xsetcursor(cursorshape);

    ARGBEGIN
    {
        case 'a':
            allowaltscreen = 0;
            break;
        case 'c':
            opt_class = EARGF();
            break;
        case 'e':
            if (argc > 0)
            {
                --argc, ++argv;
            }
            goto run;
        case 'f':
            opt_font = EARGF();
            break;
        case 'g':
            xw.gm = XParseGeometry(EARGF(),
                                   &xw.l, &xw.t, &cols, &rows);
            break;
        case 'i':
            xw.isfixed = 1;
            break;
        case 'o':
            opt_io = EARGF();
            break;
        case 'l':
            opt_line = EARGF();
            break;
        case 'n':
            opt_name = EARGF();
            break;
        case 't':
        case 'T':
            opt_title = EARGF();
            break;
        case 'w':
            opt_embed = EARGF();
            break;
        case 'v':
            die("%s 0.9.2 \n", argv0);
            break;
        default:
            exit(EXIT_FAILURE);
    } ARGEND;

run:
    if (argc > 0) /* eat all remaining arguments */
    {
        opt_cmd = argv;
    }

    if (!opt_title)
    {
        opt_title = (opt_line || !opt_cmd) ? "st" : opt_cmd[0];
    }

    setlocale(LC_CTYPE, "");
    XSetLocaleModifiers("");
    cols = MAX(cols, 1);
    rows = MAX(rows, 1);
    tnew(cols, rows);
    xinit(cols, rows);
    xsetenv();
    selinit();
    run();

    return 0;
}
