#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <time.h>
#include <unistd.h>
#include <errno.h>
#include <stdarg.h>

#include <X11/Xlib.h>
#include <X11/Xatom.h>
#include <X11/Xutil.h>
#include <X11/Xft/Xft.h>

#define UTF_INVALID 0xFFFD
#define TEXTW(X)              (drw_fontset_getwidth(drw, (X)) + lrpad)
#define MAX(A, B)               ((A) > (B) ? (A) : (B))
#define MIN(A, B)               ((A) < (B) ? (A) : (B))
#define BETWEEN(X, A, B)        ((A) <= (X) && (X) <= (B))
#define LENGTH(X)               (sizeof (X) / sizeof (X)[0])

enum { SchemeNorm, SchemeSel, SchemeOut, SchemeLast };
enum { ColFg, ColBg };

typedef struct {
	Cursor cursor;
} Cur;

typedef struct Fnt {
	Display *dpy;
	unsigned int h;
	XftFont *xfont;
	FcPattern *pattern;
	struct Fnt *next;
} Fnt;

typedef XftColor Clr;

typedef struct {
	unsigned int w, h;
	Display *dpy;
	int screen;
	Window root;
	Drawable drawable;
	GC gc;
	Clr *scheme;
	Fnt *fonts;
} Drw;

struct item {
	char *text;
	struct item *left, *right;
	int out;
};

static char text[BUFSIZ] = "";
static int bh, mw, screen, inputw = 0, lrpad;
static size_t cursor;
static struct item *items = NULL;
static struct item *matches, *matchend;
static struct item *prev, *curr, *next, *sel;

static Atom clip, utf8;
static Display *dpy;
static Window root, win;
static XIC xic;

static Drw *drw;
static Clr *scheme[SchemeLast];

/* Drawable abstraction */
Drw *drw_create(Display *dpy, int screen, Window win, unsigned int w, unsigned int h);
void drw_resize(Drw *drw, unsigned int w, unsigned int h);
void drw_free(Drw *drw);

/* Fnt abstraction */
Fnt *drw_fontset_create(Drw* drw, const char *fonts[], size_t fontcount);
void drw_fontset_free(Fnt* set);
unsigned int drw_fontset_getwidth(Drw *drw, const char *text);
unsigned int drw_fontset_getwidth_clamp(Drw *drw, const char *text, unsigned int n);
void drw_font_getexts(Fnt *font, const char *text, unsigned int len, unsigned int *w, unsigned int *h);

/* Colorscheme abstraction */
void drw_clr_create(Drw *drw, Clr *dest, const char *clrname);
Clr *drw_scm_create(Drw *drw, const char *clrnames[], size_t clrcount);

/* Cursor abstraction */
Cur *drw_cur_create(Drw *drw, int shape);
void drw_cur_free(Drw *drw, Cur *cursor);

/* Drawing context manipulation */
void drw_setfontset(Drw *drw, Fnt *set);
void drw_setscheme(Drw *drw, Clr *scm);

/* Drawing functions */
void drw_rect(Drw *drw, int x, int y, unsigned int w, unsigned int h, int filled, int invert);
int drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lpad, const char *text, int invert);

/* Map functions */
void drw_map(Drw *drw, Window win, int x, int y, unsigned int w, unsigned int h);

static const char *fonts[] = {
	"CaskaydiaCove NFM style:SemiBold:size=11"
};
static const char *colors[SchemeLast][2] = {
	[SchemeNorm] = { "#D3C6AA", "#272E33" },
	[SchemeSel] = { "#272E33", "#DBBC7F" },
	[SchemeOut] = { "#E67E80", "#272E33" },
};

static int (*fstrncmp)(const char *, const char *, size_t) = strncmp;
static char *(*fstrstr)(const char *, const char *) = strstr;

void die(const char *fmt, ...) {
	va_list ap;
	int saved_errno = errno;

	va_start(ap, fmt);
	vfprintf(stderr, fmt, ap);
	va_end(ap);

	if (fmt[0] && fmt[strlen(fmt)-1] == ':') fprintf(stderr, " %s", strerror(saved_errno));
	fputc('\n', stderr);
	exit(1);
}

void * ecalloc(size_t nmemb, size_t size) {
	void *p;
	if (!(p = calloc(nmemb, size))) die("calloc:");
	return p;
}

static int utf8decode(const char *s_in, long *u, int *err) {
	static const unsigned char lens[] = {
		/* 0XXXX */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
		/* 10XXX */ 0, 0, 0, 0, 0, 0, 0, 0,  /* invalid */
		/* 110XX */ 2, 2, 2, 2,
		/* 1110X */ 3, 3,
		/* 11110 */ 4,
		/* 11111 */ 0,  /* invalid */
	};
	static const unsigned char leading_mask[] = { 0x7F, 0x1F, 0x0F, 0x07 };
	static const unsigned int overlong[] = { 0x0, 0x80, 0x0800, 0x10000 };

	const unsigned char *s = (const unsigned char *)s_in;
	int len = lens[*s >> 3];
	*u = UTF_INVALID;
	*err = 1;
	if (len == 0) return 1;

	long cp = s[0] & leading_mask[len - 1];
	for (int i = 1; i < len; ++i) {
		if (s[i] == '\0' || (s[i] & 0xC0) != 0x80)
			return i;
		cp = (cp << 6) | (s[i] & 0x3F);
	}
	/* out of range, surrogate, overlong encoding */
	if (cp > 0x10FFFF || (cp >> 11) == 0x1B || cp < overlong[len - 1]) return len;

	*err = 0;
	*u = cp;
	return len;
}

Drw * drw_create(Display *dpy, int screen, Window root, unsigned int w, unsigned int h) {
	Drw *drw = ecalloc(1, sizeof(Drw));

	drw->dpy = dpy;
	drw->screen = screen;
	drw->root = root;
	drw->w = w;
	drw->h = h;
	drw->drawable = XCreatePixmap(dpy, root, w, h, DefaultDepth(dpy, screen));
	drw->gc = XCreateGC(dpy, root, 0, NULL);
	XSetLineAttributes(dpy, drw->gc, 1, LineSolid, CapButt, JoinMiter);

	return drw;
}

void drw_resize(Drw *drw, unsigned int w, unsigned int h) {
	if (!drw) return;

	drw->w = w;
	drw->h = h;
	if (drw->drawable)
		XFreePixmap(drw->dpy, drw->drawable);
	drw->drawable = XCreatePixmap(drw->dpy, drw->root, w, h, DefaultDepth(drw->dpy, drw->screen));
}

void drw_free(Drw *drw) {
	XFreePixmap(drw->dpy, drw->drawable);
	XFreeGC(drw->dpy, drw->gc);
	drw_fontset_free(drw->fonts);
	free(drw);
}

/* This function is an implementation detail. Library users should use
 * drw_fontset_create instead.
 */
static Fnt * xfont_create(Drw *drw, const char *fontname, FcPattern *fontpattern) {
	Fnt *font;
	XftFont *xfont = NULL;
	FcPattern *pattern = NULL;

	if (fontname) {
		/* Using the pattern found at font->xfont->pattern does not yield the
		 * same substitution results as using the pattern returned by
		 * FcNameParse; using the latter results in the desired fallback
		 * behaviour whereas the former just results in missing-character
		 * rectangles being drawn, at least with some fonts. */
		if (!(xfont = XftFontOpenName(drw->dpy, drw->screen, fontname))) {
			fprintf(stderr, "error, cannot load font from name: '%s'\n", fontname);
			return NULL;
		}
		if (!(pattern = FcNameParse((FcChar8 *) fontname))) {
			fprintf(stderr, "error, cannot parse font name to pattern: '%s'\n", fontname);
			XftFontClose(drw->dpy, xfont);
			return NULL;
		}
	} else if (fontpattern) {
		if (!(xfont = XftFontOpenPattern(drw->dpy, fontpattern))) {
			fprintf(stderr, "error, cannot load font from pattern.\n");
			return NULL;
		}
	} else {
		die("no font specified.");
	}

	font = ecalloc(1, sizeof(Fnt));
	font->xfont = xfont;
	font->pattern = pattern;
	font->h = xfont->ascent + xfont->descent;
	font->dpy = drw->dpy;

	return font;
}

static void xfont_free(Fnt *font) {
	if (!font) return;
	if (font->pattern) FcPatternDestroy(font->pattern);
	XftFontClose(font->dpy, font->xfont);
	free(font);
}

Fnt* drw_fontset_create(Drw* drw, const char *fonts[], size_t fontcount) {
	Fnt *cur, *ret = NULL;
	size_t i;

	if (!drw || !fonts) return NULL;

	for (i = 1; i <= fontcount; i++) {
		if ((cur = xfont_create(drw, fonts[fontcount - i], NULL))) {
			cur->next = ret;
			ret = cur;
		}
	}
	return (drw->fonts = ret);
}

void drw_fontset_free(Fnt *font) {
	if (font) {
		drw_fontset_free(font->next);
		xfont_free(font);
	}
}

void drw_clr_create(Drw *drw, Clr *dest, const char *clrname) {
	if (!drw || !dest || !clrname) return;

	if (!XftColorAllocName(drw->dpy, DefaultVisual(drw->dpy, drw->screen),
	                       DefaultColormap(drw->dpy, drw->screen),
	                       clrname, dest))
		die("error, cannot allocate color '%s'", clrname);
}

Clr * drw_scm_create(Drw *drw, const char *clrnames[], size_t clrcount) {
	size_t i;
	Clr *ret;

	if (!drw || !clrnames || clrcount < 2 || !(ret = ecalloc(clrcount, sizeof(XftColor)))) return NULL;
	for (i = 0; i < clrcount; i++) drw_clr_create(drw, &ret[i], clrnames[i]);
	return ret;
}

void drw_setfontset(Drw *drw, Fnt *set) {
	if (drw) drw->fonts = set;
}

void drw_setscheme(Drw *drw, Clr *scm) {
	if (drw) drw->scheme = scm;
}

void drw_rect(Drw *drw, int x, int y, unsigned int w, unsigned int h, int filled, int invert) {
	if (!drw || !drw->scheme) return;
	XSetForeground(drw->dpy, drw->gc, invert ? drw->scheme[ColBg].pixel : drw->scheme[ColFg].pixel);
	if (filled) XFillRectangle(drw->dpy, drw->drawable, drw->gc, x, y, w, h);
	else XDrawRectangle(drw->dpy, drw->drawable, drw->gc, x, y, w - 1, h - 1);
}

int drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lpad, const char *text, int invert) {
	int ty, ellipsis_x = 0;
	unsigned int tmpw, ew, ellipsis_w = 0, ellipsis_len, hash, h0, h1;
	XftDraw *d = NULL;
	Fnt *usedfont, *curfont, *nextfont;
	int utf8strlen, utf8charlen, utf8err, render = x || y || w || h;
	long utf8codepoint = 0;
	const char *utf8str;
	FcCharSet *fccharset;
	FcPattern *fcpattern;
	FcPattern *match;
	XftResult result;
	int charexists = 0, overflow = 0;
	/* keep track of a couple codepoints for which we have no match. */
	static unsigned int nomatches[128], ellipsis_width, invalid_width;
	static const char invalid[] = "�";

	if (!drw || (render && (!drw->scheme || !w)) || !text || !drw->fonts) return 0;
	if (!render) {
		w = invert ? invert : ~invert;
	} else {
		XSetForeground(drw->dpy, drw->gc, drw->scheme[invert ? ColFg : ColBg].pixel);
		XFillRectangle(drw->dpy, drw->drawable, drw->gc, x, y, w, h);
		if (w < lpad) return x + w;
		d = XftDrawCreate(drw->dpy, drw->drawable,
		                  DefaultVisual(drw->dpy, drw->screen),
		                  DefaultColormap(drw->dpy, drw->screen));
		x += lpad;
		w -= lpad;
	}

	usedfont = drw->fonts;
	if (!ellipsis_width && render) ellipsis_width = drw_fontset_getwidth(drw, "...");
	if (!invalid_width && render) invalid_width = drw_fontset_getwidth(drw, invalid);
	while (1) {
		ew = ellipsis_len = utf8err = utf8charlen = utf8strlen = 0;
		utf8str = text;
		nextfont = NULL;
		while (*text) {
			utf8charlen = utf8decode(text, &utf8codepoint, &utf8err);
			for (curfont = drw->fonts; curfont; curfont = curfont->next) {
				charexists = charexists || XftCharExists(drw->dpy, curfont->xfont, utf8codepoint);
				if (charexists) {
					drw_font_getexts(curfont, text, utf8charlen, &tmpw, NULL);
					if (ew + ellipsis_width <= w) {
						/* keep track where the ellipsis still fits */
						ellipsis_x = x + ew;
						ellipsis_w = w - ew;
						ellipsis_len = utf8strlen;
					}

					if (ew + tmpw > w) {
						overflow = 1;
						/* called from drw_fontset_getwidth_clamp():
						 * it wants the width AFTER the overflow
						 */
						if (!render) x += tmpw;
						else utf8strlen = ellipsis_len;
					} else if (curfont == usedfont) {
						text += utf8charlen;
						utf8strlen += utf8err ? 0 : utf8charlen;
						ew += utf8err ? 0 : tmpw;
					} else {
						nextfont = curfont;
					}
					break;
				}
			}

			if (overflow || !charexists || nextfont || utf8err) break;
			else charexists = 0;
		}

		if (utf8strlen) {
			if (render) {
				ty = y + (h - usedfont->h) / 2 + usedfont->xfont->ascent;
				XftDrawStringUtf8(d, &drw->scheme[invert ? ColBg : ColFg],
				                  usedfont->xfont, x, ty, (XftChar8 *)utf8str, utf8strlen);
			}
			x += ew;
			w -= ew;
		}
		if (utf8err && (!render || invalid_width < w)) {
			if (render) drw_text(drw, x, y, w, h, 0, invalid, invert);
			x += invalid_width;
			w -= invalid_width;
		}
		if (render && overflow) drw_text(drw, ellipsis_x, y, ellipsis_w, h, 0, "...", invert);

		if (!*text || overflow) {
			break;
		} else if (nextfont) {
			charexists = 0;
			usedfont = nextfont;
		} else {
			/* Regardless of whether or not a fallback font is found, the
			 * character must be drawn. */
			charexists = 1;

			hash = (unsigned int)utf8codepoint;
			hash = ((hash >> 16) ^ hash) * 0x21F0AAAD;
			hash = ((hash >> 15) ^ hash) * 0xD35A2D97;
			h0 = ((hash >> 15) ^ hash) % LENGTH(nomatches);
			h1 = (hash >> 17) % LENGTH(nomatches);
			/* avoid expensive XftFontMatch call when we know we won't find a match */
			if (nomatches[h0] == utf8codepoint || nomatches[h1] == utf8codepoint)
				goto no_match;

			fccharset = FcCharSetCreate();
			FcCharSetAddChar(fccharset, utf8codepoint);

			if (!drw->fonts->pattern) {
				/* Refer to the comment in xfont_create for more information. */
				die("the first font in the cache must be loaded from a font string.");
			}

			fcpattern = FcPatternDuplicate(drw->fonts->pattern);
			FcPatternAddCharSet(fcpattern, FC_CHARSET, fccharset);
			FcPatternAddBool(fcpattern, FC_SCALABLE, FcTrue);

			FcConfigSubstitute(NULL, fcpattern, FcMatchPattern);
			FcDefaultSubstitute(fcpattern);
			match = XftFontMatch(drw->dpy, drw->screen, fcpattern, &result);

			FcCharSetDestroy(fccharset);
			FcPatternDestroy(fcpattern);

			if (match) {
				usedfont = xfont_create(drw, NULL, match);
				if (usedfont && XftCharExists(drw->dpy, usedfont->xfont, utf8codepoint)) {
					for (curfont = drw->fonts; curfont->next; curfont = curfont->next)
						; /* NOP */
					curfont->next = usedfont;
				} else {
					xfont_free(usedfont);
					nomatches[nomatches[h0] ? h1 : h0] = utf8codepoint;
no_match:
					usedfont = drw->fonts;
				}
			}
		}
	}
	if (d) XftDrawDestroy(d);
	return x + (render ? w : 0);
}

void drw_map(Drw *drw, Window win, int x, int y, unsigned int w, unsigned int h) {
	if (!drw) return;
	XCopyArea(drw->dpy, drw->drawable, win, drw->gc, x, y, w, h, x, y);
	XSync(drw->dpy, False);
}

unsigned int drw_fontset_getwidth(Drw *drw, const char *text) {
	if (!drw || !drw->fonts || !text) return 0;
	return drw_text(drw, 0, 0, 0, 0, 0, text, 0);
}

unsigned int drw_fontset_getwidth_clamp(Drw *drw, const char *text, unsigned int n) {
	unsigned int tmp = 0;
	if (drw && drw->fonts && text && n) tmp = drw_text(drw, 0, 0, 0, 0, 0, text, n);
	return MIN(n, tmp);
}

void drw_font_getexts(Fnt *font, const char *text, unsigned int len, unsigned int *w, unsigned int *h) {
	XGlyphInfo ext;

	if (!font || !text) return;

	XftTextExtentsUtf8(font->dpy, font->xfont, (XftChar8 *)text, len, &ext);
	if (w) *w = ext.xOff;
	if (h) *h = font->h;
}

Cur * drw_cur_create(Drw *drw, int shape) {
	Cur *cur;
	if (!drw || !(cur = ecalloc(1, sizeof(Cur)))) return NULL;
	cur->cursor = XCreateFontCursor(drw->dpy, shape);

	return cur;
}

void drw_cur_free(Drw *drw, Cur *cursor) {
	if (!cursor) return;

	XFreeCursor(drw->dpy, cursor->cursor);
	free(cursor);
}

static unsigned int textw_clamp(const char *str, unsigned int n) {
	unsigned int w = drw_fontset_getwidth_clamp(drw, str, n) + lrpad;
	return MIN(w, n);
}

static void appenditem(struct item *item, struct item **list, struct item **last) {
	if (*last) (*last)->right = item;
	else *list = item;

	item->left = *last;
	item->right = NULL;
	*last = item;
}

static void calcoffsets(void) {
	int i, n;

	n = mw - (inputw + TEXTW("<") + TEXTW(">"));
	/* calculate which items will begin the next page and previous page */
	for (i = 0, next = curr; next; next = next->right)
		if ((i += textw_clamp(next->text, n)) > n) break;
	for (i = 0, prev = curr; prev && prev->left; prev = prev->left)
		if ((i += textw_clamp(prev->left->text, n)) > n) break;
}

static void cleanup(void) {
	size_t i;

	XUngrabKey(dpy, AnyKey, AnyModifier, root);
	for (i = 0; i < SchemeLast; i++) free(scheme[i]);
	for (i = 0; items && items[i].text; ++i) free(items[i].text);
	free(items);
	drw_free(drw);
	XSync(dpy, False);
	XCloseDisplay(dpy);
}

static int drawitem(struct item *item, int x, int y, int w) {
	if (item == sel) drw_setscheme(drw, scheme[SchemeSel]);
	else if (item->out) drw_setscheme(drw, scheme[SchemeOut]);
	else drw_setscheme(drw, scheme[SchemeNorm]);
	return drw_text(drw, x, y, w, bh, lrpad / 2, item->text, 0);
}

static void drawmenu(void) {
	unsigned int curpos;
	struct item *item;
	int x = 0;
	unsigned int w;

	drw_setscheme(drw, scheme[SchemeNorm]);
	drw_rect(drw, 0, 0, mw, bh, 1, 1);

	/* draw input field */
	w = (!matches) ? mw - x : inputw;
	drw_setscheme(drw, scheme[SchemeNorm]);
	drw_text(drw, x, 0, w, bh, lrpad / 2, text, 0);

	curpos = TEXTW(text) - TEXTW(&text[cursor]);
	if ((curpos += lrpad / 2 - 1) < w) {
		drw_setscheme(drw, scheme[SchemeNorm]);
		drw_rect(drw, x + curpos, 2, 2, bh - 4, 1, 0);
	}


	if (matches) {
		/* draw horizontal list */
		x += inputw;
		w = TEXTW("<");
		if (curr->left) {
			drw_setscheme(drw, scheme[SchemeNorm]);
			drw_text(drw, x, 0, w, bh, lrpad / 2, "<", 0);
		}
		x += w;
		for (item = curr; item != next; item = item->right)
			x = drawitem(item, x, 0, textw_clamp(item->text, mw - x - TEXTW(">")));
		if (next) {
			w = TEXTW(">");
			drw_setscheme(drw, scheme[SchemeNorm]);
			drw_text(drw, mw - w, 0, w, bh, lrpad / 2, ">", 0);
		}
	}
	drw_map(drw, win, 0, 0, mw, bh);
}

static void grabfocus(void) {
	struct timespec ts = { .tv_sec = 0, .tv_nsec = 10000000  };
	Window focuswin;
	int i, revertwin;

	for (i = 0; i < 100; ++i) {
		XGetInputFocus(dpy, &focuswin, &revertwin);
		if (focuswin == win) return;
		XSetInputFocus(dpy, win, RevertToParent, CurrentTime);
		nanosleep(&ts, NULL);
	}
	die("cannot grab focus");
}

static void grabkeyboard(void) {
	struct timespec ts = { .tv_sec = 0, .tv_nsec = 1000000  };
	int i;

	/* try to grab keyboard, we may have to wait for another process to ungrab */
	for (i = 0; i < 1000; i++) {
		if (XGrabKeyboard(dpy, DefaultRootWindow(dpy), True, GrabModeAsync,
		                  GrabModeAsync, CurrentTime) == GrabSuccess)
			return;
		nanosleep(&ts, NULL);
	}
	die("cannot grab keyboard");
}

static void match(void) {
	static char **tokv = NULL;
	static int tokn = 0;

	char buf[sizeof text], *s;
	int i, tokc = 0;
	size_t len, textsize;
	struct item *item, *lprefix, *lsubstr, *prefixend, *substrend;

	strcpy(buf, text);
	/* separate input text into tokens to be matched individually */
	for (s = strtok(buf, " "); s; tokv[tokc - 1] = s, s = strtok(NULL, " "))
		if (++tokc > tokn && !(tokv = realloc(tokv, ++tokn * sizeof *tokv)))
			die("cannot realloc %zu bytes:", tokn * sizeof *tokv);
	len = tokc ? strlen(tokv[0]) : 0;

	matches = lprefix = lsubstr = matchend = prefixend = substrend = NULL;
	textsize = strlen(text) + 1;
	for (item = items; item && item->text; item++) {
		for (i = 0; i < tokc; i++)
			if (!fstrstr(item->text, tokv[i]))
				break;
		if (i != tokc) /* not all tokens match */
			continue;
		/* exact matches go first, then prefixes, then substrings */
		if (!tokc || !fstrncmp(text, item->text, textsize)) appenditem(item, &matches, &matchend);
		else if (!fstrncmp(tokv[0], item->text, len)) appenditem(item, &lprefix, &prefixend);
		else appenditem(item, &lsubstr, &substrend);
	}
	if (lprefix) {
		if (matches) {
			matchend->right = lprefix;
			lprefix->left = matchend;
		} else matches = lprefix;
		matchend = prefixend;
	}
	if (lsubstr) {
		if (matches) {
			matchend->right = lsubstr;
			lsubstr->left = matchend;
		} else matches = lsubstr;
		matchend = substrend;
	}
	curr = sel = matches;
	calcoffsets();
}

static void insert(const char *str, ssize_t n) {
	if (strlen(text) + n > sizeof text - 1) return;
	/* move existing text out of the way, insert new text, and update cursor */
	memmove(&text[cursor + n], &text[cursor], sizeof text - cursor - MAX(n, 0));
	if (n > 0) memcpy(&text[cursor], str, n);
	cursor += n;
	match();
}

static void keypress(XKeyEvent *ev) {
	char buf[64];
	int len;
	KeySym ksym = NoSymbol;
	Status status;

	len = XmbLookupString(xic, ev, buf, sizeof buf, &ksym, &status);
	switch (status) {
		default: return; /* XLookupNone, XBufferOverflow */
		case XLookupChars: goto insert; /* composed string from input method */
		case XLookupKeySym:
		case XLookupBoth: break; /* a KeySym and a string are returned: use keysym */
	}

	switch(ksym) {
		default:
		insert:
			insert(buf, len);
			break;
		case XK_Escape:
			cleanup();
			exit(1);
		case XK_Left:
			if (sel && sel->left && (sel = sel->left)->right == curr) {
				curr = prev;
				calcoffsets();
			}
			break;
		case XK_Right:
			if (sel && sel->right && (sel = sel->right) == next) {
				curr = next;
				calcoffsets();
			}
			break;
		case XK_Return:
			puts(sel ? sel->text : text);
			cleanup();
			exit(0);
			break;
		case XK_BackSpace:
			if (cursor == 0) return;
			insert(NULL, -1);
			break;
	}
	drawmenu();
}


static void readstdin(void) {
	char *line = NULL;
	size_t i, itemsiz = 0, linesiz = 0;
	ssize_t len;

	/* read each line from stdin and add it to the item list */
	for (i = 0; (len = getline(&line, &linesiz, stdin)) != -1; i++) {
		if (i + 1 >= itemsiz) {
			itemsiz += 256;
			if (!(items = realloc(items, itemsiz * sizeof(*items))))
				die("cannot realloc %zu bytes:", itemsiz * sizeof(*items));
		}
		if (line[len - 1] == '\n') line[len - 1] = '\0';
		if (!(items[i].text = strdup(line))) die("strdup:");
		items[i].out = 0;
	}
	free(line);
	if (items) items[i].text = NULL;
}

static void run(void) {
	XEvent ev;

	while (!XNextEvent(dpy, &ev)) {
		if (XFilterEvent(&ev, win)) continue;
		switch(ev.type) {
		case DestroyNotify:
			if (ev.xdestroywindow.window != win) break;
			cleanup();
			exit(1);
		case Expose:
			if (ev.xexpose.count == 0) drw_map(drw, win, 0, 0, mw, bh);
			break;
		case FocusIn:
			/* regrab focus from parent window */
			if (ev.xfocus.window != win) grabfocus();
			break;
		case KeyPress:
			keypress(&ev.xkey);
			break;
		case VisibilityNotify:
			if (ev.xvisibility.state != VisibilityUnobscured) XRaiseWindow(dpy, win);
			break;
		}
	}
}

static void setup(void) {
	int x = 0, y = 0;
	XSetWindowAttributes swa;
	XIM xim;
	XWindowAttributes wa;
	XClassHint ch = {"dmenu", "dmenu"};
	/* init appearance */
	for (int j = 0; j < SchemeLast; j++) scheme[j] = drw_scm_create(drw, colors[j], 2);

	clip = XInternAtom(dpy, "CLIPBOARD",   False);
	utf8 = XInternAtom(dpy, "UTF8_STRING", False);

	/* calculate menu geometry */
	bh = drw->fonts->h + 2;
	{
		if (!XGetWindowAttributes(dpy, root, &wa))
			die("could not get embedding window attributes: 0x%lx", root);
		mw = wa.width;
	}
	inputw = mw / 5; /* input width: ~20% of monitor width */
	match();

	/* create menu window */
	swa.override_redirect = True;
	swa.background_pixel = scheme[SchemeNorm][ColBg].pixel;
	swa.event_mask = ExposureMask | KeyPressMask | VisibilityChangeMask;
	win = XCreateWindow(dpy, root, x, y, mw, bh, 0,
	                    CopyFromParent, CopyFromParent, CopyFromParent,
	                    CWOverrideRedirect | CWBackPixel | CWEventMask, &swa);
	XSetClassHint(dpy, win, &ch);

	/* input methods */
	if ((xim = XOpenIM(dpy, NULL, NULL, NULL)) == NULL) die("XOpenIM failed: could not open input device");

	xic = XCreateIC(xim, XNInputStyle, XIMPreeditNothing | XIMStatusNothing, XNClientWindow, win, XNFocusWindow, win, NULL);

	XMapRaised(dpy, win);
	drw_resize(drw, mw, bh);
	drawmenu();
}

int main(int argc, char *argv[]) {
	XWindowAttributes wa;

	if (!setlocale(LC_CTYPE, "") || !XSupportsLocale()) fputs("warning: no locale support\n", stderr);
	if (!(dpy = XOpenDisplay(NULL))) die("cannot open display");
	screen = DefaultScreen(dpy);
	root = RootWindow(dpy, screen);
	if (!XGetWindowAttributes(dpy, root, &wa)) die("could not get embedding window attributes: 0x%lx", root);
	drw = drw_create(dpy, screen, root, wa.width, wa.height);
	if (!drw_fontset_create(drw, fonts, LENGTH(fonts))) die("no fonts could be loaded.");
	lrpad = drw->fonts->h;

	readstdin();
	grabkeyboard();
	setup();
	run();

	return 1; /* unreachable */
}