/* See LICENSE file for copyright and license details. */
#include <ctype.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <time.h>
#include <unistd.h>

#include <X11/Xlib.h>
#include <X11/Xatom.h>
#include <X11/Xutil.h>
#ifdef XINERAMA
#include <X11/extensions/Xinerama.h>
#endif
#include <X11/Xft/Xft.h>

#include "drw.h"
#include "util.h"

/* macros */
#define INTERSECT(x,y,w,h,r)  (MAX(0, MIN((x)+(w),(r).x_org+(r).width)  - MAX((x),(r).x_org)) \
                             * MAX(0, MIN((y)+(h),(r).y_org+(r).height) - MAX((y),(r).y_org)))
#define LENGTH(X)             (sizeof X / sizeof X[0])
#define TEXTW(X)              (drw_fontset_getwidth(drw, (X)) + lrpad)

/* enums */
enum { SchemeNorm, SchemeSel, SchemeOut, SchemeLast }; /* color schemes */

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

static char text[BUFSIZ] = "";
static char *embed;
static int bh, mw, mh;
static int inputw = 0, promptw;
static int lrpad; /* sum of left and right padding */
static struct item *items = NULL;
static struct item *matches, *matchend;
static struct item *prev, *curr, *next, *sel;
static int mon = -1, screen;

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

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

#include "config.h"

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

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 - (promptw + 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 ? bh : MIN(TEXTW(next->text), n)) > n)
			break;
	for (i = 0, prev = curr; prev && prev->left; prev = prev->left)
		if ((i ? bh : MIN(TEXTW(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]);
	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)
{
	struct item *item;
	int x = 0, y = 0, w;

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

	if (prompt && *prompt) {
		drw_setscheme(drw, scheme[SchemeSel]);
		x = drw_text(drw, x, 0, promptw, bh, lrpad / 2, prompt, 0);
	}

	drw_map(drw, win, 0, 0, mw, mh);
}

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 %u 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
readstdin(void)
{
	char buf[sizeof text], *p;
	size_t i, imax = 0, size = 0;
	unsigned int tmpmax = 0;

	/* read each line from stdin and add it to the item list */
	for (i = 0; fgets(buf, sizeof buf, stdin); i++) {
		if (i + 1 >= size / sizeof *items)
			if (!(items = realloc(items, (size += BUFSIZ))))
				die("cannot realloc %u bytes:", size);
		if ((p = strchr(buf, '\n')))
			*p = '\0';
		if (!(items[i].text = strdup(buf)))
			die("cannot strdup %u bytes:", strlen(buf) + 1);
		items[i].out = 0;
		drw_font_getexts(drw->fonts, buf, strlen(buf), &tmpmax, NULL);
		if (tmpmax > inputw) {
			inputw = tmpmax;
			imax = i;
		}
	}
	if (items)
		items[i].text = NULL;
	inputw = items ? TEXTW(items[imax].text) : 0;
}

static void
setup(void)
{
	int x, y, i, j;
	unsigned int du;
	XSetWindowAttributes swa;
	XIM xim;
	Window w, dw, *dws;
	XWindowAttributes wa;
	XClassHint ch = {"dmenu", "dmenu"};
#ifdef XINERAMA
	XineramaScreenInfo *info;
	Window pw;
	int a, di, n, area = 0;
#endif
	/* init appearance */
	for (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;
	mh = bh;
#ifdef XINERAMA
	i = 0;
	if (parentwin == root && (info = XineramaQueryScreens(dpy, &n))) {
		XGetInputFocus(dpy, &w, &di);
		if (mon >= 0 && mon < n)
			i = mon;
		else if (w != root && w != PointerRoot && w != None) {
			/* find top-level window containing current input focus */
			do {
				if (XQueryTree(dpy, (pw = w), &dw, &w, &dws, &du) && dws)
					XFree(dws);
			} while (w != root && w != pw);
			/* find xinerama screen with which the window intersects most */
			if (XGetWindowAttributes(dpy, pw, &wa))
				for (j = 0; j < n; j++)
					if ((a = INTERSECT(wa.x, wa.y, wa.width, wa.height, info[j])) > area) {
						area = a;
						i = j;
					}
		}
		/* no focused window is on screen, so use pointer location instead */
		if (mon < 0 && !area && XQueryPointer(dpy, root, &dw, &dw, &x, &y, &di, &di, &du))
			for (i = 0; i < n; i++)
				if (INTERSECT(x, y, 1, 1, info[i]))
					break;

		x = info[i].x_org;
		y = info[i].y_org + (topbar ? 0 : info[i].height - mh);
		mw = info[i].width;
		XFree(info);
	} else
#endif
	{
		if (!XGetWindowAttributes(dpy, parentwin, &wa))
			die("could not get embedding window attributes: 0x%lx",
			    parentwin);
		x = 0;
		y = topbar ? 0 : wa.height - mh;
		mw = wa.width;
	}
	promptw = (prompt && *prompt) ? TEXTW(prompt) - lrpad / 4 : 0;
	inputw = MIN(inputw, mw/3);
	match();

	/* create menu window */
	swa.override_redirect = True;
	swa.background_pixel = scheme[SchemeNorm][ColBg].pixel;
	swa.event_mask = ExposureMask | KeyPressMask | VisibilityChangeMask;
	win = XCreateWindow(dpy, parentwin, x, y, mw, mh, 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);
	if (embed) {
		XSelectInput(dpy, parentwin, FocusChangeMask | SubstructureNotifyMask);
		if (XQueryTree(dpy, parentwin, &dw, &w, &dws, &du) && dws) {
			for (i = 0; i < du && dws[i] != win; ++i)
				XSelectInput(dpy, dws[i], FocusChangeMask);
			XFree(dws);
		}
	}
	drw_resize(drw, mw, mh);
	drawmenu();
}

static void
usage(void)
{
	fputs("usage: dmenu [-bfiv] [-p prompt] [-fn font] [-m monitor]\n"
	      "             [-nb color] [-nf color] [-sb color] [-sf color] [-w windowid]\n", stderr);
	exit(1);
}

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

	for (i = 1; i < argc; i++)
		/* these options take no arguments */
		if (!strcmp(argv[i], "-v")) {      /* prints version information */
			puts("dmenu-"VERSION);
			exit(0);
		} else if (!strcmp(argv[i], "-b")) /* appears at the bottom of the screen */
			topbar = 0;
		else if (i + 1 == argc)
			usage();
		/* these options take one argument */
		else if (!strcmp(argv[i], "-m"))
			mon = atoi(argv[++i]);
		else if (!strcmp(argv[i], "-p"))   /* adds prompt to left of input field */
			prompt = argv[++i];
		else if (!strcmp(argv[i], "-fn"))  /* font or font set */
			fonts[0] = argv[++i];
		else if (!strcmp(argv[i], "-nb"))  /* normal background color */
			colors[SchemeNorm][ColBg] = argv[++i];
		else if (!strcmp(argv[i], "-nf"))  /* normal foreground color */
			colors[SchemeNorm][ColFg] = argv[++i];
		else if (!strcmp(argv[i], "-sb"))  /* selected background color */
			colors[SchemeSel][ColBg] = argv[++i];
		else if (!strcmp(argv[i], "-sf"))  /* selected foreground color */
			colors[SchemeSel][ColFg] = argv[++i];
		else if (!strcmp(argv[i], "-w"))   /* embedding window id */
			embed = argv[++i];
		else
			usage();

	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 (!embed || !(parentwin = strtol(embed, NULL, 0)))
		parentwin = root;
	if (!XGetWindowAttributes(dpy, parentwin, &wa))
		die("could not get embedding window attributes: 0x%lx",
		    parentwin);
	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;

#ifdef __OpenBSD__
	if (pledge("stdio rpath", NULL) == -1)
		die("pledge");
#endif

	readstdin();

	setup();
	while(1); // bodge

	return 1; /* unreachable */
}