/* See LICENSE file for copyright and license details. */
#include <ctype.h>
#include <libconfig.h>
#include <locale.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <pwd.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"

#include "pinentry/pinentry.h"
#include "pinentry/memory.h"

#define CONFIG "/.gnupg/pinentry-dmenu.conf"
#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)
#define MINDESCLEN 8


enum { SchemePrompt, SchemeNormal, SchemeSelect, SchemeDesc, SchemeLast };
enum { WinPin, WinConfirm };
enum { Ok, NotOk, Cancel };
enum { Nothing, Yes, No };

static int bh, mw, mh;
static int sel;
static int promptw, ppromptw, pdescw;
/* Sum of left and right padding */
static int lrpad;
static size_t cursor;
static int mon = -1, screen;

static char* pin;

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

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

static int timed_out;
static int winmode;
pinentry_t pinentry;

#include "config.h"

static int
drawitem(const char* text, Bool sel, int x, int y, int w) {
	unsigned int i = (sel) ? SchemeSelect : SchemeNormal;

	drw_setscheme(drw, scheme[i]);

	return drw_text(drw, x, y, w, bh, lrpad / 2, text, 0);
}

static void
grabfocus(void) {
	Window focuswin;
	int i, revertwin;

	for (i = 0; i < 100; ++i) {
		XGetInputFocus(dpy, &focuswin, &revertwin);
		if (focuswin == win) {
			return;
		}
		XSetInputFocus(dpy, win, RevertToParent, CurrentTime);
		usleep(1000);
	}

	die("cannot grab focus");
}

static void
grabkeyboard(void) {
	int i;

	if (embedded) {
		return;
	}

	/* 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;
		}
		usleep(1000);
	}

	die("cannot grab keyboard");
}

static size_t
nextrune(int cursor, int inc) {
	ssize_t n;

	/* Return location of next utf8 rune in the given direction (+1 or -1) */
	for (n = cursor + inc;
	     n + inc >= 0 && (pin[n] & 0xc0) == 0x80;
	     n += inc);
	
	return n;
}

static void
insert(const char *str, ssize_t n) {
	int repeat;

	if (strlen(pin) + n > pinentry->pin_len - 1) {
		repeat = (pin == pinentry->pin) ? 0 : 1;

		if (!pinentry_setbufferlen(pinentry, 2 * pinentry->pin_len)) {
			printf("Error: Couldn't allocate secure memory\n");
			return;
		}

		pin = (repeat) ? pinentry->pin : pinentry->repeat_passphrase;
	}

	if (n > 0) {
		memcpy(&pin[cursor], str, n);
	}

	cursor += n;
	pin[cursor] = '\0';
}

static void
drawwin(void) {
	unsigned int curpos;
	int x = 0, pb, pbw = 0, i;
	size_t asterlen = strlen(asterisk);
	size_t pdesclen;
	int leftinput;
	char* censort = ecalloc(1, asterlen * pinentry->pin_len);
	
	unsigned int censortl = minpwlen * TEXTW(asterisk) / strlen(asterisk);
	unsigned int confirml = TEXTW(" YesNo ") + 3 * lrpad;

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

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

	if (pinentry->prompt) {
		drw_setscheme(drw, scheme[SchemePrompt]);
		drw_text(drw, x, 0, ppromptw, bh, lrpad / 2, pinentry->prompt, 0);
		x += ppromptw;
	}

	if (pinentry->description) {
		pb = mw - x;
		pdesclen = strlen(pinentry->description);
		
		if (pb > 0) {
			pb -= (winmode == WinPin) ? censortl : confirml;
			pbw = MINDESCLEN * pdescw / pdesclen;
			pbw = MIN(pbw, pdescw);

			if (pb >= pbw) {
				pbw = MAX(pbw, pdescw);
				pbw = MIN(pbw, pb);
				pb = mw - pbw;

				for (i = 0; i < pdesclen; i++) {
					if (pinentry->description[i] == '\n') {
						pinentry->description[i] = ' ';
					}
				}

				drw_setscheme(drw, scheme[SchemeDesc]);
				drw_text(drw, pb, 0, pbw, bh, lrpad / 2, pinentry->description,
				         0);
			} else {
				pbw = 0;
			}
		}
	}

	/* Draw input field */
	drw_setscheme(drw, scheme[SchemeNormal]);

	if (winmode == WinPin) {
		for (i = 0; i < asterlen * strlen(pin); i += asterlen) {
			memcpy(&censort[i], asterisk, asterlen);
		}

		censort[i+1] = '\n';
		leftinput = mw - x - pbw;
		drw_text(drw, x, 0, leftinput, bh, lrpad / 2, censort, 0);
		drw_font_getexts(drw->fonts, censort, cursor * asterlen, &curpos, NULL);

		if ((curpos += lrpad / 2 - 1) < leftinput) {
			drw_setscheme(drw, scheme[SchemeNormal]);
			drw_rect(drw, x + curpos, 2, 2, bh - 4, 1, 0);
		}
	} else {
		x += TEXTW(" ");
		x = drawitem("No", (sel == No), x, 0, TEXTW("No"));
		x = drawitem("Yes", (sel == Yes), x, 0, TEXTW("Yes"));
	}

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

static void
setup_pin(char* pinlink) {
	pin = pinlink;
	pin[0] = '\0';
	cursor = 0;
}

static void
setup(void) {
	int x, y, i = 0;
	unsigned int du;
	XSetWindowAttributes swa;
	XIM xim;
	Window w, dw, *dws;
	XWindowAttributes wa;
#ifdef XINERAMA
	XineramaScreenInfo *info;
	Window pw;
	int a, j, di, n, area = 0;
#endif

	/* Init appearance */
	scheme[SchemePrompt] = drw_scm_create(drw, colors[SchemePrompt], 2);
	scheme[SchemeNormal] = drw_scm_create(drw, colors[SchemeNormal], 2);
	scheme[SchemeSelect] = drw_scm_create(drw, colors[SchemeSelect], 2);
	scheme[SchemeDesc]   = drw_scm_create(drw, colors[SchemeDesc],   2);

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

	/* Calculate menu geometry */
	bh = drw->fonts->h + 2;
	mh = bh;
#ifdef XINERAMA
	info = XineramaQueryScreens(dpy, &n);

	if (parentwin == root && info) {
		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++) {
					a = INTERSECT(wa.x, wa.y, wa.width, wa.height, info[j]);
					if (a > 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) ? TEXTW(prompt) - lrpad / 4 : 0;
	ppromptw = (pinentry->prompt) ? TEXTW(pinentry->prompt) : 0;
	pdescw = (pinentry->description) ? TEXTW(pinentry->description) : 0;

	/* Create menu window */
	swa.override_redirect = True;
	swa.background_pixel = scheme[SchemePrompt][ColBg].pixel;
	swa.event_mask = ExposureMask | KeyPressMask | VisibilityChangeMask;
	win = XCreateWindow(dpy, parentwin, x, y, mw, mh, 0,
	                    CopyFromParent, CopyFromParent, CopyFromParent,
	                    CWOverrideRedirect | CWBackPixel | CWEventMask, &swa);

	/* Open input methods */
	xim = XOpenIM(dpy, NULL, NULL, NULL);
	xic = XCreateIC(xim, XNInputStyle, XIMPreeditNothing | XIMStatusNothing,
	                XNClientWindow, win, XNFocusWindow, win, NULL);
	XMapRaised(dpy, win);

	if (embedded) {
		XSelectInput(dpy, parentwin, FocusChangeMask);

		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);
		}
		grabfocus();
	}

	drw_resize(drw, mw, mh);
}

static void
cleanup(void) {
	XUngrabKey(dpy, AnyKey, AnyModifier, root);
	free(scheme[SchemeDesc]);
	free(scheme[SchemeSelect]);
	free(scheme[SchemeNormal]);
	free(scheme[SchemePrompt]);
	drw_free(drw);
	XSync(dpy, False);
	XCloseDisplay(dpy);
}

static int
keypress(XKeyEvent *ev) {
	char buf[32];
	int len;

	KeySym ksym = NoSymbol;
	Status status;
	len = XmbLookupString(xic, ev, buf, sizeof buf, &ksym, &status);
	
	if (status == XBufferOverflow) {
		return 0;
	}

	if (winmode == WinConfirm) {
		switch(ksym) {
		case XK_KP_Enter:
		case XK_Return:
			if (sel != Nothing) {
				return 1;
			}
			break;
		case XK_y:
		case XK_Y:
			sel = Yes;
			return 1;
		case XK_n:
		case XK_N:
			sel = No;
			return 1;
		case XK_c:
			if (ev->state == ControlMask) {
				pinentry->canceled = 1;
				sel = No;
				return 1;
			}
		case XK_Escape:
			pinentry->canceled = 1;
			sel = No;
			return 1;
		case XK_Left:
			sel = No;
			break;
		case XK_Right:
			sel = Yes;
			break;
		}
	} else {
		switch(ksym) {
		case XK_Delete:
			if (pin[cursor] == '\0') {
				return 0;
			}
			cursor = nextrune(cursor, +1);
			/* Fallthrough */
		case XK_BackSpace:
			if (cursor == 0) {
				return 0;
			}
			insert(NULL, nextrune(cursor, -1) - cursor);
			break;
		case XK_c:
			if (ev->state == ControlMask) {
				pinentry->canceled = 1;
				return 1;
			}
		case XK_Escape:
			pinentry->canceled = 1;
			return 1;
			//Cleanup();
			//exit(1);
			break;
		case XK_Left:
			if (cursor > 0) {
				cursor = nextrune(cursor, -1);
			}
			break;
		case XK_Right:
			if (pin[cursor] != '\0') {
				cursor = nextrune(cursor, +1);
			}
			break;
		case XK_Return:
		case XK_KP_Enter:
			return 1;
			break;
		default:
			if (!iscntrl(*buf)) {
				insert(buf, len);
			}
		}
	}

	drawwin();

	return 0;
}

static void
paste(void) {
	char *p, *q;
	int di;
	unsigned long dl;
	Atom da;

	/* We have been given the current selection, now insert it into input */
	XGetWindowProperty(dpy, win, utf8, 0, (sizeof pin / 4) + 1, False,
	                   utf8, &da, &di, &dl, &dl, (unsigned char **)&p);
	insert(p, (q = strchr(p, '\n')) ? q - p : (ssize_t) strlen(p));
	XFree(p);
	drawwin();
}

void
run(void) {
	XEvent ev;

	drawwin();

	while (!XNextEvent(dpy, &ev)) {
		if (XFilterEvent(&ev, win)) {
			/* What is this I don't even */
			continue;
		}
		switch(ev.type) {
		case Expose:
			if (ev.xexpose.count == 0) {
				drw_map(drw, win, 0, 0, mw, mh);
			}
			break;
		case KeyPress:
			if (keypress(&ev.xkey)) {
				return;
			}
			break;
		case SelectionNotify:
			if (ev.xselection.property == utf8) {
				paste();
			}
			break;
		case VisibilityNotify:
			if (ev.xvisibility.state != VisibilityUnobscured) {
				XRaiseWindow(dpy, win);
			}
			break;
		}
	}
}

static void
catchsig(int sig) {
	if (sig == SIGALRM) {
		timed_out = 1;
	}
}

static int
password(void) {
	winmode = WinPin;

	setup_pin(pinentry->pin);
	run();

	if (pinentry->repeat_passphrase) {
		setup_pin(pinentry->repeat_passphrase);
		// TODO: Add repeat text
		run();

		if (strcmp(pinentry->pin, pinentry->repeat_passphrase)) {
			pinentry->repeat_okay = 0;
			return 0;
		}

		pinentry->repeat_okay = 1;
	}

	return (pinentry->canceled) ? -1 : 1;
}

static int
confirm(void) {
	winmode = WinConfirm;
	sel = Nothing;

	run();
	
	return sel != No;
}

static int
cmdhandler(pinentry_t received_pinentry) {
	struct sigaction sa;
	XWindowAttributes wa;
	int ret;
	
	pinentry = received_pinentry;

	if (!setlocale(LC_CTYPE, "") || !XSupportsLocale()) {
		fputs("warning: no locale support\n", stderr);
	}
	if (!(dpy = XOpenDisplay(pinentry->display))) {
		die("cannot open display");
	}
	screen = DefaultScreen(dpy);
	root = RootWindow(dpy, screen);
	embedded = (pinentry->parent_wid) ? embedded : 0;
	parentwin = (embedded) ? pinentry->parent_wid : 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;
	drw_setscheme(drw, scheme[SchemePrompt]);

	if (pinentry->timeout) {
		memset(&sa, 0, sizeof(sa));
		sa.sa_handler = catchsig;
		sigaction(SIGALRM, &sa, NULL);
		alarm(pinentry->timeout);
	}

	grabkeyboard();
	setup();

	if (pinentry->pin) {
		ret = password();
	} else {
		ret = confirm();
	}

	cleanup();

	return ret;
}

pinentry_cmd_handler_t pinentry_cmd_handler = cmdhandler;

int
main(int argc, char *argv[]) {
	Bool bval;
	int i, val;
	const char *str;
	struct passwd *pw;
	char path[PATH_MAX];
	char *sudo_uid = getenv("SUDO_UID");
	char *home = getenv("HOME");
	config_t cfg;

	// This is a little workaround to get the home dir even if the user used
	// sudo or logged in as root
	if (sudo_uid) {
		i = atoi(sudo_uid);
		pw = getpwuid(i);
		home = pw->pw_dir;
	}

	config_init(&cfg);
	i = strlen(home);
	strcpy(path, home);
	strcpy(&path[i], CONFIG);
	endpwent();

	/* Read the file. If there is an error, report it and exit. */
	if (config_read_file(&cfg, path)) {
		if (config_lookup_string(&cfg, "asterisk", &str)) {
			asterisk = str;
		}
		if (config_lookup_bool(&cfg, "buttom", &bval)) {
			topbar = !bval;
		}
		if (config_lookup_int(&cfg, "min_password_length", &val)) {
			minpwlen = val;
		}
		if (config_lookup_int(&cfg, "monitor", &val)) {
			mon = val;
		}
		if (config_lookup_string(&cfg, "prompt", &str)) {
			prompt = str;
		}
		if (config_lookup_string(&cfg, "font", &str)) {
			fonts[0] = str;
		}
		if (config_lookup_string(&cfg, "prompt_bg", &str)) {
			colors[SchemePrompt][ColBg] = str;
		}
		if (config_lookup_string(&cfg, "prompt_fg", &str)) {
			colors[SchemePrompt][ColFg] = str;
		}
		if (config_lookup_string(&cfg, "normal_bg", &str)) {
			colors[SchemeNormal][ColBg] = str;
		}
		if (config_lookup_string(&cfg, "normal_fg", &str)) {
			colors[SchemeNormal][ColFg] = str;
		}
		if (config_lookup_string(&cfg, "select_bg", &str)) {
			colors[SchemeSelect][ColBg] = str;
		}
		if (config_lookup_string(&cfg, "select_fg", &str)) {
			colors[SchemeSelect][ColFg] = str;
		}
		if (config_lookup_string(&cfg, "desc_bg", &str)) {
			colors[SchemeDesc][ColBg] = str;
		}
		if (config_lookup_string(&cfg, "desc_fg", &str)) {
			colors[SchemeDesc][ColFg] = str;
		}
		if (config_lookup_bool(&cfg, "embedded", &bval)) {
			embedded = bval;
		}
	} else if ((str = config_error_file(&cfg))) {
		fprintf(stderr, "%s:%d: %s\n", config_error_file(&cfg),
		        config_error_line(&cfg), config_error_text(&cfg));
		return(EXIT_FAILURE);
	} else {
		printf("No config file found. Use defaults.\n");
	}

	pinentry_init("pinentry-dmenu");
	pinentry_parse_opts(argc, argv);
	
	if (pinentry_loop()) {
		return 1;
	}

	config_destroy(&cfg);
	
	return 0;
}