#define _GNU_SOURCE
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/keysym.h>
#include <errno.h>
#include <fcntl.h>
#include <locale.h>
#include <poll.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

#include "ipc.h"
#include "live.h"

enum
{
	Eventtimeout = 4000,
};

typedef struct Child Child;
typedef struct Run Run;
typedef struct Prelog Prelog;

struct Child
{
	pid_t pid;
	pid_t pgid;
	char log[320];
};

struct Run
{
	Live l;
	Child xvfb;
	Child daemon;
	char display[32];
};

struct Prelog
{
	int start;
	int nonempty;
	int empty;
	int done;
	int doneafterempty;
	int badorder;
};

static int xerror;

static int
childlog(char *path)
{
	int fd;

	fd = open(path, O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0600);
	return fd;
}

static int
spawnxvfb(Run *r, char *program)
{
	char fdstr[16], line[32];
	int displayfd[2], errfd, flags, n, status;
	int64_t deadline;
	pid_t pid;
	struct pollfd pfd;
	ssize_t nr;

	if(pipe2(displayfd, O_CLOEXEC) < 0)
		return fail("create Xvfb display pipe: %s", strerror(errno));
	errfd = childlog(r->xvfb.log);
	if(errfd < 0){
		close(displayfd[0]);
		close(displayfd[1]);
		return fail("open Xvfb log: %s", strerror(errno));
	}
	pid = fork();
	if(pid < 0){
		close(displayfd[0]);
		close(displayfd[1]);
		close(errfd);
		return fail("fork Xvfb: %s", strerror(errno));
	}
	if(pid == 0){
		setpgid(0, 0);
		close(displayfd[0]);
		flags = fcntl(displayfd[1], F_GETFD);
		if(flags < 0 || fcntl(displayfd[1], F_SETFD,
		   flags & ~FD_CLOEXEC) < 0)
			_exit(126);
		if(dup2(errfd, STDOUT_FILENO) < 0 ||
		   dup2(errfd, STDERR_FILENO) < 0)
			_exit(126);
		close(errfd);
		snprintf(fdstr, sizeof fdstr, "%d", displayfd[1]);
		execlp(program, program, "-displayfd", fdstr,
			"-screen", "0", "800x600x24", "-nolisten", "tcp",
			"-noreset", (char*)0);
		_exit(127);
	}
	close(displayfd[1]);
	close(errfd);
	if((setpgid(pid, pid) < 0 && errno != EACCES) || getpgid(pid) != pid){
		kill(pid, SIGKILL);
		while(waitpid(pid, &status, 0) < 0 && errno == EINTR)
			;
		close(displayfd[0]);
		return fail("isolate Xvfb process group: %s", strerror(errno));
	}
	r->xvfb.pid = pid;
	r->xvfb.pgid = pid;
	pfd.fd = displayfd[0];
	pfd.events = POLLIN|POLLHUP;
	deadline = nowms() + Starttimeout;
	n = 0;
	while(n + 1 < (int)sizeof line){
		pfd.revents = 0;
		status = poll(&pfd, 1, leftms(deadline));
		if(status < 0 && errno == EINTR)
			continue;
		if(status <= 0)
			break;
		nr = read(displayfd[0], line + n, sizeof line - n - 1);
		if(nr > 0){
			n += nr;
			line[n] = '\0';
			if(strchr(line, '\n') != NULL)
				break;
			continue;
		}
		if(nr < 0 && errno == EINTR)
			continue;
		break;
	}
	close(displayfd[0]);
	if(n == 0 || strchr(line, '\n') == NULL)
		return fail("Xvfb did not report a private display");
	line[strcspn(line, "\r\n")] = '\0';
	for(n = 0; line[n] != '\0'; n++)
		if(line[n] < '0' || line[n] > '9')
			return fail("invalid Xvfb display number %s", line);
	if(snprintf(r->display, sizeof r->display, ":%s", line)
	   >= (int)sizeof r->display)
		return fail("Xvfb display number is too long");
	return 1;
}

static int
spawndaemon(Run *r, char *program, char *mapdir)
{
	int errfd;
	pid_t pid;

	errfd = childlog(r->daemon.log);
	if(errfd < 0)
		return fail("open daemon log: %s", strerror(errno));
	pid = fork();
	if(pid < 0){
		close(errfd);
		return fail("fork daemon: %s", strerror(errno));
	}
	if(pid == 0){
		setpgid(0, 0);
		if(dup2(errfd, STDOUT_FILENO) < 0 ||
		   dup2(errfd, STDERR_FILENO) < 0)
			_exit(126);
		close(errfd);
		execl(program, program, mapdir, (char*)0);
		_exit(127);
	}
	close(errfd);
	if((setpgid(pid, pid) < 0 && errno != EACCES) || getpgid(pid) != pid){
		kill(pid, SIGKILL);
		while(waitpid(pid, NULL, 0) < 0 && errno == EINTR)
			;
		return fail("isolate daemon process group: %s", strerror(errno));
	}
	r->daemon.pid = pid;
	r->daemon.pgid = pid;
	return 1;
}

static int
waitsocket(Run *r)
{
	struct stat st;
	int status;
	int64_t deadline;

	deadline = nowms() + Starttimeout;
	while(leftms(deadline) > 0){
		if(lstat(r->l.socket, &st) == 0 && S_ISSOCK(st.st_mode) &&
		   (st.st_mode & 0777) == 0600)
			return 1;
		if(waitpid(r->daemon.pid, &status, WNOHANG) == r->daemon.pid){
			r->daemon.pid = -1;
			return fail("daemon exited before creating its IPC socket");
		}
		pausems(20);
	}
	return fail("timed out waiting for daemon IPC socket");
}

static int
start(Run *r, char *daemon, char *mapdir, char *xvfb)
{
	memset(r, 0, sizeof *r);
	r->xvfb.pid = r->daemon.pid = -1;
	r->xvfb.pgid = r->daemon.pgid = -1;
	if(!livesetup(&r->l, "xim"))
		return 0;
	if(snprintf(r->xvfb.log, sizeof r->xvfb.log, "%s/xvfb.log", r->l.root)
	   >= (int)sizeof r->xvfb.log ||
	   snprintf(r->daemon.log, sizeof r->daemon.log, "%s/daemon.log", r->l.root)
	   >= (int)sizeof r->daemon.log)
		return fail("temporary path is too long");
	if(!spawnxvfb(r, xvfb))
		return 0;
	if(setenv("DISPLAY", r->display, 1) < 0 ||
	   setenv("XMODIFIERS", "@im=strans", 1) < 0 ||
	   setenv("XDG_RUNTIME_DIR", r->l.runtime, 1) < 0 ||
	   setenv("XDG_CONFIG_HOME", r->l.config, 1) < 0 ||
	   setenv("HOME", r->l.home, 1) < 0 ||
	   unsetenv("DBUS_SESSION_BUS_ADDRESS") < 0 ||
	   unsetenv("IBUS_ADDRESS") < 0)
		return fail("set private environment: %s", strerror(errno));
	if(!spawndaemon(r, daemon, mapdir))
		return 0;
	return waitsocket(r);
}

static void
showlog(char *name)
{
	char buf[4096];
	ssize_t n;
	int fd;

	fd = open(name, O_RDONLY|O_CLOEXEC);
	if(fd < 0)
		return;
	while((n = read(fd, buf, sizeof buf)) > 0)
		fwrite(buf, 1, n, stderr);
	close(fd);
}

static void
stopchild(Child *c)
{
	int i, status;
	pid_t n;

	if(c->pgid > 0 && kill(-c->pgid, SIGTERM) < 0 && errno != ESRCH)
		fail("terminate process group %ld: %s", (long)c->pgid,
			strerror(errno));
	if(c->pid > 0)
		for(i = 0; i < Stoptimeout / 20; i++){
			n = waitpid(c->pid, &status, WNOHANG);
			if(n == c->pid || (n < 0 && errno == ECHILD)){
				c->pid = -1;
				break;
			}
			if(n < 0 && errno != EINTR)
				break;
			pausems(20);
		}
	if(c->pgid > 0)
		kill(-c->pgid, SIGKILL);
	if(c->pid > 0){
		while(waitpid(c->pid, &status, 0) < 0 && errno == EINTR)
			;
		c->pid = -1;
	}
	c->pgid = -1;
}

static void
cleanup(Run *r, int noisy)
{
	stopchild(&r->daemon);
	stopchild(&r->xvfb);
	if(noisy){
		fprintf(stderr, "%s: daemon log:\n", testname);
		showlog(r->daemon.log);
		fprintf(stderr, "%s: Xvfb log:\n", testname);
		showlog(r->xvfb.log);
	}
	if(r->daemon.log[0] != '\0')
		unlink(r->daemon.log);
	if(r->xvfb.log[0] != '\0')
		unlink(r->xvfb.log);
	liveclean(&r->l);
}

static int
xerr(Display *dpy, XErrorEvent *e)
{
	char msg[128];

	xerror++;
	XGetErrorText(dpy, e->error_code, msg, sizeof msg);
	fail("X error: %s (request %d.%d)", msg, e->request_code, e->minor_code);
	return 0;
}

static int
pumpinput(Display *dpy, XIC ic, char *commit, size_t cap, int timeout)
{
	struct pollfd pfd;
	XEvent ev;
	KeySym sym;
	Status status;
	char buf[Ipcfieldmax+1];
	int n;

	XFlush(dpy);
	if(XPending(dpy) == 0){
		pfd.fd = ConnectionNumber(dpy);
		pfd.events = POLLIN;
		pfd.revents = 0;
		while(poll(&pfd, 1, timeout) < 0 && errno == EINTR)
			;
	}
	while(XPending(dpy) != 0){
		XNextEvent(dpy, &ev);
		if(XFilterEvent(&ev, None) || ic == NULL || ev.type != KeyPress)
			continue;
		n = Xutf8LookupString(ic, &ev.xkey, buf, sizeof buf - 1,
			&sym, &status);
		if(n < 0 || ((status == XLookupChars || status == XLookupBoth) &&
		   ((size_t)n >= cap || commit == NULL)))
			return 0;
		if((status == XLookupChars || status == XLookupBoth) && n != 0){
			memcpy(commit, buf, n);
			commit[n] = '\0';
		}
	}
	return 1;
}

static void
pump(Display *dpy, int timeout)
{
	pumpinput(dpy, NULL, NULL, 0, timeout);
}

static int
prestart(XIC ic, XPointer data, XPointer call)
{
	Prelog *p;

	(void)ic;
	(void)call;
	p = (Prelog*)data;
	if(p->start != p->done)
		p->badorder++;
	p->start++;
	return Ipcfieldmax;
}

static void
predraw(XIM im, XPointer data, XPointer call)
{
	Prelog *p;
	XIMPreeditDrawCallbackStruct *draw;

	(void)im;
	p = (Prelog*)data;
	draw = (XIMPreeditDrawCallbackStruct*)call;
	if(draw != NULL && draw->text != NULL && draw->text->length != 0){
		if(p->start != p->done + 1)
			p->badorder++;
		p->nonempty++;
	}else{
		if(p->start != p->done + 1)
			p->badorder++;
		p->empty++;
	}
}

static void
predone(XIM im, XPointer data, XPointer call)
{
	Prelog *p;

	(void)im;
	(void)call;
	p = (Prelog*)data;
	if(p->empty > p->done)
		p->doneafterempty++;
	else
		p->badorder++;
	p->done++;
}

static void
precaret(XIM im, XPointer data, XPointer call)
{
	(void)im;
	(void)data;
	(void)call;
}

static XIC
callbackic(XIM im, Window win, Prelog *log)
{
	union {
		int (*start)(XIC, XPointer, XPointer);
		XIMProc xim;
	} fn;
	XIMCallback start, draw, done, caret;
	XVaNestedList pre;
	XIC ic;

	start.client_data = (XPointer)log;
	fn.start = prestart;
	start.callback = fn.xim;
	draw.client_data = (XPointer)log;
	draw.callback = predraw;
	done.client_data = (XPointer)log;
	done.callback = predone;
	caret.client_data = (XPointer)log;
	caret.callback = precaret;
	pre = XVaCreateNestedList(0,
		XNPreeditStartCallback, &start,
		XNPreeditDrawCallback, &draw,
		XNPreeditDoneCallback, &done,
		XNPreeditCaretCallback, &caret,
		NULL);
	if(pre == NULL)
		return NULL;
	ic = XCreateIC(im,
		XNInputStyle, XIMPreeditCallbacks|XIMStatusNothing,
		XNClientWindow, win,
		XNFocusWindow, win,
		XNPreeditAttributes, pre,
		NULL);
	XFree(pre);
	return ic;
}

static int
sendkey(Display *dpy, XIC ic, Window win, KeySym sym, unsigned int state,
	char *commit, size_t cap)
{
	XKeyPressedEvent key;
	XEvent ev;
	KeySym got;
	Status status;
	char buf[Ipcfieldmax+1];
	int n;

	if(cap != 0)
		commit[0] = '\0';
	memset(&key, 0, sizeof key);
	key.type = KeyPress;
	key.display = dpy;
	key.window = win;
	key.root = DefaultRootWindow(dpy);
	key.time = CurrentTime;
	key.x = key.y = key.x_root = key.y_root = 1;
	key.same_screen = True;
	key.keycode = XKeysymToKeycode(dpy, sym);
	key.state = state;
	memset(&ev, 0, sizeof ev);
	ev.xkey = key;
	if(XFilterEvent(&ev, None)){
		return pumpinput(dpy, ic, commit, cap, 20);
	}
	n = Xutf8LookupString(ic, &key, buf, sizeof buf - 1, &got, &status);
	if(n < 0)
		return fail("Xutf8LookupString failed for keysym %#lx",
			(unsigned long)sym);
	if((status == XLookupChars || status == XLookupBoth) && n != 0){
		if((size_t)n >= cap)
			return fail("commit buffer overflow");
		memcpy(commit, buf, n);
		commit[n] = '\0';
	}
	return pumpinput(dpy, ic, commit, cap, 20);
}

static int
waitcommit(Display *dpy, XIC ic, char *commit, size_t cap)
{
	int64_t deadline;

	deadline = nowms() + Eventtimeout;
	while(leftms(deadline) > 0){
		if(!pumpinput(dpy, ic, commit, cap, leftms(deadline)))
			return fail("read committed XIM text");
		if(commit[0] != '\0')
			return 1;
	}
	return 0;
}

static int
waitpreedit(Display *dpy, Prelog *p)
{
	int64_t deadline;

	deadline = nowms() + Eventtimeout;
	while(leftms(deadline) > 0){
		pump(dpy, leftms(deadline));
		if(p->empty != 0 || p->done != 0 || p->badorder != 0)
			return -1;
		if(p->start != 0 && p->nonempty != 0)
			return 1;
	}
	return 0;
}

static XIM
openim(Display *dpy)
{
	XIM im;
	int64_t deadline;

	deadline = nowms() + Starttimeout;
	do{
		im = XOpenIM(dpy, NULL, "strans", "Strans");
		if(im != NULL)
			return im;
		pump(dpy, 20);
	}while(leftms(deadline) > 0);
	return NULL;
}

static int
testcallbacks(Display *dpy, XIM im, Window win)
{
	char commit[Ipcfieldmax+1], *reset;
	Prelog log;
	XIC ic;

	memset(&log, 0, sizeof log);
	ic = callbackic(im, win, &log);
	if(ic == NULL)
		return fail("create PreeditCallbacks input context");
	XSetICFocus(ic);
	if(!sendkey(dpy, ic, win, XK_s, ControlMask, commit, sizeof commit) ||
	   !sendkey(dpy, ic, win, XK_r, 0, commit, sizeof commit)){
		XDestroyIC(ic);
		return 0;
	}
	if(waitpreedit(dpy, &log) != 1){
		int start, draw, empty, done;

		start = log.start;
		draw = log.nonempty;
		empty = log.empty;
		done = log.done;
		XDestroyIC(ic);
		return fail("invalid callback preedit: start=%d draw=%d empty=%d done=%d",
			start, draw, empty, done);
	}
	pump(dpy, 50);
	if(log.start != 1 || log.nonempty < 1 || log.done != 0 ||
	   log.empty != 0 || log.badorder != 0){
		int start, draw, empty, done, ordered, bad;

		start = log.start;
		draw = log.nonempty;
		empty = log.empty;
		done = log.done;
		ordered = log.doneafterempty;
		bad = log.badorder;
		XDestroyIC(ic);
		return fail("bad initial callback sequence: start=%d draw=%d empty=%d done=%d ordered=%d bad=%d",
			start, draw, empty, done, ordered, bad);
	}
	reset = Xutf8ResetIC(ic);
	if(reset == NULL || strcmp(reset, "ㄱ") != 0){
		if(reset != NULL)
			XFree(reset);
		XDestroyIC(ic);
		return fail("ResetIC did not return pending preedit");
	}
	XFree(reset);
	if(!sendkey(dpy, ic, win, XK_r, 0, commit, sizeof commit) ||
	   !sendkey(dpy, ic, win, XK_k, 0, commit, sizeof commit) ||
	   !sendkey(dpy, ic, win, XK_Return, 0, commit, sizeof commit)){
		XDestroyIC(ic);
		return 0;
	}
	if(commit[0] == '\0' && !waitcommit(dpy, ic, commit, sizeof commit)){
		XDestroyIC(ic);
		return fail("input context did not compose after ResetIC");
	}
	if(strcmp(commit, "가") != 0){
		XDestroyIC(ic);
		return fail("post-reset composition did not contain 가");
	}
	XUnsetICFocus(ic);
	XDestroyIC(ic);
	pump(dpy, 100);
	if(log.badorder != 0)
		return fail("bad callback order after ResetIC");
	return 1;
}

static int
testnothing(Display *dpy, XIM im, Window win)
{
	char commit[Ipcfieldmax+1];
	XIC ic;

	ic = XCreateIC(im,
		XNInputStyle, XIMPreeditNothing|XIMStatusNothing,
		XNClientWindow, win,
		XNFocusWindow, win,
		NULL);
	if(ic == NULL)
		return fail("create PreeditNothing input context");
	XSetICFocus(ic);
	if(!sendkey(dpy, ic, win, XK_s, ControlMask, commit, sizeof commit)){
		XDestroyIC(ic);
		return 0;
	}
	pump(dpy, 100);
	if(!sendkey(dpy, ic, win, XK_r, 0, commit, sizeof commit) ||
	   !sendkey(dpy, ic, win, XK_k, 0, commit, sizeof commit) ||
	   !sendkey(dpy, ic, win, XK_Return, 0, commit, sizeof commit)){
		XDestroyIC(ic);
		return 0;
	}
	if(commit[0] == '\0' &&
	   !waitcommit(dpy, ic, commit, sizeof commit)){
		XDestroyIC(ic);
		return fail("PreeditNothing composition produced no commit");
	}
	if(strcmp(commit, "\352\260\200") != 0){
		XDestroyIC(ic);
		return fail("PreeditNothing commit did not contain 가");
	}
	XUnsetICFocus(ic);
	XDestroyIC(ic);
	return 1;
}

static int
testposition(Display *dpy, XIM im, Window client, Window focus)
{
	char commit[Ipcfieldmax+1];
	char **missing, *def;
	int nmissing;
	XPoint spot;
	XVaNestedList pre;
	XFontSet fontset;
	XIC ic;

	missing = NULL;
	nmissing = 0;
	def = NULL;
	fontset = XCreateFontSet(dpy, "fixed", &missing, &nmissing, &def);
	if(missing != NULL)
		XFreeStringList(missing);
	if(fontset == NULL)
		return fail("create XIM position font set");
	spot.x = 7;
	spot.y = 11;
	pre = XVaCreateNestedList(0, XNSpotLocation, &spot,
		XNFontSet, fontset, NULL);
	if(pre == NULL){
		XFreeFontSet(dpy, fontset);
		return fail("create XNSpotLocation list");
	}
	ic = XCreateIC(im,
		XNInputStyle, XIMPreeditPosition|XIMStatusNothing,
		XNClientWindow, client,
		XNFocusWindow, focus,
		XNPreeditAttributes, pre,
		NULL);
	XFree(pre);
	if(ic == NULL){
		XFreeFontSet(dpy, fontset);
		return fail("create nested PreeditPosition input context");
	}
	XSetICFocus(ic);
	if(!sendkey(dpy, ic, focus, XK_s, ControlMask, commit, sizeof commit) ||
	   !sendkey(dpy, ic, focus, XK_r, 0, commit, sizeof commit)){
		XDestroyIC(ic);
		XFreeFontSet(dpy, fontset);
		return 0;
	}
	spot.x = 13;
	spot.y = 17;
	pre = XVaCreateNestedList(0, XNSpotLocation, &spot, NULL);
	if(pre == NULL || XSetICValues(ic, XNPreeditAttributes, pre, NULL) != NULL){
		if(pre != NULL)
			XFree(pre);
		XDestroyIC(ic);
		XFreeFontSet(dpy, fontset);
		return fail("update nested XNSpotLocation");
	}
	XFree(pre);
	if(!sendkey(dpy, ic, focus, XK_Escape, 0, commit, sizeof commit)){
		XDestroyIC(ic);
		XFreeFontSet(dpy, fontset);
		return 0;
	}
	XUnsetICFocus(ic);
	XDestroyIC(ic);
	XFreeFontSet(dpy, fontset);
	return 1;
}

int
main(int argc, char **argv)
{
	Display *dpy;
	Window client, focus, root;
	XIM im;
	Run run;
	int ok;
	char *xvfb;

	testname = "xim_live_test";
	if(argc != 3 && argc != 4){
		fprintf(stderr, "usage: xim_live_test daemon mapdir [Xvfb]\n");
		return 2;
	}
	memset(&run, 0, sizeof run);
	run.xvfb.pid = run.daemon.pid = -1;
	run.xvfb.pgid = run.daemon.pgid = -1;
	xvfb = argc == 4 ? argv[3] : "Xvfb";
	ok = start(&run, argv[1], argv[2], xvfb);
	if(!ok){
		cleanup(&run, 1);
		return 1;
	}
	if(setlocale(LC_CTYPE, "C.UTF-8") == NULL || !XSupportsLocale() ||
	   XSetLocaleModifiers("@im=strans") == NULL){
		fail("initialize UTF-8 X locale for strans");
		cleanup(&run, 1);
		return 1;
	}
	XSetErrorHandler(xerr);
	dpy = XOpenDisplay(run.display);
	if(dpy == NULL){
		fail("open private display %s", run.display);
		cleanup(&run, 1);
		return 1;
	}
	im = openim(dpy);
	if(im == NULL){
		fail("open strans XIM on private display %s", run.display);
		XCloseDisplay(dpy);
		cleanup(&run, 1);
		return 1;
	}
	root = DefaultRootWindow(dpy);
	client = XCreateSimpleWindow(dpy, root, 41, 53, 240, 100, 0, 0, 0);
	focus = XCreateSimpleWindow(dpy, client, 17, 19, 160, 50, 0, 0, 0);
	XSelectInput(dpy, client, KeyPressMask|StructureNotifyMask);
	XSelectInput(dpy, focus, KeyPressMask|StructureNotifyMask);
	XMapWindow(dpy, client);
	XMapWindow(dpy, focus);
	XSync(dpy, False);
	ok = testcallbacks(dpy, im, client) &&
		testnothing(dpy, im, client) &&
		testposition(dpy, im, client, focus);
	XDestroyWindow(dpy, focus);
	XDestroyWindow(dpy, client);
	XCloseIM(im);
	XSync(dpy, False);
	XCloseDisplay(dpy);
	if(xerror != 0){
		fail("observed %d X protocol errors", xerror);
		ok = 0;
	}
	cleanup(&run, !ok);
	if(!ok)
		return 1;
	printf("xim_live_test: ok\n");
	return 0;
}