#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <sys/wait.h>
#include <sys/stat.h>

#include "list.h"
#include "apps.h"

/* ------------------------------------------------------------------ */

enum desktop_type desktop_type = DESKTOP_OTHER;
char app_error[256];

/* ------------------------------------------------------------------ */

static int debug = 0;

struct have_app {
    char              *name;
    int               present;
    struct list_head  next;
};
static LIST_HEAD(apps);

/* ------------------------------------------------------------------ */

static struct have_app *find_app_entry(char *name)
{
    struct list_head *item;
    struct have_app  *app;

    list_for_each(item, &apps) {
	app = list_entry(item, struct have_app, next);
	if (0 == strcmp(app->name, name))
	    return app;
    }
    app = malloc(sizeof(*app));
    memset(app,0,sizeof(*app));
    app->name = strdup(name);
    app->present = -1;
    list_add_tail(&app->next, &apps);
    return app;
}

int have_application(char *name)
{
    struct have_app *app;
    char *path, *elem, *binary;
    struct stat st;
    int rc;

    app = find_app_entry(name);
    if (-1 != app->present)
	goto done;
    app->present = 0;
    
    if (strchr(name,'/')) {
	/* path specified ... */
	if (-1 == stat(name, &st))
	    goto done;
	if (!S_ISREG(st.st_mode))
	    goto done;
	if (!(st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH)))
	    goto done;
	app->present = 1;
	goto done;
    }

    /* walk $PATH */
    path = getenv("PATH");
    if (NULL == path)
	goto done;
    path = strdup(path);
    for (elem = strtok(path, ":"); NULL != elem; elem = strtok(NULL, ":")) {
	binary = malloc(strlen(elem)+strlen(name)+2);
	sprintf(binary, "%s/%s", elem, name);
	rc = stat(binary, &st);
	free(binary);
	if (-1 == rc)
	    continue;
	if (!S_ISREG(st.st_mode))
	    continue;
	if (!(st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH)))
	    continue;
	app->present = 1;
	break;
    }
    free(path);

 done:
    return app->present;
}

/* ------------------------------------------------------------------ */

int run_application_va(int do_wait, const char *app, char **argv)
{
    int status, rc;
    pid_t pid;

    while (waitpid(-1, &status, WNOHANG) > 0)
	/* collect zombies */;
    
    if (0 == (pid = fork())) {
	/* child */
	execvp(app, argv);
	fprintf(stderr,"%s: execvp(%s): %s\n", __FUNCTION__,
		app, strerror(errno));
	exit(1);
    }

    if (!do_wait)
	return 0;

    rc = waitpid(pid, &status, 0);
    if (rc != pid) {
	/* Huh? */
	fprintf(stderr,"%s: waidpid(%d): %s\n", __FUNCTION__,
		pid, strerror(errno));
	exit(1);
    }
    if (!WIFEXITED(status))
	return -1;
    return WEXITSTATUS(status);
}

int run_application(int do_wait, const char *app, ...)
{
    va_list args;
    char *argv[64];
    int i;

    if (debug)
	fprintf(stderr,"%s: %s |", __FUNCTION__, app);
    va_start(args, app);
    for (i = 0; i < array_size(argv); i++) {
	argv[i] = va_arg(args, char*);
	if (NULL == argv[i])
	    break;
	if (debug)
	    fprintf(stderr,"%s \"%s\"", (0 == i) ? "" : ",", argv[i]);
    }
    va_end(args);
    if (debug)
	fprintf(stderr,"\n");

    if (array_size(argv) == i) {
	fprintf(stderr,"%s: oops: argv too small\n", __FUNCTION__);
	return -1;
    }

    return run_application_va(do_wait, app, argv);
}

int run_cmdline(int do_wait, char *line)
{
    char *argbuf, *token, *h;
    char *argv[64];
    int rc = -1, argc = 0;

    h = argbuf = strdup(line);
    for (;;) {
	while (' ' == *h  ||  '\t' == *h)
	    h++;
	if ('\0' == *h)
	    break;
	if ('"' == *h) {
	    /* quoted string */
	    h++;
	    token = h;
	    while ('\0' != *h  &&  '"' != *h)
		h++;
	} else {
	    /* normal string */
	    token = h;
	    while ('\0' != *h  &&  ' ' != *h  &&  '\t' != *h)
		h++;
	}
	if ('\0' != *h) {
	    *h = 0;
	    h++;
	}
	argv[argc++] = token;
	if (argc == array_size(argv)-1) {
	    fprintf(stderr,"%s: oops: argv too small\n", __FUNCTION__);
	    goto out;
	}
    }
    if (!argc)
	goto out;

    argv[argc++] = NULL;
    rc = run_application_va(do_wait, argv[0], argv);

 out:
    free(argbuf);
    return rc;
}

int run_cmdline_replace(int do_wait, char *str, ...)
{
    va_list args;
    char *tag, *val;
    char *src, *dst, *pos;
    int start, end, cont, rc = 0;

    va_start(args, str);
    src = strdup(str);
    for (;;) {
	tag = va_arg(args, char*);
	if (NULL == tag)
	    break;
	val = va_arg(args, char*);
	if (NULL == val)
	    break;
	for (cont = 0;;) {
	    if (NULL == (pos = strstr(src + cont, tag)))
		break;
	    start = pos - src;
	    end   = start + strlen(tag);
	    cont  = start + strlen(val);
	    dst = malloc(strlen(src) + strlen(val));
	    strncpy(dst, src, start);
	    strcpy(dst + start, val);
	    strcpy(dst + cont, src + end);
	    free(src);
	    src = dst;
	}
    }
    va_end(args);

    if (1 || debug)
	fprintf(stderr,"run: %s\n", src);
    rc = run_cmdline(do_wait, src);
    free(src);
    return rc;
}

/* ------------------------------------------------------------------ */

int open_vnc_session(char *host, int tcpport)
{
    char display[64];
    char javaurl[64];
    char vncurl[64];

    snprintf(display, sizeof(display), "%s::%d", host, tcpport);
    snprintf(javaurl, sizeof(javaurl), "http://%s:%d/", host, tcpport - 100);
    snprintf(vncurl,  sizeof(vncurl),  "vnc://%s:%d/",  host, tcpport);

    /* --- try client apps --- */
    if (have_application("vncviewer"))
	return run_application(0, "vncviewer", "vncviewer",
			       "-xrm", "vncviewer*passwordDialog: true",
			       display, NULL);
    if (have_application("krdc"))
	/* KDE remote desktop client */
	return run_application(0, "krdc", "krdc", display, NULL);

    /* --- try web browser (java applet client) --- */
    if (DESKTOP_KDE == desktop_type && have_application("kfmclient"))
	/* open new konqueror window */
	return run_application(0, "kfmclient", "kfmclient", "openURL", javaurl, NULL);
    if (have_application("firefox"))
	return run_application(0, "firefox", "firefox", javaurl, NULL);

    snprintf(app_error, sizeof(app_error),
	     "no vnc client found, please install one\n");
    return -1;
}