#include <glib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>

#include "kernel/menu.h"
#include "kernel/event.h"

static char *PLUGIN_NAME = "fifo_menu";

typedef struct Fifo_Menu_Data{
    char *fifo;
    char *buf; /* buffer to hold partially read menu */
    unsigned long buflen; /* how many bytes are in the buffer */
    int fd; /* file descriptor to read menu from */
    event_fd_handler *handler;
} Fifo_Menu_Data;

#define FIFO_MENU(m) ((Menu *)m)
#define FIFO_MENU_DATA(m) ((Fifo_Menu_Data *)((Menu *)m)->plugin_data)


void fifo_menu_clean_up(Menu *m) {
    if (FIFO_MENU_DATA(m)->buf != NULL) {
        g_free(FIFO_MENU_DATA(m)->buf);
        FIFO_MENU_DATA(m)->buf = NULL;
        FIFO_MENU_DATA(m)->buflen = 0;
    }

    if (FIFO_MENU_DATA(m)->fd != -1) {
        close(FIFO_MENU_DATA(m)->fd);
        FIFO_MENU_DATA(m)->fd = -1;
    }
}

void plugin_setup_config() { }
void plugin_startup()
{ }
void plugin_shutdown() { }

void fifo_menu_handler(int fd, void *d) {
    Menu *menu = d;
    char *tmpbuf = NULL;
    unsigned long num_read;
#ifdef DEBUG
    /* because gdb is dumb */
#if 0
    Fifo_Menu_Data *d = FIFO_MENU_DATA(menu);
#endif
#endif
    
    /* if the menu is shown this will go into busy loop :(
     fix me*/
    if (!menu->shown) { 
        unsigned long num_realloc;
        /* if we have less than a quarter BUFSIZ left, allocate more */
        num_realloc = (BUFSIZ - (FIFO_MENU_DATA(menu)->buflen % BUFSIZ) <
                       BUFSIZ >> 2) ?
            0 : BUFSIZ;
    
        tmpbuf = g_try_realloc(FIFO_MENU_DATA(menu)->buf,             
                               FIFO_MENU_DATA(menu)->buflen + num_realloc);

        if (tmpbuf == NULL) {
            g_warning("Unable to allocate memory for read()");
            return;
        }
    
        FIFO_MENU_DATA(menu)->buf = tmpbuf;
    
        num_read = read(fd,
                        FIFO_MENU_DATA(menu)->buf + FIFO_MENU_DATA(menu)->buflen,
                        num_realloc);

        if (num_read == 0) { /* eof */
            unsigned long count = 0;
            char *found = NULL;

            menu->invalid = TRUE;
            menu_clear(menu);

            /* TEMP: list them */
            while (NULL !=
                   (found = strchr(&FIFO_MENU_DATA(menu)->buf[count], '\n'))) {
                FIFO_MENU_DATA(menu)->buf
                    [found - FIFO_MENU_DATA(menu)->buf] = '\0';
                menu_add_entry(menu,
                               menu_entry_new_separator
                               (&FIFO_MENU_DATA(menu)->buf[count]));
                count = found - FIFO_MENU_DATA(menu)->buf + 1;
            }

            FIFO_MENU_DATA(menu)->buf[FIFO_MENU_DATA(menu)->buflen] = '\0';
            fifo_menu_clean_up(menu);

            event_remove_fd(FIFO_MENU_DATA(menu)->handler->fd);
        
            if ((FIFO_MENU_DATA(menu)->fd =
                 open(FIFO_MENU_DATA(menu)->fifo, O_NONBLOCK | O_RDONLY)) == -1) {
                g_warning("Can't reopen FIFO");
                fifo_menu_clean_up(menu);
                return;
            }

            FIFO_MENU_DATA(menu)->handler->fd = FIFO_MENU_DATA(menu)->fd;
        
            event_add_fd_handler(FIFO_MENU_DATA(menu)->handler);
        } else if (num_read > 0) {
            FIFO_MENU_DATA(menu)->buflen += num_read;
            FIFO_MENU_DATA(menu)->buf[FIFO_MENU_DATA(menu)->buflen] = '\0';
        }
    }
}

void plugin_destroy (Menu *m)
{
    fifo_menu_clean_up(m);
    if (FIFO_MENU_DATA(m)->handler != NULL) {
        g_free(FIFO_MENU_DATA(m)->handler);
        FIFO_MENU_DATA(m)->handler = NULL;
    }

    if (FIFO_MENU_DATA(m)->fifo != NULL) {
        g_free(FIFO_MENU_DATA(m)->fifo);
        FIFO_MENU_DATA(m)->fifo = NULL;
    }

    g_free(m->plugin_data);

    menu_free(m->name);
}

void *plugin_create() /* TODO: need config */
{
    char *fifo;
    char *dir;
    event_fd_handler *h;
    
    Fifo_Menu_Data *d = g_new(Fifo_Menu_Data, 1);
    Menu *m = menu_new("", PLUGIN_NAME, NULL);

    d->fd = -1;
    d->buf = NULL;
    d->buflen = 0;
    d->handler = NULL;
    
    m->plugin = PLUGIN_NAME;

    d->fd = -1;
    
    m->plugin_data = (void *)d;

    dir = g_build_filename(g_get_home_dir(), ".openbox", PLUGIN_NAME, NULL);

    if (mkdir(dir, S_IRWXU | S_IRWXG | S_IRWXO) == -1 && errno != EEXIST) {
/* technically, if ~/.openbox/fifo_menu exists and isn't a directory
   this will fail, but we don't care because mkfifo will fail and warn
   anyway */
        g_warning("Can't create %s: %s", dir, strerror(errno));
        g_free(dir);
        plugin_destroy(m);
        return NULL;
    }

    fifo = g_build_filename(g_get_home_dir(), ".openbox", PLUGIN_NAME,
                            m->name, NULL);
    if (mkfifo(fifo, S_IRUSR | S_IWUSR |
               S_IRGRP | S_IWGRP | /* let umask do its thing */
               S_IROTH | S_IWOTH) == -1 && errno != EEXIST) {
        g_warning("Can't create FIFO %s: %s", fifo, strerror(errno));
        g_free(fifo);
        g_free(d);
        menu_free(m->name);
        return NULL;
    }

/* open in non-blocking mode so we don't wait for a process to open FIFO
   for writing */
    if ((d->fd = open(fifo, O_NONBLOCK | O_RDONLY)) == -1) { 
        g_warning("Can't open FIFO %s: %s", fifo, strerror(errno));
        g_free(fifo);
        g_free(d);
        menu_free(m->name);
        return NULL;
    }

    d->fifo = fifo;
    
    h = g_new(event_fd_handler, 1);

    if (h == NULL) {
        g_warning("Out of memory");
        close(d->fd);
        g_free(fifo);
        g_free(d);
        menu_free(m->name);
        return NULL;
    }
    
    h->fd = d->fd;
    h->data = m;
    h->handler = fifo_menu_handler;
    d->handler = h;
    
    event_add_fd_handler(h);
    
    g_free(dir);
    return (void *)m;
}