/*
winnie - an experimental window system

Copyright (C) 2013 Eleni Maria Stea

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

Author: Eleni Maria Stea <elene.mst@gmail.com>
*/

#include "client_plugins.h"
#include <ctype.h>
#include <dlfcn.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <vector>

struct Plugin {
  void *so;

  bool (*init)();
  void (*cleanup)();
};

static char *strip_wspace(char *s);

static std::vector<Plugin> plugins;

bool
init_client_plugins()
{
  FILE *fp = fopen("plugins.conf", "r");
  if (!fp) {
    fprintf(stderr,
            "failed to load plugin list: plugins.conf: %s\n",
            strerror(errno));
    return false;
  }

  plugins.clear();

  char buf[512];
  while (fgets(buf, sizeof buf, fp)) {
    char *line = strip_wspace(buf);

    if (!*line || *line == '#') {
      continue;
    }

    Plugin plugin;

    plugin.so = dlopen(line, RTLD_LAZY);
    if (!plugin.so) {
      fprintf(stderr, "failed to load plugin: %s: %s\n", line, dlerror());
      continue;
    }

    if (!(plugin.init = (bool (*)()) dlsym(plugin.so, "init"))) {
      fprintf(stderr, "invalid plugin: %s: no init function\n", line);
      dlclose(plugin.so);
      continue;
    }
    plugin.cleanup = (void (*)()) dlsym(plugin.so, "cleanup");

    if (!plugin.init()) {
      fprintf(stderr, "failed to initialize plugin: %s\n", line);
      dlclose(plugin.so);
      continue;
    }

    printf("loaded plugin: %s\n", line);
    plugins.push_back(plugin);
  }

  fclose(fp);
  return true;
}

void
destroy_client_plugins()
{
  for (size_t i = 0; i < plugins.size(); i++) {
    if (plugins[i].cleanup) {
      plugins[i].cleanup();
    }
    dlclose(plugins[i].so);
  }
  plugins.clear();
}

static char *
strip_wspace(char *s)
{
  if (!s || !*s) {
    return s;
  }

  while (*s && isspace(*s))
    s++;

  char *endp = s + strlen(s) - 1;
  while (*endp && isspace(*endp)) {
    *endp-- = 0;
  }
  return s;
}