#include <stdlib.h>
#include <dlfcn.h>
#include <string.h>
#include <libgen.h>

#include "plugin_manager.h"
#include "plugin.h"
#include "debug.h"
#include "version.h"
#include "utils.h"

static char *exec_path;

int init_plugin_manager(const char *_exec_path)
{
	char *str = strdup(_exec_path);
	exec_path = strdup(dirname(str));

	free(str);
	return 0;
}

int load_plugin(const char *path)
{
	struct plugin_info *info;
	void *handle;
	int ret = -1;

	handle = dlopen(path, RTLD_NOW);
	if (!handle) {
		pr_err("Failed to load plugin %s: %s\n", path, dlerror());
		return -1;
	}

	info = dlsym(handle, "plugin_info");
	if (!info) {
		pr_err("Plugin %s does not contain plugin info\n", path);
		goto out;
	}

	if (!info->version) {
		pr_err("Plugin %s version info missing\n", path);
		ret = -1;
		goto out;
	}

	if (strcmp(RRDD_VERSION, info->version)) {
		pr_err("Plugin %s version mismatch, expected %s, got %s\n",
			path, RRDD_VERSION, info->version);
		ret = -1;
		goto out;
	}

	if (!info->init) {
		pr_err("Plugin info structure has NULL .init callback\n");
		goto out;
	}

	ret = info->init();
	pr_info("Loading plugin %s %s\n", path,
		ret ? "failed" : "succeeded");

out:
	if (ret)
		dlclose(handle);

	return ret;
}

/*
 * Try to load a parser plugin with file name matching some of the
 * following candidates (%s being the requested name):
 *
 * "%s_parser.so"
 * "./%s_parser.so"
 * "<exec_path>/%s_parser.so"
 */
int load_parser_plugin(const char *name)
{
	char str[256], parser[] = "_parser.so";
	int ret;

	strncpy(str, name, sizeof(str));
	str[sizeof(str) - 1] = '\0';
	_strlcat(str, parser, sizeof(str));
	ret = load_plugin(str);
	if (!ret)
		return 0;

	strncpy(str, "./", sizeof(str));
	str[sizeof(str) - 1] = '\0';
	_strlcat(str, name, sizeof(str));
	_strlcat(str, parser, sizeof(str));
	ret = load_plugin(str);
	if (!ret)
		return 0;

	if (!exec_path)
		return 0;

	strncpy(str, exec_path, sizeof(str));
	str[sizeof(str) - 1] = '\0';
	_strlcat(str, "/", sizeof(str));
	_strlcat(str, name, sizeof(str));
	_strlcat(str, parser, sizeof(str));
	return load_plugin(str);
}