/*
 *  upkg: tool for manipulating Unreal Tournament packages.
 *  Copyright © 2009-2011 Nick Bowler
 *
 *  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/>.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <glib-object.h>
#include <ltdl.h>

#include <uobject/module.h>
#include <uobject/uobject.h>
#include <uobject/package.h>
#include <upkg.h>
#include "avl.h"

static unsigned initialized;
static struct avl_table *package_tree;

static char *str_cpy_lower(char *dst, const char *src)
{
	size_t i;

	for (i = 0; src[i]; i++)
		dst[i] = tolower(src[i]);
	dst[i] = 0;

	return dst;
}

static int modcmp(const void *a, const void *b, void *_data)
{
	const GTypeModule *ma = a;
	const GTypeModule *mb = b;

	return strcmp(ma->name, mb->name);
}

int u_object_module_init(void)
{
	if (!initialized) {
		package_tree = avl_create(modcmp, NULL, NULL);
		if (!package_tree) {
			fprintf(stderr, "%s: failed to create package tree.\n", __func__);
			return -1;
		}

		g_type_init();
	}

	initialized++;
	return 0;
}

int u_object_module_exit(void)
{
	if (--initialized)
		return 0;

	avl_destroy(package_tree, NULL);

	return 0;
}

static int lookup_module(GTypeModule **out, const char *name)
{
	struct { GTypeModule pkg; char buf[]; } *search_key;
	GTypeModule *result;

	search_key = malloc(sizeof *search_key + strlen(name) + 1);
	if (!search_key)
		return -1;

	search_key->pkg = (GTypeModule) {
		.name = str_cpy_lower(search_key->buf, name),
	};

	result = avl_find(package_tree, search_key);
	free(search_key);

	*out = result;
	return 0;
}

GTypeModule *
u_module_get_from_import(GTypeModule *pkg, const struct upkg_import *i)
{
	GTypeModule *result;

	while (i->parent != NULL)
		i = i->parent;

	if (strcmp(i->class_package, "Core") != 0
	    || strcmp(i->class_name, "Package") != 0) {
		u_err(pkg, "import root must be an instance of Core.Package");
		return NULL;
	}

	if (lookup_module(&result, i->name) != 0) {
		u_err(pkg, "fatal error performing package lookup");
		return NULL;
	}

	if (!result) {
		void **p;

		result = u_pkg_open(i->name);
		if (!result) {
			u_warn(pkg, "failed to open package: %s", i->name);
			return NULL;
		}

		p = avl_probe(package_tree, result);
		if (!p) {
			u_err(pkg, "fatal error inserting package");
			g_object_unref(result);
			return NULL;
		}
	}

	return result;
}

GType u_object_module_get_class(GTypeModule *pkg, long class)
{
	GTypeModule *mod;
	const char *classname;

	if (class == 0) {
		u_warn(pkg, "class implementations not supported yet");
		return 0;
	} else if (class < 0) {
		const struct upkg_import *import;

		import = upkg_get_import(U_PKG(pkg)->pkg, -(class+1));
		if (!import) {
			u_err(pkg, "invalid package import: %ld", -(class+1));
			return 0;
		}

		mod = u_module_get_from_import(pkg, import);
		if (!mod)
			return 0;

		classname = import->name;
	} else if (class > 0) {
		const struct upkg_export *export;

		export = upkg_get_export(U_PKG(pkg)->pkg, class-1);
		if (!export) {
			u_err(pkg, "invalid package export: %ld", class-1);
			return 0;
		}

		mod = pkg;
		classname = export->name;
	}

	if (!g_type_module_use(mod))
		return 0;

	/* XXX: Do this better. */
	char typename[strlen(mod->name) + strlen(classname) + 1];
	str_cpy_lower(typename, mod->name);
	str_cpy_lower(typename+strlen(mod->name), classname);
	typename[0] = toupper(typename[0]);
	typename[strlen(mod->name)] = toupper(typename[strlen(mod->name)]);

	return g_type_from_name(typename);
}