/* -*- Mode: C; tab-width: 8; c-basic-offset: 8; indent-tabs-mode: nil -*- */
/* dllmain.c: DLL entry point for libmate on Win32
 * Copyright (C) 2005 Novell, Inc
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include <config.h>
#include <windows.h>
#include <string.h>
#include <mbstring.h>
#include <glib.h>

#include "mate-init.h"

/* localedir uses system codepage as it is passed to the non-UTF8ified
 * gettext library
 */
static const char* localedir = NULL;

/* The others are in UTF-8 */
static char* prefix;
static const char* libdir;
static const char* datadir;
static const char* localstatedir;
static const char* sysconfdir;

static HMODULE hmodule;
G_LOCK_DEFINE_STATIC(mutex);

/* Silence gcc with prototype. Yes, this is silly. */
BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved);

/* DllMain used to tuck away the libmate DLL's HMODULE */
BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
{
	switch (fdwReason)
	{
		case DLL_PROCESS_ATTACH:
			hmodule = hinstDLL;
			break;
	}

	return TRUE;
}

static char* replace_prefix(const char* runtime_prefix, const char* configure_time_path)
{
	if (runtime_prefix && strncmp(configure_time_path, LIBMATE_PREFIX "/", strlen (LIBMATE_PREFIX) + 1) == 0)
	{
		return g_strconcat(runtime_prefix, configure_time_path + strlen (LIBMATE_PREFIX), NULL);
	}
	else
	{
		return g_strdup (configure_time_path);
	}
}

/**
 * mate_win32_get_prefixes:
 * @hmodule: The handle to a DLL (a HMODULE).
 * @full_prefix: Where the full UTF-8 path to the DLL's installation folder
 *               will be returned.
 * @cp_prefix: Where a system codepage version of
 *             the installation folder will be returned.
 *
 * This function looks up the installation prefix of the DLL (or EXE)
 * with handle @hmodule. The prefix using long filenames and in UTF-8
 * form is returned in @full_prefix. The prefix using short file names
 * (if present in the file system) and in the system codepage is
 * returned in @cp_prefix. To determine the installation prefix, the
 * full path to the DLL or EXE is first fetched. If the last folder
 * component in that path is called "bin", its parent folder is used,
 * otherwise the folder itself.
 *
 * If either can't be obtained, %NULL is stored. The caller should be
 * prepared to handle that.
 *
 * The returned character pointers are newly allocated and should be
 * freed with g_free when not longer needed.
 */
void mate_win32_get_prefixes(gpointer  hmodule, char** full_prefix, char** cp_prefix)
{
	wchar_t wcbfr[1000];
	char cpbfr[1000];

	g_return_if_fail(full_prefix != NULL);
	g_return_if_fail(cp_prefix != NULL);

	*full_prefix = NULL;
	*cp_prefix = NULL;

	if (GetModuleFileNameW((HMODULE) hmodule, wcbfr, G_N_ELEMENTS(wcbfr)))
	{
		*full_prefix = g_utf16_to_utf8(wcbfr, -1, NULL, NULL, NULL);
		/* WideCharToMultiByte
		 * Short pathnames always contain only
		 * ASCII, I think, but just in case, be
		 * prepared.
		 */
		if (GetShortPathNameW(wcbfr, wcbfr, G_N_ELEMENTS(wcbfr)) && WideCharToMultiByte(CP_ACP, 0, wcbfr, -1, cpbfr, G_N_ELEMENTS(cpbfr), NULL, NULL))
		{
			*cp_prefix = g_strdup(cpbfr);
		}
		else if (*full_prefix)
		{
			*cp_prefix = g_locale_from_utf8(*full_prefix, -1, NULL, NULL, NULL);
		}
	}

	if (*full_prefix != NULL)
	{
		gchar* p = strrchr(*full_prefix, '\\');

		if (p != NULL)
			*p = '\0';

		p = strrchr(*full_prefix, '\\');

		if (p && (g_ascii_strcasecmp(p + 1, "bin") == 0))
			*p = '\0';
	}

	/* cp_prefix is in system codepage */
	if (*cp_prefix != NULL)
	{
		gchar* p = _mbsrchr(*cp_prefix, '\\');

		if (p != NULL)
			*p = '\0';

		p = _mbsrchr (*cp_prefix, '\\');

		if (p && (g_ascii_strcasecmp(p + 1, "bin") == 0))
			*p = '\0';
	}
}

static void setup(void)
{
	char* cp_prefix;

	G_LOCK(mutex);

	if (localedir != NULL)
	{
		G_UNLOCK(mutex);
		return;
	}

	mate_win32_get_prefixes(hmodule, &prefix, &cp_prefix);

	localedir = replace_prefix(cp_prefix, LIBMATE_LOCALEDIR);
	g_free(cp_prefix);

	libdir = replace_prefix(prefix, LIBMATE_LIBDIR);
	datadir = replace_prefix(prefix, LIBMATE_DATADIR);
	localstatedir = replace_prefix(prefix, LIBMATE_LOCALSTATEDIR);
	sysconfdir = replace_prefix(prefix, LIBMATE_SYSCONFDIR);

	G_UNLOCK(mutex);
}

/* Include libmate-private.h now to get prototypes for the getter
 * functions, to silence gcc. Can't include earlier as we need the
 * definitions of the LIBMATE_*DIR macros from the Makefile above.
 */
#include "libmate-private.h"

#define GETTER(varbl)                           \
const char* _mate_get_##varbl(void)             \
{                                               \
	setup();                                    \
	return varbl;                               \
}

GETTER(prefix)
GETTER(localedir)
GETTER(libdir)
GETTER(datadir)
GETTER(localstatedir)
GETTER(sysconfdir)