/*
 Derived from source code of TrueCrypt 7.1a, which is
 Copyright (c) 2008-2012 TrueCrypt Developers Association and which is governed
 by the TrueCrypt License 3.0.

 Modifications and additions to the original source code (contained in this file)
 and all other portions of this file are Copyright (c) 2013-2017 IDRIX
 and are governed by the Apache License 2.0 the full text of which is
 contained in the file License.txt included in VeraCrypt binary and source
 code distribution packages.
*/

#include "Language.h"
#include "Dlgcode.h"
#include "Dictionary.h"
#include "Tcdefs.h"
#include "Xml.h"

#include "../Common/Resource.h"

#ifdef TCMOUNT
#include "../Mount/Resource.h"
#endif

#ifdef VOLFORMAT
#include "../Format/Resource.h"
#endif

#ifdef SETUP
#include "../Setup/Resource.h"
#endif

#include <Strsafe.h>

BOOL LocalizationActive;
int LocalizationSerialNo;

wchar_t UnknownString[1024]  = {0};
static char *LanguageFileBuffer = NULL;
static HANDLE LanguageFileFindHandle = INVALID_HANDLE_VALUE;
static char PreferredLangId[6] = {0};
static char *LanguageResource = NULL;
static DWORD LanguageResourceSize = 0;
static char *HeaderResource[2] = {NULL, NULL};
static DWORD HeaderResourceSize[2] = {0, 0};
static char ActiveLangPackVersion[6] = {0};
static int LanguageResourceId = 0;

static char *MapFirstLanguageFile ()
{
	if (LanguageFileFindHandle != INVALID_HANDLE_VALUE)
	{
		FindClose (LanguageFileFindHandle);
		LanguageFileFindHandle = INVALID_HANDLE_VALUE;
	}

	if (LanguageFileBuffer != NULL)
	{
		free (LanguageFileBuffer);
		LanguageFileBuffer = NULL;
	}

	LanguageResourceId = 0;

	if (LanguageResource == NULL)
	{
		DWORD size;
		LanguageResource = MapResource (L"Xml", IDR_LANGUAGE, &size);
		if (LanguageResource)
			LanguageResourceSize = size;
	}

	if (LanguageResource)
	{
		LanguageFileBuffer = malloc(LanguageResourceSize + 1);
		if (LanguageFileBuffer)
		{
			memcpy (LanguageFileBuffer, LanguageResource, LanguageResourceSize);
			LanguageFileBuffer[LanguageResourceSize] = 0;
		}
	}

	return LanguageFileBuffer;
}

static int IsValidLanguageFileName(const wchar_t* filename) {
    size_t len = wcslen(filename);
    
    // Check the base format and length directly
    if (_wcsnicmp(filename, L"Language.", 9) != 0 || (len != 15 && len != 18))
        return 0; // Does not start with "Language." or has incorrect length

    // Check for the ".xml" suffix
    if (_wcsicmp(filename + len - 4, L".xml") != 0)
        return 0; // Does not end with ".xml"

    // Detailed checks based on the specific length
    if (len == 15) {
        // Format should be Language.xx.xml
        if (iswalpha(filename[9]) && iswalpha(filename[10]))
            return 1; // Valid format for short code
    } else if (len == 18) {
        // Format should be Language.xx-yy.xml
        if (iswalpha(filename[9]) && iswalpha(filename[10]) && filename[11] == L'-' &&
            iswalpha(filename[12]) && iswalpha(filename[13]))
            return 1; // Valid format for long code
    }

    return 0; // If none of the conditions are met, the filename is invalid
}

static char *MapNextLanguageFile (int resourceid)
{
	wchar_t f[TC_MAX_PATH*2], *t;
	WIN32_FIND_DATAW find;
	HANDLE file;
	DWORD read;
	BOOL bStatus;
	BOOL validFileFound = FALSE;

	/* free memory here to avoid leaks */
	if (LanguageFileBuffer != NULL)
	{
		free (LanguageFileBuffer);
		LanguageFileBuffer = NULL;
	}

	if (resourceid == 0)
	{
		if (LanguageFileFindHandle == INVALID_HANDLE_VALUE)
		{
			GetModuleFileNameW (NULL, f, sizeof (f) / sizeof (f[0]));
			t = wcsrchr (f, L'\\');
			if (t == NULL) return NULL;

			*t = 0;
			StringCbCatW (f, sizeof(f), L"\\Languages\\Language*.xml");

			LanguageFileFindHandle = FindFirstFileW (f, &find);
		}
		else if (!FindNextFileW (LanguageFileFindHandle, &find))
		{
			FindClose (LanguageFileFindHandle);
			LanguageFileFindHandle = INVALID_HANDLE_VALUE;
			return NULL;
		}

		if (LanguageFileFindHandle == INVALID_HANDLE_VALUE) return NULL;
		if (find.nFileSizeHigh != 0) return NULL;

        // Validate the file name format
        while (!validFileFound)
        {
            if (!IsValidLanguageFileName(find.cFileName))
            {
                if (!FindNextFileW(LanguageFileFindHandle, &find))
                {
                    FindClose(LanguageFileFindHandle);
                    LanguageFileFindHandle = INVALID_HANDLE_VALUE;
                    return NULL;
                }
            }
            else
            {
                validFileFound = TRUE;
            }
        }

		LanguageFileBuffer = malloc(find.nFileSizeLow + 1);
		if (LanguageFileBuffer == NULL) return NULL;

		GetModuleFileNameW (NULL, f, sizeof (f) / sizeof(f[0]));
		t = wcsrchr (f, L'\\');
		if (t == NULL)
		{
			free(LanguageFileBuffer);
			LanguageFileBuffer = NULL;
			return NULL;
		}

		t[1] = 0;
		StringCbCatW (f, sizeof(f), L"Languages\\");
		StringCbCatW (f, sizeof(f),find.cFileName);

		file = CreateFileW (f, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL);
		if (file == INVALID_HANDLE_VALUE)
		{
			free(LanguageFileBuffer);
			LanguageFileBuffer = NULL;
			return NULL;
		}

		bStatus = ReadFile (file, LanguageFileBuffer, find.nFileSizeLow, &read, NULL);
		CloseHandle (file);
		if (!bStatus || (read != find.nFileSizeLow))
		{
			free(LanguageFileBuffer);
			LanguageFileBuffer = NULL;
			return NULL;
		}

		LanguageFileBuffer [find.nFileSizeLow] = 0; // we have allocated (find.nFileSizeLow + 1) bytes
	}
	else if (LanguageResourceId != resourceid)
	{
		DWORD size;

		LanguageResourceId = resourceid;

		LanguageResource = MapResource (L"Languages", LanguageResourceId, &size);
		if (LanguageResource)
			LanguageResourceSize = size;

		if (LanguageResource)
		{
			LanguageFileBuffer = malloc(LanguageResourceSize + 1);
			if (LanguageFileBuffer)
			{
				memcpy (LanguageFileBuffer, LanguageResource, LanguageResourceSize);
				LanguageFileBuffer[LanguageResourceSize] = 0;
			}
		}
	}

	return LanguageFileBuffer;
}


static BOOL LoadLanguageData (int resourceid, BOOL bForceSetPreferredLanguage, BOOL bForceSilent)
{
	DWORD size;
	BYTE *res;
	char *xml, *header, *headerPtr;
	char langId[6] = "en", attr[32768], key[128];
	BOOL defaultLangParsed = FALSE, langFound = FALSE;
	WCHAR wattr[32768];
	int i, intKey, len;

	char *xmlElements[] = {"entry", 0};

#ifdef TCMOUNT
	int headers[] = { IDR_COMMON_RSRC_HEADER, IDR_MOUNT_RSRC_HEADER, 0 };
#endif

#ifdef VOLFORMAT
	int headers[] = { IDR_COMMON_RSRC_HEADER, IDR_FORMAT_RSRC_HEADER, 0 };
#endif

#ifdef SETUP
	int headers[] = { IDR_COMMON_RSRC_HEADER, IDR_SETUP_RSRC_HEADER, 0 };
#endif

	LocalizationActive = FALSE;
	ActiveLangPackVersion[0] = 0;
	ClearDictionaryPool ();
	LanguageResource = NULL;

	if ((resourceid == 0) && (PreferredLangId[0] != 0))
		StringCbCopyA (langId, sizeof(langId), PreferredLangId);

	// Parse all available language files until preferred language is found
	for (res = MapFirstLanguageFile (); res != NULL; res = MapNextLanguageFile (resourceid))
	{
		xml = (char *) res;
		xml = XmlFindElement (xml, "localization");
		if (!xml)
			continue;

		// Required TrueCrypt version
		XmlGetAttributeText (xml, "prog-version", attr, sizeof (attr));

		// Check version of external language file
		if (defaultLangParsed && strcmp (attr, VERSION_STRING) && strcmp (attr, "DEBUG"))
		{
			wchar_t m[2048];
			StringCbPrintfW (m, sizeof(m), L"The installed language pack is incompatible with this version of VeraCrypt (the language pack is for VeraCrypt %hs). A newer version may be available at www.idrix.fr.\n\nTo prevent this message from being displayed, do any of the following:\n\n- Select 'Settings' > 'Language'; then select 'English' and click 'OK'.\n\n- Remove or replace the language pack with a compatible version (the language pack may reside e.g. in 'C:\\Program Files\\VeraCrypt' or '%%LOCALAPPDATA%%\\VirtualStore\\Program Files\\VeraCrypt', etc.)", attr);
			if (!bForceSilent)
				MessageBoxW (NULL, m, L"VeraCrypt", MB_ICONERROR);
			continue;
		}

		// Search language id in language file
		if (defaultLangParsed)
		{
			while (xml = XmlFindElement (xml, "language"))
			{
				XmlGetAttributeText (xml, "langid", attr, sizeof (attr));
				if (resourceid == 0)
				{
					if (strcmp (attr, langId) == 0)
					{
						XmlGetAttributeText (xml++, "version", ActiveLangPackVersion, sizeof (ActiveLangPackVersion));
						langFound = TRUE;
						break;
					}
					xml++;
				}
				else
				{
					StringCbCopyA (langId, sizeof (langId), attr);
					XmlGetAttributeText (xml++, "version", ActiveLangPackVersion, sizeof (ActiveLangPackVersion));
					langFound = TRUE;
					break;
				}
			}

			if (!langFound) continue;
		}

		// Create font dictionary
		xml = (char *) res;
		while (xml = XmlFindElement (xml, "font"))
		{
			XmlGetAttributeText (xml, "lang", attr, sizeof (attr));
			if (!defaultLangParsed
				|| strcmp (attr, langId) == 0)
			{
				Font font;
				memset (&font, 0, sizeof (font));

				XmlGetAttributeText (xml, "face", attr, sizeof (attr));

				len = MultiByteToWideChar (CP_UTF8, 0, attr, -1, wattr, sizeof (wattr) / sizeof(wattr[0]));
				font.FaceName = AddPoolData ((void *) wattr, len * 2);

				XmlGetAttributeText (xml, "size", attr, sizeof (attr));
				sscanf (attr, "%d", &font.Size);

				StringCbCopyA (attr, sizeof(attr), "font_");
				XmlGetAttributeText (xml, "class", attr + 5, sizeof (attr) - 5);
				AddDictionaryEntry (
					AddPoolData ((void *) attr, strlen (attr) + 1), 0,
					AddPoolData ((void *) &font, sizeof(font)));
			}

			xml++;
		}

		// Create string and control dictionaries
		for (i = 0; xmlElements[i] != 0; i++)
		{
			xml = (char *) res;
			while (xml = XmlFindElement (xml, xmlElements[i]))
			{
				void *pkey;
				void *text;

				XmlGetAttributeText (xml, "lang", attr, sizeof (attr));
				if (!defaultLangParsed
					|| strcmp (attr, langId) == 0)
				{
					if (XmlGetAttributeText (xml, "key", attr, sizeof (attr)))
					{
						pkey = AddPoolData (attr, strlen (attr) + 1);
						if (pkey == NULL) return FALSE;

						XmlGetNodeText (xml, attr, sizeof (attr));

						// Parse \ escape sequences
						{
							char *in = attr, *out = attr;
							while (*in)
							{
								if (*in == '\\')
								{
									in++;
									switch (*in++)
									{
									case '\\': *out++ = '\\'; break;
									case 't': *out++ = '\t'; break;
									case 'n': *out++ = 13; *out++ = 10; break;
									default:
										if (!bForceSilent)
											MessageBoxA (0, pkey, "VeraCrypt: Unknown '\\' escape sequence in string", MB_ICONERROR);
										return FALSE;
									}
								}
								else
									*out++ = *in++;
							}
							*out = 0;
						}

						// UTF8 => wide char
						len = MultiByteToWideChar (CP_UTF8, 0, attr, -1, wattr, sizeof (wattr) / sizeof(wattr[0]));
						if (len == 0)
						{
							if (!bForceSilent)
								MessageBoxA (0, pkey, "VeraCrypt: Error while decoding UTF-8 string", MB_ICONERROR);
							return FALSE;
						}

						// Add to dictionary
						text = AddPoolData ((void *) wattr, len * 2);
						if (text == NULL) return FALSE;

						AddDictionaryEntry ((char *)pkey, 0, text);
					}
				}

				xml++;
			}
		}

		if (langFound)
			break;

		if (!defaultLangParsed)
		{
			defaultLangParsed = TRUE;
			if ((resourceid == 0) && (langId[0] == 0 || strcmp (langId, "en") == 0))
				break;
		}
	}

	LocalizationActive = langFound && strcmp (langId, "en") != 0;
	LocalizationSerialNo++;

	if (bForceSetPreferredLanguage)
		StringCbCopyA (PreferredLangId, sizeof (PreferredLangId), langId);

	// Create control ID dictionary

	// Default controls
	AddDictionaryEntry (NULL, 1, GetString ("IDOK"));
	AddDictionaryEntry (NULL, 2, GetString ("IDCANCEL"));
	AddDictionaryEntry (NULL, 8, GetString ("IDCLOSE"));
	AddDictionaryEntry (NULL, 9, GetString ("IDHELP"));

	for (i = 0; headers[i] != 0; i++)
	{
		if (HeaderResource[i] == NULL)
		{
			HeaderResource[i] = MapResource (L"Header", headers[i], &size);
			if (HeaderResource[i])
				HeaderResourceSize[i] = size;
		}

		headerPtr = NULL;
		if (HeaderResource[i])
		{
			headerPtr = (char*) malloc (HeaderResourceSize[i] + 1);
			if (headerPtr)
			{
				memcpy (headerPtr, HeaderResource[i], HeaderResourceSize[i]);
				headerPtr [HeaderResourceSize[i]] = 0;
			}
		}

		header = headerPtr;
		if (header == NULL) return FALSE;
		header--;

		do
		{
			header++;
			if (sscanf (header, "#define %127s %d", key, &intKey) == 2)
			{
				WCHAR *str = GetString (key);

				if (str != UnknownString)
					AddDictionaryEntry (NULL, intKey, str);
			}

		} while ((header = strchr (header, '\n')) != NULL);

		free (headerPtr);
	}

	return TRUE;
}

BOOL LoadLanguageFile ()
{
	return LoadLanguageData (0, FALSE, FALSE);
}

BOOL LoadLanguageFromResource (int resourceid, BOOL bSetPreferredLanguage, BOOL bForceSilent)
{
	return LoadLanguageData (resourceid, bSetPreferredLanguage, bForceSilent);
}

// lParam = 1: auto mode
BOOL CALLBACK LanguageDlgProc (HWND hwndDlg, UINT msg, WPARAM wParam, LPARAM lParam)
{
	WORD lw = LOWORD (wParam);
	WORD hw = HIWORD (wParam);

	switch (msg)
	{
	case WM_INITDIALOG:
		{
			char *xml;
			char attr[2048], lastLangId[10];
			WCHAR wattr[2048];
			int len;
			int langCount = 0;
			BOOL defaultLangFound = FALSE;

			LocalizeDialog (hwndDlg, "IDD_LANGUAGE");
			ToHyperlink (hwndDlg, IDC_GET_LANG_PACKS);

			for (xml = MapFirstLanguageFile (); xml != NULL; xml = MapNextLanguageFile (0))
			{
				while (xml = XmlFindElement (xml, "language"))
				{
					XmlGetAttributeText (xml, "name", attr, sizeof (attr));
					len = MultiByteToWideChar (CP_UTF8, 0, attr, -1, wattr, sizeof (wattr) / sizeof(wattr[0]));

					if (len != 0
						&& (!defaultLangFound || wcscmp (wattr, L"English") != 0))
					{
						int i = (int) SendDlgItemMessageW (hwndDlg, IDC_LANGLIST, LB_ADDSTRING, 0, (LPARAM)wattr);
						if (i >= 0)
						{
							int id;

							// Encode language id in LPARAM
							XmlGetAttributeText (xml, "langid", attr, sizeof (attr));
							switch (strlen (attr))
							{
							case 2: id = attr[0] | attr[1] << 8; break;
							case 5: id = attr[0] | attr[1] << 8 | attr[3] << 16 | attr[4] << 24; break;
							default: continue;
							}

							if (!defaultLangFound)
								defaultLangFound = TRUE;

							SendDlgItemMessage (hwndDlg, IDC_LANGLIST, LB_SETITEMDATA, i, (LPARAM) id);

							if (strcmp (attr, PreferredLangId) == 0)
							{
								char credits [10000];
								WCHAR wcredits [10000];
								WCHAR wversion [20];
								wchar_t szVers [200];
								int nLen;

								SendDlgItemMessage (hwndDlg, IDC_LANGLIST, LB_SETCURSEL, i, 0);

								// Language pack version
								if (!ActiveLangPackVersion[0] || memcmp (ActiveLangPackVersion, "0.0.0", 5) == 0)
								{
									StringCbPrintfW (szVers, sizeof(szVers), GetString("LANG_PACK_VERSION"), L"--");
								}
								else
								{
									nLen = MultiByteToWideChar (CP_UTF8, 0, ActiveLangPackVersion, -1, wversion, sizeof (wversion) / sizeof(wversion[0]));
									if (nLen != 0)
										StringCbPrintfW (szVers, sizeof(szVers),GetString("LANG_PACK_VERSION"), wversion);
								}
								SetWindowTextW (GetDlgItem (hwndDlg, IDC_LANGPACK_VERSION), szVers);

								// Translator credits
								XmlGetAttributeText (xml, "translators", credits, sizeof (credits));
								nLen = MultiByteToWideChar (CP_UTF8, 0, credits, -1, wcredits, sizeof (wcredits) / sizeof(wcredits[0]));
								if (nLen != 0)
								{
									SetWindowTextW (GetDlgItem (hwndDlg, IDC_LANGPACK_CREDITS), wcredits);
								}
							}

							StringCbCopyA (lastLangId, sizeof(lastLangId),attr);
							langCount++;
						}
					}

					xml++;
				}
			}

			if (lParam == 1)
			{
				// Auto mode
				if (langCount < 2)
					EndDialog (hwndDlg, IDCANCEL);

				if (langCount == 2)
					StringCbCopyA (PreferredLangId, sizeof(PreferredLangId), lastLangId);

				EndDialog (hwndDlg, IDOK);
			}

			return 1;
		}

	case WM_COMMAND:

		if (lw == IDOK || hw == LBN_DBLCLK)
		{
			int i = (int) SendDlgItemMessage (hwndDlg, IDC_LANGLIST, LB_GETCURSEL, 0, 0);

			if (i >= 0)
			{
				int id = (int) SendDlgItemMessage (hwndDlg, IDC_LANGLIST, LB_GETITEMDATA, i, 0);

				if (id != LB_ERR)
				{
					char l[6];

					// Decode language id from LPARAM
					l[0] = (char) id;
					l[1] = (char) (id >> 8);
					l[2] = 0;

					if ((id & 0xffff0000) != 0)
					{
						l[2] = '-';
						l[3] = (char) (id >> 16);
						l[4] = id >> 24;
						l[5] = 0;
					}

					if (SendDlgItemMessage (hwndDlg, IDC_LANGLIST, LB_GETCOUNT, 0, 0) > 1)
						StringCbCopyA (PreferredLangId, sizeof(PreferredLangId), l);
				}
			}

			EndDialog (hwndDlg, IDOK);
			return 1;
		}

		if (lw == IDCANCEL)
		{
			EndDialog (hwndDlg, lw);
			return 1;
		}

		if (lw == IDC_GET_LANG_PACKS)
		{
			char tmpstr [256];

			if (strlen (ActiveLangPackVersion) > 0 && strlen (GetPreferredLangId()) > 0)
				StringCbPrintfA (tmpstr, sizeof(tmpstr), "&langpackversion=%s&lang=%s", ActiveLangPackVersion, GetPreferredLangId());
			else
				tmpstr[0] = 0;

			Applink ("localizations");

			return 1;
		}
		return 0;
	}

	return 0;
}


char *GetPreferredLangId ()
{
	return PreferredLangId;
}


void SetPreferredLangId (char *langId)
{
	if (strlen(langId) < sizeof(PreferredLangId))
		StringCbCopyA (PreferredLangId, sizeof(PreferredLangId), langId);
}


char *GetActiveLangPackVersion ()
{
	return ActiveLangPackVersion;
}


wchar_t *GetString (const char *stringId)
{
	WCHAR *str = (WCHAR *) GetDictionaryValue (stringId);
	if (str != NULL) return str;

	StringCbPrintfW (UnknownString, sizeof(UnknownString), UNKNOWN_STRING_ID L"%hs" UNKNOWN_STRING_ID, stringId);
	return UnknownString;
}


Font *GetFont (char *fontType)
{
	return (Font *) GetDictionaryValue (fontType);

}