/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * This is a utility for create the translations.dat file from all the po files.
 * The generated files is used by ScummVM to propose translation of its GUI.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#include "po_parser.h"

PoMessageList::PoMessageList() : _messages(NULL), _size(0), _allocated(0) {
}

PoMessageList::~PoMessageList() {
	for (int i = 0 ; i < _size ; ++i)
		delete [] _messages[i];
	delete [] _messages;
}

void PoMessageList::insert(const char *msg) {
	if (msg == NULL || *msg == '\0')
		return;
	
	// binary-search for the insertion index
	int leftIndex = 0;
	int rightIndex = _size - 1;
	while (rightIndex >= leftIndex) {
		int midIndex = (leftIndex + rightIndex) / 2;
		int compareResult = strcmp(msg, _messages[midIndex]);
		if (compareResult == 0)
			return;
		else if (compareResult < 0)
			rightIndex = midIndex - 1;
		else
			leftIndex = midIndex + 1;
	}
	// We now have rightIndex = leftIndex - 1 and we need to insert the new message
	// between the two (i.a. at leftIndex).
	if (_size + 1 > _allocated) {
		_allocated += 100;
		char** newMessages = new char*[_allocated];
		for (int i = 0 ; i < leftIndex ; ++i)
			newMessages[i] = _messages[i];
		for (int i = leftIndex ; i < _size ; ++i)
			newMessages[i+1] = _messages[i];
		delete [] _messages;
		_messages = newMessages;
	} else {
		for (int i = _size - 1 ; i >= leftIndex ; --i)
			_messages[i+1] = _messages[i];
	}
	_messages[leftIndex] = new char[1+strlen(msg)];
	strcpy(_messages[leftIndex], msg);
	++_size;
}

int PoMessageList::findIndex(const char *msg) {
	if (msg == NULL || *msg == '\0')
		return -1;
	
	// binary-search for the message
	int leftIndex = 0;
	int rightIndex = _size - 1;
	
	while (rightIndex >= leftIndex) {
		const int midIndex = (leftIndex + rightIndex) / 2;
		const int compareResult = strcmp(msg, _messages[midIndex]);
		if (compareResult == 0)
			return midIndex;
		else if (compareResult < 0)
			rightIndex = midIndex - 1;
		else
			leftIndex = midIndex + 1;
	}

	return -1;
}

int PoMessageList::size() const {
	return _size;
}

const char* PoMessageList::operator[](int index) const {
	if (index < 0 || index >= _size)
		return NULL;
	return _messages[index];
}

PoMessageEntryList::PoMessageEntryList(const char* lang) :
	_lang(NULL), _charset(NULL), _langName(NULL),
	_list(NULL), _size(0), _allocated(0)
{
	_lang = new char[1 + strlen(lang)];
	strcpy(_lang, lang);
	// Set default charset to empty string
	_charset = new char[1];
	_charset[0] = '\0';
	// Set default langName to lang
	_langName = new char[1 + strlen(lang)];
	strcpy(_langName, lang);
}

PoMessageEntryList::~PoMessageEntryList() {
	delete [] _lang;
	delete [] _charset;
	delete [] _langName;
	for (int i = 0 ; i < _size ; ++i)
		delete _list[i];
	delete [] _list;
}

void PoMessageEntryList::addMessageEntry(const char *translation, const char *message, const char *context) {
	if (*message == '\0') {
		// This is the header.
		// We get the charset and the language name from the translation string
		char* str = parseLine(translation, "Language:");
		if (str != NULL) {
			delete [] _langName;
			_langName = str;
		}
		str = parseLine(translation, "charset=");
		if (str != NULL) {
			delete [] _charset;
			_charset = str;
		}
		return;
	}	
	
	// binary-search for the insertion index
	int leftIndex = 0;
	int rightIndex = _size - 1;
	while (rightIndex >= leftIndex) {
		int midIndex = (leftIndex + rightIndex) / 2;
		int compareResult = strcmp(message, _list[midIndex]->msgid);
		if (compareResult == 0) {
			if (context == NULL) {
				if (_list[midIndex]->msgctxt == NULL)
					return;
				compareResult = -1;
			} else {
				if (_list[midIndex]->msgctxt == NULL)
					compareResult = 1;
				else {
					compareResult = strcmp(context, _list[midIndex]->msgctxt);
					if (compareResult == 0)
						return;
				}
			}
		}
		if (compareResult < 0)
			rightIndex = midIndex - 1;
		else
			leftIndex = midIndex + 1;
	}
	// We now have rightIndex = leftIndex - 1 and we need to insert the new message
	// between the two (i.a. at leftIndex).
	if (_size + 1 > _allocated) {
		_allocated += 100;
		PoMessageEntry** newList = new PoMessageEntry*[_allocated];
		for (int i = 0 ; i < leftIndex ; ++i)
			newList[i] = _list[i];
		for (int i = leftIndex ; i < _size ; ++i)
			newList[i+1] = _list[i];
		delete [] _list;
		_list = newList;
	} else {
		for (int i = _size - 1 ; i >= leftIndex ; --i)
			_list[i+1] = _list[i];
	}
	_list[leftIndex] = new PoMessageEntry(translation, message, context);
	++_size;
}

const char* PoMessageEntryList::language() const {
	return _lang;
}

const char* PoMessageEntryList::languageName() const {
	return _langName;
}

const char* PoMessageEntryList::charset() const {
	return _charset;
}

int PoMessageEntryList::size() const {
	return _size;
}

const PoMessageEntry* PoMessageEntryList::entry(int index) const {
	if (index < 0 || index >= _size)
		return NULL;
	return _list[index];
}


PoMessageEntryList* parsePoFile(const char* file, PoMessageList& messages) {
	FILE* inFile = fopen(file, "r");
	if (!inFile)
		return NULL;
	
	char msgidBuf[1024], msgctxtBuf[1024], msgstrBuf[1024];
	char line[1024], *currentBuf = NULL;
	
	// Get language from file name and create PoMessageEntryList
	int index = 0, start_index = strlen(file) - 1;
	while (start_index > 0 && file[start_index-1] != '/' && file[start_index-1] != '\\') {
		--start_index;
	}
	while (file[start_index+index] != '.' && file[start_index+index] != '\0') {
		msgidBuf[index] = file[start_index+index];
		++index;
	}
	msgidBuf[index] = '\0';
	PoMessageEntryList *list = new PoMessageEntryList(msgidBuf);
	
	// Parse the file line by line.
	// The msgstr is always the last line of an entry (i.e. msgid and msgctxt always
	// precede the corresponding msgstr).
	msgidBuf[0] = msgstrBuf[0] = msgctxtBuf[0] = '\0';
	while (!feof(inFile) && fgets(line, 1024, inFile)) {
		// Skip empty and comment line
		if (*line == '\n' || *line == '#')
			continue;
		if (strncmp(line, "msgid", 5) == 0) {
			if (currentBuf == msgstrBuf) {
				// add previous entry
				if (*msgstrBuf != '\0') {
					messages.insert(msgidBuf);
					list->addMessageEntry(msgstrBuf, msgidBuf, msgctxtBuf);
				}
				msgidBuf[0] = msgstrBuf[0] = msgctxtBuf[0] = '\0';
			}
			strcpy(msgidBuf, stripLine(line));
			currentBuf = msgidBuf;
		} else if (strncmp(line, "msgctxt", 7) == 0) {
			if (currentBuf == msgstrBuf) {
				// add previous entry
				if (*msgstrBuf != '\0') {
					messages.insert(msgidBuf);
					list->addMessageEntry(msgstrBuf, msgidBuf, msgctxtBuf);
				}
				msgidBuf[0] = msgstrBuf[0] = msgctxtBuf[0] = '\0';
			}
			strcpy(msgctxtBuf, stripLine(line));
			currentBuf = msgctxtBuf;
		} else if (strncmp(line, "msgstr", 6) == 0) {
			strcpy(msgstrBuf, stripLine(line));
			currentBuf = msgstrBuf;
		} else {
			// concatenate the string at the end of the current buffer
			if (currentBuf)
				strcat(currentBuf, stripLine(line));
		}
	}
	
	fclose(inFile);
	return list;
}

char* stripLine(char* line) {
	// This function modifies line in place and return it.
	// Keep only the text between the first two unprotected quotes.
	// Look for the first quote
	int start = 0;
	int len = strlen(line);
	while (start < len && line[start++] != '"') {}
	// shift characters until we reach the end of the string or an unprotected quote
	int i = 0;
	while (start+i < len && (line[start+i] != '"' || (i > 0 && line[start+i-1] == '\\'))) {
		line[i] = line[start+i];
		++i;
	}
	line[i] = '\0';
	return line;
}

char* parseLine(const char* line, const char* field) {
	// This function allocate and return a new char*.
	// It will return a NULL pointer if the field is not found.
	// It is used to parse the header of the po files to find the language name
	// and the charset.
	char* str = strstr(line, field);
	if (str == NULL)
		return NULL;
	str += strlen(field);
	// Skip spaces
	while (*str != '\0' && isspace(*str)) {
		++str;
	}
	// Find string length (top at the first '\\'
	// (since the string we want is followed by a '\\n')
	int len = 0;
	while (str[len] != '\0' && str[len] != '\\') {
		++len;
	}
	if (len == 0)
		return NULL;
	// Create result string
	char* result = new char[len+1];
	strncpy(result, str, len);
	result[len] = '\0';
	return result;
}