/*
Copyright (C) 2009-2016 Parallel Realities

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, 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA.
*/

#include "i18n.h"

char *getTranslatedString(char *);
void setLanguage(char *, char *);
void cleanupLanguage(void);
static int hashCode(char *);
static void put(char *, char *);
static void initTable(void);

static HashTable table;

void setLanguage(char *applicationName, char *languageCode)
{
	char language[MAX_DESCRIPTION_LENGTH], c[MAX_LINE_LENGTH];
	char **key, **value;
	#ifndef _WIN32
	char *lang;
	#endif
	int i, swap;
	FILE *fp;
	MOHeader header;
	MOEntry *original, *translation;
	#if DEV == 1
		int read;
	#endif

	initTable();

	language[0] = '\0';

	if (languageCode == NULL)
	{
		#ifdef _WIN32
			GetLocaleInfoA(LOCALE_USER_DEFAULT, LOCALE_SISO639LANGNAME, c, MAX_LINE_LENGTH);

			if (c[0] != '\0')
			{
				STRNCPY(language, c, MAX_DESCRIPTION_LENGTH);

				GetLocaleInfoA(LOCALE_USER_DEFAULT, LOCALE_SISO3166CTRYNAME, c, MAX_LINE_LENGTH);

				if (c[0] != '\0')
				{
					strncat(language, "_", MAX_DESCRIPTION_LENGTH - strlen(language) - 1);

					strncat(language, c, MAX_DESCRIPTION_LENGTH - strlen(language) - 1);
				}
			}
		#else
			if ((lang = getenv("LC_ALL")) || (lang = getenv("LC_CTYPE")) || (lang = getenv("LANG")))
			{
				STRNCPY(language, lang, MAX_DESCRIPTION_LENGTH);
			}
		#endif
	}

	else
	{
		STRNCPY(language, languageCode, MAX_DESCRIPTION_LENGTH);
	}
	
	strtok(language, ".");

	SDL_LogMessage(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO, "Locale is %s", language);

	sprintf(c, "%s/%s/LC_MESSAGES/%s.mo", LOCALE_DIR, language, applicationName);

	#if DEV == 1
		printf("Opening %s\n", c);
	#endif

	fp = fopen(c, "rb");

	if (fp == NULL)
	{
		#if DEV == 1
			printf("Failed to open %s/%s/LC_MESSAGES/%s.mo\n", LOCALE_DIR, language, applicationName);
		#endif

		if (strstr(language, "_") == NULL)
		{
			return;
		}
		
		strtok(language, "_");
		
		SDL_LogMessage(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO, "Language is %s", language);

		sprintf(c, "%s/%s/LC_MESSAGES/%s.mo", LOCALE_DIR, language, applicationName);

		#if DEV == 1
			printf("Opening %s\n", c);
		#endif

		fp = fopen(c, "rb");

		if (fp == NULL)
		{
			#if DEV == 1
				printf("Failed to open %s/%s/LC_MESSAGES/%s.mo\n", LOCALE_DIR, language, applicationName);
			#endif

			return;
		}
	}

	fread(&header, sizeof(header), 1, fp);

	swap = header.magicNumber == 0x950412de ? 0 : 1;

	if (swap)
	{
		header.stringCount = SDL_Swap32(header.stringCount);
		header.originalOffset = SDL_Swap32(header.originalOffset);
		header.translationOffset = SDL_Swap32(header.translationOffset);
	}

	original = malloc(sizeof(MOEntry) * header.stringCount);

	translation = malloc(sizeof(MOEntry) * header.stringCount);

	if (original == NULL || translation == NULL)
	{
		printf("Failed to allocate %d bytes for translation strings\n", (int)sizeof(MOEntry) * header.stringCount);

		exit(1);
	}

	#if DEV == 1
		printf("MO file has %d entries\n", header.stringCount);
	#endif

	fseek(fp, header.originalOffset, SEEK_SET);

	key = malloc(sizeof(char *) * header.stringCount);

	value = malloc(sizeof(char *) * header.stringCount);

	if (key == NULL || value == NULL)
	{
		printf("Failed to allocate a whole %d bytes for translation strings\n", (int)sizeof(char *) * header.stringCount);

		exit(1);
	}

	for (i=0;i<header.stringCount;i++)
	{
		fread(&original[i].length, sizeof(int32_t), 1, fp);
		fread(&original[i].offset, sizeof(int32_t), 1, fp);

		if (swap)
		{
			original[i].length = SDL_Swap32(original[i].length);
			original[i].offset = SDL_Swap32(original[i].offset);
		}

		key[i] = malloc(original[i].length + 1);

		if (key[i] == NULL)
		{
			printf("Failed to allocate a whole %d bytes for translation string\n", original[i].length + 1);

			exit(1);
		}
	}

	fseek(fp, header.translationOffset, SEEK_SET);

	for (i=0;i<header.stringCount;i++)
	{
		fread(&translation[i].length, sizeof(int32_t), 1, fp);
		fread(&translation[i].offset, sizeof(int32_t), 1, fp);

		if (swap)
		{
			translation[i].length = SDL_Swap32(translation[i].length);
			translation[i].offset = SDL_Swap32(translation[i].offset);
		}

		value[i] = malloc(translation[i].length + 1);

		if (value[i] == NULL)
		{
			printf("Failed to allocate a whole %d bytes for translation string\n", translation[i].length + 1);

			exit(1);
		}
	}

	for (i=0;i<header.stringCount;i++)
	{
		fseek(fp, original[i].offset, SEEK_SET);

		fread(key[i], original[i].length, 1, fp);

		key[i][original[i].length] = '\0';
	}

	for (i=0;i<header.stringCount;i++)
	{
		fseek(fp, translation[i].offset, SEEK_SET);

		fread(value[i], translation[i].length, 1, fp);

		value[i][translation[i].length] = '\0';
	}

	fclose(fp);

	for (i=0;i<header.stringCount;i++)
	{
		put(key[i], value[i]);

		free(key[i]);

		free(value[i]);
	}

	free(key);

	free(value);

	free(original);

	free(translation);

	#if DEV == 1
		read = 0;

		for (i=0;i<TABLE_SIZE;i++)
		{
			if (table.bucketCount[i] != 0)
			{
				read++;
			}
		}

		printf("Using %d of %d buckets (%d%%)\n", read, TABLE_SIZE, (read *  100) / TABLE_SIZE);
	#endif
}

static int hashCode(char *data)
{
	int i, length;
	unsigned int hash;

	length = strlen(data);

	hash = 0;

	for (i=0;i<length;i++)
	{
		hash = data[i] + (hash << 5) - hash;
	}

	return hash % TABLE_SIZE;
}

static void initTable()
{
	int i;

	table.bucket = malloc(sizeof(Bucket *) * TABLE_SIZE);

	table.bucketCount = malloc(sizeof(int) * TABLE_SIZE);

	if (table.bucket == NULL || table.bucketCount == NULL)
	{
		printf("Failed to allocate %d bytes for a HashTable\n", (int)sizeof(Bucket *) * TABLE_SIZE);

		exit(1);
	}

	for (i=0;i<TABLE_SIZE;i++)
	{
		table.bucket[i] = malloc(sizeof(Bucket));

		table.bucket[i]->next = NULL;

		table.bucketCount[i] = 0;
	}
}

static void put(char *key, char *value)
{
	Bucket *bucket, *newBucket;
	unsigned int hash = hashCode(key);

	#if DEV == 1
		printf("%s = %d\n", key, hash);
	#endif

	bucket = table.bucket[hash];

	while (bucket->next != NULL)
	{
		bucket = bucket->next;
	}

	newBucket = malloc(sizeof(Bucket));

	if (newBucket == NULL)
	{
		printf("Failed to allocate a whole %d bytes for a HashTable bucket\n", (int)sizeof(Bucket));

		exit(1);
	}

	newBucket->key   = malloc(strlen(key) + 1);
	newBucket->value = malloc(strlen(value) + 1);

	if (newBucket->key == NULL || newBucket->value == NULL)
	{
		printf("Failed to allocate a whole %d bytes for a translation\n", (int)strlen(newBucket->key) + 1);

		exit(1);
	}

	STRNCPY(newBucket->key, key, strlen(key) + 1);
	STRNCPY(newBucket->value, value, strlen(value) + 1);

	newBucket->next = NULL;

	bucket->next = newBucket;

	table.bucketCount[hash]++;
}

char *getTranslatedString(char *key)
{
	Bucket *bucket;
	unsigned int hash = hashCode(key);

	bucket = table.bucket[hash]->next;

	for (;bucket!=NULL;bucket=bucket->next)
	{
		if (strcasecmp(key, bucket->key) == 0)
		{
			return strlen(bucket->value) == 0 ? key : bucket->value;
		}
	}

	return key;
}

void cleanupLanguage()
{
	int i;
	Bucket *bucket, *p, *q;

	for (i=0;i<TABLE_SIZE;i++)
	{
		bucket = table.bucket[i];

		for (p=bucket->next;p!=NULL;p=q)
		{
			free(p->key);
			free(p->value);

			q = p->next;

			free(p);
		}

		free(bucket);
	}

	table.bucket = NULL;
}