/*-------------------------------------------------------------------------
 *
 *	  WIN <--> UTF8
 *
 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *	  src/backend/utils/mb/conversion_procs/utf8_and_win/utf8_and_win.c
 *
 *-------------------------------------------------------------------------
 */

#include "postgres.h"
#include "fmgr.h"
#include "mb/pg_wchar.h"
#include "../../Unicode/utf8_to_win1250.map"
#include "../../Unicode/utf8_to_win1251.map"
#include "../../Unicode/utf8_to_win1252.map"
#include "../../Unicode/utf8_to_win1253.map"
#include "../../Unicode/utf8_to_win1254.map"
#include "../../Unicode/utf8_to_win1255.map"
#include "../../Unicode/utf8_to_win1256.map"
#include "../../Unicode/utf8_to_win1257.map"
#include "../../Unicode/utf8_to_win1258.map"
#include "../../Unicode/utf8_to_win866.map"
#include "../../Unicode/utf8_to_win874.map"
#include "../../Unicode/win1250_to_utf8.map"
#include "../../Unicode/win1251_to_utf8.map"
#include "../../Unicode/win1252_to_utf8.map"
#include "../../Unicode/win1253_to_utf8.map"
#include "../../Unicode/win1254_to_utf8.map"
#include "../../Unicode/win1255_to_utf8.map"
#include "../../Unicode/win1256_to_utf8.map"
#include "../../Unicode/win1257_to_utf8.map"
#include "../../Unicode/win866_to_utf8.map"
#include "../../Unicode/win874_to_utf8.map"
#include "../../Unicode/win1258_to_utf8.map"

PG_MODULE_MAGIC_EXT(
					.name = "utf8_and_win",
					.version = PG_VERSION
);

PG_FUNCTION_INFO_V1(win_to_utf8);
PG_FUNCTION_INFO_V1(utf8_to_win);

/* ----------
 * conv_proc(
 *		INTEGER,	-- source encoding id
 *		INTEGER,	-- destination encoding id
 *		CSTRING,	-- source string (null terminated C string)
 *		CSTRING,	-- destination string (null terminated C string)
 *		INTEGER,	-- source string length
 *		BOOL		-- if true, don't throw an error if conversion fails
 * ) returns INTEGER;
 *
 * Returns the number of bytes successfully converted.
 * ----------
 */

typedef struct
{
	pg_enc		encoding;
	const pg_mb_radix_tree *map1;	/* to UTF8 map name */
	const pg_mb_radix_tree *map2;	/* from UTF8 map name */
} pg_conv_map;

static const pg_conv_map maps[] = {
	{PG_WIN866, &win866_to_unicode_tree, &win866_from_unicode_tree},
	{PG_WIN874, &win874_to_unicode_tree, &win874_from_unicode_tree},
	{PG_WIN1250, &win1250_to_unicode_tree, &win1250_from_unicode_tree},
	{PG_WIN1251, &win1251_to_unicode_tree, &win1251_from_unicode_tree},
	{PG_WIN1252, &win1252_to_unicode_tree, &win1252_from_unicode_tree},
	{PG_WIN1253, &win1253_to_unicode_tree, &win1253_from_unicode_tree},
	{PG_WIN1254, &win1254_to_unicode_tree, &win1254_from_unicode_tree},
	{PG_WIN1255, &win1255_to_unicode_tree, &win1255_from_unicode_tree},
	{PG_WIN1256, &win1256_to_unicode_tree, &win1256_from_unicode_tree},
	{PG_WIN1257, &win1257_to_unicode_tree, &win1257_from_unicode_tree},
	{PG_WIN1258, &win1258_to_unicode_tree, &win1258_from_unicode_tree},
};

Datum
win_to_utf8(PG_FUNCTION_ARGS)
{
	int			encoding = PG_GETARG_INT32(0);
	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
	int			len = PG_GETARG_INT32(4);
	bool		noError = PG_GETARG_BOOL(5);
	int			i;

	CHECK_ENCODING_CONVERSION_ARGS(-1, PG_UTF8);

	for (i = 0; i < lengthof(maps); i++)
	{
		if (encoding == maps[i].encoding)
		{
			int			converted;

			converted = LocalToUtf(src, len, dest,
								   maps[i].map1,
								   NULL, 0,
								   NULL,
								   encoding,
								   noError);
			PG_RETURN_INT32(converted);
		}
	}

	ereport(ERROR,
			(errcode(ERRCODE_INTERNAL_ERROR),
			 errmsg("unexpected encoding ID %d for WIN character sets",
					encoding)));

	PG_RETURN_INT32(0);
}

Datum
utf8_to_win(PG_FUNCTION_ARGS)
{
	int			encoding = PG_GETARG_INT32(1);
	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
	int			len = PG_GETARG_INT32(4);
	bool		noError = PG_GETARG_BOOL(5);
	int			i;

	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, -1);

	for (i = 0; i < lengthof(maps); i++)
	{
		if (encoding == maps[i].encoding)
		{
			int			converted;

			converted = UtfToLocal(src, len, dest,
								   maps[i].map2,
								   NULL, 0,
								   NULL,
								   encoding,
								   noError);
			PG_RETURN_INT32(converted);
		}
	}

	ereport(ERROR,
			(errcode(ERRCODE_INTERNAL_ERROR),
			 errmsg("unexpected encoding ID %d for WIN character sets",
					encoding)));

	PG_RETURN_INT32(0);
}