/*

 * cjkcodecs.h: common header for cjkcodecs

 *

 * Written by Hye-Shik Chang <perky@FreeBSD.org>

 */

#ifndef _CJKCODECS_H_

#define _CJKCODECS_H_

#define PY_SSIZE_T_CLEAN

#include "Python.h"

#include "multibytecodec.h"

/* a unicode "undefined" codepoint */

#define UNIINV	0xFFFE

/* internal-use DBCS codepoints which aren't used by any charsets */

#define NOCHAR	0xFFFF

#define MULTIC	0xFFFE

#define DBCINV	0xFFFD

/* shorter macros to save source size of mapping tables */

#define U UNIINV

#define N NOCHAR

#define M MULTIC

#define D DBCINV

struct dbcs_index {

	const ucs2_t *map;

	unsigned char bottom, top;

};

typedef struct dbcs_index decode_map;

struct widedbcs_index {

	const ucs4_t *map;

	unsigned char bottom, top;

};

typedef struct widedbcs_index widedecode_map;

struct unim_index {

	const DBCHAR *map;

	unsigned char bottom, top;

};

typedef struct unim_index encode_map;

struct unim_index_bytebased {

	const unsigned char *map;

	unsigned char bottom, top;

};

struct dbcs_map {

	const char *charset;

	const struct unim_index *encmap;

	const struct dbcs_index *decmap;

};

struct pair_encodemap {

	ucs4_t uniseq;

	DBCHAR code;

};

static const MultibyteCodec *codec_list;

static const struct dbcs_map *mapping_list;

#define CODEC_INIT(encoding)						\

	static int encoding##_codec_init(const void *config)

#define ENCODER_INIT(encoding)						\

	static int encoding##_encode_init(				\

		MultibyteCodec_State *state, const void *config)

#define ENCODER(encoding)						\

	static Py_ssize_t encoding##_encode(				\

		MultibyteCodec_State *state, const void *config,	\

		const Py_UNICODE **inbuf, Py_ssize_t inleft,		\

		unsigned char **outbuf, Py_ssize_t outleft, int flags)

#define ENCODER_RESET(encoding)						\

	static Py_ssize_t encoding##_encode_reset(			\

		MultibyteCodec_State *state, const void *config,	\

		unsigned char **outbuf, Py_ssize_t outleft)

#define DECODER_INIT(encoding)						\

	static int encoding##_decode_init(				\

		MultibyteCodec_State *state, const void *config)

#define DECODER(encoding)						\

	static Py_ssize_t encoding##_decode(				\

		MultibyteCodec_State *state, const void *config,	\

		const unsigned char **inbuf, Py_ssize_t inleft,		\

		Py_UNICODE **outbuf, Py_ssize_t outleft)

#define DECODER_RESET(encoding)						\

	static Py_ssize_t encoding##_decode_reset(			\

		MultibyteCodec_State *state, const void *config)

#if Py_UNICODE_SIZE == 4

#define UCS4INVALID(code)	\

	if ((code) > 0xFFFF)	\

	return 1;

#else

#define UCS4INVALID(code)	\

	if (0) ;

#endif

#define NEXT_IN(i)				\

	(*inbuf) += (i);			\

	(inleft) -= (i);

#define NEXT_OUT(o)				\

	(*outbuf) += (o);			\

	(outleft) -= (o);

#define NEXT(i, o)				\

	NEXT_IN(i) NEXT_OUT(o)

#define REQUIRE_INBUF(n)			\

	if (inleft < (n))			\

		return MBERR_TOOFEW;

#define REQUIRE_OUTBUF(n)			\

	if (outleft < (n))			\

		return MBERR_TOOSMALL;

#define IN1 ((*inbuf)[0])

#define IN2 ((*inbuf)[1])

#define IN3 ((*inbuf)[2])

#define IN4 ((*inbuf)[3])

#define OUT1(c) ((*outbuf)[0]) = (c);

#define OUT2(c) ((*outbuf)[1]) = (c);

#define OUT3(c) ((*outbuf)[2]) = (c);

#define OUT4(c) ((*outbuf)[3]) = (c);

#define WRITE1(c1)		\

	REQUIRE_OUTBUF(1)	\

	(*outbuf)[0] = (c1);

#define WRITE2(c1, c2)		\

	REQUIRE_OUTBUF(2)	\

	(*outbuf)[0] = (c1);	\

	(*outbuf)[1] = (c2);

#define WRITE3(c1, c2, c3)	\

	REQUIRE_OUTBUF(3)	\

	(*outbuf)[0] = (c1);	\

	(*outbuf)[1] = (c2);	\

	(*outbuf)[2] = (c3);

#define WRITE4(c1, c2, c3, c4)	\

	REQUIRE_OUTBUF(4)	\

	(*outbuf)[0] = (c1);	\

	(*outbuf)[1] = (c2);	\

	(*outbuf)[2] = (c3);	\

	(*outbuf)[3] = (c4);

#if Py_UNICODE_SIZE == 2

# define WRITEUCS4(c)						\

	REQUIRE_OUTBUF(2)					\

	(*outbuf)[0] = 0xd800 + (((c) - 0x10000) >> 10);	\

	(*outbuf)[1] = 0xdc00 + (((c) - 0x10000) & 0x3ff);	\

	NEXT_OUT(2)

#else

# define WRITEUCS4(c)						\

	REQUIRE_OUTBUF(1)					\

	**outbuf = (Py_UNICODE)(c);				\

	NEXT_OUT(1)

#endif

#define _TRYMAP_ENC(m, assi, val)				\

	((m)->map != NULL && (val) >= (m)->bottom &&		\

	    (val)<= (m)->top && ((assi) = (m)->map[(val) -	\

	    (m)->bottom]) != NOCHAR)

#define TRYMAP_ENC_COND(charset, assi, uni)			\

	_TRYMAP_ENC(&charset##_encmap[(uni) >> 8], assi, (uni) & 0xff)

#define TRYMAP_ENC(charset, assi, uni)				\

	if TRYMAP_ENC_COND(charset, assi, uni)

#define _TRYMAP_DEC(m, assi, val)				\

	((m)->map != NULL && (val) >= (m)->bottom &&		\

	    (val)<= (m)->top && ((assi) = (m)->map[(val) -	\

	    (m)->bottom]) != UNIINV)

#define TRYMAP_DEC(charset, assi, c1, c2)			\

	if _TRYMAP_DEC(&charset##_decmap[c1], assi, c2)

#define _TRYMAP_ENC_MPLANE(m, assplane, asshi, asslo, val)	\

	((m)->map != NULL && (val) >= (m)->bottom &&		\

	    (val)<= (m)->top &&					\

	    ((assplane) = (m)->map[((val) - (m)->bottom)*3]) != 0 && \

	    (((asshi) = (m)->map[((val) - (m)->bottom)*3 + 1]), 1) && \

	    (((asslo) = (m)->map[((val) - (m)->bottom)*3 + 2]), 1))

#define TRYMAP_ENC_MPLANE(charset, assplane, asshi, asslo, uni)	\

	if _TRYMAP_ENC_MPLANE(&charset##_encmap[(uni) >> 8], \

			   assplane, asshi, asslo, (uni) & 0xff)

#define TRYMAP_DEC_MPLANE(charset, assi, plane, c1, c2)		\

	if _TRYMAP_DEC(&charset##_decmap[plane][c1], assi, c2)

#if Py_UNICODE_SIZE == 2

#define DECODE_SURROGATE(c)					\

	if (c >> 10 == 0xd800 >> 10) { /* high surrogate */	\

		REQUIRE_INBUF(2)				\

		if (IN2 >> 10 == 0xdc00 >> 10) { /* low surrogate */ \

		    c = 0x10000 + ((ucs4_t)(c - 0xd800) << 10) + \

			((ucs4_t)(IN2) - 0xdc00);		\

		}						\

	}

#define GET_INSIZE(c)	((c) > 0xffff ? 2 : 1)

#else

#define DECODE_SURROGATE(c) {;}

#define GET_INSIZE(c)	1

#endif

#define BEGIN_MAPPINGS_LIST static const struct dbcs_map _mapping_list[] = {

#define MAPPING_ENCONLY(enc) {#enc, (void*)enc##_encmap, NULL},

#define MAPPING_DECONLY(enc) {#enc, NULL, (void*)enc##_decmap},

#define MAPPING_ENCDEC(enc) {#enc, (void*)enc##_encmap, (void*)enc##_decmap},

#define END_MAPPINGS_LIST				\

	{"", NULL, NULL} };				\

	static const struct dbcs_map *mapping_list =	\

		(const struct dbcs_map *)_mapping_list;

#define BEGIN_CODECS_LIST static const MultibyteCodec _codec_list[] = {

#define _STATEFUL_METHODS(enc)		\

	enc##_encode,			\

	enc##_encode_init,		\

	enc##_encode_reset,		\

	enc##_decode,			\

	enc##_decode_init,		\

	enc##_decode_reset,

#define _STATELESS_METHODS(enc)		\

	enc##_encode, NULL, NULL,	\

	enc##_decode, NULL, NULL,

#define CODEC_STATEFUL(enc) {		\

	#enc, NULL, NULL,		\

	_STATEFUL_METHODS(enc)		\

},

#define CODEC_STATELESS(enc) {		\

	#enc, NULL, NULL,		\

	_STATELESS_METHODS(enc)		\

},

#define CODEC_STATELESS_WINIT(enc) {	\

	#enc, NULL,			\

	enc##_codec_init,		\

	_STATELESS_METHODS(enc)		\

},

#define END_CODECS_LIST					\

	{"", NULL,} };					\

	static const MultibyteCodec *codec_list =	\

		(const MultibyteCodec *)_codec_list;

static PyObject *

getmultibytecodec(void)

{

	static PyObject *cofunc = NULL;

	if (cofunc == NULL) {

		PyObject *mod = PyImport_ImportModuleNoBlock("_multibytecodec");

		if (mod == NULL)

			return NULL;

		cofunc = PyObject_GetAttrString(mod, "__create_codec");

		Py_DECREF(mod);

	}

	return cofunc;

}

static PyObject *

getcodec(PyObject *self, PyObject *encoding)

{

	PyObject *codecobj, *r, *cofunc;

	const MultibyteCodec *codec;

	const char *enc;

	if (!PyString_Check(encoding)) {

		PyErr_SetString(PyExc_TypeError,

				"encoding name must be a string.");

		return NULL;

	}

	cofunc = getmultibytecodec();

	if (cofunc == NULL)

		return NULL;

	enc = PyString_AS_STRING(encoding);

	for (codec = codec_list; codec->encoding[0]; codec++)

		if (strcmp(codec->encoding, enc) == 0)

			break;

	if (codec->encoding[0] == '\0') {

		PyErr_SetString(PyExc_LookupError,

				"no such codec is supported.");

		return NULL;

	}

	codecobj = PyCObject_FromVoidPtr((void *)codec, NULL);

	if (codecobj == NULL)

		return NULL;

	r = PyObject_CallFunctionObjArgs(cofunc, codecobj, NULL);

	Py_DECREF(codecobj);

	return r;

}

static struct PyMethodDef __methods[] = {

	{"getcodec", (PyCFunction)getcodec, METH_O, ""},

	{NULL, NULL},

};

static int

register_maps(PyObject *module)

{

	const struct dbcs_map *h;

	for (h = mapping_list; h->charset[0] != '\0'; h++) {

		char mhname[256] = "__map_";

		int r;

		strcpy(mhname + sizeof("__map_") - 1, h->charset);

		r = PyModule_AddObject(module, mhname,

				PyCObject_FromVoidPtr((void *)h, NULL));

		if (r == -1)

			return -1;

	}

	return 0;

}

#ifdef USING_BINARY_PAIR_SEARCH

static DBCHAR

find_pairencmap(ucs2_t body, ucs2_t modifier,

		const struct pair_encodemap *haystack, int haystacksize)

{

	int pos, min, max;

	ucs4_t value = body << 16 | modifier;

	min = 0;

	max = haystacksize;

	for (pos = haystacksize >> 1; min != max; pos = (min + max) >> 1)

		if (value < haystack[pos].uniseq) {

			if (max == pos) break;

			else max = pos;

		}

		else if (value > haystack[pos].uniseq) {

			if (min == pos) break;

			else min = pos;

		}

		else

			break;

		if (value == haystack[pos].uniseq)

			return haystack[pos].code;

		else

			return DBCINV;

}

#endif

#ifdef USING_IMPORTED_MAPS

#define IMPORT_MAP(locale, charset, encmap, decmap) \

	importmap("_codecs_" #locale, "__map_" #charset, \

		  (const void**)encmap, (const void**)decmap)

static int

importmap(const char *modname, const char *symbol,

	  const void **encmap, const void **decmap)

{

	PyObject *o, *mod;

	mod = PyImport_ImportModule((char *)modname);

	if (mod == NULL)

		return -1;

	o = PyObject_GetAttrString(mod, (char*)symbol);

	if (o == NULL)

		goto errorexit;

	else if (!PyCObject_Check(o)) {

		PyErr_SetString(PyExc_ValueError,

				"map data must be a CObject.");

		goto errorexit;

	}

	else {

		struct dbcs_map *map;

		map = PyCObject_AsVoidPtr(o);

		if (encmap != NULL)

			*encmap = map->encmap;

		if (decmap != NULL)

			*decmap = map->decmap;

		Py_DECREF(o);

	}

	Py_DECREF(mod);

	return 0;

errorexit:

	Py_DECREF(mod);

	return -1;

}

#endif

#define I_AM_A_MODULE_FOR(loc)						\

	void								\

	init_codecs_##loc(void)						\

	{								\

		PyObject *m = Py_InitModule("_codecs_" #loc, __methods);\

		if (m != NULL)						\

			(void)register_maps(m);				\

	}

#endif