/*

 charencode.c - miscellaneous character encoding

 Copyright 2008 Matt Mackall <mpm@selenic.com> and others

 This software may be used and distributed according to the terms of

 the GNU General Public License, incorporated herein by reference.

*/

#define PY_SSIZE_T_CLEAN

#include <Python.h>

#include <assert.h>

#include "charencode.h"

#include "compat.h"

#include "util.h"

#ifdef IS_PY3K

/* The mapping of Python types is meant to be temporary to get Python

 * 3 to compile. We should remove this once Python 3 support is fully

 * supported and proper types are used in the extensions themselves. */

#define PyInt_Type PyLong_Type

#define PyInt_AS_LONG PyLong_AS_LONG

#endif

/* clang-format off */

static const char lowertable[128] = {

	'\x00', '\x01', '\x02', '\x03', '\x04', '\x05', '\x06', '\x07',

	'\x08', '\x09', '\x0a', '\x0b', '\x0c', '\x0d', '\x0e', '\x0f',

	'\x10', '\x11', '\x12', '\x13', '\x14', '\x15', '\x16', '\x17',

	'\x18', '\x19', '\x1a', '\x1b', '\x1c', '\x1d', '\x1e', '\x1f',

	'\x20', '\x21', '\x22', '\x23', '\x24', '\x25', '\x26', '\x27',

	'\x28', '\x29', '\x2a', '\x2b', '\x2c', '\x2d', '\x2e', '\x2f',

	'\x30', '\x31', '\x32', '\x33', '\x34', '\x35', '\x36', '\x37',

	'\x38', '\x39', '\x3a', '\x3b', '\x3c', '\x3d', '\x3e', '\x3f',

	'\x40',

	        '\x61', '\x62', '\x63', '\x64', '\x65', '\x66', '\x67', /* A-G */

	'\x68', '\x69', '\x6a', '\x6b', '\x6c', '\x6d', '\x6e', '\x6f', /* H-O */

	'\x70', '\x71', '\x72', '\x73', '\x74', '\x75', '\x76', '\x77', /* P-W */

	'\x78', '\x79', '\x7a',                                         /* X-Z */

	                        '\x5b', '\x5c', '\x5d', '\x5e', '\x5f',

	'\x60', '\x61', '\x62', '\x63', '\x64', '\x65', '\x66', '\x67',

	'\x68', '\x69', '\x6a', '\x6b', '\x6c', '\x6d', '\x6e', '\x6f',

	'\x70', '\x71', '\x72', '\x73', '\x74', '\x75', '\x76', '\x77',

	'\x78', '\x79', '\x7a', '\x7b', '\x7c', '\x7d', '\x7e', '\x7f'

};

static const char uppertable[128] = {

	'\x00', '\x01', '\x02', '\x03', '\x04', '\x05', '\x06', '\x07',

	'\x08', '\x09', '\x0a', '\x0b', '\x0c', '\x0d', '\x0e', '\x0f',

	'\x10', '\x11', '\x12', '\x13', '\x14', '\x15', '\x16', '\x17',

	'\x18', '\x19', '\x1a', '\x1b', '\x1c', '\x1d', '\x1e', '\x1f',

	'\x20', '\x21', '\x22', '\x23', '\x24', '\x25', '\x26', '\x27',

	'\x28', '\x29', '\x2a', '\x2b', '\x2c', '\x2d', '\x2e', '\x2f',

	'\x30', '\x31', '\x32', '\x33', '\x34', '\x35', '\x36', '\x37',

	'\x38', '\x39', '\x3a', '\x3b', '\x3c', '\x3d', '\x3e', '\x3f',

	'\x40', '\x41', '\x42', '\x43', '\x44', '\x45', '\x46', '\x47',

	'\x48', '\x49', '\x4a', '\x4b', '\x4c', '\x4d', '\x4e', '\x4f',

	'\x50', '\x51', '\x52', '\x53', '\x54', '\x55', '\x56', '\x57',

	'\x58', '\x59', '\x5a', '\x5b', '\x5c', '\x5d', '\x5e', '\x5f',

	'\x60',

		'\x41', '\x42', '\x43', '\x44', '\x45', '\x46', '\x47', /* a-g */

	'\x48', '\x49', '\x4a', '\x4b', '\x4c', '\x4d', '\x4e', '\x4f', /* h-o */

	'\x50', '\x51', '\x52', '\x53', '\x54', '\x55', '\x56', '\x57', /* p-w */

	'\x58', '\x59', '\x5a', 					/* x-z */

				'\x7b', '\x7c', '\x7d', '\x7e', '\x7f'

};

/* 1: no escape, 2: \<c>, 6: \u<x> */

static const uint8_t jsonlentable[256] = {

	6, 6, 6, 6, 6, 6, 6, 6, 2, 2, 2, 6, 2, 2, 6, 6, /* b, t, n, f, r */

	6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,

	1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* " */

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, /* \\ */

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 6, /* DEL */

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

};

static const uint8_t jsonparanoidlentable[128] = {

	6, 6, 6, 6, 6, 6, 6, 6, 2, 2, 2, 6, 2, 2, 6, 6, /* b, t, n, f, r */

	6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,

	1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* " */

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 6, 1, 6, 1, /* <, > */

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, /* \\ */

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 6, /* DEL */

};

static const char hexchartable[16] = {

	'0', '1', '2', '3', '4', '5', '6', '7',

	'8', '9', 'a', 'b', 'c', 'd', 'e', 'f',

};

/* clang-format on */

/*

 * Turn a hex-encoded string into binary.

 */

PyObject *unhexlify(const char *str, Py_ssize_t len)

{

	PyObject *ret;

	char *d;

	Py_ssize_t i;

	ret = PyBytes_FromStringAndSize(NULL, len / 2);

	if (!ret)

		return NULL;

	d = PyBytes_AsString(ret);

	for (i = 0; i < len;) {

		int hi = hexdigit(str, i++);

		int lo = hexdigit(str, i++);

		*d++ = (hi << 4) | lo;

	}

	return ret;

}

PyObject *isasciistr(PyObject *self, PyObject *args)

{

	const char *buf;

	Py_ssize_t i, len;

	if (!PyArg_ParseTuple(args, PY23("s#:isasciistr", "y#:isasciistr"),

	                      &buf, &len))

		return NULL;

	i = 0;

	/* char array in PyStringObject should be at least 4-byte aligned */

	if (((uintptr_t)buf & 3) == 0) {

		const uint32_t *p = (const uint32_t *)buf;

		for (; i < len / 4; i++) {

			if (p[i] & 0x80808080U)

				Py_RETURN_FALSE;

		}

		i *= 4;

	}

	for (; i < len; i++) {

		if (buf[i] & 0x80)

			Py_RETURN_FALSE;

	}

	Py_RETURN_TRUE;

}

static inline PyObject *

_asciitransform(PyObject *str_obj, const char table[128], PyObject *fallback_fn)

{

	char *str, *newstr;

	Py_ssize_t i, len;

	PyObject *newobj = NULL;

	PyObject *ret = NULL;

	str = PyBytes_AS_STRING(str_obj);

	len = PyBytes_GET_SIZE(str_obj);

	newobj = PyBytes_FromStringAndSize(NULL, len);

	if (!newobj)

		goto quit;

	newstr = PyBytes_AS_STRING(newobj);

	for (i = 0; i < len; i++) {

		char c = str[i];

		if (c & 0x80) {

			if (fallback_fn != NULL) {

				ret = PyObject_CallFunctionObjArgs(

				    fallback_fn, str_obj, NULL);

			} else {

				PyObject *err = PyUnicodeDecodeError_Create(

				    "ascii", str, len, i, (i + 1),

				    "unexpected code byte");

				PyErr_SetObject(PyExc_UnicodeDecodeError, err);

				Py_XDECREF(err);

			}

			goto quit;

		}

		newstr[i] = table[(unsigned char)c];

	}

	ret = newobj;

	Py_INCREF(ret);

quit:

	Py_XDECREF(newobj);

	return ret;

}

PyObject *asciilower(PyObject *self, PyObject *args)

{

	PyObject *str_obj;

	if (!PyArg_ParseTuple(args, "O!:asciilower", &PyBytes_Type, &str_obj))

		return NULL;

	return _asciitransform(str_obj, lowertable, NULL);

}

PyObject *asciiupper(PyObject *self, PyObject *args)

{

	PyObject *str_obj;

	if (!PyArg_ParseTuple(args, "O!:asciiupper", &PyBytes_Type, &str_obj))

		return NULL;

	return _asciitransform(str_obj, uppertable, NULL);

}

PyObject *make_file_foldmap(PyObject *self, PyObject *args)

{

	PyObject *dmap, *spec_obj, *normcase_fallback;

	PyObject *file_foldmap = NULL;

	enum normcase_spec spec;

	PyObject *k, *v;

	dirstateTupleObject *tuple;

	Py_ssize_t pos = 0;

	const char *table;

	if (!PyArg_ParseTuple(args, "O!O!O!:make_file_foldmap", &PyDict_Type,

	                      &dmap, &PyInt_Type, &spec_obj, &PyFunction_Type,

	                      &normcase_fallback))

		goto quit;

	spec = (int)PyInt_AS_LONG(spec_obj);

	switch (spec) {

	case NORMCASE_LOWER:

		table = lowertable;

		break;

	case NORMCASE_UPPER:

		table = uppertable;

		break;

	case NORMCASE_OTHER:

		table = NULL;

		break;

	default:

		PyErr_SetString(PyExc_TypeError, "invalid normcasespec");

		goto quit;

	}

	/* Add some more entries to deal with additions outside this

	   function. */

	file_foldmap = _dict_new_presized((PyDict_Size(dmap) / 10) * 11);

	if (file_foldmap == NULL)

		goto quit;

	while (PyDict_Next(dmap, &pos, &k, &v)) {

		if (!dirstate_tuple_check(v)) {

			PyErr_SetString(PyExc_TypeError,

			                "expected a dirstate tuple");

			goto quit;

		}

		tuple = (dirstateTupleObject *)v;

		if (tuple->state != 'r') {

			PyObject *normed;

			if (table != NULL) {

				normed = _asciitransform(k, table,

				                         normcase_fallback);

			} else {

				normed = PyObject_CallFunctionObjArgs(

				    normcase_fallback, k, NULL);

			}

			if (normed == NULL)

				goto quit;

			if (PyDict_SetItem(file_foldmap, normed, k) == -1) {

				Py_DECREF(normed);

				goto quit;

			}

			Py_DECREF(normed);

		}

	}

	return file_foldmap;

quit:

	Py_XDECREF(file_foldmap);

	return NULL;

}

/* calculate length of JSON-escaped string; returns -1 if unsupported */

static Py_ssize_t jsonescapelen(const char *buf, Py_ssize_t len, bool paranoid)

{

	Py_ssize_t i, esclen = 0;

	if (paranoid) {

		/* don't want to process multi-byte escapes in C */

		for (i = 0; i < len; i++) {

			char c = buf[i];

			if (c & 0x80) {

				PyErr_SetString(PyExc_ValueError,

				                "cannot process non-ascii str");

				return -1;

			}

			esclen += jsonparanoidlentable[(unsigned char)c];

			if (esclen < 0) {

				PyErr_SetString(PyExc_MemoryError,

				                "overflow in jsonescapelen");

				return -1;

			}

		}

	} else {

		for (i = 0; i < len; i++) {

			char c = buf[i];

			esclen += jsonlentable[(unsigned char)c];

			if (esclen < 0) {

				PyErr_SetString(PyExc_MemoryError,

				                "overflow in jsonescapelen");

				return -1;

			}

		}

	}

	return esclen;

}

/* map '\<c>' escape character */

static char jsonescapechar2(char c)

{

	switch (c) {

	case '\b':

		return 'b';

	case '\t':

		return 't';

	case '\n':

		return 'n';

	case '\f':

		return 'f';

	case '\r':

		return 'r';

	case '"':

		return '"';

	case '\\':

		return '\\';

	}

	return '\0'; /* should not happen */

}

/* convert 'origbuf' to JSON-escaped form 'escbuf'; 'origbuf' should only

   include characters mappable by json(paranoid)lentable */

static void encodejsonescape(char *escbuf, Py_ssize_t esclen,

                             const char *origbuf, Py_ssize_t origlen,

                             bool paranoid)

{

	const uint8_t *lentable =

	    (paranoid) ? jsonparanoidlentable : jsonlentable;

	Py_ssize_t i, j;

	for (i = 0, j = 0; i < origlen; i++) {

		char c = origbuf[i];

		uint8_t l = lentable[(unsigned char)c];

		assert(j + l <= esclen);

		switch (l) {

		case 1:

			escbuf[j] = c;

			break;

		case 2:

			escbuf[j] = '\\';

			escbuf[j + 1] = jsonescapechar2(c);

			break;

		case 6:

			memcpy(escbuf + j, "\\u00", 4);

			escbuf[j + 4] = hexchartable[(unsigned char)c >> 4];

			escbuf[j + 5] = hexchartable[(unsigned char)c & 0xf];

			break;

		}

		j += l;

	}

}

PyObject *jsonescapeu8fast(PyObject *self, PyObject *args)

{

	PyObject *origstr, *escstr;

	const char *origbuf;

	Py_ssize_t origlen, esclen;

	int paranoid;

	if (!PyArg_ParseTuple(args, "O!i:jsonescapeu8fast", &PyBytes_Type,

	                      &origstr, &paranoid))

		return NULL;

	origbuf = PyBytes_AS_STRING(origstr);

	origlen = PyBytes_GET_SIZE(origstr);

	esclen = jsonescapelen(origbuf, origlen, paranoid);

	if (esclen < 0)

		return NULL; /* unsupported char found or overflow */

	if (origlen == esclen) {

		Py_INCREF(origstr);

		return origstr;

	}

	escstr = PyBytes_FromStringAndSize(NULL, esclen);

	if (!escstr)

		return NULL;

	encodejsonescape(PyBytes_AS_STRING(escstr), esclen, origbuf, origlen,

	                 paranoid);

	return escstr;

}