# charencode.py - miscellaneous character encoding

#

#  Copyright 2005-2009 Matt Mackall <mpm@selenic.com> and others

#

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

# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import array

from .. import (

    pycompat,

)

def asciilower(s):

    '''convert a string to lowercase if ASCII

    Raises UnicodeDecodeError if non-ASCII characters are found.'''

    s.decode('ascii')

    return s.lower()

def asciiupper(s):

    '''convert a string to uppercase if ASCII

    Raises UnicodeDecodeError if non-ASCII characters are found.'''

    s.decode('ascii')

    return s.upper()

_jsonmap = []

_jsonmap.extend("\\u%04x" % x for x in range(32))

_jsonmap.extend(pycompat.bytechr(x) for x in range(32, 127))

_jsonmap.append('\\u007f')

_jsonmap[0x09] = '\\t'

_jsonmap[0x0a] = '\\n'

_jsonmap[0x22] = '\\"'

_jsonmap[0x5c] = '\\\\'

_jsonmap[0x08] = '\\b'

_jsonmap[0x0c] = '\\f'

_jsonmap[0x0d] = '\\r'

_paranoidjsonmap = _jsonmap[:]

_paranoidjsonmap[0x3c] = '\\u003c'  # '<' (e.g. escape "</script>")

_paranoidjsonmap[0x3e] = '\\u003e'  # '>'

_jsonmap.extend(pycompat.bytechr(x) for x in range(128, 256))

def jsonescapeu8fast(u8chars, paranoid):

    """Convert a UTF-8 byte string to JSON-escaped form (fast path)

    Raises ValueError if non-ASCII characters have to be escaped.

    """

    if paranoid:

        jm = _paranoidjsonmap

    else:

        jm = _jsonmap

    try:

        return ''.join(jm[x] for x in bytearray(u8chars))

    except IndexError:

        raise ValueError

def jsonescapeu8fallback(u8chars, paranoid):

    """Convert a UTF-8 byte string to JSON-escaped form (slow path)

    Escapes all non-ASCII characters no matter if paranoid is False.

    """

    if paranoid:

        jm = _paranoidjsonmap

    else:

        jm = _jsonmap

    # non-BMP char is represented as UTF-16 surrogate pair

    u16codes = array.array('H', u8chars.decode('utf-8').encode('utf-16'))

    u16codes.pop(0)  # drop BOM

    return ''.join(jm[x] if x < 128 else '\\u%04x' % x for x in u16codes)