# 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, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

import codecs
import sys
import traceback

QUESTION_MARK = chr(0x3f)

# data from
# http://snoops.roy202.org/testerman/browser/trunk/plugins/codecs/gsm0338.py

mapping = [
    ('\x00', u'\u0040'),  # COMMERCIAL AT
    ('\x00', u'\u0000'),  # NULL (see note above)
    ('\x01', u'\u00A3'),  # POUND SIGN
    ('\x02', u'\u0024'),  # DOLLAR SIGN
    ('\x03', u'\u00A5'),  # YEN SIGN
    ('\x04', u'\u00E8'),  # LATIN SMALL LETTER E WITH GRAVE
    ('\x05', u'\u00E9'),  # LATIN SMALL LETTER E WITH ACUTE
    ('\x06', u'\u00F9'),  # LATIN SMALL LETTER U WITH GRAVE
    ('\x07', u'\u00EC'),  # LATIN SMALL LETTER I WITH GRAVE
    ('\x08', u'\u00F2'),  # LATIN SMALL LETTER O WITH GRAVE
    ('\x09', u'\u00E7'),  # LATIN SMALL LETTER C WITH CEDILLA
    ('\x09', u'\u00C7'),  # LATIN CAPITAL LETTER C WITH CEDILLA
    ('\x0A', u'\u000A'),  # LINE FEED
    ('\x0B', u'\u00D8'),  # LATIN CAPITAL LETTER O WITH STROKE
    ('\x0C', u'\u00F8'),  # LATIN SMALL LETTER O WITH STROKE
    ('\x0D', u'\u000D'),  # CARRIAGE RETURN
    ('\x0E', u'\u00C5'),  # LATIN CAPITAL LETTER A WITH RING ABOVE
    ('\x0F', u'\u00E5'),  # LATIN SMALL LETTER A WITH RING ABOVE
    ('\x10', u'\u0394'),  # GREEK CAPITAL LETTER DELTA
    ('\x11', u'\u005F'),  # LOW LINE
    ('\x12', u'\u03A6'),  # GREEK CAPITAL LETTER PHI
    ('\x13', u'\u0393'),  # GREEK CAPITAL LETTER GAMMA
    ('\x14', u'\u039B'),  # GREEK CAPITAL LETTER LAMDA
    ('\x15', u'\u03A9'),  # GREEK CAPITAL LETTER OMEGA
    ('\x16', u'\u03A0'),  # GREEK CAPITAL LETTER PI
    ('\x17', u'\u03A8'),  # GREEK CAPITAL LETTER PSI
    ('\x18', u'\u03A3'),  # GREEK CAPITAL LETTER SIGMA
    ('\x19', u'\u0398'),  # GREEK CAPITAL LETTER THETA
    ('\x1A', u'\u039E'),  # GREEK CAPITAL LETTER XI
    ('\x1C', u'\u00C6'),  # LATIN CAPITAL LETTER AE
    ('\x1D', u'\u00E6'),  # LATIN SMALL LETTER AE
    ('\x1E', u'\u00DF'),  # LATIN SMALL LETTER SHARP S (German)
    ('\x1F', u'\u00C9'),  # LATIN CAPITAL LETTER E WITH ACUTE
    ('\x20', u'\u0020'),  # SPACE
    ('\x21', u'\u0021'),  # EXCLAMATION MARK
    ('\x22', u'\u0022'),  # QUOTATION MARK
    ('\x23', u'\u0023'),  # NUMBER SIGN
    ('\x24', u'\u00A4'),  # CURRENCY SIGN
    ('\x25', u'\u0025'),  # PERCENT SIGN
    ('\x26', u'\u0026'),  # AMPERSAND
    ('\x27', u'\u0027'),  # APOSTROPHE
    ('\x28', u'\u0028'),  # LEFT PARENTHESIS
    ('\x29', u'\u0029'),  # RIGHT PARENTHESIS
    ('\x2A', u'\u002A'),  # ASTERISK
    ('\x2B', u'\u002B'),  # PLUS SIGN
    ('\x2C', u'\u002C'),  # COMMA
    ('\x2D', u'\u002D'),  # HYPHEN-MINUS
    ('\x2E', u'\u002E'),  # FULL STOP
    ('\x2F', u'\u002F'),  # SOLIDUS
    ('\x30', u'\u0030'),  # DIGIT ZERO
    ('\x31', u'\u0031'),  # DIGIT ONE
    ('\x32', u'\u0032'),  # DIGIT TWO
    ('\x33', u'\u0033'),  # DIGIT THREE
    ('\x34', u'\u0034'),  # DIGIT FOUR
    ('\x35', u'\u0035'),  # DIGIT FIVE
    ('\x36', u'\u0036'),  # DIGIT SIX
    ('\x37', u'\u0037'),  # DIGIT SEVEN
    ('\x38', u'\u0038'),  # DIGIT EIGHT
    ('\x39', u'\u0039'),  # DIGIT NINE
    ('\x3A', u'\u003A'),  # COLON
    ('\x3B', u'\u003B'),  # SEMICOLON
    ('\x3C', u'\u003C'),  # LESS-THAN SIGN
    ('\x3D', u'\u003D'),  # EQUALS SIGN
    ('\x3E', u'\u003E'),  # GREATER-THAN SIGN
    ('\x3F', u'\u003F'),  # QUESTION MARK
    ('\x40', u'\u00A1'),  # INVERTED EXCLAMATION MARK
    ('\x41', u'\u0041'),  # LATIN CAPITAL LETTER A
    ('\x41', u'\u0391'),  # GREEK CAPITAL LETTER ALPHA
    ('\x42', u'\u0042'),  # LATIN CAPITAL LETTER B
    ('\x42', u'\u0392'),  # GREEK CAPITAL LETTER BETA
    ('\x43', u'\u0043'),  # LATIN CAPITAL LETTER C
    ('\x44', u'\u0044'),  # LATIN CAPITAL LETTER D
    ('\x45', u'\u0045'),  # LATIN CAPITAL LETTER E
    ('\x45', u'\u0395'),  # GREEK CAPITAL LETTER EPSILON
    ('\x46', u'\u0046'),  # LATIN CAPITAL LETTER F
    ('\x47', u'\u0047'),  # LATIN CAPITAL LETTER G
    ('\x48', u'\u0048'),  # LATIN CAPITAL LETTER H
    ('\x48', u'\u0397'),  # GREEK CAPITAL LETTER ETA
    ('\x49', u'\u0049'),  # LATIN CAPITAL LETTER I
    ('\x49', u'\u0399'),  # GREEK CAPITAL LETTER IOTA
    ('\x4A', u'\u004A'),  # LATIN CAPITAL LETTER J
    ('\x4B', u'\u004B'),  # LATIN CAPITAL LETTER K
    ('\x4B', u'\u039A'),  # GREEK CAPITAL LETTER KAPPA
    ('\x4C', u'\u004C'),  # LATIN CAPITAL LETTER L
    ('\x4D', u'\u004D'),  # LATIN CAPITAL LETTER M
    ('\x4D', u'\u039C'),  # GREEK CAPITAL LETTER MU
    ('\x4E', u'\u004E'),  # LATIN CAPITAL LETTER N
    ('\x4E', u'\u039D'),  # GREEK CAPITAL LETTER NU
    ('\x4F', u'\u004F'),  # LATIN CAPITAL LETTER O
    ('\x4F', u'\u039F'),  # GREEK CAPITAL LETTER OMICRON
    ('\x50', u'\u0050'),  # LATIN CAPITAL LETTER P
    ('\x50', u'\u03A1'),  # GREEK CAPITAL LETTER RHO
    ('\x51', u'\u0051'),  # LATIN CAPITAL LETTER Q
    ('\x52', u'\u0052'),  # LATIN CAPITAL LETTER R
    ('\x53', u'\u0053'),  # LATIN CAPITAL LETTER S
    ('\x54', u'\u0054'),  # LATIN CAPITAL LETTER T
    ('\x54', u'\u03A4'),  # GREEK CAPITAL LETTER TAU
    ('\x55', u'\u0055'),  # LATIN CAPITAL LETTER U
    ('\x55', u'\u03A5'),  # GREEK CAPITAL LETTER UPSILON
    ('\x56', u'\u0056'),  # LATIN CAPITAL LETTER V
    ('\x57', u'\u0057'),  # LATIN CAPITAL LETTER W
    ('\x58', u'\u0058'),  # LATIN CAPITAL LETTER X
    ('\x58', u'\u03A7'),  # GREEK CAPITAL LETTER CHI
    ('\x59', u'\u0059'),  # LATIN CAPITAL LETTER Y
    ('\x5A', u'\u005A'),  # LATIN CAPITAL LETTER Z
    ('\x5A', u'\u0396'),  # GREEK CAPITAL LETTER ZETA
    ('\x5B', u'\u00C4'),  # LATIN CAPITAL LETTER A WITH DIAERESIS
    ('\x5C', u'\u00D6'),  # LATIN CAPITAL LETTER O WITH DIAERESIS
    ('\x5D', u'\u00D1'),  # LATIN CAPITAL LETTER N WITH TILDE
    ('\x5E', u'\u00DC'),  # LATIN CAPITAL LETTER U WITH DIAERESIS
    ('\x5F', u'\u00A7'),  # SECTION SIGN
    ('\x60', u'\u00BF'),  # INVERTED QUESTION MARK
    ('\x61', u'\u0061'),  # LATIN SMALL LETTER A
    ('\x62', u'\u0062'),  # LATIN SMALL LETTER B
    ('\x63', u'\u0063'),  # LATIN SMALL LETTER C
    ('\x64', u'\u0064'),  # LATIN SMALL LETTER D
    ('\x65', u'\u0065'),  # LATIN SMALL LETTER E
    ('\x66', u'\u0066'),  # LATIN SMALL LETTER F
    ('\x67', u'\u0067'),  # LATIN SMALL LETTER G
    ('\x68', u'\u0068'),  # LATIN SMALL LETTER H
    ('\x69', u'\u0069'),  # LATIN SMALL LETTER I
    ('\x6A', u'\u006A'),  # LATIN SMALL LETTER J
    ('\x6B', u'\u006B'),  # LATIN SMALL LETTER K
    ('\x6C', u'\u006C'),  # LATIN SMALL LETTER L
    ('\x6D', u'\u006D'),  # LATIN SMALL LETTER M
    ('\x6E', u'\u006E'),  # LATIN SMALL LETTER N
    ('\x6F', u'\u006F'),  # LATIN SMALL LETTER O
    ('\x70', u'\u0070'),  # LATIN SMALL LETTER P
    ('\x71', u'\u0071'),  # LATIN SMALL LETTER Q
    ('\x72', u'\u0072'),  # LATIN SMALL LETTER R
    ('\x73', u'\u0073'),  # LATIN SMALL LETTER S
    ('\x74', u'\u0074'),  # LATIN SMALL LETTER T
    ('\x75', u'\u0075'),  # LATIN SMALL LETTER U
    ('\x76', u'\u0076'),  # LATIN SMALL LETTER V
    ('\x77', u'\u0077'),  # LATIN SMALL LETTER W
    ('\x78', u'\u0078'),  # LATIN SMALL LETTER X
    ('\x79', u'\u0079'),  # LATIN SMALL LETTER Y
    ('\x7A', u'\u007A'),  # LATIN SMALL LETTER Z
    ('\x7B', u'\u00E4'),  # LATIN SMALL LETTER A WITH DIAERESIS
    ('\x7C', u'\u00F6'),  # LATIN SMALL LETTER O WITH DIAERESIS
    ('\x7D', u'\u00F1'),  # LATIN SMALL LETTER N WITH TILDE
    ('\x7E', u'\u00FC'),  # LATIN SMALL LETTER U WITH DIAERESIS
    ('\x7F', u'\u00E0'),  # LATIN SMALL LETTER A WITH GRAVE
]

# Escaped characters
escaped_mapping = [
    ('\x0A', u'\u000C'),  # FORM FEED
    ('\x14', u'\u005E'),  # CIRCUMFLEX ACCENT
    ('\x28', u'\u007B'),  # LEFT CURLY BRACKET
    ('\x29', u'\u007D'),  # RIGHT CURLY BRACKET
    ('\x2F', u'\u005C'),  # REVERSE SOLIDUS
    ('\x3C', u'\u005B'),  # LEFT SQUARE BRACKET
    ('\x3D', u'\u007E'),  # TILDE
    ('\x3E', u'\u005D'),  # RIGHT SQUARE BRACKET
    ('\x40', u'\u007C'),  # VERTICAL LINE
    ('\x65', u'\u20AC'),  # EURO SIGN
]

# unicode -> GSM 03.38
regular_encode_dict = dict([(u, g) for g, u in mapping])

# unicode -> escaped GSM 03.38 characters
escape_encode_dict = dict([(u, g) for g, u in escaped_mapping])

# GSM 03.38 -> unicode
# Only first corresponding unicode character is
# taken into account (see 0x41, etc)
regular_decode_dict = {}
for g, u in mapping:
    if g not in regular_decode_dict:
        regular_decode_dict[g] = u

escape_decode_dict = dict([(g, u) for g, u in escaped_mapping])


def encode(input_, errors='strict'):
    """
    :type input_: unicode

    :return: string
    """
    result = []
    for c in input_:
        try:
            result.append(regular_encode_dict[c])
        except KeyError:
            if c in escape_encode_dict:
                # OK, let's encode it as an escaped characters
                result.append('\x1b')
                result.append(escape_encode_dict[c])
            else:
                if errors == 'strict':
                    raise UnicodeError("Invalid SMS character")
                elif errors == 'replace':
                    result.append(QUESTION_MARK)
                elif errors == 'ignore':
                    pass
                else:
                    raise UnicodeError("Unknown error handling")

    ret = ''.join(result)
    return ret, len(ret)


def decode(input_, errors='strict'):
    """
    :type input_: str

    :return: unicode
    """
    result = []
    index = 0
    while index < len(input_):
        c = input_[index]
        index += 1
        if c == '\x1b':
            if index < len(input_):
                c = input_[index]
                index += 1
                result.append(escape_decode_dict.get(c, '\xa0'))
            else:
                result.append('\xa0')
        else:
            try:
                result.append(regular_decode_dict[c])
            except KeyError:
                # error handling: unassigned byte, must be > 0x7f
                if errors == 'strict':
                    raise UnicodeError("Unrecognized SMS character")
                elif errors == 'replace':
                    result.append('?')
                elif errors == 'ignore':
                    pass
                else:
                    raise UnicodeError("Unknown error handling")

    ret = u''.join(result)
    return ret, len(ret)


# encodings module API
def getregentry(encoding):
    if encoding == 'gsm0338':
        return codecs.CodecInfo(name='gsm0338',
                                encode=encode,
                                decode=decode)

# Codec registration
codecs.register(getregentry)


def is_gsm_text(text):
    """Returns True if ``text`` can be encoded as gsm text"""
    try:
        text.encode("gsm0338")
    except UnicodeError:
        return False
    except:
        traceback.print_exc(file=sys.stdout)
        return False

    return True