#
# Usage:
#     gen_xmlpool.py /path/to/t_option.h localedir lang lang lang ...
#
# For each given language, this script expects to find a .mo file at
# `{localedir}/{language}/LC_MESSAGES/options.mo`.
#

from __future__ import print_function
import argparse
import gettext
import io
import os
import re
import sys

if sys.version_info < (3, 0):
    gettext_method = 'ugettext'
else:
    gettext_method = 'gettext'

# Escape special characters in C strings
def escapeCString(s):
    escapeSeqs = {'\a' : '\\a', '\b' : '\\b', '\f' : '\\f', '\n' : '\\n',
                  '\r' : '\\r', '\t' : '\\t', '\v' : '\\v', '\\' : '\\\\'}
    # " -> '' is a hack. Quotes (") aren't possible in XML attributes.
    # Better use Unicode characters for typographic quotes in option
    # descriptions and translations.
    i = 0
    r = ''
    while i < len(s):
        # Special case: escape double quote with \u201c or \u201d, depending
        # on whether it's an open or close quote. This is needed because plain
        # double quotes are not possible in XML attributes.
        if s[i] == '"':
            if i == len(s) - 1 or s[i + 1].isspace():
                # close quote
                q = u'\u201c'
            else:
                # open quote
                q = u'\u201d'
            r = r + q
        elif s[i] in escapeSeqs:
            r = r + escapeSeqs[s[i]]
        else:
            r = r + s[i]
        i = i + 1
    return r

# Expand escape sequences in C strings (needed for gettext lookup)
def expandCString(s):
    escapeSeqs = {'a' : '\a', 'b' : '\b', 'f' : '\f', 'n' : '\n',
                  'r' : '\r', 't' : '\t', 'v' : '\v',
                  '"' : '"', '\\' : '\\'}
    i = 0
    escape = False
    hexa = False
    octa = False
    num = 0
    digits = 0
    r = u''
    while i < len(s):
        if not escape:
            if s[i] == '\\':
                escape = True
            else:
                r = r + s[i]
        elif hexa:
            if (s[i] >= '0' and s[i] <= '9') or \
               (s[i] >= 'a' and s[i] <= 'f') or \
               (s[i] >= 'A' and s[i] <= 'F'):
                num = num * 16 + int(s[i],16)
                digits = digits + 1
            else:
                digits = 2
            if digits >= 2:
                hexa = False
                escape = False
                r = r + chr(num)
        elif octa:
            if s[i] >= '0' and s[i] <= '7':
                num = num * 8 + int(s[i],8)
                digits = digits + 1
            else:
                digits = 3
            if digits >= 3:
                octa = False
                escape = False
                r = r + chr(num)
        else:
            if s[i] in escapeSeqs:
                r = r + escapeSeqs[s[i]]
                escape = False
            elif s[i] >= '0' and s[i] <= '7':
                octa = True
                num = int(s[i],8)
                if num <= 3:
                    digits = 1
                else:
                    digits = 2
            elif s[i] == 'x' or s[i] == 'X':
                hexa = True
                num = 0
                digits = 0
            else:
                r = r + s[i]
                escape = False
        i = i + 1
    return r

# Expand matches. The first match is always a DESC or DESC_BEGIN match.
# Subsequent matches are ENUM matches.
#
# DESC, DESC_BEGIN format: \1 \2=<lang> \3 \4=gettext(" \5=<text> \6=") \7
# ENUM format:             \1 \2=gettext(" \3=<text> \4=") \5
def expandMatches(matches, translations, end=None):
    assert len(matches) > 0
    nTranslations = len(translations)
    i = 0
    # Expand the description+enums for all translations
    for lang,trans in translations:
        i = i + 1
        # Make sure that all but the last line of a simple description
        # are extended with a backslash.
        suffix = ''
        if len(matches) == 1 and i < len(translations) and \
               not matches[0].expand(r'\7').endswith('\\'):
            suffix = ' \\'
        text = escapeCString(getattr(trans, gettext_method)(expandCString(
            matches[0].expand (r'\5'))))
        text = (matches[0].expand(r'\1' + lang + r'\3"' + text + r'"\7') + suffix)

        # In Python 2, stdout expects encoded byte strings, or else it will
        # encode them with the ascii 'codec'
        if sys.version_info.major == 2:
            text = text.encode('utf-8')

        print(text)

        # Expand any subsequent enum lines
        for match in matches[1:]:
            text = escapeCString(getattr(trans, gettext_method)(expandCString(
                match.expand(r'\3'))))
            text = match.expand(r'\1"' + text + r'"\5')

            # In Python 2, stdout expects encoded byte strings, or else it will
            # encode them with the ascii 'codec'
            if sys.version_info.major == 2:
                text = text.encode('utf-8')

            print(text)

        # Expand description end
        if end:
            print(end, end='')

# Regular expressions:
reLibintl_h = re.compile(r'#\s*include\s*<libintl.h>')
reDESC = re.compile(r'(\s*DRI_CONF_DESC\s*\(\s*)([a-z]+)(\s*,\s*)(gettext\s*\(\s*")(.*)("\s*\))(\s*\)[ \t]*\\?)$')
reDESC_BEGIN = re.compile(r'(\s*DRI_CONF_DESC_BEGIN\s*\(\s*)([a-z]+)(\s*,\s*)(gettext\s*\(\s*")(.*)("\s*\))(\s*\)[ \t]*\\?)$')
reENUM = re.compile(r'(\s*DRI_CONF_ENUM\s*\([^,]+,\s*)(gettext\s*\(\s*")(.*)("\s*\))(\s*\)[ \t]*\\?)$')
reDESC_END = re.compile(r'\s*DRI_CONF_DESC_END')


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('template')
    parser.add_argument('localedir')
    parser.add_argument('languages', nargs='*')
    args = parser.parse_args()

    # Compile a list of translation classes to all supported languages.
    # The first translation is always a NullTranslations.
    translations = [("en", gettext.NullTranslations())]
    for lang in args.languages:
        try:
            filename = os.path.join(args.localedir, '{}.gmo'.format(lang))
            with io.open(filename, 'rb') as f:
                trans = gettext.GNUTranslations(f)
        except (IOError, OSError):
            print("Warning: language '%s' not found." % lang, file=sys.stderr)
            continue
        translations.append((lang, trans))

    print("/***********************************************************************\n" \
    " ***        THIS FILE IS GENERATED AUTOMATICALLY. DON'T EDIT!        ***\n" \
    " ***********************************************************************/")

    # Process the options template and generate options.h with all
    # translations.
    with io.open(args.template, mode="rt", encoding='utf-8') as template:
        descMatches = []
        for line in template:
            if len(descMatches) > 0:
                matchENUM = reENUM.match(line)
                matchDESC_END = reDESC_END.match(line)
                if matchENUM:
                    descMatches.append(matchENUM)
                elif matchDESC_END:
                    expandMatches(descMatches, translations, line)
                    descMatches = []
                else:
                    print("Warning: unexpected line inside description dropped:\n",
                          line, file=sys.stderr)
                continue
            if reLibintl_h.search(line):
                # Ignore (comment out) #include <libintl.h>
                print("/* %s * commented out by gen_xmlpool.py */" % line)
                continue
            matchDESC = reDESC.match(line)
            matchDESC_BEGIN = reDESC_BEGIN.match(line)
            if matchDESC:
                assert len(descMatches) == 0
                expandMatches([matchDESC], translations)
            elif matchDESC_BEGIN:
                assert len(descMatches) == 0
                descMatches = [matchDESC_BEGIN]
            else:
                # In Python 2, stdout expects encoded byte strings, or else it will
                # encode them with the ascii 'codec'
                if sys.version_info.major == 2:
                   line = line.encode('utf-8')

                print(line, end='')

    if len(descMatches) > 0:
        print("Warning: unterminated description at end of file.", file=sys.stderr)
        expandMatches(descMatches, translations)


if __name__ == '__main__':
    main()