#
#  Copyright (c) 2013-present, Anoop Kunchukuttan
#  All rights reserved.
#
#  This source code is licensed under the MIT license found in the
#  LICENSE file in the root directory of this source tree.
#

# Program for detokenizing Indian language input
#
# @author Anoop Kunchukuttan
#
"""
De-tokenizer for Indian languages.
"""

import regex as re

## detokenizer patterns
left_attach = r"!%)\]},.:;>?\u0964\u0965"
pat_la = re.compile(r"[ ]([" + left_attach + r"])")

right_attach = r"#$(\[{<@"
pat_ra = re.compile(r"([" + right_attach + r"])[ ]")

lr_attach = r"-/\\"
pat_lra = re.compile(r"[ ]([" + lr_attach + r"])[ ]")

# donknow=u'&*+=^_|~'

## date, numbers, section/article numbering
## TODO: handle indic numbers
pat_num_seq = re.compile(r"([0-9]+ [,.:/] )+[0-9]+")

### e-mail address
# pat_num=re.compile(ur'[a-zA-Z]+[ ]?


def trivial_detokenize_indic(text):
    """detokenize string for Indian language scripts using Brahmi-derived scripts

    A trivial detokenizer which:

        - decides whether punctuation attaches to left/right or both
        - handles number sequences
        - handles quotes smartly (deciding left or right attachment)

    Args:
        text (str): tokenized text to process

    Returns:
        str: detokenized string
    """

    s = text
    ### some normalizations

    # numbers and dates
    new_s = ""
    prev = 0
    for m in pat_num_seq.finditer(s):
        start = m.start()
        end = m.end()
        if start > prev:
            new_s = new_s + s[prev:start]
            new_s = new_s + s[start:end].replace(" ", "")
            prev = end

    new_s = new_s + s[prev:]
    s = new_s

    ###  consective single quotes or backslashes become double quotes
    # s=s.replace("' '", "''")
    # s=s.replace("` `", '``')

    s = pat_lra.sub("\\1", s)
    s = pat_la.sub("\\1", s)
    s = pat_ra.sub("\\1", s)

    # assumes well formedness of quotes and alternates between right and left attach

    alt_attach = "'\"`"
    for punc in alt_attach:
        cnt = 0
        out_str = []
        for c in s:
            if c == punc:
                if cnt % 2 == 0:
                    out_str.append("@RA")
                else:
                    out_str.append("@LA")
                cnt += 1
            else:
                out_str.append(c)

        s = (
            "".join(out_str)
            .replace("@RA ", punc)
            .replace(" @LA", punc)
            .replace("@RA", punc)
            .replace("@LA", punc)
        )

    return s


def trivial_detokenize(text, lang="hi"):
    """detokenize string for languages of the Indian subcontinent

    A trivial detokenizer which:

        - decides whether punctuation attaches to left/right or both
        - handles number sequences
        - handles quotes smartly (deciding left or right attachment)

    Args:
        text (str): tokenized text to process

    Returns:
        str: detokenized string

    Raises:
        IndicNlpException: If language is not supported
    """
    return trivial_detokenize_indic(text)