"""
Copied from https://github.com/neonbjb/tortoise-tts/blob/main/tortoise/utils/text.py
"""
import re


def split_and_recombine_text(text, desired_length=1, max_length=300):
    """Split text it into chunks of a desired length trying to keep sentences intact."""
    # normalize text, remove redundant whitespace and convert non-ascii quotes to ascii
    text = re.sub(r'\n\n+', '\n', text)
    text = re.sub(r'\s+', ' ', text)
    text = re.sub(r'[“”]', '"', text)

    rv = []
    in_quote = False
    current = ""
    split_pos = []
    pos = -1
    end_pos = len(text) - 1

    def seek(delta):
        nonlocal pos, in_quote, current
        is_neg = delta < 0
        for _ in range(abs(delta)):
            if is_neg:
                pos -= 1
                current = current[:-1]
            else:
                pos += 1
                current += text[pos]
            if text[pos] == '"':
                in_quote = not in_quote
        return text[pos]

    def peek(delta):
        p = pos + delta
        return text[p] if p < end_pos and p >= 0 else ""

    def commit():
        nonlocal rv, current, split_pos
        rv.append(current)
        current = ""
        split_pos = []

    while pos < end_pos:
        c = seek(1)
        # do we need to force a split?
        if len(current) >= max_length:
            if len(split_pos) > 0 and len(current) > (desired_length / 2):
                # we have at least one sentence and we are over half the desired length, seek back to the last split
                d = pos - split_pos[-1]
                seek(-d)
            else:
                # no full sentences, seek back until we are not in the middle of a word and split there
                while c not in '!?.\n ' and pos > 0 and len(current) > desired_length:
                    c = seek(-1)
            commit()
        # check for sentence boundaries
        elif not in_quote and (c in '!?\n' or (c == '.' and peek(1) in '\n ')):
            # seek forward if we have consecutive boundary markers but still within the max length
            while pos < len(text) - 1 and len(current) < max_length and peek(1) in '!?.':
                c = seek(1)
            split_pos.append(pos)
            if len(current) >= desired_length:
                commit()
        # treat end of quote as a boundary if its followed by a space or newline
        elif in_quote and peek(1) == '"' and peek(2) in '\n ':
            seek(2)
            split_pos.append(pos)
    rv.append(current)

    # clean up, remove lines with only whitespace or punctuation
    rv = [s.strip() for s in rv]
    rv = [s for s in rv if len(s) > 0 and not re.match(r'^[\s\.,;:!?]*$', s)]

    return rv