#!/usr/bin/env python

from itertools import batched
from random import choice
from re import compile, sub, split

from evennia.utils import logger, dedent

def paragraph(text):
    """
    Removes initial spaces as well as final newlines.

    Blank lines, however, are preserved.
    """
    # Shame we can chain this or _thread_, but:
    return sub(r";;", "\n\n",
               sub(r"\n", " ",
                   sub(r"\n\n+", ";;",
                       dedent(text)))).strip()

def squish(text):
    "Remove series of spaces from the text."
    return sub('[ \t]+', ' ', text).strip()

def _routput_choose(text):
    """
    Pick a choice when text is: one ^ two ^ three
    Done by splitting the text, and calling random.choice().
    """
    choices = split(r" *\^ *", text)
    return choice(choices)

def _routput_empty(entry):
    """
    Return True if entry is empty, e.g. None or blank.
    False otherwise. Note: Spaces are ignored.
    """
    if entry:
        if isinstance(entry, str) and entry.strip() == '':
            return True
        if isinstance(entry, (list, tuple)) and len(entry) == 0:
            return True
        return False
    return True

def _routput_pair(no_choice, choices = None):
    """
    Return a list based on the ^-separated options in 'choices'.

    Give a pair of split items, the 'no_choice' is the first section
    (before the << ... >>>), and the 'choices' is the section between
    the '<< ... >>' delimiter.
    """

    # While unlikely, the text before << and the options between the
    # << ...>> text may be blank:
    if _routput_empty(no_choice) and _routput_empty(choices):
        return ''

    # If we start a string with <<...>>, then thte 'no_choice' option
    # is blank, so we only return a choice:
    if _routput_empty(no_choice):
        return _routput_choose(choices)

    # With text before, but not inside the <<...>> section, we just
    # return the first part:
    if _routput_empty(choices):
        return no_choice

    return no_choice + ' ' + _routput_choose(choices)

def routput(text, *substitutions):
    """
    Return string with internal word choices replaced randomly.
    For instance, the string:

    'This feels <<^ very ^ quite>> <<nice^cozy^comfortable>>.'

    Could return any of the following strings:

    'This feels quite nice.'
    'This feels cozy.'
    'This feels very comfortable.'
    """
    if text:
        # section is a list of some phrase followed by another phrase
        # that contains ^-separate choices:
        sections = split(r" *<< *(.*?) *>> *", text)

        # Parts are the first section followed by the _rendered_
        # choices, so this^that is either 'this' or 'that':
        parts = [_routput_pair(*pair) for pair in batched(sections, 2)]

        # The parts may have empty strings, so we filter those out,
        # leaving on the phrases to join:
        phrases = [phrase for phrase in parts  if not _routput_empty(phrase)]

        proposal = ' '.join(phrases).format(*substitutions)

        # If a choice is at the end of a sentence, and we could have
        # "no choice", as in:
        #     "He searches <<thoroughly ^ quickly ^>>."
        # We don't want a version that looks like:
        #     "He searches # ."
        # with a space before the punctuation:
        #
        # Also, we should remove all double spaces that may show:
        return squish(sub(r"\s+([!?.,])", "\\1", proposal))


def choices(text, *substitutions):
    """
    Returns a section of 'text' based on separating semicolons.

    Note that text can already be separated as a list or tuple.
    """
    if isinstance(text, str):
        text = split(r"\s*;;\s*", text)

    if text:
        return routput(choice(text), *substitutions)


def split_party_msg(viewer, msg, *substitutions):
    """
    Send a message to 'viewer' as well as all people in the area.

    Note that 'msg' could have choices separated by ;;
    As well as random words, separated by << one ^ two ^ three >>
    As well as one word for 'viewer' and other for rest, as in
    <( You ^ {0} )> <( give ^ gives )> the ball.
    """
    text = choices(msg, viewer.name.title())
    pattern = compile(r"\<\( *(.*?) *\^ *(.*?) *\)\>")

    # First a message for the view:
    viewer.msg( pattern.sub("\\1", text) )

    # Then the message for the rest of the area:
    viewer.location.msg_contents(
        pattern.sub("\\2", text), exclude=viewer)

# def searsonal(text, **kwargs):
#     season = kwargs['season'] or kwargs['location'].get_season()
#     time_of_day = kwargs['time_of_day'] or kwargs['location'].get_time_of_day()