# coding: utf8
from __future__ import unicode_literals

import bz2
import regex as re
import ujson
import sys
import random
import datetime
import plac
from pathlib import Path

_unset = object()


class Reddit(object):
    """Stream cleaned comments from Reddit."""
    pre_format_re = re.compile(r'^[\`\*\~]')
    post_format_re = re.compile(r'[\`\*\~]$')
    url_re = re.compile(r'\[([^]]+)\]\(%%URL\)')
    link_re = re.compile(r'\[([^]]+)\]\(https?://[^\)]+\)')

    def __init__(self, file_path, meta_keys={'subreddit': 'section'}):
        """
        file_path (unicode / Path): Path to archive or directory of archives.
        meta_keys (dict): Meta data key included in the Reddit corpus, mapped
            to display name in Prodigy meta.
        RETURNS (Reddit): The Reddit loader.
        """
        self.meta = meta_keys
        file_path = Path(file_path)
        if not file_path.exists():
            raise IOError("Can't find file path: {}".format(file_path))
        if not file_path.is_dir():
            self.files = [file_path]
        else:
            self.files = list(file_path.iterdir())

    def __iter__(self):
        for file_path in self.iter_files():
            with bz2.open(str(file_path)) as f:
                for line in f:
                    line = line.strip()
                    if not line:
                        continue
                    comment = ujson.loads(line)
                    if self.is_valid(comment):
                        text = self.strip_tags(comment['body'])
                        yield {'text': text}

    def get_meta(self, item):
        return {name: item.get(key, 'n/a') for key, name in self.meta.items()}

    def iter_files(self):
        for file_path in self.files:
            yield file_path

    def strip_tags(self, text):
        text = self.link_re.sub(r'\1', text)
        text = text.replace('&gt;', '>').replace('&lt;', '<')
        text = self.pre_format_re.sub('', text)
        text = self.post_format_re.sub('', text)
        text = re.sub(r'\s+', ' ', text)
        return text.strip()

    def is_valid(self, comment):
        return comment['body'] is not None \
            and comment['body'] != '[deleted]' \
            and comment['body'] != '[removed]'


def main(path):
    reddit = Reddit(path)
    for comment in reddit:
        print(ujson.dumps(comment))


if __name__ == '__main__':
    import socket
    try:
        BrokenPipeError
    except NameError:
        BrokenPipeError = socket.error
    try:
        plac.call(main)
    except BrokenPipeError: 
        import os, sys
        # Python flushes standard streams on exit; redirect remaining output
        # to devnull to avoid another BrokenPipeError at shutdown
        devnull = os.open(os.devnull, os.O_WRONLY)
        os.dup2(devnull, sys.stdout.fileno())
        sys.exit(1)  # Python exits with error code 1 on EPIPE