""" Script used to clean the data. """

import os
import re
from nltk import tokenize

def clean_aochildes(lines):
    """ For aochildes, we remove the space between the punctuation mark and the final word and join together every 5 lines """
    new_lines = []
    joined = []
    for i, line in enumerate(lines):
        new_line = line[:-3] + line[-2:]
        joined.append(new_line.strip())
        if i % 5 == 0:
            new_lines.append(" ".join(joined) + "\n")
            joined = []
    return new_lines

def clean_bnc_spoken(lines):
    """ For bnc_spoken, we lowercase """
    new_lines = []
    for line in lines:
        new_line = line.lower()
        if new_line != '\n':
            new_lines.append(new_line)
    return new_lines

def clean_cbt(lines):
    """ For cbt, we lowercase and normalise punctuation """
    punctuation = ['.', ',', '?', '!', ':', ';', '(', ')', '[', ']', '{', '}', '"', "'", '“', '”', '—', '–']
    new_lines = []
    for line in lines:
        new_line = line.lower()
        new_line = new_line.replace(": ' ", ":  \"")
        new_line = new_line.replace("''", "\"")
        new_line = new_line.replace(" '\n", "\"\n")
        new_line = new_line.replace(" ' ", "\" ")
        new_line = new_line.replace(" `` ", "  \"")
        new_line = new_line.replace("` ", " \"")
        new_line = new_line.replace("`", "\"")
        new_line = new_line.replace("’", "\"")
        for punct in punctuation:
            new_line = new_line.replace(f" {punct}", punct)
        new_lines.append(new_line)
    return new_lines

def clean_children_stories(lines):
    """ For children_stories, we lowercase """
    new_lines = []
    for line in lines:
        new_line = line.lower().strip()
        if new_line != '':
            new_lines.append(new_line + "\n")
    return new_lines

def clean_gutenberg(lines):
    """ For gutenberg, we lowercase, remove italics and group lines into paragraphs. We also remove any lines containing '*' or 'p.' """
    # Get paragraphs
    paragraphs = []
    paragraph = ""
    for line in lines:
        # Remove italics
        tmp_line = line.lower().strip().replace('_','')
        if tmp_line == "" and paragraph != "":
            if len(paragraph.split()) > 2 and not paragraph.split()[-1][-1].isnumeric(): # Remove paragraphs with less than 3 words and those that end in a number (probably part of a bibliography)
                paragraphs.append(paragraph[:-1] + '\n')
            paragraph = ""
        else:
            paragraph += tmp_line + " "
    
    # Bad characters - gutenberg has a lot of figures, footnotes, chapter names etc that we want to remove
    bad_chars = ['*', 'p.', '=', '|', '[', ']', '       ', '    ', 'v.']
    new_lines = [p.strip()+'\n' for p in paragraphs if not any([c in p for c in bad_chars]) and p != '' and p != '\n' and p[0] != '(']
    return new_lines

def clean_open_subtitles(lines):
    """ For open_subtitles, we lowercase, remove subtitle dashes and fix the lowercase 'l' problem. We also join every 5 lines. """
    punctuation = ['.', ',', '?', '!', ':', ';', '(', ')', '[', ']', '{', '}', '"', "'", '“', '”', '—', '–', ' ', '\n']
    new_lines = []
    joined = []
    count = 0
    for line in lines:
        new_line = line.lower()
        # Skip music lines
        if '♪' in new_line or '[' in new_line or ']' in new_line or '‎' in new_line:
            continue
        if new_line[0:2] in ["- ", "– ", "— "]:
            new_line = new_line[2:]
        if new_line[0] in ["-", "–", "—"]:
            new_line = new_line[1:]
        new_line = ' ' + new_line
        for punct in punctuation:
            new_line = new_line.replace(f" l{punct}", f" i{punct}")
            new_line = new_line.replace(f" lm{punct}", f" im{punct}")
            new_line = new_line.replace(f" lf{punct}", f" if{punct}")
        new_line = new_line.replace(' lc', ' ic')
        new_line = new_line.replace(' ld', ' id')
        new_line = new_line.replace(' lj', ' i j')
        new_line = new_line.replace(' ln', ' in')
        new_line = new_line.replace(' lp', ' ip')
        new_line = new_line.replace(' lr', ' ir')
        new_line = new_line.replace(' ls', ' is')
        new_line = new_line.replace(' isd', ' lsd')
        new_line = new_line.replace(' lt', ' it')
        new_line = new_line.replace(' lt', ' it')
        new_line = new_line.replace(' lv', ' iv')
        if new_line.strip() != '':
            joined.append(new_line.strip())
            count += 1
            if count % 5 == 0:
                new_lines.append(" ".join(joined) + '\n')
                joined = []
    return new_lines

def clean_qed(lines):
    """ For qed, we lowercase and normalise punctuation, remove words contained in parentheses,
    remove lines that are just character's names and fix the lowercase 'l' problem. We also join every 5 lines. """

    new_lines = []
    count = 0
    joined = []
    for line in lines:
        # Before lowercasing, check if the words in the line are uppercase containing lowercase 'l' instead of 'I' and fix accordingly
        words = line.split()
        for i, word in enumerate(words):
            if word.replace('l','I').isupper() and 'l' in word and word != 'I\'ll':
                words[i] = word.replace('l', 'I')
        new_line = ' '.join(words).lower()
        new_line = new_line.replace(' lc', ' ic')
        new_line = new_line.replace(' ld', ' id')
        new_line = new_line.replace(' lj', ' i j')
        new_line = new_line.replace(' ln', ' in')
        new_line = new_line.replace(' lp', ' ip')
        new_line = new_line.replace(' lr', ' ir')
        new_line = new_line.replace(' ls', ' is')
        new_line = new_line.replace(' isd', ' lsd')
        new_line = new_line.replace(' lt', ' it')
        new_line = new_line.replace(' lt', ' it')
        new_line = new_line.replace(' lv', ' iv')
        new_line = new_line.replace('>', '')
        new_line = new_line.replace('<i', '')
        new_line = new_line.replace('</i', '')
        new_line = new_line.replace('>i', '')
        new_line = new_line.replace('>/i', '')
        new_line = new_line.replace('&gt', '')
        new_line = new_line.replace('&lt', '')
        new_line = new_line.replace('&', '')

        # Skip lines that are just character names, e.g. "AMY GOODMAN:"
        if len(new_line.strip()) < 1 or (len(words) <= 3 and new_line.strip()[-1] == ':'):
            continue

        # Remove subtitle dashes
        if new_line[0:2] == "- ":
            new_line = new_line[2:]
        if new_line[0] == "-":
            new_line = new_line[1:]

        # Remove substrings contained within circular or square parantheses (screen descriptions)
        pattern = r'\([^)]*\)'
        new_line = re.sub(pattern, '', new_line)
        pattern = r'\[[^)]*\]'
        new_line = re.sub(pattern, '', new_line)
        new_line = new_line.replace('"', '\'')

        # Remove strange characters
        new_line = new_line.replace('#','')
        new_line = new_line.replace('*','')

        new_line = new_line.strip()
        if new_line != "":
            joined.append(new_line)
            count += 1
            if count % 5 == 0:
                new_lines.append(" ".join(joined) + '\n')
                joined = []
    return new_lines

def clean_simple_wikipedia(lines):
    """ For simple_wikipedia, we lowercase, remove empty lines and article names."""
    new_lines = []
    next_line_is_article_name = False
    for line in lines:
        if next_line_is_article_name:
            next_line_is_article_name = False
            continue
        if line.strip() == "":
            next_line_is_article_name = True
            continue
        if len(line.split()) > 2:
            new_lines.append(line.lower())
    return new_lines

def clean_switchboard(lines):
    """ For switchboard, we lowercase and join every 5 lines. """
    new_lines = []
    count = 0
    joined = []
    for line in lines:
        new_line = line.lower().strip()
        joined.append(new_line)
        count += 1
        if count % 5 == 0:
            new_lines.append(" ".join(joined) + '\n')
            joined = []
    return new_lines

def clean_wikipedia(lines):
    """ For wikipedia, we lowercase and remove empty lines and article names.
     We also remove lines that seem to be figure names or table entries. """
    new_lines = []
    for line in lines:
        new_line = line.strip()
        words = new_line.split()
        
        # Remove empty lines and article names
        if new_line == "":
            continue
        if new_line[0] == "=" and new_line[-1] == "=":
            continue

        # Filter out lines that seem to be figure names or table entries
        all_numeric = True
        all_uppercase = True
        for word in words:
            if not word.isnumeric():
                all_numeric = False
            if not word[0].isupper():
                all_uppercase = False
        if all_numeric or all_uppercase:
            continue
    
        new_lines.append(new_line.lower().strip() + '\n')
    return new_lines

CLEAN_FUNCTIONS = {'aochildes' : clean_aochildes, 'bnc_spoken' : clean_bnc_spoken, 'cbt' : clean_cbt, 'children_stories' : clean_children_stories, 'gutenberg' : clean_gutenberg, 'open_subtitles' : clean_open_subtitles, 'qed' : clean_qed, 'simple_wikipedia' : clean_simple_wikipedia, 'switchboard' : clean_switchboard, 'wikipedia' : clean_wikipedia}
FOLDERS = ['10M', '100M', 'dev', 'test']

if __name__ == "__main__":

    # Read all text files from directory "BabyLM"
    all_files = []
    for folder in FOLDERS:
        for root, dirs, files in os.walk(f"original/{folder}"):
            for file in files:
                if file.endswith(".txt"):
                    all_files.append(os.path.join(root, file))

    for file in all_files:
        print(file)
        with open(file, 'r') as f:
            lines = f.readlines()

        # Get the corpus name
        corpus_name = os.path.basename(file).split('.')[0]

        # Clean the data
        if CLEAN_FUNCTIONS[corpus_name] is not None:
            lines = CLEAN_FUNCTIONS[corpus_name](lines)
            # Replace multiple spaces with single space
            lines = [re.sub(' +', ' ', line) for line in lines if line.strip() != '']

        # Write the new file
        new_file = file.replace('original', 'clean')
        os.makedirs(os.path.dirname(new_file), exist_ok=True)
        with open(new_file, 'w') as f:
           # Save file name to file, so we can later recover the original file names
           f.write(new_file.split('/')[-1] + '\n')
           f.writelines(lines)