import os
import re

# Directory containing the .txt files
directory = '.'

# Name of the output file
output_file = 'merged_content.txt'

# Function to extract the numerical part of the filename
def extract_number(filename):
    match = re.search(r'content_(\d+)\.txt', filename)
    return int(match.group(1)) if match else float('inf')

# Get a sorted list of files
files = sorted([f for f in os.listdir(directory) if f.startswith('content_') and f.endswith('.txt')], key=extract_number)

# Open the output file in write mode
with open(output_file, 'w', encoding='utf-8') as outfile:
    # Iterate over the sorted list of files
    for filename in files:
        with open(os.path.join(directory, filename), 'r', encoding='utf-8') as infile:
            # Write the content of the file to the output file
            outfile.write(infile.read())
            outfile.write('\n')  # Add a newline after each file's content

# Convert the merged text file to .epub format using Calibre's ebook-convert
os.system('ebook-convert merged_content.txt merged_content.mobi')