lightnovel.py

import os
import sys
import traceback
import base64
from bs4 import BeautifulSoup
from ebooklib import epub

from utils import echo
from utils import downloader
from utils.checker import is_not_null, is_null

class LightNovel():
	'''
	object of light novel
	'''
	
	source = ''
	'''
	source of light novel
	'''

	authors = []
	'''
	author (Optional)
	'''
	
	identifier = None
	'''
	identifier (Optional)
	'''

	title = ''
	'''
	title of the book
	'''

	contents = ''
	'''
	can be either str or list
	the format of list is [{'conent': content, 'title': title}]
	'''

	cover_link = None
	'''
	link of cover. if `None`, then use the first picture of webpage.\n
	cover_link can either be web link or file path.\n
	if it is not beginned with `http`, it would be recognized as file path.
	'''

	def __init__(self, source: str, authors=None, identifier=None, title=None, cover_link=None):
		'''
		initialize light novel object
		'''
		self.source = source
		if authors is not None: self.authors = authors
		if identifier is not None: self.identifier = identifier
		if title is not None: self.title = title
		if cover_link is not None: self.cover_link = cover_link


	def process_image_content(self, content, book):
		'''
		process image content
		:param content: HTML content
		:return: content, first image bytes
		'''
		echo.push_subroutine(sys._getframe().f_code.co_name)

		# parse images
		try:
			soup = BeautifulSoup(content, 'lxml')
			image_tags = soup.find_all('img')
		except Exception as e:
			echo.cerr(f'Error: {repr(e)}')
			traceback.print_exc()
			echo.cexit('PARSING HTML FAILED')

		# store images
		first_flag = True # flag for storing first image
		first_image = None

		try:
			i = 0
			for tag in image_tags:
				i = i + 1
				echo.clog(f'Processing images: ({i} / {len(image_tags)})')
				# parse
				link = str(tag.attrs['src'])

				r_image = None

				if link.startswith('data:'):
					r_image = base64.decodebytes(link.split(';')[1].split(',')[1].encode('utf-8'))
				else:
					file_name = os.path.basename(link)
					file_dir = link
					
					# convert href
					tag.attrs['src'] = f'../Images/{file_name}'
					image = epub.EpubImage()
					image.file_name = f'Images/{file_name}'
					image.content = open(file_dir, 'rb').read()
					book.add_item(image)
					r_image = image.content
				
				if first_flag and r_image is not None:
					first_image = r_image
					first_flag = False
		except Exception as e:
			echo.cerr(f'Error: {repr(e)}')
			traceback.print_exc()
			echo.cexit('PROCESSING IMAGES FAILED')
		
		return soup, first_image


	def write_epub(self, path: str):
		'''
		generate the ebook to `path`
		'''
		echo.push_subroutine(sys._getframe().f_code.co_name)

		echo.clog(f'start generating...')

		try:
			# create epub book
			book = epub.EpubBook()
			
			# set metadata
			if is_not_null(self.authors):
				for author in self.authors:
					book.add_author(author=author)
			
			if is_not_null(self.identifier):
				book.set_identifier(self.identifier)

			book.set_title(self.title)
			book.set_language('zh-CN')
		except Exception as e:
			echo.cerr(f'Error: {repr(e)}')
			traceback.print_exc()
			echo.cexit('CREATING EPUB BOOK FAILED')
		
		if type(self.contents) == str:
			soup, first_image = self.process_image_content(self.contents, book)
		elif type(self.contents) == list:
			_contents = []
			first_image = None
			for content in self.contents:
				soup, _first_image = self.process_image_content(content['content'], book)
				if first_image is None:
					first_image = _first_image
				_contents.append({
					'content': str(soup),
					'title': content['title'],
				})
		else:
			echo.cexit('CONTENTS MUST BE STRING OR LIST')
		
		# set cover
		try:
			if is_not_null(self.cover_link):
				if os.path.exists(self.cover_link):
					book.set_cover(os.path.basename(self.cover_link), open(self.cover_link, 'rb').read())
			elif first_image is not None:
				book.set_cover('cover', first_image)
		except Exception as e:
			echo.cerr(f'Error: {repr(e)}')
			traceback.print_exc()
			echo.cexit('SETTING COVER IMAGE FAILED')
		
		try:
			# set content
			about_text = f'<p>本书由<a href="https://github.com/JeffersonQin/lightnovel_epub">JeffersonQin/lightnovel_epub</a>工具自动生成。<br>仅供学习交流使用，禁作商业用途。</p><br><p>本书根据 {self.source} 生成</p>'
			if type(self.contents) == str:
				about_content = epub.EpubHtml(title='关于本电子书', file_name='Text/about.xhtml', lang='zh-CN', content=about_text)
				main_content = epub.EpubHtml(title=self.title, file_name='Text/lightnovel.xhtml', lang='zh-CN', content=str(soup))

				book.add_item(about_content)
				book.add_item(main_content)

				# configure book
				book.toc = (about_content, main_content)
				# add default NCX and Nav file
				book.add_item(epub.EpubNcx())
				book.add_item(epub.EpubNav())
				book.spine = ['nav', about_content, main_content]
			elif type(self.contents) == list:
				about_content = epub.EpubHtml(title='关于本电子书', file_name='Text/about.xhtml', lang='zh-CN', content=about_text)
				i = 0
				epub_nav = ['nav', about_content]
				epub_toc = [about_content]
				epub_contents = [about_content]
				for content in _contents:
					i += 1
					item = (epub.EpubHtml(title=content['title'], file_name=f'Text/Section{i}.xhtml', lang='zh-CN', content=content['content']))
					epub_toc.append(item)
					epub_nav.append(item)
					epub_contents.append(item)
				
				for epub_content in epub_contents:
					book.add_item(epub_content)

				# configure book
				book.toc = tuple(epub_toc)
				
				# add default NCX and Nav file
				book.add_item(epub.EpubNcx())
				book.add_item(epub.EpubNav())
				
				book.spine = epub_nav

			# generate book
			epub.write_epub(os.path.join(path, f'{self.title}.epub'), book, {})
		except Exception as e:
			echo.cerr(f'Error: {repr(e)}')
			traceback.print_exc()
			echo.cexit('BOOK CONFIGURATION & GENERATION FAILED')
		
		echo.pop_subroutine()