from re import match
from typing import List, Optional

from scrapthechan.parser import Parser
from scrapthechan.fileinfo import FileInfo


__all__ = ["TinyboardLikeParser"]


class TinyboardLikeParser(Parser):
	"""Base parser for imageboards that are based on Tinyboard, or have similar
	JSON API."""
	def __init__(self, board: str, thread: str,
				 skip_posts: Optional[int] = None) -> None:
		super().__init__(board, thread, skip_posts)

	def _extract_posts_list(self, lst: List) -> List[dict]:
		return lst['posts']

	def _parse_post(self, post: dict) -> Optional[List[FileInfo]]:
		if not 'tim' in post: return None

		dlfname = f"{post['tim']}{post['ext']}"

		if "filename" in post:
			if match(r"^image\.\w+$", post['filename']) is None:
				filename = dlfname
			else:
				filename = f"{post['filename']}{post['ext']}"

		files = []

		files.append(FileInfo(filename, post['fsize'],
			self.file_base_url.format(board=self.board, filename=dlfname),
			post['md5'], 'md5'))

		if "extra_files" in post:
			for f in post["extra_files"]:
				dlfname = f"{f['tim']}{f['ext']}"
				if "filename" in post:
					if match(r"^image\.\w+$", post['filename']) is None:
						filename = dlfname
					else:
						filename = f"{post['filename']}{post['ext']}"
				dlurl = self.file_base_url.format(board=self.board, \
					filename=dlfname)
				files.append(FileInfo(filename, f['fsize'], \
					dlurl, f['md5'], 'md5'))

		return files