import json
import socket
from typing import Optional

from edmond.bot import Bot
from edmond.plugin import Plugin


class ShrlokPlugin(Plugin):
    """Use an available shrlok server to allow sharing longer stuff.

    This plugin does not do anything on its own, but can be used from other
    plugins to share longer texts through a Web portal.
    """

    def __init__(self, bot: Bot):
        super().__init__(bot)
        self.socket = ""
        self.file_root = ""
        self.url_root = ""

    def on_welcome(self, _):
        if all(
            conf in self.config
            for conf in ("socket_path", "file_root", "url_root")
        ):
            self.socket = self.config["socket_path"]
            self.file_root = self.config["file_root"]
            self.url_root = self.config["url_root"]
            self.bot.log_d(f"shrlok socket path '{self.socket}'")
        else:
            self.bot.log_d("No socket path specified, shrlok plugin disabled.")
            self.is_ready = False

    def post(self, header: dict, data: bytes) -> Optional[str]:
        encoded_header = json.dumps(header).encode()
        try:
            with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as sock:
                sock.connect(self.socket)
                header_and_data = encoded_header + b"\0" + data
                length = len(header_and_data)
                packet = str(length).encode() + b"\0" + header_and_data
                sock.sendall(packet)
                response = sock.recv(4096)
        except OSError as exc:
            self.bot.log_e(f"Can't post data: {exc}")
            return None
        url = response.decode().replace(self.file_root, self.url_root, 1)
        return url or None  # returning empty strings could cause confusion