import logging
from urllib.parse import urlparse

from client.ResponseHandler import ResponseHandler
from client.httpclient import FORMAT, HTTPClient, InvalidResponse, InvalidStatusLine, UnsupportedEncoding


class Command:
    command: str

    def __init__(self, url: str, port: str):
        self.url = url
        self.port = port

    @staticmethod
    def create(command: str, url: str, port: str):
        if command == "GET":
            return GetCommand(url, port)
        elif command == "HEAD":
            return HeadCommand(url, port)
        elif command == "POST":
            return PostCommand(url, port)
        elif command == "PUT":
            return PutCommand(url, port)
        else:
            raise ValueError()

    def execute(self):
        (host, path) = self.parse_uri()

        client = HTTPClient(host)
        client.connect((host, int(self.port)))

        message = f"{self.command} {path} HTTP/1.1\r\n"
        message += f"Host: {host}\r\n"
        message += "Accept: */*\r\nAccept-Encoding: identity\r\n"
        encoded_msg = self._build_message(message)

        logging.info("---request begin---\r\n%s---request end---", encoded_msg.decode(FORMAT))

        logging.debug("Sending HTTP message: %r", encoded_msg)
        client.sendall(encoded_msg)

        logging.info("HTTP request sent, awaiting response...")

        try:
            self._await_response(client)
        except InvalidResponse as e:
            logging.debug("Internal error: Response could not be parsed", exc_info=e)
            return
        except InvalidStatusLine as e:
            logging.debug("Internal error: Invalid status-line in response", exc_info=e)
            return
        except UnsupportedEncoding as e:
            logging.debug("Internal error: Unsupported encoding in response", exc_info=e)
        finally:
            client.close()

    def _await_response(self, client: HTTPClient):
        pass

    def _build_message(self, message: str) -> bytes:
        return (message + "\r\n").encode(FORMAT)

    def parse_uri(self):
        parsed = urlparse(self.url)

        # If there is no netloc, the url is invalid, so prepend `//` and try again
        if parsed.netloc == "":
            parsed = urlparse("//" + self.url)

        host = parsed.netloc
        path = parsed.path
        if len(path) == 0 or path[0] != '/':
            path = "/" + path

        port_pos = host.find(":")
        if port_pos >= 0:
            host = host[:port_pos]

        return host, path


class HeadCommand(Command):
    command = "HEAD"

    def _await_response(self, client):
        while True:
            line = client.read_line()
            print(line, end="")
            if line in ("\r\n", "\n", ""):
                break


class GetCommand(Command):
    command = "GET"

    def _await_response(self, client):
        (version, status, msg) = ResponseHandler.get_status_line(client)
        logging.debug("Parsed status-line: version: %s, status: %s", version, status)
        headers = ResponseHandler.get_headers(client)
        logging.debug("Parsed headers: %r", headers)

        handler = ResponseHandler.create(client, headers, status, self.url)
        handler.handle()


class PostCommand(HeadCommand):
    command = "POST"

    def _build_message(self, message: str) -> bytes:
        body = input("Enter POST data: ").encode(FORMAT)
        print()

        message += "Content-Type: text/plain\r\n"
        message += f"Content-Length: {len(body)}\r\n"
        message += "\r\n"
        message = message.encode(FORMAT)
        message += body
        message += b"\r\n"

        return message


class PutCommand(PostCommand):
    command = "PUT"