PyWebBrowser/browser.py

import socket
import ssl


class URL:
    def __init__(self, url: str):
        self.scheme, url = url.split("://", 1)
        assert self.scheme in ["http", "https"]
        if "/" not in url:
            url = url + "/"
        self.host, url = url.split("/", 1)
        self.path = "/" + url

        if self.scheme == "http":
            self.port = 80
        elif self.scheme == "https":
            self.port = 443

        if ":" in self.host:
            self.host, port = self.host.split(":", 1)
            self.port = int(port)

    def request(self) -> str:
        s = socket.socket(
            family=socket.AF_INET,
            type=socket.SOCK_STREAM,
            proto=socket.IPPROTO_TCP,
        )
        s.connect((self.host, self.port))
        if self.scheme == "https":
            ssl.create_default_context()
            context = ssl.SSLContext(ssl.PROTOCOL_TLS)
            s = context.wrap_socket(s, server_hostname=self.host)

        request_str = f"GET {self.path} HTTP/1.0\r\n"
        request_str += f"Host: {self.host}\r\n"
        request_str += "\r\n"
        s.send(request_str.encode("utf8"))

        response = s.makefile("r", encoding="utf8", newline="\r\n")
        status_line = response.readline()
        version, status, explanation = status_line.split(" ", 2)

        response_headers = {}
        while True:
            line = response.readline()
            if line == "\r\n":
                break
            header, value = line.split(":", 1)
            response_headers[header.casefold()] = value.strip()

        assert "transfer-encoding" not in response_headers
        assert "content-encoding" not in response_headers

        content = response.read()
        s.close()
        return content


def show(body: str) -> None:
    in_tag = False
    for char in body:
        if char == "<":
            in_tag = True
        elif char == ">":
            in_tag = False
        elif not in_tag:
            print(char, end="")


def load(url: URL):
    body = url.request()
    show(body)


if __name__ == '__main__':
    import sys
    load(URL(sys.argv[1]))