http_server.py

import mimetypes
import os

from constants import DEFAULT_HEADERS, STATUS_CODES
from http_request import HTTPRequest
from tcp_server import TCPServer


class HTTPServer(TCPServer):
    def handle_request(self, data):
        request = HTTPRequest(data)

        try:
            handler = getattr(self, f"handle_{request.method}", None)
            response = handler(request) if handler else self.error_501()
        except Exception as e:
            response = self.error_500()

        return response.encode() if isinstance(response, str) else response

    def handle_GET(self, request):
        path = request.uri.lstrip("/") or "index.html"

        if os.path.exists(path):
            return self.serve_file(path)
        return self.error_404()

    def serve_file(self, path):
        content_type, _ = mimetypes.guess_type(path)
        headers = {**DEFAULT_HEADERS, "Content-Type": content_type or "text/html"}

        try:
            with open(path, "rb") as f:
                return self.build_response(200, headers, f.read())
        except IOError:
            return self.error_500()

    def build_response(self, status_code, headers, body):
        status_line = f"HTTP/1.1 {status_code} {STATUS_CODES[status_code]}\r\n"
        header_lines = "".join(f"{k}: {v}\r\n" for k, v in headers.items())
        return b"".join([status_line.encode(), header_lines.encode(), b"\r\n", body])

    def error_404(self):
        return self.build_response(404, DEFAULT_HEADERS, b"<h1>404 Not Found</h1>")

    def error_501(self):
        return self.build_response(
            501, DEFAULT_HEADERS, b"<h1>501 Not Implemented</h1>"
        )

    def error_500(self):
        return self.build_response(
            500, DEFAULT_HEADERS, b"<h1>500 Internal Server Error</h1>"
        )