# SPDX-FileCopyrightText: Copyright (c) 2022 Dan Halbert for Adafruit Industries
#
# SPDX-License-Identifier: MIT
"""
`adafruit_httpserver.request.HTTPRequest`
====================================================
* Author(s): Dan Halbert, Michał Pokusa
"""

try:
    from typing import Dict, Tuple
except ImportError:
    pass


class HTTPRequest:  # pylint: disable=too-few-public-methods
    """
    Incoming request, constructed from raw incoming bytes.
    It is passed as first argument to route handlers.
    """

    method: str
    """Request method e.g. "GET" or "POST"."""

    path: str
    """Path of the request."""

    query_params: Dict[str, str]
    """
    Query/GET parameters in the request.

    Example::

            request  = HTTPRequest(raw_request=b"GET /?foo=bar HTTP/1.1...")
            request.query_params
            # {"foo": "bar"}
    """

    http_version: str
    """HTTP version, e.g. "HTTP/1.1"."""

    headers: Dict[str, str]
    """Headers from the request."""

    body: bytes
    """Body of the request, as bytes."""

    raw_request: bytes
    """Raw bytes passed to the constructor."""

    def __init__(self, raw_request: bytes = None) -> None:
        self.raw_request = raw_request

        if raw_request is None:
            raise ValueError("raw_request cannot be None")

        empty_line_index = raw_request.find(b"\r\n\r\n")

        header_bytes = raw_request[:empty_line_index]
        body_bytes = raw_request[empty_line_index + 4 :]

        try:
            (
                self.method,
                self.path,
                self.query_params,
                self.http_version,
            ) = self._parse_start_line(header_bytes)
            self.headers = self._parse_headers(header_bytes)
            self.body = body_bytes
        except Exception as error:
            raise ValueError("Unparseable raw_request: ", raw_request) from error

    @staticmethod
    def _parse_start_line(header_bytes: bytes) -> Tuple[str, str, Dict[str, str], str]:
        """Parse HTTP Start line to method, path, query_params and http_version."""

        start_line = header_bytes.decode("utf8").splitlines()[0]

        method, path, http_version = start_line.split()

        if "?" not in path:
            path += "?"

        path, query_string = path.split("?", 1)

        query_params = {}
        for query_param in query_string.split("&"):
            if "=" in query_param:
                key, value = query_param.split("=", 1)
                query_params[key] = value
            else:
                query_params[query_param] = ""

        return method, path, query_params, http_version

    @staticmethod
    def _parse_headers(header_bytes: bytes) -> Dict[str, str]:
        """Parse HTTP headers from raw request."""
        header_lines = header_bytes.decode("utf8").splitlines()[1:]

        return dict([header.split(": ", 1) for header in header_lines[1:]])