import io
from typing import Any
from typing import Callable
from typing import Dict
from typing import Iterable
from typing import List
from typing import Optional
from typing import Tuple
from typing import Union


WSGIEnv = Dict[str, Any]  # Cannot use TypedDict because of 'HTTP_' variables
StartResponse = Callable[[str, List[Tuple[str, str]]], None]
WSGIApp = Callable[[WSGIEnv, StartResponse], Iterable[bytes]]


def create_wsgi_env(
    path: str,
    method: str,
    content_type: str,
    body: bytes,
    queries: Dict[str, str],
    headers: Dict[str, str],
) -> WSGIEnv:
    # 'key1=value1&key2=value2'
    query_string = "&".join([f"{k}={v}" for k, v in queries.items()])

    # See https://www.python.org/dev/peps/pep-3333/#environ-variables
    env = {
        "PATH_INFO": path,
        "REQUEST_METHOD": method.upper(),
        "SCRIPT_NAME": "",
        "QUERY_STRING": query_string,
        "CONTENT_TYPE": content_type,
        "CONTENT_LENGTH": len(body),
        "SERVER_PROTOCOL": "http",
        "SERVER_NAME": "localhost",
        "wsgi.input": io.BytesIO(body),
        "wsgi.version": (1, 0),
        "wsgi.errors": io.StringIO(""),
        "wsgi.multithread": True,
        "wsgi.multiprocess": True,
        "wsgi.run_once": False,
    }
    for k, v in headers.items():
        env[f"HTTP_{k.upper()}"] = v
    return env


def send_request(
    app: WSGIApp,
    path: str,
    method: str,
    body: Union[str, bytes] = b"",
    queries: Optional[Dict[str, str]] = None,
    headers: Optional[Dict[str, str]] = None,
    content_type: str = "text/plain; charset=utf-8",
) -> Tuple[int, List[Tuple[str, str]], bytes]:
    status: str = ""
    response_headers: List[Tuple[str, str]] = []

    def start_response(status_: str, headers_: List[Tuple[str, str]]) -> None:
        nonlocal status, response_headers
        status = status_
        response_headers = headers_

    bytes_body = body if isinstance(body, bytes) else body.encode("utf-8")
    headers = headers or {}
    queries = queries or {}
    env = create_wsgi_env(path, method, content_type, bytes_body, queries, headers)
    body = b""
    iterable_body = app(env, start_response)
    for b in iterable_body:
        body += b

    status_code = int(status.split()[0])
    return status_code, response_headers, body