import asyncio
import json
import re
from pathlib import Path

PR = re.compile(r"\<([a-zA-Z_]+)\>")


async def _default_404_route(request):
    return "HTTP/1.1 404 Not Found\r\nContent-Type: text/html\r\n\r\n404 Not Found contact admin"


async def _default_405_route(request):
    return "HTTP/1.1 405 Method Not Allowed\r\nContent-Type: text/html\r\n\r\n405 Method Not Allowed"


class App:
    def __init__(self):
        self.routes: dict[re.Pattern[str], dict[str, callable]] = {}
        self.error_routes: dict[int, callable] = {
            404: _default_404_route,
            405: _default_405_route,
        }

    def _pattern_to_regex(self, temp) -> re.Pattern[str]:
        re_temp = temp
        iter = PR.finditer(temp)
        for m in iter:
            name = m[1]
            re_temp = re.sub(m[0], r"(?P<" + name + r">[a-zA-Z0-9_-]+)", re_temp)
        return re.compile(re_temp)

    def _serve(self, path, method, func):
        if method not in ["GET", "POST", "PUT", "DELETE"]:
            raise RuntimeError(f'Invalid method "{method}".')
        pat = self._pattern_to_regex(path)
        if pat not in self.routes:
            self.routes[pat] = {}
        if method in self.routes[pat]:
            raise RuntimeWarning(f'Path "{path}" already exists.')
        self.routes[pat][method] = func

    def GET(self, path):
        """Decorator to register a GET HTTP route."""

        def decorator(func):
            self._serve(path, "GET", func)
            return func

        return decorator

    def POST(self, path):
        """Decorator to register a POST HTTP route."""

        def decorator(func):
            self._serve(path, "POST", func)
            return func

        return decorator

    def PUT(self, path):
        """Decorator to register a PUT HTTP route."""

        def decorator(func):
            self._serve(path, "PUT", func)
            return func

    def DELETE(self, path):
        """Decorator to register a DELETE HTTP route."""

        def decorator(func):
            self._serve(path, "DELETE", func)
            return func

        return decorator

    def error(self, code):
        """Decorator to register an error route."""

        def decorator(func):
            self.error_routes[code] = func
            return func

        return decorator

    def resolve(self, path, method) -> tuple[callable, dict]:
        for pattern, route in self.routes.items():
            if m := pattern.fullmatch(path):
                if method not in route:
                    return self.error_routes[405], {}
                return route[method], m.groupdict()
        return self.error_routes[404], {}

    async def handle_client(
        self, reader: asyncio.StreamReader, writer: asyncio.StreamWriter
    ):
        """Handle an incoming connection (HTTP or WebSocket)."""
        try:
            # Read the initial HTTP request line
            request_line = await reader.readline()
            if not request_line:
                return

            # Parse request line
            parts = request_line.decode(encoding="utf-8").strip().split()
            if len(parts) < 3:
                return

            method, path, protocol = parts[0], parts[1], parts[2]

            assert protocol == "HTTP/1.1"

            headers = {}

            content_length = int(headers.get("Content-Length", 0))
            body = await reader.read(content_length) if content_length else b""

            route, kwargs = self.resolve(path)
            response = await route(
                request={
                    "method": method,
                    "path": path,
                    "headers": headers,
                    "body": body,
                },
                **kwargs,
            )
            writer.write(response.encode(encoding="utf-8"))

            await writer.drain()
        except Exception as e:
            print(f"Error: {e}")
        finally:
            writer.close()
            await writer.wait_closed()

    async def run(self, host="127.0.0.1", port=80):
        """Start the async server."""

        server = await asyncio.start_server(self.handle_client, host, port)

        print(f"Serving on {host}:{port}")
        async with server:
            await server.serve_forever()


def HTTPResponse(content: str, status=200, content_type="text/plain; charset=utf-8"):
    return f"HTTP/1.1 {status} OK\r\nContent-Type: {content_type}\r\n\r\n{content}"


def render(file: str | Path):
    if type(file) is str:
        file = Path(file)
    content: str = file.read_text()
    return HTTPResponse(content, content_type="text/html; charset=utf-8")


def JSONResponse(d: dict, status=200):
    return HTTPResponse(
        json.dumps(d), status=status, content_type="text/json; charset=utf-8"
    )


def JSONAPI(func):
    def wrapper(*args, **kwargs):
        result = func(*args, **kwargs)
        if not isinstance(result, dict):
            if (
                isinstance(result, tuple)
                and len(result) == 2
                and isinstance(result[1], dict)
                and isinstance(result[0], int)
            ):
                return JSONResponse(result[1], result[0])
            raise RuntimeError("Return value of JSONAPI route is not a dictionary")
        return JSONResponse(result)