"""Framework-neutral MCP method and tool dispatch."""

from __future__ import annotations

import json
from dataclasses import dataclass
from typing import Callable, Protocol

from bot_bottle.gateway.egress.context import resolve_client_context
from bot_bottle.gateway.egress.schema import route_to_yaml_dict
from bot_bottle.gateway.policy_resolver import PolicyResolver
from bot_bottle.supervisor import types as _sv


class Request(Protocol):
    @property
    def method(self) -> str: ...

    @property
    def params(self) -> dict[str, object]: ...


class MethodNotFoundError(Exception):
    """Raised when a JSON-RPC method has no MCP handler."""


Handler = Callable[[dict[str, object]], object]


@dataclass(frozen=True)
class Handlers:
    initialize: Handler
    tools_list: Handler
    list_routes: Handler
    check_proposal: Handler
    propose: Handler


def dispatch(request: Request, handlers: Handlers) -> object:
    """Route one parsed request without depending on the HTTP server."""
    if request.method == "initialize":
        return handlers.initialize(request.params)
    if request.method == "notifications/initialized":
        return None
    if request.method == "tools/list":
        return handlers.tools_list(request.params)
    if request.method != "tools/call":
        raise MethodNotFoundError(request.method)

    tool = request.params.get("name")
    if tool == _sv.TOOL_LIST_EGRESS_ROUTES:
        return handlers.list_routes(request.params)
    if tool == _sv.TOOL_CHECK_PROPOSAL:
        return handlers.check_proposal(request.params)
    return handlers.propose(request.params)


def resolved_routes_payload(
    resolver: PolicyResolver,
    source_ip: str,
    identity_token: str,
) -> dict[str, object]:
    """Render the calling bottle's routes, failing closed to an empty list."""
    config, _slug, _tokens = resolve_client_context(
        resolver, source_ip, identity_token,
    )
    body = json.dumps(
        {"routes": [route_to_yaml_dict(route) for route in config.routes]},
        indent=2,
    )
    return {"content": [{"type": "text", "text": body}], "isError": False}


__all__ = [
    "Handlers",
    "MethodNotFoundError",
    "dispatch",
    "resolved_routes_payload",
]