"""MCP tools for Fable chat — create conversations and stream responses."""
from __future__ import annotations

import json
from typing import Any

from fable_mcp.client import FableClient


async def list_conversations(
    client: FableClient,
    *,
    limit: int = 20,
    offset: int = 0,
) -> dict[str, Any]:
    """List MCP chat conversations."""
    params: dict[str, Any] = {"limit": limit, "offset": offset, "type": "mcp"}
    return await client.get("/api/chat/conversations", params=params)


async def send_message(
    client: FableClient,
    *,
    message: str,
    conversation_id: str | None = None,
    think: bool = False,
) -> dict[str, Any]:
    """Send a message to Fable and return the full assistant response.

    Creates a new MCP conversation if conversation_id is None.
    Streams the SSE response and accumulates token chunks into a single string.

    Returns:
        Dict with:
          - "conversation_id": str
          - "response": str (full assistant message)
          - "tool_calls": list of any tool_call events observed
    """
    if conversation_id is None:
        conv = await client.post(
            "/api/chat/conversations",
            json={"conversation_type": "mcp"},
        )
        conversation_id = conv["id"]

    # Build SSE stream URL with message as query param
    params: dict[str, Any] = {"message": message}
    if think:
        params["think"] = "true"

    tokens: list[str] = []
    tool_calls: list[Any] = []

    stream_path = f"/api/chat/conversations/{conversation_id}/stream"
    async for raw_line in client.stream_get(stream_path, params=params):
        if not raw_line.startswith("data: "):
            continue
        payload_str = raw_line[len("data: "):]
        try:
            event = json.loads(payload_str)
        except json.JSONDecodeError:
            continue
        event_type = event.get("type")
        if event_type == "token":
            tokens.append(event.get("content", ""))
        elif event_type == "tool_call":
            tool_calls.append(event)
        elif event_type == "done":
            break

    return {
        "conversation_id": conversation_id,
        "response": "".join(tokens),
        "tool_calls": tool_calls,
    }