"""FastMCP server exposing bridge tools to claude.ai."""

import json
from datetime import datetime, timezone

from fastmcp import FastMCP

from .db import Database
from .config import get_group_chat_id

# Will be initialized in __main__ with shared db instance
db: Database | None = None

mcp = FastMCP(
    name="homelab-bridge",
    instructions=(
        "This MCP server bridges claude.ai to a homelab Telegram group chat. "
        "Use pull_updates to read conversation history (supports cursor-based pagination). "
        "Use send_message to post messages to the group (attributed as [claude.ai]). "
        "Use queue_status for a quick summary."
    ),
)


def init(database: Database):
    """Set the shared database instance."""
    global db
    db = database


@mcp.tool()
def send_message(message: str) -> str:
    """Send a message to the homelab Telegram group chat.

    The message will be posted with [claude.ai] attribution so participants
    know the message came from claude.ai.

    Args:
        message: The text to send to the group chat.
    """
    chat_id = get_group_chat_id()
    outbound_id = db.queue_outbound(chat_id, message)
    return json.dumps({"sent": True, "id": outbound_id})


@mcp.tool()
def pull_updates(since_id: int = 0, since: str | None = None, limit: int = 50) -> str:
    """Pull conversation messages from the Telegram group.

    Returns messages from all participants (Mikkel, homelab bot, MCP bot).
    Supports cursor-based pagination: use the returned 'cursor' value as
    'since_id' in the next call to get only new messages.

    Args:
        since_id: Return messages with id > this value. Use cursor from previous response.
        since: ISO 8601 timestamp. Alternative to since_id — returns messages after this time.
        limit: Maximum number of messages to return (default 50, max 200).
    """
    limit = min(limit, 200)

    if since:
        messages = db.get_messages_since_timestamp(since, limit)
    else:
        messages = db.get_messages_since_id(since_id, limit)

    # Enrich with attachment info
    for msg in messages:
        if msg["has_attachment"]:
            msg["attachments"] = db.get_attachments_for_message(msg["id"])
        else:
            msg["attachments"] = []
        del msg["has_attachment"]

    cursor = messages[-1]["id"] if messages else since_id

    return json.dumps({
        "messages": messages,
        "cursor": cursor,
        "count": len(messages),
    })


@mcp.tool()
def queue_status() -> str:
    """Get current status of the bridge.

    Returns message counts, last activity, and pending outbound messages.
    """
    status = db.get_status()
    return json.dumps(status)