from __future__ import annotations

import json
import sys

TOOLS = [
    {
        "name": "get_file_contents",
        "title": "Get file contents",
        "description": "Read file contents at a given ref.",
        "inputSchema": {
            "type": "object",
            "properties": {
                "owner": {"type": "string"},
                "repo": {"type": "string"},
                "ref": {"type": "string"},
                "filePath": {"type": "string"},
                "withLines": {"type": "boolean"},
            },
            "required": ["owner", "repo", "ref", "filePath"],
            "additionalProperties": False,
        },
    },
    {
        "name": "list_branches",
        "description": "List all branches in a repository for a given owner and repo.",
        "inputSchema": {
            "type": "object",
            "properties": {
                "owner": {"type": "string"},
                "repo": {"type": "string"}
            },
            "required": ["owner", "repo"],
            "additionalProperties": False
        }
    },
    {
        "name": "delete_file",
        "title": "Delete file",
        "description": "Dangerous write tool.",
        "inputSchema": {
            "type": "object",
            "properties": {"filePath": {"type": "string"}},
            "required": ["filePath"],
        },
    },
]


def send(message: dict) -> None:
    sys.stdout.write(json.dumps(message, separators=(",", ":")) + "\n")
    sys.stdout.flush()


for line in sys.stdin:
    raw = line.strip()
    if not raw:
        continue
    msg = json.loads(raw)
    method = msg.get("method")
    msg_id = msg.get("id")

    if method == "initialize":
        send(
            {
                "jsonrpc": "2.0",
                "id": msg_id,
                "result": {
                    "protocolVersion": msg["params"]["protocolVersion"],
                    "capabilities": {"tools": {"listChanged": False}},
                    "serverInfo": {"name": "fake-mcp", "version": "1.0"},
                },
            }
        )
        continue

    if method == "notifications/initialized":
        continue

    if method == "tools/list":
        cursor = (msg.get("params") or {}).get("cursor")
        if not cursor:
            send(
                {
                    "jsonrpc": "2.0",
                    "id": msg_id,
                    "result": {"tools": [TOOLS[0], TOOLS[1]], "nextCursor": "page-2"},
                }
            )
        else:
            send(
                {
                    "jsonrpc": "2.0",
                    "id": msg_id,
                    "result": {"tools": [TOOLS[2]]},
                }
            )
        continue

    if method == "tools/call":
        params = msg.get("params") or {}
        name = params["name"]
        arguments = params.get("arguments") or {}
        if name == "get_file_contents":
            payload = {
                "content": [
                    {
                        "type": "text",
                        "text": "README line\n" * 3000,
                    }
                ],
                "structuredContent": {
                    "owner": arguments.get("owner"),
                    "repo": arguments.get("repo"),
                    "ref": arguments.get("ref"),
                    "filePath": arguments.get("filePath"),
                },
                "isError": False,
            }
            send({"jsonrpc": "2.0", "id": msg_id, "result": payload})
            continue
        send({"jsonrpc": "2.0", "id": msg_id, "error": {"code": -32601, "message": f"Unknown tool: {name}"}})
        continue

    send({"jsonrpc": "2.0", "id": msg_id, "error": {"code": -32601, "message": f"Unknown method: {method}"}})