You are tasked with transforming the agent's interaction history from ALFWorld into a structured summary in dict format (JSON format).

Desired Summary Format:
{
    "reachable_locations": ["cabinet 1", "countertop 1", ...],
    "items_in_locations": {
        "cabinet 1": ["soapbottle", "cloth", ...],
        "countertop 1": ["bread", ...],
        ...
    },
    "item_in_hand": {
        "item_name": "spraybottle",
        "status": "normal" // The status of the item the agent is currently holding.
    },
    "current_position": {
        "location_name": "toilet 1",
        "status": "null" // The status of the agent's current position.
    }
}

Reachable Locations: List all locations the agent can reach.
Items in Locations: Items are grouped by location. For each location the agent arrives at, list the items found in each location. Note that if an item is taken from a location, it should disappear from the list of items at that location.
Item in Hand: Specifies the item the agent is holding, along with its status (e.g., "heated," "cooled," "normal"). Leave it 'null', if holding nothing.
Current Position: Provides both the agent's current location and the status of that location. If the location is openable, provide the status ('closed' or 'open'). If the location is unopenable, fill with 'null'.

Ensure the response can be parsed by Python json.loads, e.g.: no trailing commas, **no single quotes**, etc.