Debug Feature Updates in a Laptop Management CLI

Problem Statement

An internal IT provisioning service manages software feature flags and installed configurations across company laptops. You are tasked with implementing the core execution engine for a CLI tool that parses and applies batch feature updates to a registry of laptops.

Each laptop in the inventory has:

• id (str): Unique device identifier.
• model (str): Hardware model designation.
• features (set of str): Set of currently enabled feature flags.

The update process accepts an initial list of laptop records and a sequence of text commands executed sequentially:

1. SELECT : Sets the target device for subsequent commands. If `` does not exist in inventory, the command fails and processing stops.
2. ENABLE : Stages a feature to be added to the currently selected device. If no device is selected, processing stops.
3. DISABLE : Stages a feature to be removed from the currently selected device. If no device is selected, processing stops.
4. COMMIT: Applies all staged changes for the selected device. If a feature staged for ENABLE is already present, or staged for DISABLE is not present, validation fails.
5. RESET: Clears any uncommitted staged changes for the currently selected device.

If any command encounters an error or validation failure, the function must immediately abort, discard all staged and committed changes from the entire batch, and return (False, original_devices).

If all commands complete successfully, return (True, updated_devices) where updated_devices preserves the original order of laptops.

Function Signature

def process_laptop_updates(
    devices: list[dict],
    commands: list[str]
) -> tuple[bool, list[dict]]:
    """
    Applies CLI commands to a list of device records.
    Each device dict has keys: 'id' (str), 'model' (str), 'features' (set[str]).
    Returns (success, final_devices).
    """

Constraints

• 1 <= len(devices) <= 500
• 1 <= len(commands) <= 2,000
• Device IDs, models, and feature names are alphanumeric strings (1 <= len <= 64).
• All device IDs in devices are distinct.

Examples

Example 1

devices = [
    {"id": "lap-01", "model": "X1", "features": {"docker", "vpn"}},
    {"id": "lap-02", "model": "M2", "features": {"vpn"}}
]
commands = [
    "SELECT lap-02",
    "ENABLE docker",
    "COMMIT"
]
# Returns: (True, [
#     {"id": "lap-01", "model": "X1", "features": {"docker", "vpn"}},
#     {"id": "lap-02", "model": "M2", "features": {"docker", "vpn"}}
# ])

Example 2

devices = [
    {"id": "lap-01", "model": "X1", "features": {"docker"}}
]
commands = [
    "SELECT lap-01",
    "ENABLE docker",
    "COMMIT"
]
# Returns: (False, [{"id": "lap-01", "model": "X1", "features": {"docker"}}])
# Explanation: 'docker' was already enabled on 'lap-01', causing validation to fail on COMMIT.