"""Server-side allowlist of endpoint agent commands.

The WebUI never sends an arbitrary command string. It sends an allowlisted
ACTION NAME; the concrete on-endpoint behavior (which script to run, how to stop
a process) lives in the agent. This module is the single source of truth for
which action names are legal and what they mean, so both the enqueue route and
the settings/UI surface validate against the same set.

The structure anticipates per-PC-type allowlists: today every computer may run
every action in COMMAND_ALLOWLIST, but ALLOWED_ACTIONS_FOR is the seam a later
change swaps for a type-scoped lookup (inspection PCs vs shopfloor PCs).
"""

# action name -> operator-facing metadata. label/description feed the UI; the
# agent maps the action name to its local handler (see CommandExecutor).
#
# Two families of action:
#   * Named MTConnect actions - fixed target, no parameters. The original,
#     bay-specific controls kept for the inline services-panel toggle.
#   * Generic RMM actions (service_* / process_*) - the target is supplied by
#     the policy action's params ('target' = a Windows service name or a process
#     image like 'DncMain.exe'). This is what populates the Configuration Policy
#     builder with reusable controls that any scope (PC type or application) can
#     attach. The 'targetkind' hint tells the builder which target field to show.
#     NOTE: agent-side execution of the generic actions is not wired yet; the
#     server allowlist and policy plumbing land first (the whole feature is
#     flag-gated), so a generic action saved today is authored and gated but is
#     a no-op on the endpoint until the CommandExecutor handlers ship.
COMMAND_ALLOWLIST = {
    'service_start': {
        'label': 'Start service',
        'description': 'Start a Windows service by name on the endpoint.',
        'targetkind': 'service',
    },
    'service_stop': {
        'label': 'Stop service',
        'description': 'Stop a running Windows service by name on the endpoint.',
        'targetkind': 'service',
    },
    'service_status': {
        'label': 'Check service',
        'description': 'Report whether a named Windows service is running.',
        'targetkind': 'service',
    },
    'process_start': {
        'label': 'Start process',
        'description': 'Launch a process by executable path on the endpoint.',
        'targetkind': 'process',
    },
    'process_stop': {
        'label': 'Stop process',
        'description': 'Stop a running process by image name on the endpoint.',
        'targetkind': 'process',
    },
    'process_status': {
        'label': 'Check process',
        'description': 'Report whether a named process is running.',
        'targetkind': 'process',
    },
    'mtconnect_start': {
        'label': 'Start MTConnect',
        'description': 'Run the MTConnect UDC agent start script on the endpoint.',
    },
    'mtconnect_stop': {
        'label': 'Stop MTConnect',
        'description': 'Stop the running MTConnect UDC agent on the endpoint.',
    },
    'mtconnect_status': {
        'label': 'Check MTConnect',
        'description': 'Report whether the MTConnect UDC agent is running.',
    },
    'system_restart': {
        'label': 'Restart computer',
        'description': 'Restart the endpoint computer immediately.',
    },
    'collect_now': {
        'label': 'Collect now',
        'description': 'Force the endpoint agent to report fresh telemetry off-cadence.',
    },
}


# Actions that demand a permission stricter than the base endpoints.command.
# The enqueue route requires the caller to ALSO hold the mapped permission, so a
# destructive action (a remote reboot) is a heavier grant than a routine toggle.
ELEVATED_ACTION_PERMISSIONS = {
    'system_restart': 'endpoints.restart',
}


def elevated_permission_for(action):
    """The extra permission an action requires, or None for routine actions."""
    return ELEVATED_ACTION_PERMISSIONS.get(action)


# Maps a monitored services/processes row to the start/stop/status actions that
# control it, so the services panel can render an inline toggle on exactly the
# rows that have a registered command action. The key is the agent-reported
# 'app' label; 'kind' pins the toggle to the authoritative row (for MTConnect
# the agent.exe PROCESS is the source of truth - run.bat launches it and the
# Windows service state is not reliable), so the service row stays badge-only.
ROW_COMMAND_TARGETS = {
    ('MTConnect', 'process'): {
        'start': 'mtconnect_start',
        'stop': 'mtconnect_stop',
        'status': 'mtconnect_status',
    },
}


def row_actions_for(app, kind, name=None):
    """Return the {start, stop, status, target, targetkind} map for a row.

    Two paths:
      * A row registered in ROW_COMMAND_TARGETS (MTConnect) keeps its fixed,
        named actions with no wire target - agent.exe is the source of truth and
        the behavior is pinned in the agent.
      * Any other process/service row maps to the generic primitives
        (process_* / service_*) with the row's OWN reported name as the wire
        target. This is what lets a new app light up start/stop/status without
        an agent rebuild: the target rides the wire.

    Rows with no usable kind return None and render as a plain status badge.
    """
    if not app and not name:
        return None
    fixed = ROW_COMMAND_TARGETS.get((app, (kind or '').lower()))
    if fixed:
        return {**fixed, 'target': None, 'targetkind': None}
    normalized = (kind or '').lower()
    if normalized == 'process' and name:
        return {
            'start': 'process_start',
            'stop': 'process_stop',
            'status': 'process_status',
            'target': name,
            'targetkind': 'process',
        }
    if normalized == 'service' and name:
        return {
            'start': 'service_start',
            'stop': 'service_stop',
            'status': 'service_status',
            'target': name,
            'targetkind': 'service',
        }
    return None


def is_allowed_action(action):
    """True when action is a known, allowlisted command name."""
    return action in COMMAND_ALLOWLIST


def action_targetkind(action):
    """The targetkind an action requires ('service'/'process'), or None.

    Generic actions declare a targetkind in COMMAND_ALLOWLIST; fixed-target
    actions (mtconnect_*) declare none and must not carry a wire target.
    """
    meta = COMMAND_ALLOWLIST.get(action) or {}
    return meta.get('targetkind')


def requires_target(action):
    """True when the action is generic and needs a wire target."""
    return action_targetkind(action) is not None


def ALLOWED_ACTIONS_FOR(pctype=None, assetid=None):
    """The action names an endpoint may run.

    Base allowlist is flat (every action for every computer). When the computers
    Configuration/Business Policy feature is enabled AND an assetid is given, the
    result is narrowed to the actions the endpoint's effective policy permits -
    this is the allowlist-gating half of the policy design. With the feature off
    (or no assetid), it returns the full base allowlist, so nothing changes until
    a site opts in. Policy resolution is imported lazily to keep this module free
    of a hard dependency on the computers plugin.
    """
    base = set(COMMAND_ALLOWLIST.keys())
    if assetid is None:
        return base
    try:
        from plugins.computers.services.policyresolver import effective_policy_for
    except Exception:
        return base
    effective = effective_policy_for(assetid)
    allowed = effective.allowed_actions()
    if not allowed:
        # No policy spoke for this endpoint. With the feature off the resolver
        # returns empty and we fall back to the base allowlist (unchanged
        # behavior). This is intentionally permissive; deny-by-default would be
        # a separate, explicit setting.
        return base
    # Never widen past the code-level allowlist: policy can only gate within it.
    return base & allowed