# yaml-language-server: $schema=http://json-schema.org/draft-07/schema
# SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Systems, RWTH Aachen University
# SPDX-License-Identifier: Apache-2.0
---
allOf:
- type: object
  additionalProperties:
    description: |
      The Lua hook will pass the complete hook configuration to the `prepare()` Lua function.
      So you can add arbitrary settings here which are then consumed by the Lua script.

  properties:
    use_names:
      type: boolean
      default: true
      description: Enables or disables the use of signal names in the `process()` Lua function. If disabled, numeric indices will be used.

    script:
      type: string
      description: |
        Provide the path to a Lua script containing functions for the individual hook points.
        Define some or all of the following functions in your Lua script:

        #### `prepare(cfg)`

        Called during initialization with a Lua table which contains the full hook configuration.

        #### `start()`

        Called when the associated node or path is started

        #### `stop()`

        Called when the associated node or path is stopped

        #### `restart()`

        Called when the associated node or path is restarted.
        Falls back to `stop()` + `start()` if absent.

        #### `process(smp)`

        Called for each sample which is being processed.
        The sample is passed as a Lua table with the following fields:

        - `sequence`     The sequence number of the sample.
        - `flags`        The flags field of the sample.
        - `ts_origin`    The origin timestamp as a Lua table containing the following keys:
        | Index | Description |
        |:--    |:--          |
        | 0     | seconds     |
        | 1     | nanoseconds |

        - `ts_received`  The receive timestamp a Lua table containing the following keys:
        | Index | Description |
        |:--    |:--          |
        | 0     | seconds     |
        | 1     | nanoseconds |

        - `data`         The sample data as a Lua table container either numeric indices or the signal names depending on the 'use_names' option of the hook.

        #### `periodic()`

        Called periodically with the rate of @ref node-config-stats.

    signals:
      description: |
        A definition of signals which this hook will emit.
        Here a list of signal definitions like @ref node-config-node-signals is expected.
      type: array
      items:
        allOf:
        - type: object
          properties:
            expression:
              type: string
              example: "math.sqrt(smp.data[0] ^ 2 + smp.data[1] ^ 2)"
              description: |
                An arbitrary Lua expression which will be evaluated and used for the value of the signal.
                Note you can access the current sample using the global Lua variable `smp`.
        # - $ref: ../signal_spec.yaml

- $ref: ../hook.yaml