esphome:
  name: uart-mock-modbus-offline

host:
api:
logger:
  level: DEBUG

external_components:
  - source:
      type: local
      path: EXTERNAL_COMPONENT_PATH

# Dummy uart entry to satisfy modbus's DEPENDENCIES = ["uart"]
# The actual UART bus used is the uart_mock component below
uart:
  baud_rate: 115200
  port: /dev/null

# Whether the mock device answers requests. Starts false so the controller
# runs through its retries and goes offline; the test flips it via the
# "Serve" button to exercise the offline retry/recovery path.
globals:
  - id: serve
    type: bool
    initial_value: "false"

uart_mock:
  - id: virtual_uart
    baud_rate: 9600
    auto_start: true
    debug:
    on_tx:
      # While serve is false every request times out; once true, answer the
      # (only) request - read holding register 3 on device 1 - with value 259.
      - uart_mock.inject_rx:
          id: virtual_uart
          data: !lambda |-
            if (!id(serve))
              return {};
            return {0x01, 0x03, 0x02, 0x01, 0x03, 0xF9, 0xD5};

modbus:
  - uart_id: virtual_uart
    id: virtual_modbus_client
    send_wait_time: 100ms
    turnaround_time: 10ms

modbus_controller:
  - address: 1
    modbus_id: virtual_modbus_client
    id: ctl
    max_cmd_retries: 1
    # offline_skip_updates: 1 -> once offline, the controller re-probes every second update cycle;
    # the test silences the device to force it offline, then answers again and checks it recovers.
    offline_skip_updates: 1
    update_interval: never
    on_offline:
      then:
        - lambda: id(link_state).publish_state(0);
    on_online:
      then:
        - lambda: id(link_state).publish_state(1);

sensor:
  - platform: modbus_controller
    modbus_controller_id: ctl
    name: reg
    id: reg
    address: 0x03
    register_type: holding
    value_type: U_WORD
  # Mirrors the controller's online state so the test can await the transitions.
  - platform: template
    name: link_state
    id: link_state
    update_interval: never

button:
  - platform: template
    name: "Start Scenario"
    id: start_scenario_btn
    on_press:
      - lambda: |-
          id(ctl).set_update_interval(200);
          id(ctl).start_poller();
  - platform: template
    name: "Serve"
    id: serve_btn
    on_press:
      - globals.set:
          id: serve
          value: "true"