esphome:
  name: uart-mock-modbus-cli-rw

host:
api:
logger:
  level: VERBOSE

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

# Two virtual buses looped back to each other: the client's transmissions reach the server and the
# server's replies reach the client. auto_start so forwarding is active before the button fires.
uart_mock:
  - id: virtual_uart_server
    baud_rate: 9600
    auto_start: true
    debug:
    on_tx:
      - then:
          - uart_mock.inject_rx:
              id: virtual_uart_client
              data: !lambda return data;
  - id: virtual_uart_client
    baud_rate: 9600
    auto_start: true
    debug:
    on_tx:
      - then:
          - uart_mock.inject_rx:
              id: virtual_uart_server
              data: !lambda return data;

globals:
  - id: stored_1
    type: uint16_t
    initial_value: "0"

modbus:
  - uart_id: virtual_uart_server
    id: virtual_modbus_server
    role: server
  - uart_id: virtual_uart_client
    id: virtual_modbus_client
    role: client
    turnaround_time: 10ms

modbus_server:
  - address: 1
    modbus_id: virtual_modbus_server
    registers:
      # Writable + readable register: the read publishes what it returns, so the test can confirm the
      # write half of the 0x17 ran before the read half (Modbus 6.17).
      - address: 0x01
        value_type: U_WORD
        read_lambda: |-
          id(srv_read_1).publish_state(id(stored_1));
          return id(stored_1);
        write_lambda: |-
          id(stored_1) = x;
          id(srv_write_1).publish_state(x);
          return true;
      # Read-only register, returned together with 0x01 by the 2-register read half.
      - address: 0x02
        value_type: U_WORD
        read_lambda: return 0x00AA;

sensor:
  # Server-side observations.
  - platform: template
    name: "srv_write_1"
    id: srv_write_1
  - platform: template
    name: "srv_read_1"
    id: srv_read_1
  # Client-side read-back: the values the client's on_response received.
  - platform: template
    name: "client_read_0"
    id: client_read_0
  - platform: template
    name: "client_read_1"
    id: client_read_1

button:
  - platform: template
    name: "Start Scenario"
    id: start_scenario_btn
    on_press:
      # FC 0x17: write reg 0x0001 = 0x1234, then read regs 0x0001..0x0002 back in the same transaction.
      - modbus_client.read_write_multiple_registers:
          address: 0x01
          read_address: 0x0001
          read_count: 2
          write_address: 0x0001
          values: [0x1234]
          on_response:
            then:
              - lambda: |-
                  // values is the read-back block: reg 0x0001 (must be the just-written 0x1234) and reg 0x0002.
                  if (values.size() >= 2) {
                    id(client_read_0).publish_state(values[0]);
                    id(client_read_1).publish_state(values[1]);
                  }