Feature: Non-interactive execution

  keld is often invoked from systemd timers, cron jobs, CI pipelines,
  and shell scripts where no controlling terminal is attached. In those
  contexts it must run restic directly without attempting to launch the
  interactive TUI. When a user wants scripted behaviour even on a
  terminal, an environment variable provides an escape hatch.

  Rule: Without a terminal keld never launches the interactive TUI

    Scenario: Wrapped subcommand runs restic when the preset supplies everything
      Given keld is invoked with a wrapped subcommand and no positional arguments
      And standard input is not a terminal
      And the selected preset supplies every value the command needs
      When keld runs
      Then restic is executed with the resolved configuration
      And no interactive TUI is launched

    Scenario: Wrapped subcommand runs restic when positional arguments cover missing values
      Given keld is invoked with a wrapped subcommand and positional arguments
      And standard input is not a terminal
      When keld runs
      Then restic is executed with the resolved configuration
      And no interactive TUI is launched

    Scenario: --show-command prints the resolved command without launching the TUI
      Given keld is invoked non-interactively with --show-command
      When keld runs
      Then the resolved restic command is printed
      And keld exits successfully without executing restic
      And no interactive TUI is launched

  Rule: Non-interactive mode requires explicit inputs

    Scenario: Multiple presets are configured and none is specified
      Given the configuration defines more than one preset
      And keld is invoked non-interactively without --preset
      When keld runs
      Then keld fails with an error naming the --preset flag
      And the error lists the available presets
      And no interactive TUI is launched

    Scenario: Backup invoked with no paths available
      Given keld is invoked non-interactively with the backup subcommand
      And no paths are provided on the command line
      And the resolved preset defines no backup paths
      When keld runs
      Then keld fails with an error naming the missing paths
      And no interactive TUI is launched

    Scenario: Bare keld with no subcommand
      Given keld is invoked non-interactively with no subcommand
      When keld runs
      Then keld fails with an error naming the missing subcommand
      And no interactive TUI is launched

  Rule: Interactive mode is preserved when a terminal is attached

    Scenario: Wrapped subcommand with no arguments opens the session
      Given keld is invoked with a wrapped subcommand and no positional arguments
      And standard input is a terminal
      When keld runs
      Then the interactive session is launched with the command pre-selected

    Scenario: Bare keld opens the command menu
      Given keld is invoked with no subcommand
      And standard input is a terminal
      When keld runs
      Then the interactive session is launched starting at the command menu

  Rule: KELD_NONINTERACTIVE overrides terminal detection

    Scenario: Environment variable forces non-interactive behaviour on a terminal
      Given keld is invoked with a wrapped subcommand and no positional arguments
      And standard input is a terminal
      And KELD_NONINTERACTIVE is set to a non-empty value
      When keld runs
      Then restic is executed with the resolved configuration
      And no interactive TUI is launched

    Scenario: Empty KELD_NONINTERACTIVE is treated as unset
      Given keld is invoked with a wrapped subcommand and no positional arguments
      And standard input is a terminal
      And KELD_NONINTERACTIVE is set to an empty value
      When keld runs
      Then the interactive session is launched with the command pre-selected