# Background Missions

The `auto_start` feature allows you to define background behaviors that run automatically when the robot or your custom skill manager starts. This enables you to:

* Control the **default autonomous behaviors** on the robot.
* Define your **own custom background routines** tailored to your needs.

---

## `start_background_missions` Skill

By default, the robot runs an auto-start skill called `start_background_missions`. This skill:

* Defines custom **priority levels** in the mission system.
* Enqueues built-in background behaviors grouped by priority.
* Ensures the robot starts up with essential functionality and expressiveness.

### Example

Here's a simplified version of the skill:

```python
import asyncio
from pymirokai.decorators.skill import skill
from pymirokai.enums import PreemptionStrategy
from pymirokai.robot import Robot

@skill(auto_start=True)
async def start_background_missions(robot: Robot):
    await robot.make_priority_level("SYSTEM", below="MEDIUM", mission_conflict_strategy=PreemptionStrategy.RUN_OLDEST)
    await robot.make_priority_level("VERY_LOW", below="LOW", mission_conflict_strategy=PreemptionStrategy.RUN_OLDEST)

    await robot.enqueue_mission("battery_monitor", priority="SYSTEM")
    await robot.enqueue_mission(
        "set_default_neck_mode_and_wait_infinitely",
        priority="VERY_LOW",
        restart_after_cancellation=True,
        log_level=logging.ERROR,
    )

    await asyncio.Future()
```

---

### How It Works

* **Mission Priorities**: Skills are assigned a priority level (e.g. `SYSTEM`, `LOW`, `VERY_LOW`). A skill can only take a resource if it is free or used by a lower-priority skill.
* **Persistence**: The skill ends with `await asyncio.Future()` to run indefinitely. If this line is removed, any enqueued missions would be cancelled when the skill finishes.
* **Priority Listing**: You can call `robot.get_available_priorities()` to inspect available priority levels.

---

## Default Background Skills

The following background skills are automatically launched by the `start_background_missions.py` script:

### Interaction and Reactivity

* **`obey`** – Enables voice-triggered skill execution.
* **`react_to_words`** – Responds expressively to spoken phrases.
* **`react_if_ear_touched`** – Reacts when the robot's ears are touched.

### System Monitoring

* **`battery_monitor`** – Monitors the battery and gives voice alerts when low.
* **`react_when_collisions`** – Responds to detected collisions.
* **`enable_asr_only_when_voice_resource_is_free`** – Enables speech recognition only when audio resources are free.

### Autonomy and Intelligence

* **`autonomous_planning`** – Manages high-level decision-making and mission planning.
* **`react_when_grasping`** – Provides contextual feedback during grasping attempts.
* **`react_when_navigating`** – Expresses reactions during navigation.

### Expressive and Social Behaviors

* **`human_bond`** – Enables bonding behaviors like idle animations and head tracking.
* **`look_towards_destination`** – Directs the head toward the navigation goal.
* **`wander_off`** – Triggers random expressive behaviors to simulate lifelike presence.

### Passive Fallback

* **`set_default_neck_mode_and_wait_infinitely`** – Sets the neck to a neutral position and waits indefinitely. Acts as a fallback behavior when no other task is running.

---

## Customization

You can personalize the robot's background behavior in several ways:

* **Disable a behavior**: Simply comment out the corresponding `enqueue_mission()` line in the `start_background_missions.py` file, or disable the whole custom skill file if you don't want the robot to run any background behavior.
* **Add your own logic**: Define and enqueue new background skills—either on the robot or via a remote skill manager.

This setup gives you full control over the robot's background activity, enabling intelligent, responsive, and expressive default behavior.