happy-cat/README.md

# Happy Cat 🐈🌞
A commandline utility to control your [Elgato Key Light](https://www.elgato.com/en/key-light) and [Key Light Air](https://www.elgato.com/en/key-light-air).
Change your light settings easily inside scripts or use configuration files to automatically apply your preferred setup over the course of the day, possibly even exploring the use as a [light therapy](https://en.wikipedia.org/wiki/Light_therapy) device.

## Usage
Happy cat is split up into multiple subcommands, each of which have their own parameters.
To find out more about each command, check out the help pages by appending `--help` after the command.

*Important: Happy cat uses Kelvin to measure light temperature, while Elgato lamps use their own format internally. Conversion between the two is done on the fly*
#### Apply
Reads the provided configuration file, determines the currently active state based on time definitions and applies the state to the given light once.
It's basically a oneshot version of the `daemon` command. For examples of the configuration file, check the corresponding paragraph below.  

*Example*  
```shell
hc apply ./elgato.config elgato.local
```

#### Daemon
Reads the given configuration file, then determines and applies the currently valid configuration every minute.  

*Example*
```shell
hc daemon ./elgato.config elgato.local
```

#### Get
Reads and prints the current status of the specified light.

*Example*
```shell
hc get elgato.local
```

#### Set
Sets the given values of powerstatus, brightness and temperature to the specified light.
```shell
hc set -p ON -b 70 -t 4200 elgato.local
```

## Configuration
To automatically apply settings, you can create your own configuration file which defines the settings for each timeframe.
All values inside `status` are optional, if they are not defined, those parameters will remain unchanged.
Timeframes can cross midnight, but *must not* overlap. If there are overlapping timeframes, the first valid timeframe will be chosen.
```json
{
  "config": [
    {
      "start": "8:30",
      "end": "11:00",
      "status": {
        "power": "ON",
        "brightness": 100,
        "temperature": 6500
      }
    },
    {
      "start": "11:00",
      "end": "20:00",
      "status": {
        "brightness": 70,
        "temperature": 4300
      }
    },
    {
      "start": "20:00",
      "end": "8:30",
      "status": {
        "temperature": 3000
      }
    }
  ]
}
```

## Automation
Probably one could automate the setup using systemd and/or cronjobs, but so far I didn't get to that.

## Building
It should be enough to do a simple:
```bash
./gradlew build
```
You can then find the executable in `build/bin/native/hcReleaseExecutable`.

## License
This software is licensed under the MPL 2.0, see the [LICENSE](LICENSE) file.