Theme Sender

A smart MQTT-based theme publisher that automatically switches themes based on solar events (sunrise, sunset, etc.) with support for custom theme overrides.

Features

• 🌅 Solar-Based Themes: Automatically calculates and publishes themes based on your location's solar events
• 🔄 Periodic Publishing: Regularly publishes the current theme (default: every 5 minutes)
• 🎭 Custom Theme Override: Send a custom theme via MQTT that will be published until the next solar event change
• 📍 Automatic Geolocation: Uses your IP address to determine location for solar calculations
• 🔧 CLI Tool: Convenient theme-override binary to send overrides and revert to automatic themes
• 🔐 MQTT Authentication: Supports username/password authentication
• 📊 Structured Logging: Configurable logging with trace, debug, info levels using tracing

Theme Types

The following solar-based themes are automatically calculated:

• Night (dark) - Full night, stars visible
• Astronomical Dawn (dark-dimmed) - Faint light appears in sky
• Nautical Dawn (dark-soft) - Horizon becomes visible
• Civil Dawn (light-soft) - Enough light for outdoor activities
• Sunrise (light) - Sun breaks the horizon
• Day (light) - Full daylight
• Civil Dusk (light-soft) - Sun below horizon, still light out
• Nautical Dusk (dark-soft) - Darker, horizon still visible
• Astronomical Dusk (dark-dimmed) - Fading light in sky

Configuration

Command Line Arguments

theme-sender \
  --mqtt-host <HOST> \
  --mqtt-username <USERNAME> \
  --mqtt-password <PASSWORD> \
  --mqtt-topic <TOPIC> \
  --mqtt-override-topic <OVERRIDE_TOPIC> \
  --publish-interval-secs <SECONDS>

Environment Variables

All configuration can be set via environment variables:

• MQTT_HOST - MQTT broker host (default: localhost)
• MQTT_USERNAME - MQTT username (optional)
• MQTT_PASSWORD - MQTT password (optional)
• MQTT_TOPIC - Topic to publish themes to (default: neiam/sync/theme)
• MQTT_OVERRIDE_TOPIC - Topic to receive custom theme overrides (default: neiam/sync/theme/override)
• MQTT_REVERT_TOPIC - Topic to receive revert commands (default: neiam/sync/theme/revert)
• PUBLISH_INTERVAL_SECS - How often to publish the theme in seconds (default: 300)

Logging Configuration

Both binaries use the tracing library for structured logging. Configure via the RUST_LOG environment variable:

# Show all logs (default: info level)
RUST_LOG=theme_sender=info cargo run

# Show debug logs for more detail
RUST_LOG=theme_sender=debug cargo run

# Show trace logs for maximum verbosity
RUST_LOG=theme_sender=trace cargo run

Usage

Basic Usage

cargo run

Custom Configuration

MQTT_HOST=mqtt.example.com \
MQTT_USERNAME=user \
MQTT_PASSWORD=pass \
PUBLISH_INTERVAL_SECS=60 \
cargo run

Custom Theme Override

To temporarily override the automatic solar theme, publish a custom theme to the override topic:

# Using mosquitto_pub
mosquitto_pub -h localhost -t "neiam/sync/theme/override" -m "my-custom-theme"

# Using another MQTT client
# Send the theme string as the payload to the override topic

The custom theme will be published periodically until the next solar event causes a theme change, at which point it will automatically clear the override and return to solar-based themes.

Published Message Format

The theme is published as JSON:

{
  "theme": "light",
  "data": "2025-12-29T04:30:00Z"
}

How It Works

1. Startup:

   • Fetches your location based on IP address
   • Calculates today's solar events
   • Publishes the current theme immediately

2. Main Loop:

   • Every N seconds (configurable):
     • Checks for custom theme overrides
     • Determines the current solar theme
     • Publishes the appropriate theme (custom or solar)
     • Clears custom overrides when solar theme changes

3. Override Listener:

   • Runs in background
   • Listens for custom theme messages
   • Queues them for the main loop to process

Building

cargo build --release