[Unit]
Description=Wallpaper builder
PartOf=graphical-session.target

[Service]
Environment=WALLPAPER_DIRECTORY=%h/.config/i3/wallpapers
Environment=WALLPAPER_TARGET=%t/i3/current-wallpaper.png
Environment=WALLPAPER_OUTPUTS=%t/i3/outputs.txt
ExecStart=/usr/bin/mkdir -p %t/i3
ExecStart=%h/.config/i3/bin/wallpaper --directory $WALLPAPER_DIRECTORY \
                                      --target $WALLPAPER_TARGET \
                                      --outputs $WALLPAPER_OUTPUTS
ExecStart=/usr/bin/hsetroot -root -center $WALLPAPER_TARGET
Type=oneshot
RemainAfterExit=false