theme

#!/usr/bin/bash

set -Eeuo pipefail

source "$HOME/dotfiles/linux/variables.env"

state_file="$THEME_STATE_FILE"

current_theme() {
  local theme

  if [ -r "$state_file" ]; then
    read -r theme < "$state_file"
  else
    theme=dark
  fi

  case "$theme" in
    dark|light) printf '%s\n' "$theme" ;;
    *) printf 'dark\n' ;;
  esac
}

write_gtk_settings() {
  local theme="$1"
  local gtk_theme prefer_dark

  if [ "$theme" = dark ]; then
    gtk_theme=Colloid-Teal-Dark
    prefer_dark=1
  else
    gtk_theme=Colloid-Teal-Light
    prefer_dark=0
  fi

  for gtk_version in gtk-3.0 gtk-4.0; do
    mkdir -p "$XDG_CONFIG_HOME/$gtk_version"
    cat > "$XDG_CONFIG_HOME/$gtk_version/settings.ini" <<EOF
[Settings]
gtk-application-prefer-dark-theme=$prefer_dark
gtk-theme-name=$gtk_theme
gtk-icon-theme-name=Papirus-Dark
EOF
  done

  cat > "$HOME/.gtkrc-2.0" <<EOF
gtk-theme-name = "$gtk_theme"
gtk-icon-theme-name = "Papirus-Dark"
EOF
}

set_gsetting() {
  local schema="$1"
  local key="$2"
  local value="$3"

  if command -v gsettings > /dev/null 2>&1 && [ "$(gsettings writable "$schema" "$key" 2> /dev/null)" = true ]; then
    gsettings set "$schema" "$key" "$value" || true
  fi
}

apply_theme() {
  local theme="$1"
  local gtk_theme color_scheme kvantum_theme

  if [ "$theme" = dark ]; then
    gtk_theme=Colloid-Teal-Dark
    color_scheme=prefer-dark
    kvantum_theme=KvGnomeDark
  else
    gtk_theme=Colloid-Teal-Light
    color_scheme=prefer-light
    kvantum_theme=KvGnome
  fi

  write_gtk_settings "$theme"
  set_gsetting org.gnome.desktop.interface color-scheme "'$color_scheme'"
  set_gsetting org.gnome.desktop.interface gtk-theme "'$gtk_theme'"
  set_gsetting org.gnome.desktop.interface icon-theme "'Papirus-Dark'"

  if command -v kvantummanager > /dev/null 2>&1; then
    kvantummanager --set "$kvantum_theme" || true
  fi
}

show_notification() {
  local theme="$1"
  local icon summary body

  if [ "$theme" = dark ]; then
    icon=moon
    summary="Dark mode enabled"
    body="Applications will prefer dark colors."
  else
    icon=sun
    summary="Light mode enabled"
    body="Applications will prefer light colors."
  fi

  command -v notify-send > /dev/null 2>&1 || return 0
  notify-send -a System \
    -i "$LUCIDE_PATH/$icon.svg" \
    -h string:wired-tag:theme \
    -u low \
    -t 3000 \
    "$summary" "$body" || true
}

case "${1:-toggle}" in
  get)
    current_theme
    ;;
  apply)
    apply_theme "$(current_theme)"
    ;;
  init)
    if [ ! -r "$state_file" ]; then
      mkdir -p "$(dirname "$state_file")"
      printf 'dark\n' > "$state_file"
    fi
    apply_theme "$(current_theme)"
    ;;
  dark|light)
    mkdir -p "$(dirname "$state_file")"
    printf '%s\n' "$1" > "$state_file"
    apply_theme "$1"
    show_notification "$1"
    ;;
  toggle)
    if [ "$(current_theme)" = dark ]; then
      "$0" light
    else
      "$0" dark
    fi
    ;;
  *)
    printf 'Usage: %s [dark|light|toggle|get|apply|init]\n' "$0" >&2
    exit 2
    ;;
esac