{ config, lib, pkgs, ... }:

let
  stateDir = "${config.home.homeDirectory}/.config/home-manager";
  
  # Helper to read state from a file, with a default
  readState = file: default:
    if builtins.pathExists "${stateDir}/${file}" then
      let 
        content = builtins.readFile "${stateDir}/${file}";
        cleanContent = lib.removeSuffix "\n" content;
      in
      if lib.hasSuffix ".json" file then
        builtins.fromJSON cleanContent
      else
        cleanContent
    else
      default;

  # Unified state reading
  togglesState = readState "state.json" {};
in
{
  config = {
    home.activation.migrateNomarchyState = lib.hm.dag.entryAfter ["writeBoundary"] ''
      OLD_TOGGLES_DIR="${config.home.homeDirectory}/.local/state/nomarchy/toggles"
      IDLE_STATE_FILE="${stateDir}/idle-state.json"
      NIGHTLIGHT_STATE_FILE="${stateDir}/hyprsunset-state.json"
      HYPRLAND_STATE_FILE="${stateDir}/hyprland-state.json"
      THEME_STATE_FILE="${stateDir}/theme-state.nix"
      WALLPAPER_STATE_FILE="${stateDir}/wallpaper-state.nix"
      FONT_STATE_FILE="${stateDir}/font-state.nix"
      NEW_STATE_FILE="${stateDir}/state.json"
      JQ="${pkgs.jq}/bin/jq"

      mkdir -p "$(dirname "$NEW_STATE_FILE")"
      [[ ! -f $NEW_STATE_FILE ]] && echo "{}" > "$NEW_STATE_FILE"

      # 1. Migrate .local/state/nomarchy/toggles (empty 'off' flag files)
      if [[ -d $OLD_TOGGLES_DIR ]]; then
          for file in "$OLD_TOGGLES_DIR"/*; do
              [[ -e "$file" ]] || continue
              filename=$(basename "$file")
              case "$filename" in
                  suspend-off)
                      $JQ '.suspend = false' "$NEW_STATE_FILE" > "$NEW_STATE_FILE.tmp" && mv "$NEW_STATE_FILE.tmp" "$NEW_STATE_FILE"
                      ;;
                  screensaver-off)
                      $JQ '.screensaver = false' "$NEW_STATE_FILE" > "$NEW_STATE_FILE.tmp" && mv "$NEW_STATE_FILE.tmp" "$NEW_STATE_FILE"
                      ;;
                  skip-vscode-theme-changes)
                      $JQ '.skipVsCodeTheme = true' "$NEW_STATE_FILE" > "$NEW_STATE_FILE.tmp" && mv "$NEW_STATE_FILE.tmp" "$NEW_STATE_FILE"
                      ;;
              esac
              rm "$file"
          done
          rmdir "$OLD_TOGGLES_DIR" 2>/dev/null || true
      fi

      # 2. Migrate existing JSON state files
      if [[ -f $IDLE_STATE_FILE ]]; then
          ENABLED=$($JQ '.enabled' "$IDLE_STATE_FILE")
          $JQ ".idle = $ENABLED" "$NEW_STATE_FILE" > "$NEW_STATE_FILE.tmp" && mv "$NEW_STATE_FILE.tmp" "$NEW_STATE_FILE"
          rm "$IDLE_STATE_FILE"
      fi

      if [[ -f $NIGHTLIGHT_STATE_FILE ]]; then
          ENABLED=$($JQ '.enabled' "$NIGHTLIGHT_STATE_FILE")
          TEMP=$($JQ '.temperature' "$NIGHTLIGHT_STATE_FILE")
          $JQ ".nightlight = $ENABLED | .nightlightTemperature = $TEMP" "$NEW_STATE_FILE" > "$NEW_STATE_FILE.tmp" && mv "$NEW_STATE_FILE.tmp" "$NEW_STATE_FILE"
          rm "$NIGHTLIGHT_STATE_FILE"
      fi

      if [[ -f $HYPRLAND_STATE_FILE ]]; then
          GAPS_OUT=$($JQ '.gaps_out' "$HYPRLAND_STATE_FILE")
          GAPS_IN=$($JQ '.gaps_in' "$HYPRLAND_STATE_FILE")
          BORDER_SIZE=$($JQ '.border_size' "$HYPRLAND_STATE_FILE")
          $JQ ".hyprland = {\"gaps_out\": $GAPS_OUT, \"gaps_in\": $GAPS_IN, \"border_size\": $BORDER_SIZE}" "$NEW_STATE_FILE" > "$NEW_STATE_FILE.tmp" && mv "$NEW_STATE_FILE.tmp" "$NEW_STATE_FILE"
          rm "$HYPRLAND_STATE_FILE"
      fi

      # 3. Migrate plaintext string state files
      if [[ -f $THEME_STATE_FILE ]]; then
          THEME=$(cat "$THEME_STATE_FILE" | tr -d '\n')
          $JQ ".theme = \"$THEME\"" "$NEW_STATE_FILE" > "$NEW_STATE_FILE.tmp" && mv "$NEW_STATE_FILE.tmp" "$NEW_STATE_FILE"
          rm "$THEME_STATE_FILE"
      fi

      if [[ -f $WALLPAPER_STATE_FILE ]]; then
          WALLPAPER=$(cat "$WALLPAPER_STATE_FILE" | tr -d '\n')
          $JQ ".wallpaper = \"$WALLPAPER\"" "$NEW_STATE_FILE" > "$NEW_STATE_FILE.tmp" && mv "$NEW_STATE_FILE.tmp" "$NEW_STATE_FILE"
          rm "$WALLPAPER_STATE_FILE"
      fi

      if [[ -f $FONT_STATE_FILE ]]; then
          FONT=$(cat "$FONT_STATE_FILE" | tr -d '\n')
          $JQ ".font = \"$FONT\"" "$NEW_STATE_FILE" > "$NEW_STATE_FILE.tmp" && mv "$NEW_STATE_FILE.tmp" "$NEW_STATE_FILE"
          rm "$FONT_STATE_FILE"
      fi
    '';

    nomarchy = {
      toggles = {
        suspend = togglesState.suspend or true;
        screensaver = togglesState.screensaver or true;
        idle = togglesState.idle or true;
        nightlight = togglesState.nightlight or false;
        waybar = togglesState.waybar or true;
        skipVsCodeTheme = togglesState.skipVsCodeTheme or false;
      };
      nightlightTemperature = togglesState.nightlightTemperature or 4000;
      theme = togglesState.theme or "nord";
      wallpaper = togglesState.wallpaper or "";
      hyprland = {
        gaps_in = togglesState.hyprland.gaps_in or 5;
        gaps_out = togglesState.hyprland.gaps_out or 10;
        border_size = togglesState.hyprland.border_size or 2;
      };
      fonts.monospace = togglesState.font or "JetBrainsMono Nerd Font";
    };
  };
}