utility to set wezterm color schemes using a fuzzy selector

set-wezterm-color-scheme.sh

#!/usr/bin/env bash

# HACK: edit config[1] location until `wezterm config` or `wezterm debug` is
# exposed for programmatic access.
# [1]: https://github.com/wez/wezterm/issues/4238
config_file="$XDG_CONFIG_HOME/wezterm/wezterm.lua" 
script_dir="$(dirname "$(realpath "$0")")"
color_scheme_cache="$script_dir/color_schemes.txt"
one_day_in_seconds=$((24 * 60 * 60))

# functions --------------------------------------------------------------------
check_configuration() {
  if [ ! -f "$config_file" ]; then
    echo "[error]: configuration '$config_file' not found"
    exit 1
  fi

  local color_scheme_count
  color_scheme_count="$(grep --invert-match \
    --extended-regexp '^\\s*--' "$config_file" | 
    grep --count 'color_scheme')"

  if [ "$color_scheme_count" -gt 1 ]; then
    echo "[error]: multiple 'color_scheme' configurations found, expecting 1"
  elif [ "$color_scheme_count" -eq 0 ]; then
    echo "[error]: expecting at least 1 'color_scheme' configuration"
  fi
}

check_required_commands() {
  local missing=false
  for cmd in "$@"; do
    if ! command -v "$cmd" >/dev/null 2>&1; then 
      echo "[error]: $cmd command not found"
      missing=true
    fi
  done
  if [ "$missing" = true ]; then
    exit 1
  fi
}

update_color_cache() {
  local should_update=true
  if [ -f "$color_scheme_cache" ]; then
    current_time=$(date +'%s')
    modified_time=$(stat -f %m "$color_scheme_cache")
    difference=$((current_time - modified_time))

    if [ $difference -le $one_day_in_seconds ]; then
      should_update=false
    fi
  fi

  if [ ! -f "$color_scheme_cache" ] || [ "$should_update" = true ]; then
    echo "[info]: caching colors to $color_scheme_cache"
    # HACK: `wezterm ls-fonts` doesn't have an equivalent like `wezterm ls-schemes`
    url="https://raw.githubusercontent.com/wez/wezterm/refs/heads/main/docs/colorschemes/data.json" 
    
    curl --silent "$url" |
      jq --raw-output '.[].metadata.name' |
      sort --ignore-case > "$color_scheme_cache"
  fi
  
  if [ ! -f "$color_scheme_cache" ]; then
    echo "[error]: failed to create $color_scheme_cache"
  fi
}

select_color() {
  previous_color="$(awk -F"'" '/color_scheme/ {print $2}' "$config_file")"
  # HACK: use --bind to include highlighted item before exiting
  selected_colors="$(
   cat "$color_scheme_cache" | fzf \
     --reverse \
     --multi \
     --no-sort \
     --bind 'enter:execute(echo set color scheme to: {})+accept' \
     --preview-window="down,0" \
     --preview "sed -i \"\" \"s/color_scheme.*/color_scheme = {},/\" \"$config_file\""
  )"

  if [ -n "$selected_colors" ]; then
    IFS=$'\n' read -r -d '' -a selected_colors_array <<< "$selected_colors"
    if [ "${#selected_colors_array[@]}" -gt 1 ]; then
      echo "selected: "
      for x in "${selected_colors_array[@]}"; do
        echo "  - $x"
      done
    fi
  elif [ -n "$previous_color" ]; then
    echo "[warn]: no colors selected, restoring previous color '$previous_color'"
    sed -i "" "s/color_scheme.*/color_scheme = '$previous_color',/" "$config_file"
  else
    sed -i "" "s/color_scheme.*/color_scheme = 'Builtin Dark',/" "$config_file"
  fi
}

# main -------------------------------------------------------------------------
check_configuration
check_required_commands \
  "curl" \
  "fzf" \
  "jq"
update_color_cache
select_color