dctx

#!/usr/bin/env bash
set -euo pipefail

# Check for required dependencies
for dep in docker fzf jq; do
  command -v "$dep" >/dev/null 2>&1 || {
    printf "Missing dependency: %s :(\n" "$dep" >&2
    exit 1
  }
done

# It's a simple script, print a simple help please
usage() {
  printf '%s\n' "Usage: ${0##*/} [-c] [-d] [-h] [-l] [context name]

FLAGS
    -c, --current   Show current context
    -d, --default   Set default context
    -h, --help      Print help
    -l, --list      List all contexts" 1>&2
  exit 3
}

# Check for currently set context
current_context=$(docker context show)

# Catch other than current contexts
non_active_contexts=$(docker context list --format=json |
  jq -r 'select(.Current==false).Name')

# Set starting fzf options
FZF_DEFAULT_OPTS="$FZF_DEFAULT_OPTS --cycle \
                                    --reverse \
                                    --info=inline \
                                    --height=20% \
                                    --prompt=\"context[$current_context] > \""

case $# in
0)
  docker context use "$(printf '%s' "$non_active_contexts" | fzf)"
  ;;
1)
  case "$1" in
  "-c" | "--current")
    printf '%s\n' "$current_context"
    ;;
  "-d" | "--default")
    docker context use default 2>/dev/null
    ;;
  "-l" | "--list")
    docker context ls -q 2>/dev/null
    ;;
  "-h" | "--help")
    usage
    ;;
  *)
    needle=$(printf '.*%s' "$(printf '%s' "$@" |
      sed -E 's/ +//g' |
      sed -E 's/(.)/\1.*/g')")
    if ! (docker context use "$(printf '%s' "$non_active_contexts" |
      grep "$needle"'[^/]*$' |
      fzf -1 -0 -q "$@")") 2>/dev/null; then
      printf '%s\n' "Currently set context: $current_context"
    fi
    ;;
  esac
  ;;
*) usage ;;
esac