scripts/env

   1 #!/usr/bin/env bash
   2 BASEDIR="$PWD"
   3 ENVDIR="$PWD/env"
   4
   5 usage() {
   6         cat <<EOF
   7 Usage: $0 [options] <command> [arguments]
   8 Commands:
   9         help              This help text
  10         list              List environments
  11         clear             Delete all environment and revert to flat config/files
  12         new <name>        Create a new environment
  13         switch <name>     Switch to a different environment
  14         delete <name>     Delete an environment
  15         rename <newname>  Rename the current environment
  16         diff              Show differences between current state and environment
  17         save              Save your changes to the environment
  18         revert            Revert your changes since last save
  19
  20 Options:
  21
  22 EOF
  23         exit ${1:-1}
  24 }
  25
  26 error() {
  27         echo "$0: $*"
  28         exit 1
  29 }
  30
  31 ask_bool() {
  32         local DEFAULT="$1"; shift
  33         local def defstr val
  34         case "$DEFAULT" in
  35                 1) def=0; defstr="Y/n";;
  36                 0) def=1; defstr="y/N";;
  37                 *) def=;  defstr="y/n";;
  38         esac
  39         while [ -z "$val" ]; do
  40                 local VAL
  41
  42                 echo -n "$* ($defstr): "
  43                 read VAL
  44                 case "$VAL" in
  45                         y*|Y*) val=0;;
  46                         n*|N*) val=1;;
  47                         *) val="$def";;
  48                 esac
  49         done
  50         return "$val"
  51 }
  52
  53 env_init() {
  54         local CREATE="$1"
  55         if [ -z "$CREATE" ]; then
  56                 [ -d "$ENVDIR" ] || exit 0
  57         fi
  58         [ -x "$(which git 2>/dev/null)" ] || error "Git is not installed"
  59         mkdir -p "$ENVDIR" || error "Failed to create the environment directory"
  60         cd "$ENVDIR" || error "Failed to switch to the environment directory"
  61         [ -d .git ] || {
  62                 git init &&
  63                 touch .config &&
  64                 mkdir files &&
  65                 git add . &&
  66                 git commit -q -m "Initial import"
  67         } || {
  68                 rm -rf .git
  69                 error "Failed to initialize the environment directory"
  70         }
  71 }
  72
  73 env_sync_data() {
  74         [ \! -L "$BASEDIR/.config" -a -f "$BASEDIR/.config" ] && mv "$BASEDIR/.config" "$ENVDIR"
  75         git add .
  76         git add -u
  77 }
  78
  79 env_sync() {
  80         local STR="$1"
  81         env_sync_data
  82         git commit -m "${STR:-Update} at $(date)"
  83 }
  84
  85 env_link_config() {
  86         rm -f "$BASEDIR/.config"
  87         ln -s env/.config "$BASEDIR/.config"
  88         mkdir -p "$ENVDIR/files"
  89         [ -L "$BASEDIR/files" ] || ln -s env/files "$BASEDIR/files"
  90 }
  91
  92 env_do_reset() {
  93         git reset --hard HEAD
  94         git clean -d -f
  95 }
  96
  97 env_list() {
  98         env_init
  99         git branch | grep -vE '^. master$'
 100 }
 101
 102 env_diff() {
 103         env_init
 104         env_sync_data
 105         git diff --cached
 106 }
 107
 108 env_save() {
 109         env_init
 110         env_sync
 111         env_link_config
 112 }
 113
 114 env_revert() {
 115         env_init
 116         env_do_reset
 117         env_link_config
 118 }
 119
 120 env_ask_sync() {
 121         LINES="$(env_diff | wc -l)" # implies env_init
 122         [ "$LINES" -gt 0 ] && {
 123                 if ask_bool 1 "Do you want to save your changes"; then
 124                         env_sync
 125                 else
 126                         env_sync_data
 127                         env_do_reset
 128                 fi
 129         }
 130 }
 131
 132 env_clear() {
 133         env_init
 134         [ -L "$BASEDIR/.config" ] && rm -f "$BASEDIR/.config"
 135         [ -L "$BASEDIR/files" ] && rm -f "$BASEDIR/files"
 136         [ -f "$ENVDIR/.config" ] || ( cd "$ENVDIR/files" && find | grep -vE '^\.$' > /dev/null )
 137         env_sync_data
 138         if ask_bool 1 "Do you want to keep your current config and files"; then
 139                 mkdir -p "$BASEDIR/files"
 140                 cp -a "$ENVDIR/files/*" "$BASEDIR/files" 2>/dev/null >/dev/null
 141                 cp "$ENVDIR/.config" "$BASEDIR/"
 142         else
 143                 rm -rf "$BASEDIR/files" "$BASEDIR/.config"
 144         fi
 145         cd "$BASEDIR"
 146         rm -rf "$ENVDIR"
 147 }
 148
 149 env_delete() {
 150         local name="${1##*/}"
 151         env_init
 152         [ -z "$name" ] && usage
 153         branch="$(git branch | grep '^\* ' | awk '{print $2}')"
 154         [ "$name" = "$branch" ] && error "cannot delete the currently selected environment"
 155         git branch -D "$name"
 156 }
 157
 158 env_switch() {
 159         local name="${1##*/}"
 160         [ -z "$name" ] && usage
 161
 162         env_init
 163         env_ask_sync
 164         git checkout "$name" || error "environment '$name' not found"
 165         env_link_config
 166 }
 167
 168 env_rename() {
 169         local NAME="${1##*/}"
 170         env_init
 171         git branch -m "$NAME"
 172 }
 173
 174 env_new() {
 175         local NAME="$1"
 176         local branch
 177         local from="master"
 178
 179         [ -z "$NAME" ] && usage
 180         env_init 1
 181
 182         branch="$(git branch | grep '^\* ' | awk '{print $2}')"
 183         if [ -n "$branch" -a "$branch" != "master" ]; then
 184                 env_ask_sync
 185                 if ask_bool 0 "Do you want to clone the current environment?"; then
 186                         from="$branch"
 187                 fi
 188                 rm -f "$BASEDIR/.config" "$BASEDIR/files"
 189         fi
 190         git checkout -b "$1" "$from"
 191         if [ -f "$BASEDIR/.config" -o -d "$BASEDIR/files" ]; then
 192                 if ask_bool 1 "Do you want to keep your current config and files?"; then
 193                         [ -d "$BASEDIR/files" -a \! -L "$BASEDIR/files" ] && {
 194                                 mv "$BASEDIR/files/"* "$ENVDIR/" 2>/dev/null
 195                                 rmdir "$BASEDIR/files"
 196                         }
 197                         env_sync
 198                 else
 199                         rm -rf "$BASEDIR/.config" "$BASEDIR/files"
 200                 fi
 201         fi
 202         env_link_config
 203 }
 204
 205 COMMAND="$1"; shift
 206 case "$COMMAND" in
 207         help) usage 0;;
 208         new) env_new "$@";;
 209         list) env_list "$@";;
 210         clear) env_clear "$@";;
 211         switch) env_switch "$@";;
 212         delete) env_delete "$@";;
 213         rename) env_rename "$@";;
 214         diff) env_diff "$@";;
 215         save) env_save "$@";;
 216         revert) env_revert "$@";;
 217         *) usage;;
 218 esac