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$'
 100 }
 101
 102 env_diff() {
 103         env_init
 104         env_sync_data
 105         git diff --cached
 106     env_link_config
 107 }
 108
 109 env_save() {
 110         env_init
 111         env_sync
 112         env_link_config
 113 }
 114
 115 env_revert() {
 116         env_init
 117         env_do_reset
 118         env_link_config
 119 }
 120
 121 env_ask_sync() {
 122         LINES="$(env_diff | wc -l)" # implies env_init
 123         [ "$LINES" -gt 0 ] && {
 124                 if ask_bool 1 "Do you want to save your changes"; then
 125                         env_sync
 126                 else
 127                         env_sync_data
 128                         env_do_reset
 129                 fi
 130         }
 131 }
 132
 133 env_clear() {
 134         env_init
 135         [ -L "$BASEDIR/.config" ] && rm -f "$BASEDIR/.config"
 136         [ -L "$BASEDIR/files" ] && rm -f "$BASEDIR/files"
 137         [ -f "$ENVDIR/.config" ] || ( cd "$ENVDIR/files" && find | grep -vE '^\.$' > /dev/null )
 138         env_sync_data
 139         if ask_bool 1 "Do you want to keep your current config and files"; then
 140                 mkdir -p "$BASEDIR/files"
 141                 cp -a "$ENVDIR/files/*" "$BASEDIR/files" 2>/dev/null >/dev/null
 142                 cp "$ENVDIR/.config" "$BASEDIR/"
 143         else
 144                 rm -rf "$BASEDIR/files" "$BASEDIR/.config"
 145         fi
 146         cd "$BASEDIR"
 147         rm -rf "$ENVDIR"
 148 }
 149
 150 env_delete() {
 151         local name="${1##*/}"
 152         env_init
 153         [ -z "$name" ] && usage
 154         branch="$(git branch | grep '^\* ' | awk '{print $2}')"
 155         [ "$name" = "$branch" ] && error "cannot delete the currently selected environment"
 156         git branch -D "$name"
 157 }
 158
 159 env_switch() {
 160         local name="${1##*/}"
 161         [ -z "$name" ] && usage
 162
 163         env_init
 164         env_ask_sync
 165         git checkout "$name" || error "environment '$name' not found"
 166         env_link_config
 167 }
 168
 169 env_rename() {
 170         local NAME="${1##*/}"
 171         env_init
 172         git branch -m "$NAME"
 173 }
 174
 175 env_new() {
 176         local NAME="$1"
 177         local branch
 178         local from="master"
 179
 180         [ -z "$NAME" ] && usage
 181         env_init 1
 182
 183         branch="$(git branch | grep '^\* ' | awk '{print $2}')"
 184         if [ -n "$branch" -a "$branch" != "master" ]; then
 185                 env_ask_sync
 186                 if ask_bool 0 "Do you want to clone the current environment?"; then
 187                         from="$branch"
 188                 fi
 189                 rm -f "$BASEDIR/.config" "$BASEDIR/files"
 190         fi
 191         git checkout -b "$1" "$from"
 192         if [ -f "$BASEDIR/.config" -o -d "$BASEDIR/files" ]; then
 193                 if ask_bool 1 "Do you want to keep your current config and files?"; then
 194                         [ -d "$BASEDIR/files" -a \! -L "$BASEDIR/files" ] && {
 195                                 mv "$BASEDIR/files/"* "$ENVDIR/" 2>/dev/null
 196                                 rmdir "$BASEDIR/files"
 197                         }
 198                         env_sync
 199                 else
 200                         rm -rf "$BASEDIR/.config" "$BASEDIR/files"
 201                 fi
 202         fi
 203         env_link_config
 204 }
 205
 206 COMMAND="$1"; shift
 207 case "$COMMAND" in
 208         help) usage 0;;
 209         new) env_new "$@";;
 210         list) env_list "$@";;
 211         clear) env_clear "$@";;
 212         switch) env_switch "$@";;
 213         delete) env_delete "$@";;
 214         rename) env_rename "$@";;
 215         diff) env_diff "$@";;
 216         save) env_save "$@";;
 217         revert) env_revert "$@";;
 218         *) usage;;
 219 esac