# cdeh -- an automatic history and environment switch system.
#
# Copyright (C) 2007, Carlo Wood <carlo@alinoe.com>

CDEHTMP="/tmp/cdeh.$CDEHUSER/$1"
if ! test -d "$CDEHTMP"; then
  echo "Recreating $CDEHTMP" 2>&1
  mkdir -p "$CDEHTMP"
fi
if ! expr "$2" : "$CDEHHISTROOT/" >/dev/null; then
  # In case this is the very first time we run this, do some initialization.
  if ! test -f "$CDEHHISTROOT/history"; then
    if ! test -d "$CDEHHISTROOT"; then
      echo "$0: WARNING: \"$CDEHHISTROOT\": No such directory."
    fi
    touch "$CDEHHISTROOT/history"
  fi
  echo "Reloading history for $HOME"
  HISTSIZE=$CDEHHISTSIZE
  history -r "$CDEHHISTROOT/history"
  PREVIOUS_DIR="nothing"
else
  if test -e "$CDEHTMP/prevwd"; then
    source "$CDEHTMP/prevwd"
  fi
fi
EXITCODE=1
if [ "$PREVIOUS_DIR" != "$PWD" ]; then
  echo "PREVIOUS_DIR=\"$PWD\"" > "$CDEHTMP/prevwd"
  rm -f "$CDEHTMP/histfile" "$CDEHTMP/envfile"
  CURRENT_DIR="$PWD"
  until [ "$CURRENT_DIR" = "" ]; do
    if [ -f "$CDEHHISTROOT/$CURRENT_DIR/history" ]; then
      NEW_DIR="$CURRENT_DIR"
      break
    fi
    CURRENT_DIR="${CURRENT_DIR%/*}"
  done
  if [ "$CURRENT_DIR" = "" ]; then
    CURRENT_DIR="/"
  fi
  TITLE="`echo "[$CURRENT_DIR]$PWD" | sed -e 's%\[[^]]*/%[%' -e 's%\(\[[^]]*\]\)'"$CURRENT_DIR"'%\1 %' -e 's%\[\]%[/]%' -e 's% $%%' -e 's%^\[/\]$%'"$PWD"'%'`"
  xtermset -title "$TITLE"
  if [ "$CURRENT_DIR" = "/" -a -f "$CDEHHISTROOT/history" ]; then
    NEW_DIR="/"
  fi
  if [ "$NEW_DIR" = "" ]; then
    NEW_DIR="/"
  fi
  INODE='"'`stat "$NEW_DIR" | awk '/^Device:/ { printf("%s:%d\n",$2, $4); }'`'"'
  if [ -f "$CDEHTMP/prevhd" ]; then
    source "$CDEHTMP/prevhd"
  else
    PREVIOUS_INODE=
  fi
  if [ "$PREVIOUS_INODE" != "$INODE" ]; then
    echo "PREVIOUS_INODE=$INODE" > "$CDEHTMP/prevhd"
    echo "PREVIOUS_DIR=\"$NEW_DIR\"" >> "$CDEHTMP/prevhd"
    if [ "$2" != "$CDEHHISTROOT/$CURRENT_DIR/history" ]; then
      history -w "$CDEHHISTROOT/$PREVIOUS_DIR/history"
      echo "$CDEHHISTROOT/$CURRENT_DIR/history" > "$CDEHTMP/histfile"
      echo "History changed from \"$PREVIOUS_DIR\" to \"$CURRENT_DIR\""
      EXITCODE=0
    fi
  fi
  CURRENT_DIR="$PWD"
  until [ "$CURRENT_DIR" = "" ]; do
    if [ -f "$CURRENT_DIR/env.source" ]; then
      NEW_DIR="$CURRENT_DIR"
      break
    fi
    CURRENT_DIR="${CURRENT_DIR%/*}"
  done
  if [ "$CURRENT_DIR" = "" ]; then
    CURRENT_DIR="/"
  fi
  if [ "$CURRENT_DIR" = "/" -a -f "/env.source" ]; then
    NEW_DIR="/"
  fi
  if [ "$NEW_DIR" = "" ]; then
    NEW_DIR="/"
  fi
  INODE='"'`stat "$NEW_DIR" | awk '/^Device:/ { printf("%s:%d\n",$2, $4); }'`'"'
  if [ -f "$CDEHTMP/preved" ]; then
    source "$CDEHTMP/preved"
  else
    PREVIOUS_INODE=
  fi
  if [ "$PREVIOUS_INODE" != "$INODE" ]; then
    echo "PREVIOUS_INODE=$INODE" > "$CDEHTMP/preved"
    echo "PREVIOUS_DIR=\"$NEW_DIR\"" >> "$CDEHTMP/preved"
    if [ "$CDEHENVFILE" != "$CURRENT_DIR/env.source" ]; then
      echo "$CURRENT_DIR/env.source" > "$CDEHTMP/envfile"
      echo "Environment changed from \"$PREVIOUS_DIR\" to \"$CURRENT_DIR\""
      EXITCODE=0
    fi
  fi
fi
exit $EXITCODE