#

# Remove $1 desktop file from the list of default handlers for $2 mime type

# in $3 file dumping output to stdout.

#

_filter_out_default_mime_handler ()

{

  local defaults_list="$3"

  local desktop_file="$1"

  local mime_type="$2"

  awk -f- "$defaults_list" <<EOF

  BEGIN {

    mime_type="$mime_type"

    mime_type_regexp="~" mime_type "="

    desktop_file="$desktop_file"

  }

  \$0 ~ mime_type {

    \$0 = substr(\$0, length(mime_type) + 2);

    split(\$0, desktop_files, ";")

    remaining_desktop_files

    counter=0

    for (idx in desktop_files) {

      if (desktop_files[idx] != desktop_file) {

        ++counter;

      }

    }

    if (counter) {

      printf mime_type "="

      for (idx in desktop_files) {

        if (desktop_files[idx] != desktop_file) {

          printf desktop_files[idx]

          if (--counter) {

            printf ";"

          }

        }

      }

      printf "\n"

    }

    next

  }

  { print }

EOF

}

#

# Remove $2 desktop file from the list of default handlers for $@ mime types

# in $1 file.

# Result is saved in $1 file.

#

_uninstall_default_mime_handler ()

{

  local defaults_list=$1

  shift

  [ -f "$defaults_list" ] || return 0

  local desktop_file="$1"

  shift

  tmpfile1=$(mktemp)

  tmpfile2=$(mktemp)

  cat "$defaults_list" > "$tmpfile1"

  local v

  local update=

  for mime in "$@"; do

    _filter_out_default_mime_handler "$desktop_file" "$mime" "$tmpfile1" > "$tmpfile2"

    v="$tmpfile2"

    tmpfile2="$tmpfile1"

    tmpfile1="$v"

    if ! diff -q "$tmpfile1" "$tmpfile2" > /dev/null; then

      update=yes

      trace Remove $desktop_file default handler for $mime mime type from $defaults_list file

    fi

  done

  if [ -n "$update" ]; then

    cat "$tmpfile1" > "$defaults_list"

    trace "$defaults_list" file updated

  fi

  rm -f "$tmpfile1" "$tmpfile2"

}

#

# Remove $1 desktop file from the list of default handlers for $@ mime types

# in all known system defaults lists.

#

uninstall_default_mime_handler ()

{

  for f in /usr/share/applications/defaults.list /usr/local/share/applications/defaults.list; do

    _uninstall_default_mime_handler "$f" "$@"

  done

}

trace ()

{

  echo "$@"

}