#!/bin/bash

# Default configuration.
LOGS_DIR="/var/log"
DIR_MODE="0750"
UMASK="027"

# This array may be used in the defaults file.
declare -A CREATE_DIRS

# Allow /etc/default/rotate-logs-symlinks to override default configuration.
[[ -e /etc/default/rotate-logs-symlinks ]] && {
  # shellcheck disable=SC1091
  source /etc/default/rotate-logs-symlinks || {
    printf "%s: %s\\n" "${0##*/}" "failed reading /etc/default/rotate-logs-symlinks" >&2
    exit 1
  }
}

# Process the directories in the logs directory.
[[ -d "$LOGS_DIR" ]] && {
  TODAY="$(printf "%(%Y/%m/%d)T")"

  umask "$UMASK"

  # Process all the directories in the logs directory.
  for DIR in "$LOGS_DIR"/*/; do
    cd "$DIR" 2>/dev/null || {
      printf "%s: %s\\n" "${0##*/}" "failed to change directory to '$DIR'" >&2
      continue
    }

    # Create a new logs directory for today.
    # shellcheck disable=SC2174
    mkdir -p -m "$DIR_MODE" "$TODAY" 2>/dev/null || {
      printf "%s: %s\\n" "${0##*/}" "failed to create directory '$DIR/$TODAY'" >&2
      continue
    }

    # If configured to do so for this directory, create sub directories.
    for CREATE_DIR in ${CREATE_DIRS[$(printf "$DIR" | awk -F / -e '{print $4}')]}; do
      mkdir -p -m "$DIR_MODE" "$TODAY/$CREATE_DIR" 2>/dev/null || {
        printf "%s: %s\\n" "${0##*/}" "failed to create directory '$DIR/$TODAY/$CREATE_DIR'" >&2
        continue
      }
    done

    # Create a 'today' symlink to the new days' directory.
    ( cd "$DIR" 2>/dev/null && ln -sfn "$TODAY" "today" 2>/dev/null ) || {
      printf "%s: %s\\n" "${0##*/}" "updating 'today' symlink failed" >&2
      continue
    }
  done
}

exit 0