#!/usr/bin/env bash
## Update the copyright headers with the current year
##
## Copyright (C) 2022 Sylvain Benner & Contributors
##
## Author: Arif Er
## URL: https://github.com/syl20bnr/spacemacs
##
## This file is not part of GNU Emacs.
##
## License: GPLv3

## Search for files recursively in BASEDIR for copyright headers. Skip all the
## files with the current year already in the copyright header. Otherwise,
## replace the most recent copyright header entry with the current year. If
## there are files with only a single year in the copyright header, extend the
## header to the current year.

SCRIPTPATH="$( cd -- "$(dirname "$0")" >/dev/null 2>&1 ; pwd -P )"
BASEDIR=$(dirname $(dirname $(dirname $SCRIPTPATH)))  # Path to .emacs.d/
BLACKLIST=(
    "core/libs/*"
    ".cache/*"
    ".git/*"
    "assets/*"
    "*cache*/*"
    ".*"
    "persist/*"
    "private/*"
    "elpa/*"
)
ASSETS=(
    "*.jpg"
    "*.png"
    "*.json"
    "*.gpg"
)

EXCLUDES=()
for EXCLUDE in "${BLACKLIST[@]}"; do
    EXCLUDES+=(! -path "'$BASEDIR/$EXCLUDE'")
done

IGNORES=()
for IGNORE in "${ASSETS[@]}"; do
    IGNORES+=(! -name "'$IGNORE'")
done

YEAR=$(date '+%Y')
SKIP="^[#;]\{2\} Copyright ([Cc]) \([[:digit:]]\{4\}-\)\?${YEAR} .*$"

SINGLE_RX="^\([#;]\{2\} Copyright ([Cc])\) \([[:digit:]]\{4\}\) \(.*\)$"
SINGLE_RULE="s/${SINGLE_RX}/\1 \2-${YEAR} \3/"
DOUBLE_RX="^\([#;]\{2\} Copyright ([Cc]) [[:digit:]]\{4\}\)-\([[:digit:]]\{4\}\) \(.*\)$"
DOUBLE_RULE="0,/${DOUBLE_RX}/ s/${DOUBLE_RX}/\1-${YEAR} \3/"

while read FILE; do
    if grep -qe "${SKIP}" $FILE; then
        continue
    fi

    if grep -qe "$DOUBLE_RX" $FILE; then
        # No in-place replacement because there are files with multiple headers
        tac $FILE | sed "${DOUBLE_RULE}" | tac > /tmp/em-copyright
        cat /tmp/em-copyright > $FILE
        echo "$FILE has been updated. - DOUBLE"
        continue
    fi

    if grep -qe "$SINGLE_RX" $FILE; then
        sed -i "${SINGLE_RULE}" $FILE
        echo "$FILE has been updated. - SINGLE"
        continue
    fi
done <<< $(eval find "$BASEDIR/" -type f ${EXCLUDES[@]} ${IGNORES[@]})