copyright_check

#!/bin/bash

show_help() {
    echo "info: Check the copyright header in the specified files."
    echo "    If the non-empty file does not contain the copyright header, it "
    echo "    will be added. If a file looks like it does contain a copyright "
    echo "    header, it will verified that it matches exactly."
    echo "    Hash bangs are preserved."
    echo ''
    echo "usage: $0 FILEPATH..."
    echo ''
    echo 'positional arguments:'
    echo '  FILEPATH...    The file(s) to check'
    echo ""
    echo "options:"
    echo "  -h|--help     Show this help message and exit"
    echo ""
}

if [[ " $@ " =~ " --help " || " $@ " =~ " -h " ]]; then
    show_help
    exit 0
fi


copyright_header="\
# (C) Crown Copyright, Met Office. All rights reserved.\n\
#\n\
# This file is part of 'dagrunner' and is released under the BSD 3-Clause license.\n\
# See LICENSE in the root of the repository for full licensing details.\
"

contains_copyright() {
    grep -qi '# .*copyright' $1
}


defines_hash_bang() {
    grep -q '^#!' $1
}


correct_copyright() {
    python -c 'import sys; sys.exit(0 if "'"$1"'" in open("'"$2"'", "r").read() else 1)'
}


# Function to delete temporary files
cleanup() {
    for filepath in "$@"; do
        tmp_file="${filepath}.tmp"
        if [ -f "$tmp_file" ]; then
            echo "Deleting temporary file: $tmp_file"
            rm -f "$tmp_file" 2&> /dev/null
        fi
    done
}

# Trap the EXIT signal to call the cleanup function
trap 'cleanup "$@"' EXIT

found_error=0
for filepath in "$@"; do
    if contains_copyright "${filepath}"; then
        #echo "File '${filepath}' already contains Crown Copyright"
        if correct_copyright "${copyright_header}" "${filepath}"; then
            continue
        else
            echo "Incorrect Copyright header in '${filepath}'"
            found_error=1
        fi
    elif [ -s "${filepath}" ]; then  # skip empty files
        echo "Adding missing Copyright to '${filepath}'"
        tmp_file="${filepath}.tmp"
        if defines_hash_bang "${filepath}"; then
            head -n 1 ${filepath} > ${tmp_file}
            echo -e ${copyright_header} >> ${tmp_file}
            tail -n +2 ${filepath} >> ${tmp_file}
        else
            echo -e ${copyright_header} > ${tmp_file}
            cat ${filepath} >> ${tmp_file}
        fi
        mv ${tmp_file} ${filepath}
        found_error=1
    fi
done

exit ${found_error}