mkheader

# Use the current/default shell (got this idea from a script in 'copyparty' - https://github.com/9001/copyparty)
set -e

ESC="\x1b["
BOLD="1;"
NORM="22m"
RED="31m"
GREEN="32m"
YELLOW="33m"
RESET="\x1b[0m"

NAME="mkheader"
VERSION="1.2"

ERROR="$ESC$BOLD$RED[ERROR][$NAME]$ESC$RED"
WARN="$ESC$BOLD$YELLOW[WARNING][$NAME]$ESC$YELLOW"
MSG_GUARD="The header guard argument cannot be used with multiple header files!$RESET\n"
MSG_FILENAMES="Duplicate file names detected!$RESET\n"

HEADER_FILES=()
GUARD=""
FORCE=false
NOCONFIRM=false
CLOBBER=false

printHelp()
{
cat <<- EOF
    Usage: $NAME [-hv] [-n|--noconfirm] [-g|--guard <header_guard>] [-f|--force] <filename(s)>

        -h, --help              print help document
        -v, --version           print script version
            --force             process duplicate filenames and warn the user instead of exiting
        -n, --noconfirm         with -g/--guard, skip confirmation
        -g, --guard GUARD       specify the name for the header guard (cannot be used with multiple files)
        -c, --clobber           overwrite existing files

    Notes:
        When generating multiple files, '$NAME' will error out if it encounters duplicate filenames. This can
        be overridden with the '--force' flag, although it's not recommended.

    Examples:
        $NAME header_file.hpp another_header_file.h a_weird_header_file another_weird_header_file.headerfile
        $NAME -ng PROJECT_FONTS_H fonts.hpp

    $NAME v$VERSION
EOF
}

try_SetGuard()
{
    if [[ ${#HEADER_FILES[@]} -ne 1 ]]; then
        printf "$ERROR$MSG_GUARD"
        return 1
    fi

    GUARD=$(printf "$GUARD" | tr -c '[:alnum:]' '_')
    if ! $NOCONFIRM; then
        printf "::Use \"$GUARD\" as the header guard? [Y/n] "
        read -r ANSWER
        [[ $ANSWER =~ ^[Nn] ]] && printf "\n::A default header guard will be used instead.\n"
    fi
    printf "::Header guard set to '$GUARD'\n"
    return 0
}

check_DuplicateFilenames()
{
    UNIQUE_NUMBER=$(printf '%s\n' "${HEADER_FILES[@]##*/}" | awk '!($0 in seen){seen[$0];c++} END {print c}')
    if [[ $UNIQUE_NUMBER -ne ${#HEADER_FILES[@]} ]]; then
        if $FORCE; then
            printf "$WARN $MSG_FILENAMES"
        else
            printf "$ERROR $MSG_FILENAMES"
            return 1
        fi
    fi
    return 0
}

OPTIONS=$(getopt -l "help,version,noconfirm,force,guard:,clobber" -o "hvng:c" -a -- "$@")
eval set -- "$OPTIONS"

while true
do
    case "$1" in
    -h|--help)
        printHelp
        exit 0
        ;;
    -v|--version)
        printf "$NAME v$VERSION\n"
        exit 0
        ;;
    -n|--noconfirm)
        NOCONFIRM=true
        ;;
    --force)
        FORCE=true
        ;;
    -g|--guard)
        shift
        GUARD="$1"
        ;;
    -c|--clobber)
        CLOBBER=true
        ;;
    --)
        shift
        break
        ;;
    esac
    shift
done

HEADER_FILES=($@)

[[ -n "$GUARD" ]] && try_SetGuard

if [[ ${#HEADER_FILES[@]} -lt 1 ]]; then
    printHelp
    exit 1
fi

if ! check_DuplicateFilenames; then
    exit 1
fi

for FILE in ${HEADER_FILES[@]}; do
    CLOBBERING_TIME=false
    if [[ -f $FILE ]]; then
        if [[ $CLOBBER == false ]]; then
            printf "$ESC$BOLD$YELLOW::File $ESC$NORM$FILE$ESC$BOLD$YELLOW already exists; skipping\n$RESET"
            continue
        fi
        CLOBBERING_TIME=true
    fi
    if [[ -z $GUARD ]]; then
        EXTENSION="${FILE##*.}"
        [[ -z $EXTENSION ]] && EXTENSION="H"
        FILESTEM="${FILE##*/}"
        FILEBASE="${FILESTEM%%.$EXTENSION}"
        CAPITAL_EXTENSION=$(echo "$EXTENSION" | tr '[:lower:]' '[:upper:]')
        [[ $CAPITAL_EXTENSION == "HPP" ]] && CAPITAL_EXTENSION="H"
        CAPITAL_FILEBASE=$(echo "$FILEBASE" | tr '[:lower:]' '[:upper:]')
        GUARD="$CAPITAL_FILEBASE"_"$CAPITAL_EXTENSION"
    fi

    printf "#ifndef $GUARD\n#define $GUARD\n\n#endif // $GUARD\n" > "$FILE"
    [[ $CLOBBERING_TIME == true ]] && printf "::Overwrote Header File '$FILE'\n" || printf "::Created Header File '$FILE'\n"
done