#!/usr/bin/ksh
echo "Checking date command availability and date arithmetic support..."

# Check for date commands
echo "Available date commands:"
if command -v date >/dev/null 2>&1; then
    echo "  date: $(which date)"
    DATE_CMD="date"
else
    echo "  date: NOT FOUND"
fi

if command -v gdate >/dev/null 2>&1; then
    echo "  gdate: $(which gdate)"
    if [ -z "$DATE_CMD" ]; then
        DATE_CMD="gdate"
    fi
else
    echo "  gdate: NOT FOUND in PATH"
    # Check common HP-UX locations for gdate
    echo "  Checking common HP-UX locations for gdate..."
    for gdate_path in /usr/local/bin/gdate /opt/gnu/bin/gdate /usr/contrib/bin/gdate /opt/coreutils/bin/gdate; do
        if [ -x "$gdate_path" ]; then
            echo "  gdate: FOUND at $gdate_path"
            if [ -z "$DATE_CMD" ]; then
                DATE_CMD="$gdate_path"
            fi
            break
        fi
    done
    if [ -z "$DATE_CMD" ] || [ "$DATE_CMD" = "date" ]; then
        echo "  gdate: NOT FOUND in common locations"
    fi
fi

if command -v perl >/dev/null 2>&1; then
    echo "  perl: $(which perl)"
    PERL_AVAILABLE=1
else
    echo "  perl: NOT FOUND"
    PERL_AVAILABLE=0
fi

if [ -z "$DATE_CMD" ]; then
    echo "ERROR: No date command found!"
    exit 1
fi

echo ""
echo "Testing date arithmetic with: $DATE_CMD"

# Test basic date
echo "Basic date output:"
$DATE_CMD +"%Y-%m-%d %H:%M:%S"

# Test date arithmetic like used in rman_db.ksh
echo ""
echo "Testing date arithmetic: '$DATE_CMD +%m-%d-%Y\ %H:%M:%S -d \"-1 hour\"'"
if $DATE_CMD -d "-1 hour" >/dev/null 2>&1; then
    RESULT=$($DATE_CMD +%m-%d-%Y\ %H:%M:%S -d '-1 hour')
    echo "SUCCESS: Date arithmetic works"
    echo "Result: $RESULT"
else
    echo "ERROR: Date arithmetic (-d option) not supported"
    echo "This system may need GNU date (gdate) installed"
fi

# Test perl-based date arithmetic as fallback
if [ $PERL_AVAILABLE -eq 1 ]; then
    echo ""
    echo "Testing perl-based date arithmetic fallback:"
    echo "Command: perl -e 'use POSIX qw(strftime); \$time = time() - 3600; print strftime(\"%m-%d-%Y %H:%M:%S\", localtime(\$time))'"
    PERL_RESULT=$(perl -e 'use POSIX qw(strftime); $time = time() - 3600; print strftime("%m-%d-%Y %H:%M:%S", localtime($time))')
    echo "SUCCESS: Perl date arithmetic works"
    echo "Result: $PERL_RESULT"
else
    echo ""
    echo "WARNING: Perl not available - no fallback for date arithmetic"
fi

echo ""
echo "Test complete."