#!/bin/bash

if [ -z "$1" ]; then
    echo "Usage: $0 <filename>"
    exit 1
fi

TARGET="$1"

if [ ! -f "$TARGET" ]; then
    echo "Error: File '$TARGET' not found."
    exit 1
fi

# Extract just the filename (e.g., "Lecture_1.pdf") 
# and the directory path (e.g., ".")
FILENAME=$(basename "$TARGET")
DIRNAME=$(dirname "$TARGET")

BTIME=$(stat -c %W "$TARGET")

if [ "$BTIME" -eq 0 ] || [ "$BTIME" == "-" ]; then
    BTIME=$(stat -c %Y "$TARGET")
fi

FORMATTED_DATE=$(( BTIME / 60 ))

# Construct the new name using ONLY the filename, 
# then prepend the original directory path
NEW_NAME="${DIRNAME}/${FORMATTED_DATE} - ${FILENAME}"

mv "$TARGET" "$NEW_NAME"

echo "Renamed: '$TARGET' -> '$NEW_NAME'"