#!/opt/homebrew/bin/bash

FILE="$1"
PREFIX=$(date +%Y-%m-%d)

# 1. Basic error checking
if [ -z "$FILE" ]; then
    echo "Usage: date-prefix <filename>"
    exit 1
fi

if [ ! -f "$FILE" ]; then
    echo "Error: '$FILE' not found or is not a file."
    exit 1
fi

# 2. Extract extension and base filename
# This splits "photo.jpg" into EXT=".jpg" and BASE="photo"
EXT="${FILE##*.}"
BASE="${FILE%.*}"

# Handle files with no extension (where BASE and EXT would be the same)
if [ "$EXT" = "$BASE" ]; then
    EXT=""
else
    EXT=".$EXT"
fi

# 3. Determine the target name
TARGET="${PREFIX}-${BASE}${EXT}"

# 4. If the target exists, find the next available increment
if [ -e "$TARGET" ]; then
    COUNTER=2
    # New logic: Check for 2026-04-13-image-2.png
    while [ -e "${PREFIX}-${BASE}-${COUNTER}${EXT}" ]; do
        ((COUNTER++))
    done
    TARGET="${PREFIX}-${BASE}-${COUNTER}${EXT}"
fi

# 5. Perform the move
mv "$FILE" "$TARGET"
echo "Renamed: $FILE -> $TARGET"