#!/bin/bash

# Define the target bitrate
TARGET_BITRATE="192k"

echo -e "\n\033[1;32mStarting Bitrate Reduction Script...\033[0m"
echo -e "\033[1;34mTarget Bitrate: \033[0m${TARGET_BITRATE}"

# Function to process MP3 files safely
process_directory() {
    local DIR="$1"
    echo "Scanning Directory: $DIR"

    # Use find with -print0 + read -d '' → null-separated = safe with any filename
    while IFS= read -r -d '' file; do
        echo "Processing: $file"

        # Get current bitrate
        METADATA=$(ffprobe -v error -select_streams a:0 -show_entries stream=bit_rate \
            -of default=noprint_wrappers=1:nokey=1 "$file" < /dev/null 2>/dev/null)

        if ! [[ "$METADATA" =~ ^[0-9]+$ ]]; then
            METADATA=$(ffprobe -v error -show_entries format=bit_rate \
                -of default=noprint_wrappers=1:nokey=1 "$file" < /dev/null 2>/dev/null)
        fi

        if ! [[ "$METADATA" =~ ^[0-9]+$ ]]; then
            echo -e "\033[1;31mError:\033[0m Could not read bit rate for $file. Skipping."
            continue
        fi

        CURRENT_BITRATE=$((METADATA / 1024))
        echo -e "\033[1;32mCurrent Bitrate:\033[0m ${CURRENT_BITRATE} kbps"

        if [ "$CURRENT_BITRATE" -le "${TARGET_BITRATE%k}" ]; then
            echo -e "\033[1;33mInfo:\033[0m Already at or below target. Skipping."
            continue
        fi

        # Create backup
        BACKUP_FILE="${file%.mp3}.bak"
        if [ ! -f "$BACKUP_FILE" ]; then
            cp "$file" "$BACKUP_FILE"
            echo -e "\033[1;32mBackup created:\033[0m $BACKUP_FILE"
        fi

        # Convert safely using a temporary file with full path
        TEMP_FILE="${file%.mp3}_temp_$$.mp3"

        if ffmpeg -nostdin -y -i "$file" -b:a "${TARGET_BITRATE}" -id3v2_version 3 "$TEMP_FILE" > /dev/null 2>&1; then
            mv "$TEMP_FILE" "$file"
            echo -e "\033[1;32mProcessed \033[0m$file \033[1;32mto ${TARGET_BITRATE} ✅\033[0m"
        else
            echo -e "\033[1;31mError:\033[0m ffmpeg failed for $file"
            rm -f "$TEMP_FILE"
        fi

    done < <(find "$DIR" -maxdepth 1 -type f -name "*.mp3" -print0)
}

# ==================== MAIN ====================

# Calculate total size before
TOTAL_SIZE_BEFORE=$(find . -name "*.mp3" -print0 | xargs -0 stat -c '%s' 2>/dev/null | \
                    awk '{sum += $1} END {printf "%.2f MB\n", sum/1024/1024}')
echo -e "\n\033[1;32mTotal MP3 size before:\033[0m ${TOTAL_SIZE_BEFORE:-0.00 MB}"

# Process every directory (including .)
while IFS= read -r -d '' dir; do
    process_directory "$dir"
done < <(find . -type d -print0)

# Calculate total size after
TOTAL_SIZE_AFTER=$(find . -name "*.mp3" -print0 | xargs -0 stat -c '%s' 2>/dev/null | \
                   awk '{sum += $1} END {printf "%.2f MB\n", sum/1024/1024}')

echo -e "\n\033[1;32mTotal MP3 size after:\033[0m ${TOTAL_SIZE_AFTER:-0.00 MB}"
echo -e "\n\033[1;32mBitrate Reduction Script Complete! 🎉\033[0m"

# Optional: remove all .bak files at the end
# find . -name "*.bak" -type f -delete