#!/bin/bash

# Check if a directory is provided
if [ $# -ne 1 ]; then
    echo "Usage: $0 <dataset_directory>"
    exit 1
fi

dataset_dir="$1"
output_file="compression_metrics_$(date +%Y%m%d_%H%M%S).csv"

# Create output CSV file with header
echo "filename,original_size,compressor,compressed_size,compression_ratio,compression_time,decompression_time" > "$output_file"

# Process each file in the dataset
for file in "$dataset_dir"/*; do
    if [ -f "$file" ]; then
        filename=$(basename "$file")
        original_size=$(stat -c%s "$file")

        # Skip if not a regular file
        [ ! -f "$file" ] && continue

        echo "Processing: $filename"

        # Test gzip
        echo "  Testing gzip..."
        start_time=$(date +%s.%N)
        gzip -k -c "$file" > "${file}.gz"
        compression_time=$(echo "$(date +%s.%N) - $start_time" | bc)
        compressed_size=$(stat -c%s "${file}.gz")
        compression_ratio=$(echo "scale=2; $original_size / $compressed_size" | bc -l)

        # Decompress and measure time
        start_time=$(date +%s.%N)
        gzip -d -k -f "${file}.gz"
        decompression_time=$(echo "$(date +%s.%N) - $start_time" | bc)

        # Write results
        echo "$filename,$original_size,gzip,$compressed_size,$compression_ratio,$compression_time,$decompression_time" >> "$output_file"

        # Clean up
        rm -f "${file}.gz"

        # Test lz4
        echo "  Testing lz4..."
        start_time=$(date +%s.%N)
        lz4 -f -q "$file" "${file}.lz4"
        compression_time=$(echo "$(date +%s.%N) - $start_time" | bc)
        compressed_size=$(stat -c%s "${file}.lz4")
        compression_ratio=$(echo "scale=2; $original_size / $compressed_size" | bc -l)

        # Decompress and measure time
        start_time=$(date +%s.%N)
        lz4 -f -d -q "${file}.lz4" - | cat > /dev/null
        decompression_time=$(echo "$(date +%s.%N) - $start_time" | bc)

        # Write results
        echo "$filename,$original_size,lz4,$compressed_size,$compression_ratio,$compression_time,$decompression_time" >> "$output_file"

        # Clean up
        rm -f "${file}.lz4"
    fi
done

echo "All tests completed. Results saved to $output_file"