#!/bin/bash

# Add Homebrew paths to PATH (for both Intel and Apple Silicon Macs)
export PATH="/usr/local/bin:/opt/homebrew/bin:$PATH"

# Check if ghostscript is installed
if ! command -v gs &> /dev/null; then
    # Check if Homebrew is installed
    if ! command -v brew &> /dev/null; then
        result=$(osascript <<EOF
display dialog "Ghostscript is required but not installed.

To install, you need Homebrew first. Run this in Terminal:

/bin/bash -c \"\$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)\"

Then install Ghostscript:
brew install ghostscript

Would you like to open Terminal now?" buttons {"Cancel", "Open Terminal"} default button 2 with icon caution
EOF
)
        if [[ $result == *"Open Terminal"* ]]; then
            open -a Terminal
        fi
        exit 1
    else
        result=$(osascript <<EOF
display dialog "Ghostscript is required but not installed.

Homebrew is already installed. Run this in Terminal:

brew install ghostscript

Would you like to open Terminal now?" buttons {"Cancel", "Open Terminal"} default button 2 with icon caution
EOF
)
        if [[ $result == *"Open Terminal"* ]]; then
            open -a Terminal
        fi
        exit 1
    fi
fi

# Process each input file
for input_file in "$@"
do
    # Check if file exists
    if [ ! -f "$input_file" ]; then
        osascript -e 'display dialog "No valid PDF file selected." with icon caution'
        continue
    fi
    
    # Check if it's a PDF
    if [[ ! "$input_file" == *.pdf ]]; then
        osascript -e 'display dialog "Please select a PDF file." with icon caution'
        continue
    fi
    
    # Create output filename
    output_file="${input_file%.*}_compressed.pdf"
    
    # Check if output file already exists
    if [ -f "$output_file" ]; then
        result=$(osascript -e 'display dialog "Compressed file already exists. Overwrite?" buttons {"Cancel", "Overwrite"} default button 2 with icon question' 2>&1)
        if [[ $result == *"Cancel"* ]] || [[ $result == *"cancel"* ]]; then
            continue
        fi
        rm "$output_file"
    fi
    
    # Get file sizes for comparison
    input_size=$(stat -f%z "$input_file")
    input_size_mb=$(printf "%.2f" $(echo "$input_size / 1048576" | bc -l))
    
    # Compress PDF using ghostscript with high quality settings
    gs -q -dNOPAUSE -dBATCH -dSAFER \
       -sDEVICE=pdfwrite \
       -dCompatibilityLevel=1.4 \
       -dPDFSETTINGS=/ebook \
       -dEmbedAllFonts=true \
       -dSubsetFonts=true \
       -dColorImageDownsampleType=/Bicubic \
       -dColorImageResolution=150 \
       -dGrayImageDownsampleType=/Bicubic \
       -dGrayImageResolution=150 \
       -dMonoImageDownsampleType=/Bicubic \
       -dMonoImageResolution=150 \
       -sOutputFile="$output_file" \
       "$input_file" 2>/dev/null
    
    # Check if compression was successful
    if [ -f "$output_file" ] && [ -s "$output_file" ]; then
        output_size=$(stat -f%z "$output_file")
        output_size_mb=$(printf "%.2f" $(echo "$output_size / 1048576" | bc -l))
        
        # Calculate reduction (handle division by zero)
        if [ "$input_size" -gt 0 ]; then
            reduction=$(printf "%.1f" $(echo "(1 - $output_size / $input_size) * 100" | bc -l))
        else
            reduction="0.0"
        fi
        
        osascript -e "display notification \"Compressed: ${input_size_mb}MB → ${output_size_mb}MB (${reduction}% smaller)\" with title \"PDF Compression Complete\""
    else
        osascript -e 'display dialog "Compression failed. The PDF may be corrupt or protected." with icon caution'
        # Clean up failed output file
        [ -f "$output_file" ] && rm "$output_file"
    fi
done