#!/usr/bin/env bash

echo "📦 FINAL BUNDLE SIZE REPORT" >&2
echo "===========================================" >&2

# Initialize variables
TIMESTAMP=$(date +"%Y-%m-%d %H:%M:%S")
REPORT_FILE="bundle-report-$(date +%Y%m%d_%H%M%S).txt"
BUILD_DETECTED=false
TOTAL_SIZE=0
JS_SIZE=0
CSS_SIZE=0
IMAGE_SIZE=0
OTHER_SIZE=0

# Function to convert bytes to human readable
format_bytes() {
  local bytes=$1
  if [ $bytes -ge 1073741824 ]; then
    echo "$(echo "scale=2; $bytes/1073741824" | bc 2>/dev/null || echo $((bytes/1073741824)))GB"
  elif [ $bytes -ge 1048576 ]; then
    echo "$(echo "scale=2; $bytes/1048576" | bc 2>/dev/null || echo $((bytes/1048576)))MB"
  elif [ $bytes -ge 1024 ]; then
    echo "$(echo "scale=2; $bytes/1024" | bc 2>/dev/null || echo $((bytes/1024)))KB"
  else
    echo "${bytes}B"
  fi
}

# Function to analyze directory
analyze_directory() {
  local dir="$1"
  local label="$2"
  
  if [ ! -d "$dir" ]; then
    return
  fi
  
  echo "📁 Analyzing $label: $dir" >&2
  BUILD_DETECTED=true
  
  # Calculate total directory size
  DIR_SIZE=$(du -sb "$dir" 2>/dev/null | cut -f1 || echo "0")
  TOTAL_SIZE=$((TOTAL_SIZE + DIR_SIZE))
  
  echo "   Total size: $(format_bytes $DIR_SIZE)" >&2
  
  # Analyze by file types
  echo "   📊 File type breakdown:" >&2
  
  # JavaScript files
  if find "$dir" -name "*.js" -o -name "*.mjs" -o -name "*.ts" 2>/dev/null | head -1 > /dev/null; then
    JS_FILES_SIZE=$(find "$dir" \( -name "*.js" -o -name "*.mjs" -o -name "*.ts" \) -exec du -cb {} + 2>/dev/null | tail -1 | cut -f1 || echo "0")
    JS_SIZE=$((JS_SIZE + JS_FILES_SIZE))
    echo "      JavaScript: $(format_bytes $JS_FILES_SIZE)" >&2
  fi
  
  # CSS files
  if find "$dir" -name "*.css" 2>/dev/null | head -1 > /dev/null; then
    CSS_FILES_SIZE=$(find "$dir" -name "*.css" -exec du -cb {} + 2>/dev/null | tail -1 | cut -f1 || echo "0")
    CSS_SIZE=$((CSS_SIZE + CSS_FILES_SIZE))
    echo "      CSS: $(format_bytes $CSS_FILES_SIZE)" >&2
  fi
  
  # Images
  if find "$dir" \( -name "*.png" -o -name "*.jpg" -o -name "*.jpeg" -o -name "*.gif" -o -name "*.svg" -o -name "*.webp" \) 2>/dev/null | head -1 > /dev/null; then
    IMG_FILES_SIZE=$(find "$dir" \( -name "*.png" -o -name "*.jpg" -o -name "*.jpeg" -o -name "*.gif" -o -name "*.svg" -o -name "*.webp" \) -exec du -cb {} + 2>/dev/null | tail -1 | cut -f1 || echo "0")
    IMAGE_SIZE=$((IMAGE_SIZE + IMG_FILES_SIZE))
    echo "      Images: $(format_bytes $IMG_FILES_SIZE)" >&2
  fi
  
  # Show largest files in this directory
  echo "   🔍 Largest files:" >&2
  find "$dir" -type f -exec du -b {} + 2>/dev/null | sort -rn | head -5 | while read size file; do
    echo "      $(format_bytes $size) - $(basename "$file")" >&2
  done
  
  # Gzip analysis for text files
  GZIPPABLE_SIZE=$(find "$dir" \( -name "*.js" -o -name "*.css" -o -name "*.html" -o -name "*.json" \) -exec du -cb {} + 2>/dev/null | tail -1 | cut -f1 || echo "0")
  if [ "$GZIPPABLE_SIZE" -gt 0 ] && command -v gzip &> /dev/null; then
    # Estimate gzip compression
    TEMP_DIR=$(mktemp -d)
    find "$dir" \( -name "*.js" -o -name "*.css" -o -name "*.html" -o -name "*.json" \) -exec cp {} "$TEMP_DIR/" \; 2>/dev/null
    
    if [ "$(ls -A "$TEMP_DIR" 2>/dev/null)" ]; then
      cd "$TEMP_DIR" && gzip *.* 2>/dev/null && GZIPPED_SIZE=$(du -cb *.gz 2>/dev/null | tail -1 | cut -f1 || echo "0") && cd - > /dev/null
      
      if [ "$GZIPPED_SIZE" -gt 0 ]; then
        COMPRESSION_RATIO=$(echo "scale=1; ($GZIPPABLE_SIZE - $GZIPPED_SIZE) * 100 / $GZIPPABLE_SIZE" | bc 2>/dev/null || echo "N/A")
        echo "   📦 Gzip compression potential: $(format_bytes $GZIPPED_SIZE) (-${COMPRESSION_RATIO}%)" >&2
      fi
    fi
    
    rm -rf "$TEMP_DIR" 2>/dev/null
  fi
  
  echo "" >&2
}

# Start report
echo "Starting bundle analysis at $TIMESTAMP" >&2
echo "" >&2

# Check if this is a Node.js project
if [ -f "package.json" ]; then
  echo "🟢 Node.js project detected" >&2
  
  PROJECT_NAME=$(grep '"name"' package.json | head -1 | cut -d'"' -f4 2>/dev/null || echo "Unknown")
  echo "📋 Project: $PROJECT_NAME" >&2
  
  # Try to build the project
  echo "🔨 Attempting to build project..." >&2
  
  # Check for common build scripts
  BUILD_SCRIPT=""
  if grep -q '"build"' package.json; then
    BUILD_SCRIPT="npm run build"
  elif grep -q '"build:prod"' package.json; then
    BUILD_SCRIPT="npm run build:prod"
  elif grep -q '"dist"' package.json; then
    BUILD_SCRIPT="npm run dist"
  fi
  
  if [ -n "$BUILD_SCRIPT" ]; then
    echo "   Running: $BUILD_SCRIPT" >&2
    if $BUILD_SCRIPT > /tmp/build_output.log 2>&1; then
      echo "   ✅ Build completed successfully" >&2
    else
      echo "   ⚠️ Build failed or incomplete - analyzing existing output" >&2
      echo "   📝 Build log: /tmp/build_output.log" >&2
    fi
  else
    echo "   ℹ️ No build script found - analyzing existing files" >&2
  fi
  
  echo "" >&2
fi

# Common build output directories
BUILD_DIRS=("dist" "build" "out" ".next" "public" "www" "target/release")

# Analyze each potential build directory
for dir in "${BUILD_DIRS[@]}"; do
  if [ -d "$dir" ]; then
    case "$dir" in
      "dist")
        analyze_directory "$dir" "Distribution Build"
        ;;
      "build")
        analyze_directory "$dir" "Production Build"
        ;;
      "out")
        analyze_directory "$dir" "Output Build"
        ;;
      ".next")
        analyze_directory "$dir" "Next.js Build"
        ;;
      "public")
        # Only analyze if it looks like a build output
        if [ -f "$dir/index.html" ] || [ -f "$dir/main.js" ]; then
          analyze_directory "$dir" "Public Assets"
        fi
        ;;
      "www")
        analyze_directory "$dir" "Web Assets"
        ;;
      "target/release")
        analyze_directory "$dir" "Rust Release Build"
        ;;
    esac
  fi
done

# Framework-specific analysis
if [ -f "webpack.config.js" ] || [ -f "webpack.config.ts" ]; then
  echo "⚙️ Webpack configuration detected" >&2
  
  # Look for webpack-bundle-analyzer output
  if [ -f "bundle-analyzer-report.html" ]; then
    echo "   📊 Bundle analyzer report available: bundle-analyzer-report.html" >&2
  fi
fi

if [ -f "vite.config.js" ] || [ -f "vite.config.ts" ]; then
  echo "⚡ Vite configuration detected" >&2
fi

if [ -f "next.config.js" ] || [ -f "next.config.ts" ]; then
  echo "▲ Next.js configuration detected" >&2
fi

if [ -f "rollup.config.js" ]; then
  echo "📦 Rollup configuration detected" >&2
fi

# Generate summary
echo "" >&2
echo "📋 BUNDLE SIZE SUMMARY" >&2
echo "=====================================" >&2

if [ "$BUILD_DETECTED" = true ]; then
  echo "📊 Total bundle size: $(format_bytes $TOTAL_SIZE)" >&2
  echo "" >&2
  echo "📈 Breakdown by type:" >&2
  [ "$JS_SIZE" -gt 0 ] && echo "   JavaScript: $(format_bytes $JS_SIZE)" >&2
  [ "$CSS_SIZE" -gt 0 ] && echo "   CSS: $(format_bytes $CSS_SIZE)" >&2
  [ "$IMAGE_SIZE" -gt 0 ] && echo "   Images: $(format_bytes $IMAGE_SIZE)" >&2
  
  echo "" >&2
  echo "🎯 Performance Assessment:" >&2
  
  # Performance thresholds
  if [ "$TOTAL_SIZE" -gt 5242880 ]; then  # 5MB
    echo "   🔴 Large bundle size - may impact load times significantly" >&2
  elif [ "$TOTAL_SIZE" -gt 1048576 ]; then  # 1MB
    echo "   🟡 Moderate bundle size - consider optimization" >&2
  else
    echo "   🟢 Good bundle size - within performance budget" >&2
  fi
  
  if [ "$JS_SIZE" -gt 1048576 ]; then  # 1MB JS
    echo "   ⚠️ JavaScript bundle is large - consider code splitting" >&2
  fi
  
  echo "" >&2
  echo "💡 Optimization Recommendations:" >&2
  echo "   • Enable gzip/brotli compression on your server" >&2
  echo "   • Consider code splitting for large JavaScript bundles" >&2
  echo "   • Optimize images with modern formats (WebP, AVIF)" >&2
  echo "   • Remove unused CSS and JavaScript code" >&2
  echo "   • Use dynamic imports for non-critical code" >&2
  
else
  echo "ℹ️ No build output detected in common directories" >&2
  echo "   Searched: ${BUILD_DIRS[*]}" >&2
  echo "   Consider running a build command first" >&2
fi

echo "" >&2
echo "📄 Report timestamp: $TIMESTAMP" >&2
echo "💾 Full report saved to: $REPORT_FILE" >&2

# Save detailed report to file
{
  echo "BUNDLE SIZE REPORT"
  echo "Generated: $TIMESTAMP"
  echo "Project: $(basename "$(pwd)")"
  echo ""
  
  if [ "$BUILD_DETECTED" = true ]; then
    echo "SUMMARY"
    echo "======="
    echo "Total Size: $(format_bytes $TOTAL_SIZE)"
    echo "JavaScript: $(format_bytes $JS_SIZE)"
    echo "CSS: $(format_bytes $CSS_SIZE)"
    echo "Images: $(format_bytes $IMAGE_SIZE)"
    echo ""
    
    echo "DETAILED ANALYSIS"
    echo "================="
    for dir in "${BUILD_DIRS[@]}"; do
      if [ -d "$dir" ]; then
        echo "$dir directory:"
        find "$dir" -type f -exec du -b {} + 2>/dev/null | sort -rn | head -10 | while read size file; do
          echo "  $(format_bytes $size) - $file"
        done
        echo ""
      fi
    done
  else
    echo "No build output detected"
  fi
} > "$REPORT_FILE"

echo "=====================================" >&2

exit 0