#!/bin/bash
# tmpfs Information and Configuration Helper
# Shows detailed information about tmpfs setup and how to use it

set -euo pipefail

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

show_tmpfs_status() {
    echo -e "${BLUE}🚀 tmpfs Cache System Status${NC}"
    echo "============================="
    echo ""
    
    # Check if tmpfs mounts exist
    local tmpfs_count=$(mount | grep "tmpfs.*tmpfs-cache" | wc -l)
    
    if [[ $tmpfs_count -eq 0 ]]; then
        echo -e "${RED}❌ No tmpfs cache mounts found${NC}"
        echo "Run: sudo ./one-button-optimizer.sh to set up tmpfs caches"
        return 1
    fi
    
    echo -e "${GREEN}✅ Found $tmpfs_count tmpfs cache mounts${NC}"
    echo ""
    
    # Show detailed mount information
    echo "📁 Active tmpfs Mounts:"
    echo "======================"
    printf "%-20s %-10s %-10s %-10s %s\n" "Mount Point" "Size" "Used" "Avail" "Use%"
    echo "--------------------------------------------------------------------------------"
    
    mount | grep "tmpfs.*tmpfs-cache" | while read -r line; do
        local mount_point=$(echo "$line" | awk '{print $3}')
        local df_info=$(df -h "$mount_point" 2>/dev/null | tail -1)
        local name=$(basename "$mount_point")
        local size=$(echo "$df_info" | awk '{print $2}')
        local used=$(echo "$df_info" | awk '{print $3}')
        local avail=$(echo "$df_info" | awk '{print $4}')
        local use_percent=$(echo "$df_info" | awk '{print $5}')
        
        printf "%-20s %-10s %-10s %-10s %s\n" "$name" "$size" "$used" "$avail" "$use_percent"
    done
    
    echo ""
}

show_configuration_guide() {
    echo -e "${BLUE}💡 Configuration Guide${NC}"
    echo "======================"
    echo ""
    
    # Browser configuration
    if mount | grep -q "tmpfs-cache/browser"; then
        echo -e "${YELLOW}🌐 Browser Cache Configuration:${NC}"
        echo ""
        echo "Google Chrome/Chromium:"
        echo "  google-chrome --disk-cache-dir=/tmp/tmpfs-cache/browser/chrome"
        echo "  Or add to ~/.config/google-chrome/Default/Preferences:"
        echo '    "browser": {"cache_directory": "/tmp/tmpfs-cache/browser/chrome"}'
        echo ""
        echo "Firefox:"
        echo "  1. Type about:config in address bar"
        echo "  2. Set browser.cache.disk.parent_directory = /tmp/tmpfs-cache/browser/firefox"
        echo "  3. Restart Firefox"
        echo ""
    fi
    
    # Development tools
    if mount | grep -q "tmpfs-cache/development"; then
        echo -e "${YELLOW}💻 Development Tools Configuration:${NC}"
        echo ""
        echo "NPM (Node.js):"
        echo "  npm config set cache /tmp/tmpfs-cache/development/npm"
        echo "  npm config set tmp /tmp/tmpfs-cache/development/npm-tmp"
        echo ""
        echo "Python pip:"
        echo "  echo 'export PIP_CACHE_DIR=/tmp/tmpfs-cache/development/pip' >> ~/.bashrc"
        echo "  source ~/.bashrc"
        echo ""
        echo "Docker build cache:"
        echo "  docker build --build-arg BUILDKIT_INLINE_CACHE=1 ."
        echo "  export DOCKER_BUILDKIT=1"
        echo ""
    fi
    
    # IDE configuration
    if mount | grep -q "tmpfs-cache/ide"; then
        echo -e "${YELLOW}🎨 IDE Configuration:${NC}"
        echo ""
        echo "VS Code:"
        echo "  mkdir -p /tmp/tmpfs-cache/ide/vscode"
        echo "  ln -sf /tmp/tmpfs-cache/ide/vscode ~/.vscode/extensions/.cache"
        echo ""
        echo "JetBrains IDEs (IntelliJ, PyCharm, etc.):"
        echo "  Add to vmoptions file: -Djava.io.tmpdir=/tmp/tmpfs-cache/ide/jetbrains"
        echo ""
    fi
    
    # KDE configuration
    if mount | grep -q "tmpfs-cache/kde"; then
        echo -e "${YELLOW}🖥️ KDE/Plasma Configuration:${NC}"
        echo ""
        echo "Thumbnail cache:"
        echo "  mkdir -p /tmp/tmpfs-cache/kde/thumbnails"
        echo "  rm -rf ~/.cache/thumbnails"
        echo "  ln -sf /tmp/tmpfs-cache/kde/thumbnails ~/.cache/thumbnails"
        echo ""
        echo "Baloo search index (optional - disables file indexing):"
        echo "  balooctl disable"
        echo "  rm -rf ~/.local/share/baloo"
        echo ""
    fi
}

show_usage_tips() {
    echo -e "${BLUE}📊 Usage Tips and Monitoring${NC}"
    echo "============================="
    echo ""
    
    echo "Monitoring Commands:"
    echo "  df -h /tmp/tmpfs-cache/*     # Check usage of all tmpfs mounts"
    echo "  watch -n 5 'df -h | grep tmpfs-cache'  # Monitor in real-time"
    echo "  du -sh /tmp/tmpfs-cache/*    # Check actual data in each mount"
    echo ""
    
    echo "Performance Monitoring:"
    echo "  iotop -ao                    # Monitor I/O to see reduced disk usage"
    echo "  htop                         # Monitor RAM usage"
    echo "  free -h                      # Check available memory"
    echo ""
    
    echo "Maintenance:"
    echo "  sudo sync                    # Force write pending data to disk"
    echo "  sudo systemctl restart system-optimization.service  # Recreate mounts"
    echo ""
    
    echo -e "${GREEN}💡 Performance Benefits:${NC}"
    echo "  🚀 Cache operations run at RAM speed (~50-100x faster than SSD)"
    echo "  💿 Reduced SSD wear from frequent cache writes"
    echo "  🧹 Automatic cache cleanup on reboot"
    echo "  ⚡ Lower latency for application launches and file operations"
    echo ""
    
    # Calculate total tmpfs usage
    local total_allocated=0
    local total_used=0
    
    while read -r line; do
        local mount_point=$(echo "$line" | awk '{print $3}')
        local allocated_kb=$(echo "$line" | grep -o 'size=[^,]*' | cut -d= -f2 | sed 's/k$//')
        local used_kb=$(df "$mount_point" 2>/dev/null | tail -1 | awk '{print $3}' || echo "0")
        
        total_allocated=$((total_allocated + allocated_kb))
        total_used=$((total_used + used_kb))
    done < <(mount | grep "tmpfs.*tmpfs-cache")
    
    local total_allocated_mb=$((total_allocated / 1024))
    local total_used_mb=$((total_used / 1024))
    
    echo -e "${BLUE}📈 Current Resource Usage:${NC}"
    echo "  Total tmpfs allocated: ${total_allocated_mb}MB"
    echo "  Total tmpfs used: ${total_used_mb}MB"
    echo "  RAM efficiency: $(( (total_allocated_mb * 100) / ($(free -m | awk '/^Mem:/{print $2}')) ))% of total RAM allocated to caches"
}

show_troubleshooting() {
    echo -e "${BLUE}🔧 Troubleshooting${NC}"
    echo "=================="
    echo ""
    
    echo "If tmpfs mounts are missing after reboot:"
    echo "  sudo systemctl status system-optimization.service"
    echo "  sudo systemctl restart system-optimization.service"
    echo ""
    
    echo "If running out of tmpfs space:"
    echo "  df -h /tmp/tmpfs-cache/*  # Check which mount is full"
    echo "  sudo umount /tmp/tmpfs-cache/[mount]  # Temporarily unmount"
    echo "  sudo mount -t tmpfs -o size=NEWSIZE tmpfs /tmp/tmpfs-cache/[mount]"
    echo ""
    
    echo "If applications aren't using tmpfs:"
    echo "  Check application-specific configuration files"
    echo "  Some apps need restart after cache directory changes"
    echo "  Use 'lsof /tmp/tmpfs-cache/*' to see which processes are using tmpfs"
    echo ""
}

main() {
    case "${1:-status}" in
        "status"|"")
            show_tmpfs_status
            ;;
        "config"|"configure")
            show_tmpfs_status
            echo ""
            show_configuration_guide
            ;;
        "usage"|"monitor")
            show_tmpfs_status
            echo ""
            show_usage_tips
            ;;
        "help"|"troubleshoot")
            show_tmpfs_status
            echo ""
            show_configuration_guide
            echo ""
            show_usage_tips
            echo ""
            show_troubleshooting
            ;;
        *)
            echo "Usage: $0 [status|config|usage|help]"
            echo ""
            echo "  status     - Show tmpfs mount status (default)"
            echo "  config     - Show configuration guide for applications"
            echo "  usage      - Show monitoring and usage tips"
            echo "  help       - Show all information including troubleshooting"
            ;;
    esac
}

main "$@"