#!/bin/bash

# 14-admin-utilities.sh - Admin Utilities for Particle-OS apt-layer
# Provides system health monitoring, performance analytics, and admin tools

# --- Color and Symbols ---
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
RED='\033[0;31m'
CYAN='\033[0;36m'
NC='\033[0m'
CHECK="â"
WARN="â ï¸ "
CROSS="â"
INFO="â¹ï¸ "

# --- Helper: Check for WSL ---
is_wsl() {
    grep -qi microsoft /proc/version 2>/dev/null
}

get_wsl_version() {
    if is_wsl; then
        if grep -q WSL2 /proc/version 2>/dev/null; then
            echo "WSL2"
        else
            echo "WSL1"
        fi
    fi
}

# --- System Health Monitoring ---
health_check() {
    local health_status=0
    echo -e "${CYAN}================= System Health Check =================${NC}"
    echo -e "${INFO} Hostname:        $(hostname 2>/dev/null || echo N/A)"
    echo -e "${INFO} Uptime:          $(uptime -p 2>/dev/null || echo N/A)"
    echo -e "${INFO} Kernel:          $(uname -r 2>/dev/null || echo N/A)"
    if is_wsl; then
        echo -e "${INFO} WSL:             $(get_wsl_version)"
    fi
    echo -e "${INFO} Load Avg:        $(awk '{print $1, $2, $3}' /proc/loadavg 2>/dev/null || echo N/A)"
    # CPU Info
    if command -v lscpu &>/dev/null; then
        cpu_model=$(lscpu | grep 'Model name' | awk -F: '{print $2}' | xargs)
        cpu_cores=$(lscpu | grep '^CPU(s):' | awk '{print $2}')
        echo -e "${INFO} CPU:             $cpu_model ($cpu_cores cores)"
    else
        echo -e "${WARN} CPU:             lscpu not available"
        health_status=1
    fi
    # Memory
    if command -v free &>/dev/null; then
        mem_line=$(free -m | grep Mem)
        mem_total=$(echo $mem_line | awk '{print $2}')
        mem_used=$(echo $mem_line | awk '{print $3}')
        mem_free=$(echo $mem_line | awk '{print $4}')
        mem_perc=$((100 * mem_used / mem_total))
        echo -e "${INFO} Memory:          ${mem_total}MiB total, ${mem_used}MiB used (${mem_perc}%)"
    else
        echo -e "${WARN} Memory:          free not available"
        health_status=1
    fi
    # Disk
    if command -v df &>/dev/null; then
        disk_root=$(df -h / | tail -1)
        disk_total=$(echo $disk_root | awk '{print $2}')
        disk_used=$(echo $disk_root | awk '{print $3}')
        disk_avail=$(echo $disk_root | awk '{print $4}')
        disk_perc=$(echo $disk_root | awk '{print $5}')
        echo -e "${INFO} Disk /:          $disk_total total, $disk_used used, $disk_avail free ($disk_perc)"
        if [ -d /var/lib/particle-os ]; then
            disk_ublue=$(df -h /var/lib/particle-os 2>/dev/null | tail -1)
            if [ -n "$disk_ublue" ]; then
                ublue_total=$(echo $disk_ublue | awk '{print $2}')
                ublue_used=$(echo $disk_ublue | awk '{print $3}')
                ublue_avail=$(echo $disk_ublue | awk '{print $4}')
                ublue_perc=$(echo $disk_ublue | awk '{print $5}')
                echo -e "${INFO} Disk /var/lib/particle-os: $ublue_total total, $ublue_used used, $ublue_avail free ($ublue_perc)"
            fi
        fi
    else
        echo -e "${WARN} Disk:            df not available"
        health_status=1
    fi
    # OverlayFS/ComposeFS
    overlays=$(mount | grep overlay | wc -l)
    composefs=$(mount | grep composefs | wc -l)
    echo -e "${INFO} OverlayFS:       $overlays overlays mounted"
    echo -e "${INFO} ComposeFS:       $composefs composefs mounted"
    # Bootloader
    if command -v bootctl &>/dev/null; then
        boot_status=$(bootctl status 2>/dev/null | grep 'System:' | xargs)
        echo -e "${INFO} Bootloader:      ${boot_status:-N/A}"
    else
        echo -e "${WARN} Bootloader:      bootctl not available"
    fi
    # Security
    if command -v apparmor_status &>/dev/null; then
        sec_status=$(apparmor_status | grep 'profiles are in enforce mode' || echo 'N/A')
        echo -e "${INFO} Security:        $sec_status"
    else
        echo -e "${WARN} Security:        apparmor_status not available"
    fi
    # Layer Integrity/Deployment
    echo -e "${CYAN}-----------------------------------------------------${NC}"
    echo -e "${INFO} Layer Integrity: [Coming soon] (future: check layer hashes)"
    echo -e "${INFO} Deployment Status: [Coming soon] (future: show active deployments)"
    # Top processes
    echo -e "${CYAN}---------------- Top 3 Processes ---------------------${NC}"
    if command -v ps &>/dev/null; then
        echo -e "${INFO} By CPU:"
        ps -eo pid,comm,%cpu --sort=-%cpu | head -n 4 | tail -n 3 | awk '{printf "  PID: %-6s %-20s CPU: %s%%\n", $1, $2, $3}'
        echo -e "${INFO} By MEM:"
        ps -eo pid,comm,%mem --sort=-%mem | head -n 4 | tail -n 3 | awk '{printf "  PID: %-6s %-20s MEM: %s%%\n", $1, $2, $3}'
    else
        echo -e "${WARN} ps not available for process listing"
    fi
    echo -e "${CYAN}-----------------------------------------------------${NC}"
    # Summary
    if [ $health_status -eq 0 ]; then
        echo -e "${GREEN}${CHECK} System health: OK${NC}"
    else
        echo -e "${YELLOW}${WARN} System health: WARNING (see above)${NC}"
    fi
    echo -e "${CYAN}=====================================================${NC}"
}

# --- Performance Analytics ---
performance_report() {
    echo -e "${CYAN}=============== Performance Analytics ===============${NC}"
    echo -e "${INFO} Layer creation time (last 5): [Coming soon] (future: show timing logs)"
    echo -e "${INFO} Resource usage (CPU/mem): [Coming soon] (future: show resource stats)"
    if command -v iostat &>/dev/null; then
        echo -e "${INFO} Disk I/O stats:"
        iostat | grep -A1 Device | tail -n +2
    else
        echo -e "${WARN} Disk I/O stats: iostat not available"
    fi
    echo -e "${INFO} Historical trends: [Coming soon] (future: show trends if data available)"
    echo -e "${CYAN}=====================================================${NC}"
}

# --- Automated Maintenance ---
admin_cleanup() {
    # Defaults
    local days=30
    local dry_run=false
    local keep_recent=2
    local DEPLOYMENTS_DIR="/var/lib/particle-os/deployments"
    local LOGS_DIR="/var/log/apt-layer"
    local BACKUPS_DIR="/var/lib/particle-os/backups"

    # Load config from JSON if available
    local config_file="$(dirname "${BASH_SOURCE[0]}")/../config/maintenance.json"
    if [ -f "$config_file" ] && command -v jq &>/dev/null; then
        days=$(jq -r '.retention_days // 30' "$config_file")
        keep_recent=$(jq -r '.keep_recent // 2' "$config_file")
        DEPLOYMENTS_DIR=$(jq -r '.deployments_dir // "/var/lib/particle-os/deployments"' "$config_file")
        LOGS_DIR=$(jq -r '.logs_dir // "/var/log/apt-layer"' "$config_file")
        BACKUPS_DIR=$(jq -r '.backups_dir // "/var/lib/particle-os/backups"' "$config_file")
    fi

    # Parse arguments (override config)
    while [[ $# -gt 0 ]]; do
        case $1 in
            --days|-d)
                days="$2"; shift 2;;
            --dry-run)
                dry_run=true; shift;;
            --keep-recent)
                keep_recent="$2"; shift 2;;
            --deployments-dir)
                DEPLOYMENTS_DIR="$2"; shift 2;;
            --logs-dir)
                LOGS_DIR="$2"; shift 2;;
            --backups-dir)
                BACKUPS_DIR="$2"; shift 2;;
            --schedule)
                echo -e "${YELLOW}${WARN} Scheduled cleanup: Not yet implemented (will use systemd/cron)${NC}"; return;;
            *)
                shift;;
        esac
    done

    echo -e "${CYAN}--- Automated Maintenance Cleanup ---${NC}"
    echo -e "${INFO} Retention: $days days"
    echo -e "${INFO} Keep recent: $keep_recent items"
    echo -e "${INFO} Deployments dir: $DEPLOYMENTS_DIR"
    echo -e "${INFO} Logs dir: $LOGS_DIR"
    echo -e "${INFO} Backups dir: $BACKUPS_DIR"
    if [ "$dry_run" = true ]; then
        echo -e "${YELLOW}${WARN} DRY RUN MODE - No files will be deleted${NC}"
    fi

    local total_deleted=0
    
    # Helper function to cleanup directory
    cleanup_directory() {
        local dir="$1"
        local description="$2"
        local deleted_count=0
        
        if [ ! -d "$dir" ]; then
            echo -e "${INFO} $description: Directory does not exist, skipping"
            return
        fi
        
        echo -e "${INFO} $description: Scanning $dir"
        
        # Get list of files/directories older than retention period
        local old_items=()
        if command -v find &>/dev/null; then
            while IFS= read -r -d '' item; do
                old_items+=("$item")
            done < <(find "$dir" -maxdepth 1 -type f -o -type d -mtime +$days -print0 2>/dev/null)
        fi
        
        # Remove the most recent items from deletion list
        if [ ${#old_items[@]} -gt 0 ] && [ $keep_recent -gt 0 ]; then
            # Sort by modification time (newest first) and keep the most recent
            local sorted_items=($(printf '%s\n' "${old_items[@]}" | xargs -I {} stat -c '%Y %n' {} 2>/dev/null | sort -nr | tail -n +$((keep_recent + 1)) | awk '{print $2}'))
            old_items=("${sorted_items[@]}")
        fi
        
        if [ ${#old_items[@]} -eq 0 ]; then
            echo -e "${INFO} $description: No items to delete"
            return
        fi
        
        echo -e "${INFO} $description: Found ${#old_items[@]} items to delete"
        
        for item in "${old_items[@]}"; do
            if [ "$dry_run" = true ]; then
                echo -e "  ${YELLOW}Would delete: $item${NC}"
            else
                if rm -rf "$item" 2>/dev/null; then
                    echo -e "  ${GREEN}Deleted: $item${NC}"
                    ((deleted_count++))
                else
                    echo -e "  ${RED}Failed to delete: $item${NC}"
                fi
            fi
        done
        
        if [ "$dry_run" = false ]; then
            total_deleted=$((total_deleted + deleted_count))
        fi
    }
    
    # Cleanup each directory
    cleanup_directory "$DEPLOYMENTS_DIR" "Deployments"
    cleanup_directory "$LOGS_DIR" "Logs"
    cleanup_directory "$BACKUPS_DIR" "Backups"
    
    # Summary
    if [ "$dry_run" = true ]; then
        echo -e "${YELLOW}${WARN} Dry run completed - no files were deleted${NC}"
    else
        echo -e "${GREEN}${CHECK} Cleanup complete - $total_deleted items deleted${NC}"
    fi
    echo -e "${CYAN}-------------------------------------${NC}"
}

# --- Backup/Restore (Stub) ---
admin_backup() {
    echo -e "${YELLOW}${WARN} Backup: Not yet implemented${NC}"
}

admin_restore() {
    echo -e "${YELLOW}${WARN} Restore: Not yet implemented${NC}"
}

# --- Command Dispatch ---
admin_utilities_main() {
    case "${1:-}" in
        health|health-check)
            health_check
            ;;
        perf|performance|analytics)
            performance_report
            ;;
        cleanup)
            shift
            admin_cleanup "$@"
            ;;
        backup)
            admin_backup
            ;;
        restore)
            admin_restore
            ;;
        help|--help|-h|"")
            echo -e "${CYAN}Admin Utilities Commands:${NC}"
            echo -e "  ${GREEN}health${NC}         - System health check"
            echo -e "  ${GREEN}perf${NC}           - Performance analytics"
            echo -e "  ${GREEN}cleanup${NC}        - Maintenance cleanup (--days N, --dry-run, --keep-recent N)"
            echo -e "  ${GREEN}backup${NC}         - Backup configs/layers (stub)"
            echo -e "  ${GREEN}restore${NC}        - Restore from backup (stub)"
            echo -e "  ${GREEN}help${NC}           - Show this help message"
            ;;
        *)
            echo -e "${RED}${CROSS} Unknown admin command: $1${NC}"
            admin_utilities_main help
            ;;
    esac
}