#!/usr/bin/env bash
# Proxmox Storage Monitoring Script with Alerts
# Monitors storage usage across all Proxmox nodes and sends alerts

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
LOG_DIR="${PROJECT_ROOT}/logs/storage-monitoring"
ALERT_LOG="${LOG_DIR}/storage_alerts_$(date +%Y%m%d).log"
STATUS_LOG="${LOG_DIR}/storage_status_$(date +%Y%m%d).log"

# Alert thresholds
WARNING_THRESHOLD=80
CRITICAL_THRESHOLD=90
VG_FREE_WARNING=10  # GB
VG_FREE_CRITICAL=5  # GB

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
CYAN='\033[0;36m'
NC='\033[0m'

log_info() { echo -e "${BLUE}[INFO]${NC} $1"; }
log_success() { echo -e "${GREEN}[✓]${NC} $1"; }
log_warn() { echo -e "${YELLOW}[⚠]${NC} $1"; }
log_error() { echo -e "${RED}[✗]${NC} $1"; }
log_alert() { echo -e "${RED}[ALERT]${NC} $1"; }

# Create log directory
mkdir -p "$LOG_DIR"

# Proxmox nodes configuration
declare -A NODES
NODES[ml110]="192.168.11.10:L@kers2010"
NODES[r630-01]="192.168.11.11:password"
NODES[r630-02]="192.168.11.12:password"
NODES[r630-03]="192.168.11.13:L@kers2010"
NODES[r630-04]="192.168.11.14:L@kers2010"

# Alert tracking
declare -a ALERTS

# SSH helper function
ssh_node() {
    local hostname="$1"
    shift
    local ip="${NODES[$hostname]%%:*}"
    local password="${NODES[$hostname]#*:}"
    
    if command -v sshpass >/dev/null 2>&1; then
        sshpass -p "$password" ssh -o StrictHostKeyChecking=no -o ConnectTimeout=5 root@"$ip" "$@" 2>/dev/null || echo ""
    else
        ssh -o StrictHostKeyChecking=no -o ConnectTimeout=5 root@"$ip" "$@" 2>/dev/null || echo ""
    fi
}

# Check node connectivity
check_node() {
    local hostname="$1"
    local ip="${NODES[$hostname]%%:*}"
    
    ping -c 1 -W 2 "$ip" >/dev/null 2>&1
}

# Parse storage usage percentage
parse_storage_percent() {
    local percent_str="$1"
    # Remove % sign and convert to integer
    echo "$percent_str" | sed 's/%//' | awk '{print int($1)}'
}

# Check storage usage
check_storage_usage() {
    local hostname="$1"
    local storage_line="$2"
    
    local storage_name=$(echo "$storage_line" | awk '{print $1}')
    local storage_type=$(echo "$storage_line" | awk '{print $2}')
    local status=$(echo "$storage_line" | awk '{print $3}')
    local total=$(echo "$storage_line" | awk '{print $4}')
    local used=$(echo "$storage_line" | awk '{print $5}')
    local available=$(echo "$storage_line" | awk '{print $6}')
    local percent_str=$(echo "$storage_line" | awk '{print $7}')
    
    # Skip if disabled or inactive
    if [ "$status" = "disabled" ] || [ "$status" = "inactive" ] || [ "$percent_str" = "N/A" ]; then
        return 0
    fi
    
    local percent=$(parse_storage_percent "$percent_str")
    
    if [ -z "$percent" ] || [ "$percent" -eq 0 ]; then
        return 0
    fi
    
    # Check thresholds
    if [ "$percent" -ge "$CRITICAL_THRESHOLD" ]; then
        ALERTS+=("CRITICAL: $hostname:$storage_name is at ${percent}% capacity (${available} available)")
        log_alert "CRITICAL: $hostname:$storage_name is at ${percent}% capacity"
        return 2
    elif [ "$percent" -ge "$WARNING_THRESHOLD" ]; then
        ALERTS+=("WARNING: $hostname:$storage_name is at ${percent}% capacity (${available} available)")
        log_warn "WARNING: $hostname:$storage_name is at ${percent}% capacity"
        return 1
    fi
    
    return 0
}

# Check volume group free space
check_vg_free_space() {
    local hostname="$1"
    local vg_line="$2"
    
    local vg_name=$(echo "$vg_line" | awk '{print $1}')
    local vg_size=$(echo "$vg_line" | awk '{print $2}')
    local vg_free=$(echo "$vg_line" | awk '{print $3}')
    
    # Extract numeric value (remove 'g' suffix)
    local free_gb=$(echo "$vg_free" | sed 's/g//' | awk '{print int($1)}')
    
    if [ -z "$free_gb" ] || [ "$free_gb" -eq 0 ]; then
        return 0
    fi
    
    if [ "$free_gb" -le "$VG_FREE_CRITICAL" ]; then
        ALERTS+=("CRITICAL: $hostname:$vg_name volume group has only ${free_gb}GB free space")
        log_alert "CRITICAL: $hostname:$vg_name VG has only ${free_gb}GB free"
        return 2
    elif [ "$free_gb" -le "$VG_FREE_WARNING" ]; then
        ALERTS+=("WARNING: $hostname:$vg_name volume group has only ${free_gb}GB free space")
        log_warn "WARNING: $hostname:$vg_name VG has only ${free_gb}GB free"
        return 1
    fi
    
    return 0
}

# Monitor a single node
monitor_node() {
    local hostname="$1"
    
    if ! check_node "$hostname"; then
        log_warn "$hostname is not reachable"
        return 1
    fi
    
    log_info "Monitoring $hostname..."
    
    # Get storage status
    local storage_status=$(ssh_node "$hostname" 'pvesm status 2>/dev/null' || echo "")
    
    if [ -z "$storage_status" ]; then
        log_warn "Could not get storage status from $hostname"
        return 1
    fi
    
    # Process each storage line (skip header)
    echo "$storage_status" | tail -n +2 | while IFS= read -r line; do
        if [ -n "$line" ]; then
            check_storage_usage "$hostname" "$line"
        fi
    done
    
    # Check volume groups
    local vgs_info=$(ssh_node "$hostname" 'vgs --units g --noheadings -o vg_name,vg_size,vg_free 2>/dev/null' || echo "")
    
    if [ -n "$vgs_info" ]; then
        echo "$vgs_info" | while IFS= read -r line; do
            if [ -n "$line" ]; then
                check_vg_free_space "$hostname" "$line"
            fi
        done
    fi
    
    # Log storage status
    {
        echo "=== $hostname Storage Status $(date) ==="
        echo "$storage_status"
        echo ""
        echo "=== Volume Groups ==="
        echo "$vgs_info"
        echo ""
    } >> "$STATUS_LOG"
    
    return 0
}

# Send alerts (can be extended to email, Slack, etc.)
send_alerts() {
    if [ ${#ALERTS[@]} -eq 0 ]; then
        log_success "No storage alerts"
        return 0
    fi
    
    log_warn "Found ${#ALERTS[@]} storage alert(s)"
    
    {
        echo "=== Storage Alerts $(date) ==="
        for alert in "${ALERTS[@]}"; do
            echo "$alert"
        done
        echo ""
    } >> "$ALERT_LOG"
    
    # Print alerts
    for alert in "${ALERTS[@]}"; do
        echo "$alert"
    done
    
    # TODO: Add email/Slack/webhook notifications here
    # Example:
    # send_email "Storage Alerts" "$(printf '%s\n' "${ALERTS[@]}")"
    # send_slack_webhook "${ALERTS[@]}"
}

# Generate summary report
generate_summary() {
    local summary_file="${LOG_DIR}/storage_summary_$(date +%Y%m%d).txt"
    
    {
        echo "=== Proxmox Storage Summary $(date) ==="
        echo ""
        echo "Nodes Monitored:"
        for hostname in "${!NODES[@]}"; do
            if check_node "$hostname"; then
                echo "  ✅ $hostname"
            else
                echo "  ❌ $hostname (not reachable)"
            fi
        done
        echo ""
        echo "Alerts: ${#ALERTS[@]}"
        if [ ${#ALERTS[@]} -gt 0 ]; then
            echo ""
            for alert in "${ALERTS[@]}"; do
                echo "  - $alert"
            done
        fi
        echo ""
        echo "Thresholds:"
        echo "  Storage Usage Warning: ${WARNING_THRESHOLD}%"
        echo "  Storage Usage Critical: ${CRITICAL_THRESHOLD}%"
        echo "  Volume Group Free Warning: ${VG_FREE_WARNING}GB"
        echo "  Volume Group Free Critical: ${VG_FREE_CRITICAL}GB"
    } > "$summary_file"
    
    log_info "Summary saved to: $summary_file"
}

# Main monitoring function
main() {
    local mode="${1:-check}"
    
    case "$mode" in
        check)
            echo "=== Proxmox Storage Monitoring ==="
            echo "Date: $(date)"
            echo ""
            
            # Monitor all nodes
            for hostname in "${!NODES[@]}"; do
                monitor_node "$hostname"
            done
            
            # Send alerts
            send_alerts
            
            # Generate summary
            generate_summary
            
            echo ""
            log_info "Monitoring complete. Check logs in: $LOG_DIR"
            ;;
        status)
            # Show current status
            echo "=== Current Storage Status ==="
            for hostname in "${!NODES[@]}"; do
                if check_node "$hostname"; then
                    echo ""
                    echo "--- $hostname ---"
                    ssh_node "$hostname" 'pvesm status 2>/dev/null' || echo "Could not get status"
                fi
            done
            ;;
        alerts)
            # Show recent alerts
            if [ -f "$ALERT_LOG" ]; then
                tail -50 "$ALERT_LOG"
            else
                echo "No alerts found"
            fi
            ;;
        *)
            echo "Usage: $0 [check|status|alerts]"
            echo "  check   - Run full monitoring check (default)"
            echo "  status  - Show current storage status"
            echo "  alerts  - Show recent alerts"
            exit 1
            ;;
    esac
}

# Run main function
main "$@"