#!/bin/bash

################################################################################
# Acronis Backup Troubleshooter
################################################################################
# Purpose: Diagnose and troubleshoot Acronis backup failures
# Features:
# - Multi-log location scanning
# - Common failure pattern detection
# - Service health checks
# - Disk space analysis
# - Network connectivity tests
# - Automated fix suggestions
################################################################################

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
source "$SCRIPT_DIR/lib/common-functions.sh"
source "$SCRIPT_DIR/lib/system-detect.sh"

# Require root
if [ "$EUID" -ne 0 ]; then
    print_error "This script must be run as root"
    exit 1
fi

# Log locations to check
declare -A LOG_LOCATIONS=(
    ["MMS"]="/var/lib/Acronis/BackupAndRecovery/MMS/mms.0.log"
    ["MMS_OLD"]="/var/lib/Acronis/BackupAndRecovery/MMS/mms.*.log"
    ["AGENT"]="/var/log/acronis/agent/*.log"
    ["CORE"]="/var/lib/Acronis/BackupAndRecovery/aakore.log"
    ["SCHEDULE"]="/var/lib/Acronis/BackupAndRecovery/scheduler.log"
    ["SYSTEM"]="/var/log/messages"
    ["SYSLOG"]="/var/log/syslog"
)

print_banner "Acronis Backup Troubleshooter"

echo ""
echo -e "${BOLD}Diagnostic Mode${NC}"
echo ""
echo "This tool will analyze:"
echo "  • Service status and health"
echo "  • Log files for errors and failures"
echo "  • System resources (disk, memory)"
echo "  • Network connectivity to Acronis Cloud"
echo "  • Common backup failure patterns"
echo ""
echo -e "${CYAN}──────────────────────────────────────────────────────────────${NC}"
echo ""

# Track issues found
declare -a ISSUES_FOUND=()
declare -a WARNINGS_FOUND=()
declare -a RECOMMENDATIONS=()

# Function to add issue
add_issue() {
    ISSUES_FOUND+=("$1")
}

# Function to add warning
add_warning() {
    WARNINGS_FOUND+=("$1")
}

# Function to add recommendation
add_recommendation() {
    RECOMMENDATIONS+=("$1")
}

# 1. Check service status
echo -e "${BOLD}[1/7] Checking Acronis Services...${NC}"
echo ""

declare -a SERVICES=("aakore" "acronis_mms" "acronis_schedule" "active-protection")
all_services_running=true

for service in "${SERVICES[@]}"; do
    if systemctl list-unit-files | grep -q "^${service}.service"; then
        if systemctl is-active --quiet "$service"; then
            echo -e "  ${GREEN}✓${NC} $service is running"
        else
            echo -e "  ${RED}✗${NC} $service is NOT running"
            add_issue "Service $service is stopped"
            add_recommendation "Start service: systemctl start $service"
            all_services_running=false
        fi
    fi
done

if [ "$all_services_running" = false ]; then
    add_recommendation "Start all services: Go to Acronis menu → Check Agent Status → Start All Services"
fi

echo ""

# 2. Check disk space
echo -e "${BOLD}[2/7] Checking Disk Space...${NC}"
echo ""

# Check backup directory
if [ -d "/var/lib/Acronis" ]; then
    backup_disk_usage=$(df -h /var/lib/Acronis | tail -1 | awk '{print $5}' | tr -d '%')
    backup_disk_avail=$(df -h /var/lib/Acronis | tail -1 | awk '{print $4}')

    echo "  Acronis directory: /var/lib/Acronis"
    echo "  Disk usage: ${backup_disk_usage}%"
    echo "  Available: ${backup_disk_avail}"

    if [ "$backup_disk_usage" -gt 95 ]; then
        add_issue "Disk space critically low (${backup_disk_usage}% used)"
        add_recommendation "Free up disk space or change backup destination"
    elif [ "$backup_disk_usage" -gt 90 ]; then
        add_warning "Disk space running low (${backup_disk_usage}% used)"
        add_recommendation "Monitor disk space closely"
    else
        echo -e "  ${GREEN}✓${NC} Disk space OK"
    fi
fi

# Check system disk
root_disk_usage=$(df -h / | tail -1 | awk '{print $5}' | tr -d '%')
if [ "$root_disk_usage" -gt 90 ]; then
    add_warning "Root filesystem at ${root_disk_usage}% capacity"
fi

echo ""

# 3. Check memory
echo -e "${BOLD}[3/7] Checking Memory...${NC}"
echo ""

mem_total=$(free -h | grep "^Mem:" | awk '{print $2}')
mem_available=$(free -h | grep "^Mem:" | awk '{print $7}')
mem_used_percent=$(free | grep "^Mem:" | awk '{printf "%.0f", ($3/$2)*100}')

echo "  Total memory: ${mem_total}"
echo "  Available: ${mem_available}"
echo "  Used: ${mem_used_percent}%"

if [ "$mem_used_percent" -gt 95 ]; then
    add_warning "Memory usage critically high (${mem_used_percent}%)"
    add_recommendation "Check for memory leaks or reduce backup concurrency"
elif [ "$mem_used_percent" -gt 90 ]; then
    add_warning "Memory usage high (${mem_used_percent}%)"
else
    echo -e "  ${GREEN}✓${NC} Memory OK"
fi

echo ""

# 4. Check network connectivity
echo -e "${BOLD}[4/7] Checking Network Connectivity...${NC}"
echo ""

# Check if registered
if [ -f "/etc/Acronis/Global.config" ]; then
    cloud_url=$(grep -oP 'CloudUrl[>="].*?https://[^"<]+' /etc/Acronis/Global.config 2>/dev/null | grep -oP 'https://[^"<]+' | head -1)

    if [ -n "$cloud_url" ]; then
        echo "  Testing connection to: $cloud_url"

        # Extract hostname
        cloud_host=$(echo "$cloud_url" | sed 's|https://||' | sed 's|/.*||')

        # Test connectivity
        if curl -s --connect-timeout 5 -I "$cloud_url" >/dev/null 2>&1; then
            echo -e "  ${GREEN}✓${NC} Connection successful"
        else
            add_issue "Cannot connect to Acronis Cloud: $cloud_url"
            add_recommendation "Check firewall rules and network connectivity"
            add_recommendation "Test manually: curl -I $cloud_url"
        fi

        # Test DNS resolution
        if host "$cloud_host" >/dev/null 2>&1; then
            echo -e "  ${GREEN}✓${NC} DNS resolution OK"
        else
            add_issue "DNS resolution failed for $cloud_host"
            add_recommendation "Check DNS configuration: /etc/resolv.conf"
        fi
    else
        add_warning "Agent may not be registered with Acronis Cloud"
        add_recommendation "Register agent: Acronis menu → Register with Cloud"
    fi
else
    add_warning "Acronis configuration file not found"
fi

echo ""

# 5. Scan logs for errors
echo -e "${BOLD}[5/7] Scanning Logs for Errors...${NC}"
echo ""

# Common error patterns
declare -A ERROR_PATTERNS=(
    ["INSUFFICIENT_SPACE"]="insufficient.*space|no.*space.*left|disk.*full"
    ["PERMISSION_DENIED"]="permission.*denied|access.*denied|cannot.*access"
    ["CONNECTION_FAILED"]="connection.*failed|connection.*refused|timeout|network.*error"
    ["AUTH_FAILED"]="authentication.*failed|invalid.*credentials|unauthorized"
    ["BACKUP_FAILED"]="backup.*failed|backup.*error|task.*failed"
    ["VSS_ERROR"]="vss.*error|snapshot.*failed|shadow.*copy.*error"
    ["DATABASE_ERROR"]="database.*error|sql.*error|db.*lock"
    ["FILE_LOCKED"]="file.*locked|file.*in.*use|sharing.*violation"
)

# Scan primary log
primary_log="/var/lib/Acronis/BackupAndRecovery/MMS/mms.0.log"

if [ -f "$primary_log" ]; then
    echo "  Scanning primary log: mms.0.log"

    for pattern_name in "${!ERROR_PATTERNS[@]}"; do
        pattern="${ERROR_PATTERNS[$pattern_name]}"

        if grep -iE "$pattern" "$primary_log" 2>/dev/null | tail -1 | grep -q .; then
            error_count=$(grep -icE "$pattern" "$primary_log" 2>/dev/null)
            last_error=$(grep -iE "$pattern" "$primary_log" 2>/dev/null | tail -1)

            echo -e "  ${RED}⚠${NC} Found $pattern_name errors (count: $error_count)"
            echo -e "     Last: ${DIM}${last_error:0:80}...${NC}"

            add_issue "$pattern_name detected in logs (count: $error_count)"

            # Add specific recommendations
            case "$pattern_name" in
                "INSUFFICIENT_SPACE")
                    add_recommendation "Free up disk space or change backup destination"
                    ;;
                "PERMISSION_DENIED")
                    add_recommendation "Check file/directory permissions"
                    add_recommendation "Ensure Acronis agent has necessary access rights"
                    ;;
                "CONNECTION_FAILED")
                    add_recommendation "Check network connectivity and firewall rules"
                    add_recommendation "Verify Acronis Cloud URL is accessible"
                    ;;
                "AUTH_FAILED")
                    add_recommendation "Re-register agent with valid token"
                    add_recommendation "Check registration status in web console"
                    ;;
                "VSS_ERROR")
                    add_recommendation "Check VSS service: vssadmin list writers"
                    add_recommendation "Restart VSS: net stop vss && net start vss"
                    ;;
                "DATABASE_ERROR")
                    add_recommendation "Check database connections and locks"
                    add_recommendation "Consider application-aware backup settings"
                    ;;
                "FILE_LOCKED")
                    add_recommendation "Identify processes locking files: lsof"
                    add_recommendation "Schedule backups during low-activity periods"
                    ;;
            esac
        fi
    done

    # Check for recent backup failures
    recent_failures=$(grep -i "backup.*failed\|task.*failed" "$primary_log" 2>/dev/null | tail -5)
    if [ -n "$recent_failures" ]; then
        echo ""
        echo -e "  ${YELLOW}Recent backup failures:${NC}"
        echo "$recent_failures" | while read -r line; do
            echo -e "    ${DIM}${line:0:100}${NC}"
        done
    fi

else
    add_warning "Primary log file not found: $primary_log"
fi

echo ""

# 6. Check for stuck backups
echo -e "${BOLD}[6/7] Checking for Stuck Processes...${NC}"
echo ""

# Check for long-running Acronis processes
old_processes=$(ps aux | grep -i acronis | grep -v grep | awk '{if ($10 ~ /[0-9][0-9]:[0-9][0-9]/) print $0}')

if [ -n "$old_processes" ]; then
    echo -e "  ${YELLOW}⚠${NC} Long-running Acronis processes detected:"
    echo "$old_processes" | while read -r line; do
        echo -e "    ${DIM}$line${NC}"
    done
    add_warning "Long-running Acronis processes may indicate stuck backups"
    add_recommendation "Review processes and consider restarting services if stuck"
else
    echo -e "  ${GREEN}✓${NC} No stuck processes detected"
fi

echo ""

# 7. Check configuration issues
echo -e "${BOLD}[7/7] Checking Configuration...${NC}"
echo ""

# Check if backup plans are configured
if command -v acrocmd &>/dev/null; then
    plan_count=$(acrocmd list plans 2>/dev/null | grep -c "^Plan ID" || echo "0")
    echo "  Configured backup plans: $plan_count"

    if [ "$plan_count" -eq 0 ]; then
        add_warning "No backup plans configured"
        add_recommendation "Configure backup plans in Acronis web console"
    fi
else
    echo "  ${DIM}acrocmd not available - cannot check backup plans${NC}"
fi

# Check agent version
if [ -f "/usr/lib/Acronis/BackupAndRecovery/aakore" ]; then
    agent_version=$(/usr/lib/Acronis/BackupAndRecovery/aakore --version 2>/dev/null | head -1 || echo "Unknown")
    echo "  Agent version: $agent_version"
else
    add_warning "Cannot determine agent version"
fi

echo ""
echo -e "${CYAN}──────────────────────────────────────────────────────────────${NC}"
echo ""

# Summary Report
echo -e "${BOLD}DIAGNOSTIC SUMMARY${NC}"
echo ""

if [ ${#ISSUES_FOUND[@]} -eq 0 ] && [ ${#WARNINGS_FOUND[@]} -eq 0 ]; then
    echo -e "${GREEN}${BOLD}✓ No issues detected${NC}"
    echo ""
    echo "Acronis appears to be healthy. If you're experiencing backup"
    echo "failures, check the web console for detailed backup logs."
else
    # Show issues
    if [ ${#ISSUES_FOUND[@]} -gt 0 ]; then
        echo -e "${RED}${BOLD}Critical Issues (${#ISSUES_FOUND[@]}):${NC}"
        for issue in "${ISSUES_FOUND[@]}"; do
            echo -e "  ${RED}✗${NC} $issue"
        done
        echo ""
    fi

    # Show warnings
    if [ ${#WARNINGS_FOUND[@]} -gt 0 ]; then
        echo -e "${YELLOW}${BOLD}Warnings (${#WARNINGS_FOUND[@]}):${NC}"
        for warning in "${WARNINGS_FOUND[@]}"; do
            echo -e "  ${YELLOW}⚠${NC} $warning"
        done
        echo ""
    fi

    # Show recommendations
    if [ ${#RECOMMENDATIONS[@]} -gt 0 ]; then
        echo -e "${CYAN}${BOLD}Recommendations:${NC}"
        local rec_num=1
        for rec in "${RECOMMENDATIONS[@]}"; do
            echo -e "  ${CYAN}${rec_num}.${NC} $rec"
            ((rec_num++))
        done
        echo ""
    fi
fi

echo -e "${CYAN}──────────────────────────────────────────────────────────────${NC}"
echo ""

# Quick actions
echo -e "${BOLD}Quick Actions:${NC}"
echo ""
echo -e "  ${CYAN}1)${NC} View Full Logs (all errors)"
echo -e "  ${CYAN}2)${NC} Restart All Services"
echo -e "  ${CYAN}3)${NC} Generate Detailed Report"
echo -e "  ${CYAN}4)${NC} Export Logs for Support"
echo ""
echo -e "  ${RED}0)${NC} Return to Menu"
echo ""
echo -n "Select action (or press Enter to return): "
read -r action

case "$action" in
    1)
        # Show all errors
        clear
        print_banner "All Errors from Logs"
        echo ""
        if [ -f "$primary_log" ]; then
            grep -iE "error|fail|critical|warn" "$primary_log" | tail -50
        fi
        echo ""
        press_enter
        ;;
    2)
        # Restart services
        echo ""
        echo "Restarting all Acronis services..."
        systemctl restart aakore
        systemctl restart acronis_mms
        systemctl restart acronis_schedule
        systemctl restart active-protection
        echo ""
        print_success "Services restarted"
        echo ""
        echo "Waiting 5 seconds for services to stabilize..."
        sleep 5
        echo ""
        echo "Running diagnostic again..."
        sleep 2
        exec "$0"
        ;;
    3)
        # Generate detailed report
        report_file="/tmp/acronis-diagnostic-$(date +%Y%m%d-%H%M%S).txt"
        echo ""
        echo "Generating detailed report..."

        {
            echo "Acronis Diagnostic Report"
            echo "Generated: $(date)"
            echo "Hostname: $(hostname)"
            echo ""
            echo "=== Service Status ==="
            for service in "${SERVICES[@]}"; do
                systemctl status "$service" 2>&1 | head -20
                echo ""
            done
            echo ""
            echo "=== Recent Log Entries ==="
            if [ -f "$primary_log" ]; then
                tail -200 "$primary_log"
            fi
            echo ""
            echo "=== System Resources ==="
            df -h
            echo ""
            free -h
            echo ""
            echo "=== Network ==="
            netstat -tuln | grep -E "7770|7800|8443|44445"
            echo ""
            echo "=== Processes ==="
            ps aux | grep -i acronis | grep -v grep
        } > "$report_file"

        print_success "Report generated: $report_file"
        echo ""
        echo "You can send this report to Acronis support or review it locally."
        echo ""
        press_enter
        ;;
    4)
        # Export logs
        archive_file="/tmp/acronis-logs-$(date +%Y%m%d-%H%M%S).tar.gz"
        echo ""
        echo "Exporting logs..."

        if [ -d "/var/lib/Acronis/BackupAndRecovery/MMS" ]; then
            tar -czf "$archive_file" /var/lib/Acronis/BackupAndRecovery/MMS/*.log 2>/dev/null
            print_success "Logs exported: $archive_file"
            echo ""
            echo "Archive size: $(du -h "$archive_file" | awk '{print $1}')"
        else
            print_error "Log directory not found"
        fi
        echo ""
        press_enter
        ;;
    *)
        exit 0
        ;;
esac