#!/bin/bash
#
# Historical Attack Log Analyzer
# Scans past Apache/Nginx logs for attack patterns using ET Open signatures
#
# Usage: bash analyze-historical-attacks.sh [options]
#
# Options:
#   -d DAYS    Analyze logs from last N days (default: 7)
#   -l LOGFILE Analyze specific log file
#   -o OUTPUT  Output report file (default: /tmp/attack-analysis-TIMESTAMP.txt)
#   -t THRESHOLD  Minimum threat score to report (default: 50)
#   -v         Verbose mode (show all attacks)
#   -h         Show help

# Get script directory
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/.."

# Source required libraries
source "$SCRIPT_DIR/lib/attack-signatures.sh" 2>/dev/null || {
    echo "ERROR: attack-signatures.sh not found"
    exit 1
}
source "$SCRIPT_DIR/lib/http-attack-analyzer.sh" 2>/dev/null || {
    echo "ERROR: http-attack-analyzer.sh not found"
    exit 1
}

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

# Default options
DAYS=7
LOG_FILE=""
OUTPUT_FILE="/tmp/attack-analysis-$(date +%Y%m%d_%H%M%S).txt"
THRESHOLD=50
VERBOSE=0

# Parse command line arguments
while getopts "d:l:o:t:vh" opt; do
    case $opt in
        d) DAYS="$OPTARG" ;;
        l) LOG_FILE="$OPTARG" ;;
        o) OUTPUT_FILE="$OPTARG" ;;
        t) THRESHOLD="$OPTARG" ;;
        v) VERBOSE=1 ;;
        h)
            cat << EOF
Historical Attack Log Analyzer
Scans past Apache/Nginx logs for attack patterns using ET Open signatures

Usage: $0 [options]

Options:
  -d DAYS     Analyze logs from last N days (default: 7)
  -l LOGFILE  Analyze specific log file
  -o OUTPUT   Output report file (default: /tmp/attack-analysis-TIMESTAMP.txt)
  -t THRESHOLD Minimum threat score to report (default: 50)
  -v          Verbose mode (show all attacks)
  -h          Show this help

Examples:
  # Analyze last 7 days
  $0

  # Analyze last 30 days
  $0 -d 30

  # Analyze specific log file
  $0 -l /var/log/apache2/access.log

  # Show all attacks (including low severity)
  $0 -t 0 -v

  # Save report to custom location
  $0 -o /root/attack-report.txt
EOF
            exit 0
            ;;
        \?)
            echo "Invalid option: -$OPTARG" >&2
            exit 1
            ;;
    esac
done

echo "================================================================================
"
echo -e "${CYAN}${BOLD}Historical Attack Log Analyzer${NC}"
echo "Powered by Emerging Threats Open Ruleset"
echo "================================================================================
"

# Find log files to analyze
LOG_FILES=()

if [ -n "$LOG_FILE" ]; then
    # Specific log file provided
    if [ ! -f "$LOG_FILE" ]; then
        echo -e "${RED}ERROR: Log file not found: $LOG_FILE${NC}"
        exit 1
    fi
    LOG_FILES=("$LOG_FILE")
    echo -e "${GREEN}✓${NC} Analyzing specific file: $LOG_FILE"
else
    # Auto-detect log files
    echo -e "${BLUE}[*]${NC} Searching for Apache/Nginx log files..."

    # Common log locations
    SEARCH_PATHS=(
        "/var/log/apache2"
        "/var/log/httpd"
        "/usr/local/apache/logs"
        "/var/log/nginx"
        "/usr/local/apache/domlogs"
    )

    for path in "${SEARCH_PATHS[@]}"; do
        if [ -d "$path" ]; then
            # Find access logs modified in last N days
            while IFS= read -r log; do
                LOG_FILES+=("$log")
            done < <(find "$path" -type f \( -name "access*.log*" -o -name "access_log*" -o -name "*.com" -o -name "*.net" -o -name "*.org" \) -mtime -"$DAYS" 2>/dev/null)
        fi
    done

    if [ ${#LOG_FILES[@]} -eq 0 ]; then
        echo -e "${RED}ERROR: No log files found in last $DAYS days${NC}"
        exit 1
    fi

    echo -e "${GREEN}✓${NC} Found ${#LOG_FILES[@]} log files from last $DAYS days"
fi

# Initialize counters
TOTAL_LINES=0
TOTAL_ATTACKS=0
CRITICAL_ATTACKS=0
HIGH_ATTACKS=0
MEDIUM_ATTACKS=0

declare -A ATTACK_TYPES
declare -A TOP_ATTACKERS
declare -A SIGNATURE_HITS

# Progress indicator
show_progress() {
    local count=$1
    local total=$2
    local percent=$((count * 100 / total))
    echo -ne "\r${BLUE}[*]${NC} Processing: $count/$total lines ($percent%) "
}

# Start analysis
echo ""
echo -e "${BLUE}[*]${NC} Starting analysis (Threshold: $THRESHOLD)..."
echo ""

{
    # Write report header
    echo "================================================================================
"
    echo "HISTORICAL ATTACK ANALYSIS REPORT"
    echo "Generated: $(date)"
    echo "Period: Last $DAYS days"
    echo "Threshold: $THRESHOLD"
    echo "================================================================================
"
    echo ""

    # Analyze each log file
    for log_file in "${LOG_FILES[@]}"; do
        echo "[*] Analyzing: $log_file"

        # Handle compressed logs
        if [[ "$log_file" =~ \.gz$ ]]; then
            CAT_CMD="zcat"
        elif [[ "$log_file" =~ \.bz2$ ]]; then
            CAT_CMD="bzcat"
        else
            CAT_CMD="cat"
        fi

        local file_attacks=0
        local line_count=0

        while IFS= read -r line; do
            line_count=$((line_count + 1))
            TOTAL_LINES=$((TOTAL_LINES + 1))

            # Show progress every 1000 lines
            if [ $((line_count % 1000)) -eq 0 ]; then
                show_progress "$TOTAL_LINES" "unknown"
            fi

            # Analyze line
            local result=$(analyze_http_log_line "$line" 2>/dev/null)
            local threat_score="${result%%||*}"

            if [ "$threat_score" -ge "$THRESHOLD" ]; then
                local temp="${result#*||}"
                local attack_types="${temp%%||*}"
                temp="${temp#*||}"
                local signatures="${temp%%||*}"
                temp="${temp#*||}"
                local ip="${temp%%||*}"
                local uri="${temp#*||}"

                # Count attacks
                TOTAL_ATTACKS=$((TOTAL_ATTACKS + 1))
                file_attacks=$((file_attacks + 1))

                # Categorize by severity
                if [ "$threat_score" -ge 85 ]; then
                    CRITICAL_ATTACKS=$((CRITICAL_ATTACKS + 1))
                elif [ "$threat_score" -ge 70 ]; then
                    HIGH_ATTACKS=$((HIGH_ATTACKS + 1))
                elif [ "$threat_score" -ge 50 ]; then
                    MEDIUM_ATTACKS=$((MEDIUM_ATTACKS + 1))
                fi

                # Track attack types
                IFS=',' read -ra types <<< "$attack_types"
                for type in "${types[@]}"; do
                    ATTACK_TYPES["$type"]=$((${ATTACK_TYPES[$type]:-0} + 1))
                done

                # Track top attackers
                TOP_ATTACKERS["$ip"]=$((${TOP_ATTACKERS[$ip]:-0} + threat_score))

                # Track signatures
                IFS=',' read -ra sigs <<< "$signatures"
                for sig in "${sigs[@]}"; do
                    SIGNATURE_HITS["$sig"]=$((${SIGNATURE_HITS[$sig]:-0} + 1))
                done

                # Log if verbose or critical
                if [ "$VERBOSE" -eq 1 ] || [ "$threat_score" -ge 85 ]; then
                    echo "" >> "$OUTPUT_FILE"
                    echo "[Score: $threat_score] $ip → $attack_types" >> "$OUTPUT_FILE"
                    echo "  URI: ${uri:0:150}" >> "$OUTPUT_FILE"
                    echo "  Signatures: $signatures" >> "$OUTPUT_FILE"
                fi
            fi
        done < <($CAT_CMD "$log_file" 2>/dev/null)

        echo "  → Found $file_attacks attacks" >> "$OUTPUT_FILE"
    done

    echo "" >> "$OUTPUT_FILE"
    echo "================================================================================
" >> "$OUTPUT_FILE"
    echo "SUMMARY STATISTICS" >> "$OUTPUT_FILE"
    echo "================================================================================
" >> "$OUTPUT_FILE"
    echo "" >> "$OUTPUT_FILE"
    echo "Total lines processed: $TOTAL_LINES" >> "$OUTPUT_FILE"
    echo "Total attacks detected: $TOTAL_ATTACKS" >> "$OUTPUT_FILE"
    echo "  - Critical (≥85): $CRITICAL_ATTACKS" >> "$OUTPUT_FILE"
    echo "  - High (70-84): $HIGH_ATTACKS" >> "$OUTPUT_FILE"
    echo "  - Medium (50-69): $MEDIUM_ATTACKS" >> "$OUTPUT_FILE"
    echo "" >> "$OUTPUT_FILE"

    # Top Attack Types
    echo "Top Attack Types:" >> "$OUTPUT_FILE"
    for type in "${!ATTACK_TYPES[@]}"; do
        echo "$type:${ATTACK_TYPES[$type]}"
    done | sort -t: -k2 -nr | head -15 | while IFS=: read -r type count; do
        printf "  %-20s %5d attacks\n" "$type" "$count" >> "$OUTPUT_FILE"
    done
    echo "" >> "$OUTPUT_FILE"

    # Top Attackers
    echo "Top 20 Attacking IPs (by cumulative threat score):" >> "$OUTPUT_FILE"
    for ip in "${!TOP_ATTACKERS[@]}"; do
        echo "$ip:${TOP_ATTACKERS[$ip]}"
    done | sort -t: -k2 -nr | head -20 | while IFS=: read -r ip score; do
        printf "  %-15s  Score: %5d\n" "$ip" "$score" >> "$OUTPUT_FILE"
    done
    echo "" >> "$OUTPUT_FILE"

    # Top Signatures
    echo "Top 20 Triggered Signatures:" >> "$OUTPUT_FILE"
    for sig in "${!SIGNATURE_HITS[@]}"; do
        echo "$sig:${SIGNATURE_HITS[$sig]}"
    done | sort -t: -k2 -nr | head -20 | while IFS=: read -r sig count; do
        printf "  %-30s %5d hits\n" "$sig" "$count" >> "$OUTPUT_FILE"
    done
    echo "" >> "$OUTPUT_FILE"

    echo "================================================================================
" >> "$OUTPUT_FILE"
    echo "END OF REPORT" >> "$OUTPUT_FILE"
    echo "================================================================================
" >> "$OUTPUT_FILE"

} > "$OUTPUT_FILE"

# Clear progress line
echo -ne "\r\033[K"

# Display summary to terminal
echo ""
echo -e "${GREEN}✓${NC} Analysis complete!"
echo ""
echo "Summary:"
echo "  Lines processed:    $TOTAL_LINES"
echo "  Attacks detected:   $TOTAL_ATTACKS"
echo "    - Critical (≥85): $CRITICAL_ATTACKS"
echo "    - High (70-84):   $HIGH_ATTACKS"
echo "    - Medium (50-69): $MEDIUM_ATTACKS"
echo ""
echo -e "${GREEN}✓${NC} Full report saved to: $OUTPUT_FILE"
echo ""

# Offer to view report
read -p "View report now? [y/N]: " view_report
if [[ "$view_report" =~ ^[Yy]$ ]]; then
    less "$OUTPUT_FILE"
fi