#
# NODE1 Hardened Nginx Configuration v3
# Version: 3.0
# Last Updated: 2026-01-26
#
# v3 Features:
# - /health protected (allowlist + token)
# - Auth-gate for /v1/* endpoints
# - Nginx metrics endpoint for Prometheus
# - Enhanced WAF rules
# - Fail2ban integration ready
#

# === Rate Limit Zones ===
limit_req_zone $binary_remote_addr zone=api_per_ip:10m rate=10r/s;
limit_req_zone $binary_remote_addr zone=heavy_per_ip:10m rate=2r/s;
limit_req_zone $binary_remote_addr zone=webhook_per_ip:10m rate=50r/s;
limit_req_zone $binary_remote_addr zone=auth_fail:10m rate=5r/s;
limit_conn_zone $binary_remote_addr zone=conn_per_ip:10m;

# === Auth token (change this!) ===
# Generate: openssl rand -hex 32
map $http_x_health_token $health_token_valid {
    default 0;
    "dg-health-2026-secret-change-me" 1;
}

# API Key validation map
map $http_authorization $api_key_valid {
    default 0;
    "~^Bearer\s+sk-[a-zA-Z0-9]{32,}$" 1;
}

map $http_x_api_key $x_api_key_valid {
    default 0;
    "~^sk-[a-zA-Z0-9]{32,}$" 1;
}

# === Logging format (no auth headers, fail2ban ready) ===
log_format api_safe '$remote_addr - $remote_user [$time_local] '
                    '"$request" $status $body_bytes_sent '
                    '"$http_referer" "$http_user_agent" '
                    'rt=$request_time';

log_format fail2ban '$remote_addr - [$time_local] "$request" $status';

# === Upstream ===
upstream gateway_upstream {
    server 127.0.0.1:9300;
    keepalive 64;
}

# === HTTP → HTTPS redirect ===
server {
    listen 80;
    listen [::]:80;
    server_name gateway.daarion.city api.daarion.io 144.76.224.179 _;
    
    location /.well-known/acme-challenge/ {
        root /var/www/html;
    }
    
    location / {
        return 301 https://$host$request_uri;
    }
}

# === Main HTTPS Server ===
server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    server_name gateway.daarion.city api.daarion.io 144.76.224.179;
    
    # === SSL Configuration ===
    ssl_certificate /etc/letsencrypt/live/gateway.daarion.city/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/gateway.daarion.city/privkey.pem;
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305;
    ssl_prefer_server_ciphers off;
    ssl_session_timeout 1d;
    ssl_session_cache shared:SSL:50m;
    ssl_session_tickets off;
    
    # === Security Headers ===
    add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload" always;
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-XSS-Protection "1; mode=block" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self'; connect-src 'self' wss: https:;" always;
    
    # === Logging ===
    access_log /var/log/nginx/api-access.log api_safe;
    access_log /var/log/nginx/fail2ban.log fail2ban;
    error_log /var/log/nginx/api-error.log warn;
    
    # === WAF-lite: Block sensitive files ===
    location ~* \.(env|git|sql|bak|swp|old|backup|log|ini|conf|config|yml|yaml|json|xml|db|sqlite|pem|key)$ {
        access_log /var/log/nginx/waf-blocks.log fail2ban;
        return 444;
    }
    
    location ~* ^/(\.git|\.svn|\.hg|\.env|wp-admin|wp-login|phpmyadmin|admin\.php|xmlrpc\.php|\.aws|\.docker) {
        access_log /var/log/nginx/waf-blocks.log fail2ban;
        return 444;
    }
    
    # Block SQL injection attempts
    if ($query_string ~* "(union|select|insert|drop|delete|update|truncate|exec|script|alert|eval|base64)") {
        return 403;
    }
    
    # Block suspicious user agents
    if ($http_user_agent ~* (sqlmap|nikto|nmap|masscan|zgrab|python-requests/2\.[0-9]+\.[0-9]+$)) {
        return 444;
    }
    
    # === Nginx metrics (internal only) ===
    location = /nginx-status {
        stub_status on;
        allow 127.0.0.1;
        allow 10.42.0.0/16;  # K8s pod network
        allow 10.43.0.0/16;  # K8s service network
        deny all;
    }
    
    # === Health check (protected) ===
    location = /health {
        # Allow localhost
        set $health_allowed 0;
        if ($remote_addr = "127.0.0.1") {
            set $health_allowed 1;
        }
        # Allow with valid token
        if ($health_token_valid = 1) {
            set $health_allowed 1;
        }
        # Allow internal networks (Prometheus, K8s)
        if ($remote_addr ~ "^(10\.(42|43)\.|172\.(1[6-9]|2[0-9]|3[01])\.|192\.168\.)") {
            set $health_allowed 1;
        }
        
        if ($health_allowed = 0) {
            return 401;
        }
        
        proxy_pass http://gateway_upstream/health;
        proxy_http_version 1.1;
        proxy_set_header Connection "";
    }
    
    # === Public health (limited info) ===
    location = /ping {
        default_type application/json;
        return 200 '{"status":"ok"}';
    }
    
    # === Webhook endpoints (Telegram, etc.) - no auth ===
    location ~ ^/(webhook|telegram|bot[0-9]+) {
        limit_req zone=webhook_per_ip burst=100 nodelay;
        limit_conn conn_per_ip 50;
        
        proxy_pass http://gateway_upstream;
        proxy_http_version 1.1;
        proxy_set_header Connection "";
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        
        proxy_connect_timeout 5s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;
        
        client_max_body_size 10m;
    }
    
    # === API v1 endpoints (require auth) ===
    location ~ ^/v1/ {
        # Check for valid API key
        set $auth_valid 0;
        if ($api_key_valid = 1) {
            set $auth_valid 1;
        }
        if ($x_api_key_valid = 1) {
            set $auth_valid 1;
        }
        # Allow internal networks (service-to-service)
        if ($remote_addr ~ "^(127\.0\.0\.1|10\.(42|43)\.|172\.(1[6-9]|2[0-9]|3[01])\.)") {
            set $auth_valid 1;
        }
        
        if ($auth_valid = 0) {
            access_log /var/log/nginx/auth-fails.log fail2ban;
            return 401 '{"error":"unauthorized","message":"Valid API key required"}';
        }
        
        limit_req zone=heavy_per_ip burst=5 nodelay;
        limit_conn conn_per_ip 10;
        
        proxy_pass http://gateway_upstream;
        proxy_http_version 1.1;
        proxy_set_header Connection "";
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        
        proxy_connect_timeout 10s;
        proxy_send_timeout 300s;
        proxy_read_timeout 300s;
        
        client_max_body_size 100m;
    }
    
    # === Root / docs / public (rate limited) ===
    location / {
        limit_req zone=api_per_ip burst=20 nodelay;
        limit_conn conn_per_ip 20;
        
        proxy_pass http://gateway_upstream;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        
        proxy_connect_timeout 5s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        proxy_cache_bypass $http_upgrade;
        
        client_max_body_size 10m;
    }
    
    # === Error pages ===
    error_page 401 = @unauthorized;
    location @unauthorized {
        default_type application/json;
        return 401 '{"error":"unauthorized","message":"Authentication required"}';
    }
    
    error_page 429 = @rate_limited;
    location @rate_limited {
        default_type application/json;
        return 429 '{"error":"rate_limit_exceeded","message":"Too many requests","retry_after":1}';
    }
    
    error_page 403 = @forbidden;
    location @forbidden {
        default_type application/json;
        return 403 '{"error":"forbidden","message":"Access denied"}';
    }
}

# === WebSocket upgrade mapping ===
map $http_upgrade $connection_upgrade {
    default upgrade;
    '' close;
}

# === Admin Panel (localhost only) ===
server {
    listen 127.0.0.1:8080;
    server_name localhost;
    
    location /grafana/ {
        proxy_pass http://127.0.0.1:3030/;
        proxy_http_version 1.1;
        proxy_set_header Host $host;
    }
    
    location /prometheus/ {
        proxy_pass http://127.0.0.1:9090/;
        proxy_http_version 1.1;
        proxy_set_header Host $host;
    }
    
    location /nginx-metrics {
        stub_status on;
    }
}