# Nginx-Konfiguration für TimeClock v3
# Datei speichern unter: /etc/nginx/sites-available/stechuhr3.tsschulz.de
#
# Installation:
# sudo cp nginx.conf /etc/nginx/sites-available/stechuhr3.tsschulz.de
# sudo ln -s /etc/nginx/sites-available/stechuhr3.tsschulz.de /etc/nginx/sites-enabled/
# sudo nginx -t
# sudo systemctl reload nginx

# HTTP Server - Redirect zu HTTPS
server {
    listen 80;
    listen [::]:80;
    server_name stechuhr3.tsschulz.de;

    # Let's Encrypt ACME Challenge
    location /.well-known/acme-challenge/ {
        root /var/www/certbot;
    }

    # Alle anderen Requests zu HTTPS umleiten
    location / {
        return 301 https://$server_name$request_uri;
    }
}

# HTTPS Server - Hauptkonfiguration
server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    server_name stechuhr3.tsschulz.de;

    # =================================================================
    # SSL-Konfiguration (wird von Certbot automatisch verwaltet)
    # =================================================================
    ssl_certificate /etc/letsencrypt/live/stechuhr3.tsschulz.de/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/stechuhr3.tsschulz.de/privkey.pem;
    
    # SSL-Protokolle und Ciphers
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_prefer_server_ciphers on;
    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:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384';
    
    # SSL-Session-Cache
    ssl_session_cache shared:SSL:10m;
    ssl_session_timeout 10m;
    ssl_session_tickets off;

    # OCSP Stapling
    ssl_stapling on;
    ssl_stapling_verify on;
    ssl_trusted_certificate /etc/letsencrypt/live/stechuhr3.tsschulz.de/chain.pem;
    resolver 8.8.8.8 8.8.4.4 valid=300s;
    resolver_timeout 5s;

    # =================================================================
    # Frontend (Vue.js SPA)
    # =================================================================
    root /var/www/timeclock/frontend/dist;
    index index.html;

    # =================================================================
    # Logging
    # =================================================================
    access_log /var/log/nginx/stechuhr3.access.log;
    error_log /var/log/nginx/stechuhr3.error.log warn;

    # =================================================================
    # Gzip Compression
    # =================================================================
    gzip on;
    gzip_vary on;
    gzip_proxied any;
    gzip_comp_level 6;
    gzip_min_length 1024;
    gzip_types
        text/plain
        text/css
        text/xml
        text/javascript
        application/javascript
        application/x-javascript
        application/json
        application/xml
        application/xml+rss
        application/rss+xml
        application/atom+xml
        image/svg+xml
        font/ttf
        font/woff
        font/woff2;

    # =================================================================
    # Security Headers
    # =================================================================
    # X-Frame-Options: Schutz vor Clickjacking
    add_header X-Frame-Options "SAMEORIGIN" always;
    
    # X-Content-Type-Options: Verhindert MIME-Type Sniffing
    add_header X-Content-Type-Options "nosniff" always;
    
    # X-XSS-Protection: XSS-Schutz für ältere Browser
    add_header X-XSS-Protection "1; mode=block" always;
    
    # Referrer-Policy: Kontrolliert Referrer-Informationen
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    
    # Permissions-Policy: Kontrolliert Browser-Features
    add_header Permissions-Policy "geolocation=(), microphone=(), camera=()" always;
    
    # Content-Security-Policy (angepasst für Vue.js)
    # Kann bei Bedarf verschärft werden
    add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self' data:; connect-src 'self' https://stechuhr3.tsschulz.de;" always;
    
    # Strict-Transport-Security (HSTS)
    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;

    # =================================================================
    # API Reverse Proxy zum Backend
    # =================================================================
    location /api {
        # Proxy Pass zum Backend auf localhost:3010
        proxy_pass http://localhost:3010;
        
        # HTTP Version
        proxy_http_version 1.1;
        
        # WebSocket Support (falls später benötigt)
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        
        # Standard Proxy Headers
        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_set_header X-Forwarded-Host $server_name;
        
        # Cache Bypass
        proxy_cache_bypass $http_upgrade;
        
        # Timeouts
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
        
        # Buffer-Einstellungen
        proxy_buffering on;
        proxy_buffer_size 4k;
        proxy_buffers 8 4k;
        proxy_busy_buffers_size 8k;
        
        # Fehlerbehandlung
        proxy_next_upstream error timeout invalid_header http_500 http_502 http_503;
        proxy_next_upstream_tries 2;
    }

    # =================================================================
    # Statische Assets mit langem Cache
    # =================================================================
    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|webp|avif)$ {
        expires 1y;
        add_header Cache-Control "public, immutable";
        access_log off;
    }

    # Font-Dateien mit langem Cache
    location ~* \.(woff|woff2|ttf|eot)$ {
        expires 1y;
        add_header Cache-Control "public, immutable";
        add_header Access-Control-Allow-Origin "*";
        access_log off;
    }

    # =================================================================
    # SPA Fallback - alle anderen Requests zu index.html
    # =================================================================
    location / {
        try_files $uri $uri/ /index.html;
        
        # Cache-Control für HTML-Dateien (kein Cache)
        add_header Cache-Control "no-cache, no-store, must-revalidate";
        add_header Pragma "no-cache";
        add_header Expires "0";
    }

    # =================================================================
    # Spezielle Dateien
    # =================================================================
    # robots.txt und sitemap.xml
    location ~* ^/(robots\.txt|sitemap\.xml)$ {
        root /var/www/timeclock/frontend/dist;
        access_log off;
    }

    # favicon.ico
    location = /favicon.ico {
        root /var/www/timeclock/frontend/dist;
        access_log off;
        log_not_found off;
    }

    # =================================================================
    # Sicherheit: Verstecke sensible Dateien
    # =================================================================
    # Blockiere Zugriff auf .git, .env, etc.
    location ~ /\. {
        deny all;
        access_log off;
        log_not_found off;
    }

    # Blockiere Zugriff auf Backup-Dateien
    location ~ ~$ {
        deny all;
        access_log off;
        log_not_found off;
    }

    # =================================================================
    # Limits und Rate Limiting (optional)
    # =================================================================
    # Client Body Size Limit (z.B. für File-Uploads)
    client_max_body_size 10M;
    
    # Client Body Timeout
    client_body_timeout 30s;
    
    # Client Header Timeout
    client_header_timeout 30s;
    
    # Send Timeout
    send_timeout 30s;

    # Rate Limiting für API (optional)
    # Kommentare entfernen und in nginx.conf http-Block hinzufügen:
    # limit_req_zone $binary_remote_addr zone=api_limit:10m rate=10r/s;
    # location /api {
    #     limit_req zone=api_limit burst=20 nodelay;
    #     ... rest der Konfiguration
    # }
}

# =================================================================
# OPTIONAL: Rate Limiting Zone (in /etc/nginx/nginx.conf http-Block)
# =================================================================
# Uncomment und in die Haupt-nginx.conf einfügen, falls gewünscht:
#
# http {
#     ...
#     
#     # Rate Limiting Zones
#     limit_req_zone $binary_remote_addr zone=general_limit:10m rate=30r/s;
#     limit_req_zone $binary_remote_addr zone=api_limit:10m rate=10r/s;
#     limit_req_zone $binary_remote_addr zone=login_limit:10m rate=5r/m;
#     
#     # Connection Limiting
#     limit_conn_zone $binary_remote_addr zone=conn_limit:10m;
#     
#     ...
# }