# SOCAR AI System - Production Nginx Configuration with SSL/TLS
# This configuration provides SSL termination and reverse proxy for production

upstream socar_backend {
    server socar-ai-system:8000;
    keepalive 32;
}

# Redirect HTTP to HTTPS
server {
    listen 80;
    listen [::]:80;
    server_name _;

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

    # Redirect all other traffic to HTTPS
    location / {
        return 301 https://$host$request_uri;
    }
}

# HTTPS server block
server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    server_name _;

    # SSL Certificate Configuration
    # For production: Use Let's Encrypt or your CA certificates
    ssl_certificate /etc/nginx/ssl/fullchain.pem;
    ssl_certificate_key /etc/nginx/ssl/privkey.pem;

    # SSL Configuration - Modern settings for security
    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:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384;
    ssl_prefer_server_ciphers off;

    # SSL Session settings
    ssl_session_timeout 1d;
    ssl_session_cache shared:SSL:50m;
    ssl_session_tickets off;

    # OCSP Stapling
    ssl_stapling on;
    ssl_stapling_verify on;
    resolver 8.8.8.8 8.8.4.4 valid=300s;
    resolver_timeout 5s;

    # 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' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self' data:; connect-src 'self' https:;" always;

    # Logging
    access_log /var/log/nginx/socar_access.log;
    error_log /var/log/nginx/socar_error.log;

    # Client settings
    client_max_body_size 100M;
    client_body_buffer_size 10M;

    # Proxy settings for API
    location / {
        proxy_pass http://socar_backend;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header 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_set_header X-Forwarded-Host $host;
        proxy_set_header X-Forwarded-Port $server_port;
        proxy_cache_bypass $http_upgrade;

        # Timeouts for long-running LLM requests
        proxy_connect_timeout 60s;
        proxy_send_timeout 120s;
        proxy_read_timeout 120s;
    }

    # Static files with caching
    location /static/ {
        proxy_pass http://socar_backend;
        proxy_cache_valid 200 1d;
        add_header Cache-Control "public, max-age=86400";
    }

    # Health check endpoint (no caching)
    location /health {
        proxy_pass http://socar_backend;
        proxy_cache_bypass 1;
        add_header Cache-Control "no-cache, no-store, must-revalidate";
    }
}