# Cashumints.space API - Nginx Configuration
#
# Installation:
#   sudo cp deploy/nginx.conf /etc/nginx/sites-available/cashumints-api
#   sudo ln -s /etc/nginx/sites-available/cashumints-api /etc/nginx/sites-enabled/
#   sudo nginx -t
#   sudo systemctl reload nginx
#
# SSL Certificate (Let's Encrypt):
#   sudo certbot --nginx -d api.cashumints.space

# Rate limiting zones
limit_req_zone $binary_remote_addr zone=api_limit:10m rate=30r/s;
limit_req_zone $binary_remote_addr zone=admin_limit:10m rate=5r/s;
limit_conn_zone $binary_remote_addr zone=conn_limit:10m;

# Upstream API server
upstream cashumints_api {
    server 127.0.0.1:3000;
    keepalive 32;
}

# Redirect HTTP to HTTPS
server {
    listen 80;
    listen [::]:80;
    server_name api.cashumints.space;

    location /.well-known/acme-challenge/ {
        root /var/www/certbot;
    }

    location / {
        return 301 https://$server_name$request_uri;
    }
}

# Main HTTPS server
server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    server_name api.cashumints.space;

    # SSL Configuration
    ssl_certificate /etc/letsencrypt/live/api.cashumints.space/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/api.cashumints.space/privkey.pem;
    ssl_session_timeout 1d;
    ssl_session_cache shared:SSL:50m;
    ssl_session_tickets off;

    # Modern SSL configuration
    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;

    # HSTS
    add_header Strict-Transport-Security "max-age=63072000" always;

    # Security headers
    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;

    # Logging
    access_log /var/log/nginx/cashumints-api.access.log;
    error_log /var/log/nginx/cashumints-api.error.log;

    # Connection limits
    limit_conn conn_limit 20;

    # Gzip compression
    gzip on;
    gzip_vary on;
    gzip_proxied any;
    gzip_comp_level 6;
    gzip_types application/json application/javascript text/plain text/css text/xml;

    # Client settings
    client_max_body_size 1m;
    client_body_timeout 10s;
    client_header_timeout 10s;

    # Proxy settings
    proxy_http_version 1.1;
    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 Connection "";
    proxy_connect_timeout 5s;
    proxy_send_timeout 60s;
    proxy_read_timeout 60s;
    proxy_buffering on;
    proxy_buffer_size 4k;
    proxy_buffers 8 4k;

    # Health check (no rate limit)
    location = /v1/health {
        proxy_pass http://cashumints_api;
        proxy_cache_bypass 1;
    }

    # Swagger documentation (relaxed rate limit)
    location /docs {
        limit_req zone=api_limit burst=10 nodelay;
        proxy_pass http://cashumints_api;
    }

    location = /openapi.json {
        limit_req zone=api_limit burst=10 nodelay;
        proxy_pass http://cashumints_api;
        # Cache OpenAPI spec
        proxy_cache_valid 200 5m;
    }

    # Admin endpoints (strict rate limit)
    location /v1/admin {
        limit_req zone=admin_limit burst=5 nodelay;
        proxy_pass http://cashumints_api;

        # Only allow from specific IPs (optional)
        # allow 10.0.0.0/8;
        # allow 192.168.0.0/16;
        # deny all;
    }

    # API endpoints
    location /v1 {
        limit_req zone=api_limit burst=50 nodelay;
        proxy_pass http://cashumints_api;

        # Cache GET requests for 10 seconds
        proxy_cache_valid 200 10s;
    }

    # Root and favicon
    location = / {
        proxy_pass http://cashumints_api;
    }

    location = /favicon.ico {
        return 204;
        access_log off;
    }

    # Block common attack vectors
    location ~ /\. {
        deny all;
        access_log off;
        log_not_found off;
    }

    location ~* \.(git|env|sql|bak|old|tmp)$ {
        deny all;
        access_log off;
        log_not_found off;
    }
}