# Team Tryouts - Production Nginx Configuration (Windows)
# 
# This configuration provides:
# - HTTP to HTTPS redirect
# - TLS 1.2/1.3 with strong ciphers
# - HSTS enforcement
# - Request size limits
# - gzip compression
# - Proxy to Waitress (Flask)
# - Security headers (reinforced at reverse proxy level)

worker_processes auto;

events {
    worker_connections 1024;
    multi_accept on;
}

http {
    # =========================================================================
    # Basic Settings
    # =========================================================================
    server_tokens off;                          # Hide Nginx version
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    client_max_body_size 16M;                   # Max upload size (matches Flask MAX_CONTENT_LENGTH)
    client_body_buffer_size 128k;
    client_header_buffer_size 1k;
    large_client_header_buffers 4 8k;

    include mime.types;
    default_type application/octet-stream;

    # =========================================================================
    # Logging
    # =========================================================================
    access_log logs/access.log;
    error_log logs/error.log warn;

    # =========================================================================
    # Gzip Compression
    # =========================================================================
    gzip on;
    gzip_vary on;
    gzip_proxied any;
    gzip_comp_level 6;
    gzip_min_length 256;
    gzip_types
        text/plain
        text/css
        text/xml
        text/javascript
        application/javascript
        application/json
        application/xml
        application/rss+xml
        image/svg+xml
        font/ttf
        font/otf;

    # =========================================================================
    # HTTP → HTTPS Redirect
    # =========================================================================
    server {
        listen 80;
        server_name _;
        
        # Redirect all HTTP traffic to HTTPS
        return 301 https://$host$request_uri;
    }

    # =========================================================================
    # HTTPS Server
    # =========================================================================
    server {
        listen 443 ssl http2;
        server_name _;

        # ---------------------------------------------------------------------
        # SSL/TLS Configuration
        # ---------------------------------------------------------------------
        # Paths to SSL certificate and key (update these for your deployment)
        ssl_certificate      C:/nginx/certs/fullchain.pem;
        ssl_certificate_key  C:/nginx/certs/privkey.pem;

        # Strong TLS configuration
        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 settings
        ssl_session_cache shared:SSL:10m;
        ssl_session_timeout 10m;
        ssl_session_tickets off;

        # OCSP Stapling (uncomment when running on a proper domain)
        # ssl_stapling on;
        # ssl_stapling_verify on;
        # ssl_trusted_certificate C:/nginx/certs/chain.pem;

        # Diffie-Hellman parameters (generate with: openssl dhparam -out dhparam.pem 2048)
        # ssl_dhparam C:/nginx/certs/dhparam.pem;

        # ---------------------------------------------------------------------
        # Security Headers (defense-in-depth with Flask's own headers)
        # ---------------------------------------------------------------------
        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;
        add_header X-Content-Type-Options "nosniff" always;
        add_header X-Frame-Options "DENY" always;
        # X-XSS-Protection intentionally omitted: deprecated, removed from
        # current browsers, and harmful in its last implementations.
        add_header Referrer-Policy "strict-origin-when-cross-origin" always;
        add_header Permissions-Policy "camera=(), microphone=(), geolocation=(), interest-cohort=()" always;
        add_header Cross-Origin-Opener-Policy "same-origin" always;

        # ---------------------------------------------------------------------
        # Proxy to Waitress (Flask)
        # ---------------------------------------------------------------------
        location / {
            proxy_pass http://127.0.0.1:5000;
            
            # 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 $host;
            proxy_set_header X-Forwarded-Port $server_port;

            # Timeouts
            proxy_connect_timeout 30s;
            proxy_send_timeout 30s;
            proxy_read_timeout 30s;

            # Buffer settings
            proxy_buffering on;
            proxy_buffer_size 4k;
            proxy_buffers 8 4k;
            proxy_busy_buffers_size 8k;
        }

        # ---------------------------------------------------------------------
        # Static Files (PERF-006)
        #
        # 59 KB of CSS and JS on every page load, previously proxied through
        # Waitress. Nginx serves them from disk instead.
        #
        # ADJUST THIS ONE PATH to the deployment's checkout, absolute, forward
        # slashes even on Windows. Nginx resolves a relative path against its
        # own install prefix, not against this file. The trailing slash on both
        # the location and the alias is required: without it /static/css/x.css
        # resolves one directory too high.
        #
        # `immutable` is safe here and only here: url_for('static', …) appends
        # ?v=<mtime> (see version_static_urls in app/app.py), so a deployed file
        # is requested under a new URL and the cached copy of the old one is
        # never asked for again. Removing that stamp and leaving this block
        # gives every visitor a month-old stylesheet.
        # ---------------------------------------------------------------------
        location /static/ {
            alias C:/team-tryouts/app/static/;
            expires 30d;
            access_log off;

            # These three are repeated on purpose. In nginx, add_header is
            # inherited from the enclosing block ONLY when the current block
            # declares none of its own — one add_header here silently drops
            # every security header set at server level. Dropping nosniff on
            # the JavaScript is the one that matters.
            add_header Cache-Control "public, immutable";
            add_header X-Content-Type-Options "nosniff" always;
            add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;

            # A missing static file must 404, not fall through to Flask: the
            # fallthrough would hide a broken deploy behind a working page.
            try_files $uri =404;
        }

        # ---------------------------------------------------------------------
        # Rate Limiting
        # ---------------------------------------------------------------------
        # Define rate limit zones (uncomment when rate limiting at Nginx level)
        # limit_req_zone $binary_remote_addr zone=login:10m rate=5r/m;
        # limit_req_zone $binary_remote_addr zone=global:10m rate=100r/m;

        # location /auth/login {
        #     limit_req zone=login burst=5 nodelay;
        #     proxy_pass http://127.0.0.1:5000;
        # }
    }
}