# Pad — nginx reverse proxy
#
# Usage:
#   1. Replace "pad.example.com" with your domain
#   2. Update ssl_certificate paths to your TLS certs
#   3. Include this file in your nginx config or copy to /etc/nginx/conf.d/
#
# Key settings for SSE support:
#   - proxy_buffering off
#   - proxy_read_timeout 86400s (24h for long-lived SSE connections)
#   - proxy_http_version 1.1 with Connection ""

upstream pad_backend {
    server 127.0.0.1:7777;
    # For Docker: server pad:7777;
    keepalive 32;
}

server {
    listen 80;
    server_name pad.example.com;
    return 301 https://$host$request_uri;
}

server {
    listen 443 ssl http2;
    server_name pad.example.com;

    ssl_certificate     /etc/ssl/certs/pad.example.com.pem;
    ssl_certificate_key /etc/ssl/private/pad.example.com-key.pem;

    # Modern TLS settings
    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;
    ssl_prefer_server_ciphers off;

    # Security headers
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;

    # Gzip
    gzip on;
    gzip_types text/plain application/json text/css application/javascript;

    # SSE endpoint — requires special proxy settings
    location /api/v1/events {
        proxy_pass http://pad_backend;
        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;

        # Critical for SSE:
        proxy_buffering off;
        proxy_cache off;
        proxy_read_timeout 86400s;
        proxy_send_timeout 86400s;
        chunked_transfer_encoding on;
    }

    # WebSocket endpoint for Yjs collaborative editing (PLAN-1248).
    # Differs from SSE in needing the Upgrade/Connection headers
    # forwarded so nginx negotiates the protocol switch — the default
    # `/` block clears Connection ("") and would prevent the upgrade.
    location /api/v1/collab/ {
        proxy_pass http://pad_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;

        # Long-lived WebSocket — same 24h budget as SSE so an idle
        # editor tab does not get cut off mid-session.
        proxy_buffering off;
        proxy_cache off;
        proxy_read_timeout 86400s;
        proxy_send_timeout 86400s;
    }

    # All other routes
    location / {
        proxy_pass http://pad_backend;
        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_buffering off;
        proxy_read_timeout 60s;

        # File uploads
        client_max_body_size 10M;
    }

    access_log /var/log/nginx/pad-access.log;
    error_log  /var/log/nginx/pad-error.log;
}