# ─────────────────────────────────────────────────────────────────
# Nginx config for PaperPhone — serves PWA + reverse-proxy to API
#
# This file is an envsubst template.  At container start the
# Dockerfile CMD substitutes ${SERVER_URL} and writes the final
# config to /etc/nginx/conf.d/paperphone.conf.
#
# Docker Compose:  SERVER_URL = http://server:3000
# Zeabur:          SERVER_URL = ${ZEABUR_WEB_URL}  (e.g. http://10.43.x.x:3000)
# ─────────────────────────────────────────────────────────────────

server {
    listen 80;
    server_name _;

    root /usr/share/nginx/html;
    index index.html;

    # ── Compression ──────────────────────────────────────────────
    gzip on;
    gzip_types text/plain text/css application/javascript application/json application/wasm;
    gzip_min_length 1024;
    gzip_vary on;

    # ── Security headers ─────────────────────────────────────────
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-Frame-Options "DENY" always;
    add_header Referrer-Policy "no-referrer" always;

    # ── Static asset caching ─────────────────────────────────────
    location ~* \.(css|js|wasm|png|jpg|webp|ico|svg|woff2?)$ {
        expires 7d;
        add_header Cache-Control "public, max-age=604800, immutable";
    }

    # Service worker — always revalidate so updates propagate
    location = /sw.js {
        add_header Cache-Control "no-cache, no-store, must-revalidate";
        expires 0;
    }

    # ── WebSocket — proxy to backend ─────────────────────────────
    location /ws {
        proxy_pass         ${SERVER_URL};
        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_read_timeout 3600s;
        proxy_send_timeout 3600s;
    }

    # ── REST API — proxy to backend ──────────────────────────────
    location /api/ {
        proxy_pass         ${SERVER_URL};
        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;
        client_max_body_size 51m;

        # Long-poll & upload timeout
        proxy_read_timeout 120s;
        proxy_send_timeout 120s;
    }

    # ── Health check (forwarded to backend) ──────────────────────
    location /health {
        proxy_pass ${SERVER_URL};
    }

    # ── SPA fallback ─────────────────────────────────────────────
    location / {
        try_files $uri $uri/ /index.html;
    }
}