# ─────────────────────────────────────────────────────────────────────────────
#  REBOUR — nginx.conf
#  Rôle : reverse proxy devant Elysia/Bun
#  SEO  : pas de SSR → HTML statique pré-rendu, on optimise le delivery
#         (gzip, cache, headers) et la crawlabilité
# ─────────────────────────────────────────────────────────────────────────────

user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log warn;
pid       /var/run/nginx.pid;

events {
    worker_connections 1024;
    use epoll;
}

http {
    include      /etc/nginx/mime.types;
    default_type application/octet-stream;

    log_format main '$remote_addr "$request" $status $body_bytes_sent '
                    '"$http_referer" "$http_user_agent" ${request_time}s';
    access_log /var/log/nginx/access.log main;

    sendfile           on;
    tcp_nopush         on;
    tcp_nodelay        on;
    keepalive_timeout  65;
    server_tokens      off;

    # ── Gzip : réduit poids HTML/CSS/JS → Core Web Vitals ───────────────────
    gzip              on;
    gzip_vary         on;
    gzip_proxied      any;
    gzip_comp_level   5;
    gzip_min_length   256;
    gzip_types
        text/plain text/css text/javascript text/xml
        application/javascript application/json application/xml
        image/svg+xml font/woff2;

    # ── Rate limiting ────────────────────────────────────────────────────────
    limit_req_zone $binary_remote_addr zone=api:10m     rate=10r/m;
    limit_req_zone $binary_remote_addr zone=general:10m rate=60r/s;

    # ── Resolver DNS Docker ───────────────────────────────────────────────────
    # 127.0.0.11 = resolver interne Docker. La résolution dynamique via variable
    # $backend évite le crash "host not found in upstream" au démarrage nginx
    # si le container "app" n'est pas encore prêt (upstream statique résout au
    # boot, pas à la requête — d'où le crash).
    resolver 127.0.0.11 valid=5s ipv6=off;

    # Variable résolue dynamiquement à chaque requête (pas au démarrage nginx)
    # Permet à nginx de démarrer même si "app" n'existe pas encore en DNS.
    map $host $elysia_backend {
        default "http://app:3000";
    }

    # ── Redirection HTTP → HTTPS (décommenter en prod) ──────────────────────
    # server {
    #     listen 80;
    #     server_name rebour.studio www.rebour.studio;
    #     return 301 https://rebour.studio$request_uri;
    # }

    server {
        listen 80;
        server_name _;

        # ── SSL / prod (décommenter avec Certbot) ────────────────────────────
        # listen 443 ssl http2;
        # ssl_certificate     /etc/letsencrypt/live/rebour.studio/fullchain.pem;
        # ssl_certificate_key /etc/letsencrypt/live/rebour.studio/privkey.pem;
        # ssl_protocols       TLSv1.2 TLSv1.3;
        # ssl_session_cache   shared:SSL:10m;

        # ── Headers sécurité ────────────────────────────────────────────────
        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;
        add_header Permissions-Policy     "camera=(), microphone=()"         always;
        # HSTS — décommenter en prod UNIQUEMENT après config SSL
        # add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload" always;

        # ── Images / fonts : cache 1 an immutable ───────────────────────────
        # Les crawlers sociaux (og:image) et Google téléchargent ces fichiers
        location ~* \.(jpg|jpeg|png|webp|svg|ico|woff2)$ {
            proxy_pass       $elysia_backend;
            proxy_set_header Host              $host;
            proxy_set_header X-Forwarded-Proto $scheme;
            add_header       Cache-Control "public, max-age=31536000, immutable";
            add_header       Vary "Accept-Encoding";
        }

        # ── CSS / JS : cache 1 an ────────────────────────────────────────────
        location ~* \.(css|js)$ {
            proxy_pass       $elysia_backend;
            proxy_set_header Host              $host;
            proxy_set_header X-Forwarded-Proto $scheme;
            add_header       Cache-Control "public, max-age=31536000, immutable";
            add_header       Vary "Accept-Encoding";
        }

        # ── Checkout Stripe : rate-limit strict, no-cache ───────────────────
        location = /api/checkout {
            limit_req        zone=api burst=3 nodelay;
            proxy_pass       $elysia_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;
            add_header       Cache-Control "no-store";
        }

        # ── Webhook Stripe : body raw, pas de buffering ──────────────────────
        location = /api/webhook {
            proxy_pass              $elysia_backend;
            proxy_http_version      1.1;
            proxy_set_header        Host              $host;
            proxy_set_header        X-Real-IP         $remote_addr;
            proxy_set_header        X-Forwarded-Proto $scheme;
            proxy_set_header        stripe-signature  $http_stripe_signature;
            proxy_request_buffering off;
            add_header              Cache-Control "no-store";
        }

        # ── API (session verify, etc.) ───────────────────────────────────────
        location /api/ {
            limit_req        zone=api burst=10 nodelay;
            proxy_pass       $elysia_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-Proto $scheme;
            add_header       Cache-Control "no-store";
        }

        # ── SEO : sitemap + robots ───────────────────────────────────────────
        location ~* ^/(sitemap\.xml|robots\.txt)$ {
            proxy_pass       $elysia_backend;
            proxy_set_header Host              $host;
            proxy_set_header X-Forwarded-Proto $scheme;
            add_header       Cache-Control "public, max-age=86400";
        }

        # ── Pages HTML ───────────────────────────────────────────────────────
        # Cache 1h côté client, stale-while-revalidate pour UX fluide
        # Google re-crawle dès que le cache expire → pas de contenu périmé indexé
        location / {
            limit_req        zone=general burst=20 nodelay;
            proxy_pass       $elysia_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;
            add_header       Cache-Control "public, max-age=3600, stale-while-revalidate=86400";
        }
    }
}