# =============================================================
# nginx.conf — Reverse Proxy + SSL untuk System PT. Altrak 1978
# =============================================================
# Instruksi SSL dengan Let's Encrypt:
#   sudo apt install certbot python3-certbot-nginx
#   sudo certbot --nginx -d yourdomain.com
# =============================================================

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

events {
    worker_connections 1024;
    use epoll;
    multi_accept on;
}

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

    # ── Logging ───────────────────────────────────────────────
    log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                    '$status $body_bytes_sent "$http_referer" '
                    '"$http_user_agent" "$http_x_forwarded_for"';
    access_log /var/log/nginx/access.log main;

    # ── Performance ───────────────────────────────────────────
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    server_tokens off;                       # Sembunyikan versi Nginx

    # ── Gzip Compression ──────────────────────────────────────
    gzip on;
    gzip_vary on;
    gzip_proxied any;
    gzip_comp_level 6;
    gzip_types
        text/plain
        text/css
        text/javascript
        application/javascript
        application/json
        application/xml
        image/svg+xml;

    # ── Rate Limiting ─────────────────────────────────────────
    # Limit login endpoint: 10 request/menit per IP
    limit_req_zone $binary_remote_addr zone=login_limit:10m rate=10r/m;
    # Limit API umum: 100 request/menit per IP
    limit_req_zone $binary_remote_addr zone=api_limit:10m rate=100r/m;

    # ── Upstream (Go Backend) ─────────────────────────────────
    upstream altrak_backend {
        server app:8080;           # Nama service Docker
        keepalive 32;
    }

    # ── HTTP → HTTPS Redirect ─────────────────────────────────
    server {
        listen 80;
        server_name _;             # Ganti dengan domain Anda: yourdomain.com

        # Izinkan Let's Encrypt challenge
        location /.well-known/acme-challenge/ {
            root /var/www/certbot;
        }

        # Redirect semua HTTP ke HTTPS
        location / {
            return 301 https://$host$request_uri;
        }
    }

    # ── HTTPS Server ──────────────────────────────────────────
    server {
        listen 443 ssl http2;
        server_name _;             # Ganti dengan domain Anda: yourdomain.com

        # ── SSL Configuration ─────────────────────────────────
        # Ganti path ini dengan sertifikat Anda dari Let's Encrypt:
        ssl_certificate     /etc/nginx/ssl/fullchain.pem;
        ssl_certificate_key /etc/nginx/ssl/privkey.pem;

        # SSL hardening (score A+ di SSLLabs)
        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;
        ssl_prefer_server_ciphers off;
        ssl_session_cache shared:SSL:10m;
        ssl_session_timeout 1d;
        ssl_session_tickets off;
        ssl_stapling on;
        ssl_stapling_verify on;

        # ── Security Headers ──────────────────────────────────
        add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload" always;
        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;
        add_header Permissions-Policy "camera=(), microphone=(), geolocation=()" always;

        # ── Upload Size Limit ─────────────────────────────────
        client_max_body_size 100M;           # Match dengan Go Fiber BodyLimit

        # ── Proxy ke Go Backend ───────────────────────────────
        location / {
            proxy_pass http://altrak_backend;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";   # WebSocket support
            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_cache_bypass $http_upgrade;

            # Timeout sesuai dengan Go Fiber config
            proxy_connect_timeout 60s;
            proxy_send_timeout 60s;
            proxy_read_timeout 60s;

            # Rate limit API umum
            limit_req zone=api_limit burst=20 nodelay;
        }

        # ── Rate Limit Ketat untuk Login ──────────────────────
        location /api/login {
            proxy_pass http://altrak_backend;
            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;

            limit_req zone=login_limit burst=5 nodelay;
            limit_req_status 429;
        }

        # ── WebSocket ─────────────────────────────────────────
        location /ws {
            proxy_pass http://altrak_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_read_timeout 3600s;        # WebSocket butuh timeout panjang
            proxy_send_timeout 3600s;
        }
    }
}