# Upstream backend service
upstream backend {
    server backend:8000;
    keepalive 32;
}

# HTTP server - redirect to HTTPS
server {
    listen 80;
    listen [::]:80;
    server_name getmaplepress.ca www.getmaplepress.ca;

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

    # Health check endpoint (for load balancer)
    location /health {
        access_log off;
        return 200 "healthy\n";
        add_header Content-Type text/plain;
    }

    # Redirect all other HTTP traffic to HTTPS
    location / {
        return 301 https://$host$request_uri;
    }
}

# HTTPS server
server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    server_name getmaplepress.ca www.getmaplepress.ca;

    # SSL certificates (Let's Encrypt)
    ssl_certificate /etc/letsencrypt/live/getmaplepress.ca/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/getmaplepress.ca/privkey.pem;

    # SSL configuration (Mozilla Intermediate)
    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;
    ssl_session_cache shared:SSL:10m;
    ssl_session_timeout 10m;
    ssl_stapling on;
    ssl_stapling_verify on;

    # Security headers
    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" 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;

    # Logging
    access_log /var/log/nginx/access.log main;
    error_log /var/log/nginx/error.log warn;

    # Proxy settings
    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;
    proxy_set_header X-Forwarded-Host $host;
    proxy_set_header X-Forwarded-Port $server_port;

    # Timeouts
    proxy_connect_timeout 60s;
    proxy_send_timeout 60s;
    proxy_read_timeout 60s;

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

    # API endpoints (rate limited)
    location /api/ {
        limit_req zone=api burst=20 nodelay;
        proxy_pass http://backend;
    }

    # All other requests
    location / {
        limit_req zone=general burst=5 nodelay;
        proxy_pass http://backend;
    }

    # Health check (internal)
    location /health {
        access_log off;
        proxy_pass http://backend/health;
    }

    # Metrics endpoint (if exposed)
    location /metrics {
        access_log off;
        deny all;  # Only allow from monitoring systems
        # allow 10.116.0.0/16;  # Uncomment to allow from VPC
        proxy_pass http://backend/metrics;
    }
}