# ===========================================
# NGINX Production Configuration
# Social Media Automation System
# ===========================================

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 format
    log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                    '$status $body_bytes_sent "$http_referer" '
                    '"$http_user_agent" "$http_x_forwarded_for" '
                    'rt=$request_time uct="$upstream_connect_time" '
                    'uht="$upstream_header_time" urt="$upstream_response_time"';

    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;

    # Gzip compression
    gzip on;
    gzip_vary on;
    gzip_proxied any;
    gzip_comp_level 6;
    gzip_types text/plain text/css text/xml application/json application/javascript
               application/xml application/xml+rss text/javascript application/x-font-ttf
               font/opentype image/svg+xml;

    # Security headers
    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;

    # Rate limiting
    limit_req_zone $binary_remote_addr zone=api:10m rate=10r/s;
    limit_req_zone $binary_remote_addr zone=login:10m rate=5r/m;

    # Upstreams
    upstream app {
        server app:8000;
        keepalive 32;
    }

    upstream flower {
        server flower:5555;
    }

    # HTTP - Redirect to HTTPS
    server {
        listen 80;
        server_name _;

        location /.well-known/acme-challenge/ {
            root /var/www/certbot;
        }

        location /health {
            proxy_pass http://app/api/health;
            proxy_connect_timeout 5s;
            proxy_read_timeout 5s;
        }

        location / {
            return 301 https://$host$request_uri;
        }
    }

    # HTTPS - Main server
    server {
        listen 443 ssl http2;
        server_name _;

        # SSL Configuration
        ssl_certificate /etc/nginx/ssl/fullchain.pem;
        ssl_certificate_key /etc/nginx/ssl/privkey.pem;

        # SSL Security
        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 1d;
        ssl_session_tickets off;

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

        # Client body size (for image uploads)
        client_max_body_size 10M;

        # Static files
        location /static {
            alias /usr/share/nginx/html/static;
            expires 30d;
            add_header Cache-Control "public, immutable";
            access_log off;
        }

        # API endpoints
        location /api {
            limit_req zone=api burst=20 nodelay;

            proxy_pass http://app;
            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;
            proxy_set_header Connection "";

            proxy_connect_timeout 30s;
            proxy_send_timeout 30s;
            proxy_read_timeout 60s;
        }

        # Login rate limiting
        location /api/auth/login {
            limit_req zone=login burst=5 nodelay;

            proxy_pass http://app;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        }

        # Dashboard
        location /dashboard {
            proxy_pass http://app;
            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;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
        }

        # Flower (Celery monitor) - Protected access
        location /flower/ {
            # Optional: IP whitelist
            # allow 192.168.1.0/24;
            # deny all;

            proxy_pass http://flower/;
            proxy_http_version 1.1;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
            proxy_redirect off;
        }

        # Health check
        location /health {
            proxy_pass http://app/api/health;
            proxy_connect_timeout 5s;
            proxy_read_timeout 5s;
            access_log off;
        }

        # Root
        location / {
            proxy_pass http://app;
            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;
        }

        # Error pages
        error_page 500 502 503 504 /50x.html;
        location = /50x.html {
            root /usr/share/nginx/html;
        }
    }
}