# ============================================================================
# AUTO-GENERATED NGINX UPSTREAM CONFIGURATION
# Application: {{ app_name }}
# Environment: {{ deploy_env }}{{ env_tag | default('') }}
# Generated: {{ ansible_date_time.iso8601 }}
# Replicas: {{ replica_count }}
# ============================================================================

{% if framework is defined and framework == "nextjs" %}
map $arg_url ${{app_name | regex_replace('[^A-Za-z0-9_]', '_')}}_clean_url {
    ~^(?<base>.+)%3Fv%3D\d+$                     $base;     # chỉ có ?v=xxx
    ~^(?<base>.+)%3Fv%3D\d+%26(?<rest>.+)$       $base?$rest; # có ?v=xxx&... → giữ lại phần sau
    default                                      $arg_url;  # mặc định giữ nguyên
}
{% endif %}

upstream {{ upstream_name | regex_replace('[^A-Za-z0-9_]', '_') }} {
    # Load balancing method
    {% if load_balancing_method is defined %}
    {{ load_balancing_method }};
    {% else %}
    least_conn;
    {% endif %}

    # Health check configuration
    {% if health_check_interval is defined %}
    health_check interval={{ health_check_interval }} fails={{ health_check_fails | default(1) }} passes={{ health_check_passes | default(2) }};
    {% endif %}

    # Upstream servers (auto-generated from active ports)
    {% for port in active_ports %}
    server localhost:{{ port }} weight={{ server_weight | default(1) }} max_fails={{ max_fails | default(1) }} fail_timeout={{ fail_timeout | default(10) }}s;
    {% endfor %}

    # Backup server (optional)
    {% if backup_server is defined %}
    server {{ backup_server }} backup;
    {% endif %}

    # Keep-alive connections
    keepalive {{ keepalive_connections | default(64) }};
}

{% if framework is defined and framework == "nextjs" %}
proxy_cache_path /var/cache/nginx/{{app_name | regex_replace('[^A-Za-z0-9_]', '_')}}_cache levels=1:2 keys_zone={{app_name | regex_replace('[^A-Za-z0-9_]', '_')}}_cache:512m inactive=30d max_size=100g use_temp_path=off;

#levels=1:2: Tạo cây thư mục theo hash key để phân bổ file.
#keys_zone=tkl_web_img_cache:512m: Tăng RAM dùng cho metadata (1MB chứa được ~8000 keys) → 2G = ~16 triệu keys.
#inactive=30d: Nếu file không được truy cập trong 30 ngày → bị xóa.
#max_size=100g: Giới hạn tối đa 100GB cache disk.
#use_temp_path=off: Ghi thẳng vào cache thay vì ghi tạm → hiệu quả hơn.
{% endif %}

server {
    listen {{ base_port }};
    server_name localhost;
    
    {% if framework is defined and framework == "nextjs" %}
    
    location ~* /_next/image {
        access_log off;
        proxy_pass http://{{ upstream_name | regex_replace('[^A-Za-z0-9_]', '_') }}; # upstream load balancing
        
        proxy_cache {{app_name | regex_replace('[^A-Za-z0-9_]', '_')}}_cache;
        proxy_cache_key "url=${{app_name | regex_replace('[^A-Za-z0-9_]', '_')}}_clean_url&w=$arg_w&q=$arg_q";
        proxy_cache_valid 200 180d;
        proxy_cache_use_stale error timeout updating http_502 http_503 http_504;
        proxy_next_upstream error timeout http_502 http_503 http_504;
        proxy_next_upstream_tries 3;
    
        # Chống cache stampede (bottleneck)
        proxy_cache_lock on;
        proxy_cache_lock_timeout 10s;
        proxy_cache_lock_age 5s;
        
        # Timeout & buffering
        proxy_connect_timeout       60s;
        proxy_send_timeout          60s;
        proxy_read_timeout          60s;
        send_timeout                60s;

        # Ignore upstream cache headers (Next.js gửi max-age + vary)
        proxy_ignore_headers Cache-Control Vary;
        proxy_hide_header Set-Cookie;
        proxy_set_header Connection $connection_upgrade;
        proxy_http_version 1.1;
        
        # Chuẩn hóa Accept để tránh tạo nhiều cache key khác nhau
        proxy_set_header Accept "image/webp,image/*,*/*;q=0.8";

        add_header X-Cache-Status $upstream_cache_status;
        #add_header X-Cache-Key "url=${{app_name | regex_replace('[^A-Za-z0-9_]', '_')}}_clean_url&w=$arg_w&q=$arg_q";
        
        # Keepalive settings (optional)
        keepalive_timeout 64;
    }
    
    {% endif %}

    location / {
        access_log off;

        proxy_pass http://{{ upstream_name | regex_replace('[^A-Za-z0-9_]', '_') }};
        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 REMOTE-HOST $remote_addr;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
        proxy_http_version 1.1;
        proxy_cache off;

        proxy_next_upstream error timeout http_502 http_503 http_504;
        proxy_next_upstream_tries 3;
        
        # Timeout & buffering
        proxy_connect_timeout       60s;
        proxy_send_timeout          60s;
        proxy_read_timeout          60s;
        send_timeout                60s;

        proxy_buffering on;
        client_max_body_size 256M;

        # Keepalive settings (optional)
        keepalive_timeout 64;
    }

}

# ============================================================================
# CONFIGURATION METADATA (for debugging)
# ============================================================================
# Configuration Details:
# - Base Port: {{ base_port }}
# - Load Balancing: {{ load_balancing_method | default('least_conn') }}
# - Max Fails: {{ max_fails | default(1) }}
# - Fail Timeout: {{ fail_timeout | default(10) }}s
# - Health Check: {{ 'enabled' if enable_health_check_endpoint | default(true) else 'disabled' }}
# ============================================================================