{
  "dag_id": "ecommerce_etl_pipeline",
  "description": "Daily ETL pipeline for e-commerce data warehouse",
  "schedule_interval": "0 2 * * *",
  "start_date": "2025-01-01",
  "catchup": false,
  "tags": ["etl", "ecommerce", "daily"],
  "default_args": {
    "owner": "data_engineering",
    "retries": 3,
    "retry_delay_minutes": 5,
    "email_on_failure": true
  },
  "tasks": [
    {
      "task_id": "extract_customers",
      "operator": "PythonOperator",
      "description": "Extract customer data from source database",
      "upstream_dependencies": [],
      "downstream_dependencies": ["transform_customers"],
      "source": "postgres://source_db/customers",
      "target": "s3://data-lake/raw/customers/"
    },
    {
      "task_id": "extract_orders",
      "operator": "PythonOperator",
      "description": "Extract orders data from source database",
      "upstream_dependencies": [],
      "downstream_dependencies": ["transform_orders"],
      "source": "postgres://source_db/orders",
      "target": "s3://data-lake/raw/orders/"
    },
    {
      "task_id": "extract_products",
      "operator": "PythonOperator",
      "description": "Extract products data from source database",
      "upstream_dependencies": [],
      "downstream_dependencies": ["transform_products"],
      "source": "postgres://source_db/products",
      "target": "s3://data-lake/raw/products/"
    },
    {
      "task_id": "extract_order_items",
      "operator": "PythonOperator",
      "description": "Extract order items from source database",
      "upstream_dependencies": [],
      "downstream_dependencies": ["transform_order_items"],
      "source": "postgres://source_db/order_items",
      "target": "s3://data-lake/raw/order_items/"
    },
    {
      "task_id": "transform_customers",
      "operator": "SparkSubmitOperator",
      "description": "Clean and transform customer data",
      "upstream_dependencies": ["extract_customers"],
      "downstream_dependencies": ["load_dim_customers"],
      "source": "s3://data-lake/raw/customers/",
      "target": "s3://data-lake/transformed/customers/"
    },
    {
      "task_id": "transform_orders",
      "operator": "SparkSubmitOperator",
      "description": "Clean and transform orders data",
      "upstream_dependencies": ["extract_orders"],
      "downstream_dependencies": ["load_fct_orders"],
      "source": "s3://data-lake/raw/orders/",
      "target": "s3://data-lake/transformed/orders/"
    },
    {
      "task_id": "transform_products",
      "operator": "SparkSubmitOperator",
      "description": "Clean and transform products data",
      "upstream_dependencies": ["extract_products"],
      "downstream_dependencies": ["load_dim_products"],
      "source": "s3://data-lake/raw/products/",
      "target": "s3://data-lake/transformed/products/"
    },
    {
      "task_id": "transform_order_items",
      "operator": "SparkSubmitOperator",
      "description": "Clean and transform order items data",
      "upstream_dependencies": ["extract_order_items"],
      "downstream_dependencies": ["load_fct_orders"],
      "source": "s3://data-lake/raw/order_items/",
      "target": "s3://data-lake/transformed/order_items/"
    },
    {
      "task_id": "load_dim_customers",
      "operator": "SnowflakeOperator",
      "description": "Load customer dimension to Snowflake",
      "upstream_dependencies": ["transform_customers"],
      "downstream_dependencies": ["build_customer_metrics"],
      "source": "s3://data-lake/transformed/customers/",
      "target": "snowflake://warehouse/analytics.dim_customers"
    },
    {
      "task_id": "load_dim_products",
      "operator": "SnowflakeOperator",
      "description": "Load product dimension to Snowflake",
      "upstream_dependencies": ["transform_products"],
      "downstream_dependencies": ["build_sales_report"],
      "source": "s3://data-lake/transformed/products/",
      "target": "snowflake://warehouse/analytics.dim_products"
    },
    {
      "task_id": "load_fct_orders",
      "operator": "SnowflakeOperator",
      "description": "Load orders fact table to Snowflake",
      "upstream_dependencies": ["transform_orders", "transform_order_items"],
      "downstream_dependencies": ["build_customer_metrics", "build_sales_report"],
      "source": ["s3://data-lake/transformed/orders/", "s3://data-lake/transformed/order_items/"],
      "target": "snowflake://warehouse/analytics.fct_orders"
    },
    {
      "task_id": "build_customer_metrics",
      "operator": "SnowflakeOperator",
      "description": "Calculate customer lifetime value and metrics",
      "upstream_dependencies": ["load_dim_customers", "load_fct_orders"],
      "downstream_dependencies": ["publish_to_bi"],
      "source": ["analytics.dim_customers", "analytics.fct_orders"],
      "target": "snowflake://warehouse/analytics.rpt_customer_metrics"
    },
    {
      "task_id": "build_sales_report",
      "operator": "SnowflakeOperator",
      "description": "Build daily sales report",
      "upstream_dependencies": ["load_dim_products", "load_fct_orders"],
      "downstream_dependencies": ["publish_to_bi"],
      "source": ["analytics.dim_products", "analytics.fct_orders"],
      "target": "snowflake://warehouse/analytics.rpt_daily_sales"
    },
    {
      "task_id": "publish_to_bi",
      "operator": "PythonOperator",
      "description": "Publish reports to BI tool",
      "upstream_dependencies": ["build_customer_metrics", "build_sales_report"],
      "downstream_dependencies": ["notify_stakeholders"],
      "source": ["analytics.rpt_customer_metrics", "analytics.rpt_daily_sales"],
      "target": "tableau://server/ecommerce_dashboard"
    },
    {
      "task_id": "notify_stakeholders",
      "operator": "EmailOperator",
      "description": "Send completion notification",
      "upstream_dependencies": ["publish_to_bi"],
      "downstream_dependencies": []
    }
  ],
  "notes": "Sample Airflow DAG representing a complete ETL pipeline with extract, transform, load, and reporting stages."
}