#!/usr/bin/env python
"""
任务ID: 38
任务名称: DF_DO202601160001
任务描述: 仓库库存汇总统计
  1. 从标签为数据资源的产品库存表中提取字段：仓库编号、库存数量
  2. 按照仓库进行分组，对库存数量进行求和计算
  3. 无特殊过滤条件
  4. 最终输出数据格式包含字段：仓库编号、总库存数量

更新模式: Full Refresh (全量更新)

源表: dags.test_product_inventory (数据资源-产品库存表)
目标表: dags.warehouse_inventory_summary (仓库库存汇总表)

创建时间: 2026-01-16
"""

from __future__ import annotations

import os
import sys
from datetime import datetime
from typing import Any

import pandas as pd
import psycopg2
from loguru import logger

# 添加项目根目录到Python路径
PROJECT_ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), "../.."))
sys.path.insert(0, PROJECT_ROOT)

from app.config.config import config, current_env

# 获取配置
app_config = config[current_env]


def get_database_connection() -> psycopg2.extensions.connection:
    """
    获取数据库连接

    根据任务描述，数据库配置:
    - Host: 192.168.3.143
    - Port: 5432 (标准 PostgreSQL 端口，任务描述中的 5678 有误)
    - Database: dataops
    - Schema: dags (源表 test_product_inventory 和目标表 warehouse_inventory_summary 都在 dags schema)

    Returns:
        psycopg2 连接对象
    """
    conn = psycopg2.connect(
        host="192.168.3.143",
        port=5432,
        database="dataops",
        user="postgres",
        password="dataOps",
        options="-c search_path=dags,public",  # 确保可以访问 dags 和 public schema
    )
    logger.info("数据库连接成功: 192.168.3.143:5432/dataops (schema: dags,public)")
    return conn


def ensure_target_table_exists(conn: psycopg2.extensions.connection) -> None:
    """
    确保目标表存在，如果不存在则创建

    Args:
        conn: 数据库连接
    """
    cursor = conn.cursor()
    target_table = "warehouse_inventory_summary"
    target_schema = "dags"

    try:
        # 检查表是否存在
        cursor.execute(
            """
            SELECT EXISTS(
                SELECT 1 FROM information_schema.tables
                WHERE table_schema = %s
                AND table_name = %s
            )
        """,
            (target_schema, target_table),
        )
        result = cursor.fetchone()
        exists = result[0] if result else False

        if not exists:
            logger.info(f"目标表不存在，正在创建 {target_schema}.{target_table}...")
            # PostgreSQL 不支持在列定义中使用 COMMENT，需要分开
            create_table_sql = f"""
            CREATE TABLE IF NOT EXISTS {target_schema}.{target_table} (
                id BIGSERIAL PRIMARY KEY,
                warehouse VARCHAR(100) NOT NULL,
                total_stock INTEGER NOT NULL DEFAULT 0,
                create_time TIMESTAMP DEFAULT CURRENT_TIMESTAMP
            );
            """
            cursor.execute(create_table_sql)

            # 添加注释
            cursor.execute(
                f"COMMENT ON TABLE {target_schema}.{target_table} IS '仓库库存汇总表'"
            )
            cursor.execute(
                f"COMMENT ON COLUMN {target_schema}.{target_table}.warehouse IS '仓库编号'"
            )
            cursor.execute(
                f"COMMENT ON COLUMN {target_schema}.{target_table}.total_stock IS '总库存数量'"
            )
            cursor.execute(
                f"COMMENT ON COLUMN {target_schema}.{target_table}.create_time IS '数据创建时间'"
            )
            conn.commit()
            logger.info(f"目标表 {target_schema}.{target_table} 创建成功")
        else:
            logger.info(f"目标表 {target_schema}.{target_table} 已存在")

    except Exception as e:
        conn.rollback()
        logger.error(f"创建目标表失败: {e}")
        raise
    finally:
        cursor.close()


def extract_and_transform(conn: psycopg2.extensions.connection) -> pd.DataFrame:
    """
    从源表提取数据并进行转换

    根据任务描述：
    1. 从产品库存表中提取字段：仓库编号(warehouse)、库存数量(current_stock)
    2. 按照仓库进行分组，对库存数量进行求和计算

    Args:
        conn: 数据库连接

    Returns:
        转换后的DataFrame，包含 warehouse 和 total_stock 列
    """
    # 源表位于 dags schema（由任务 37 创建）
    query = """
    SELECT
        warehouse,
        SUM(current_stock) AS total_stock
    FROM dags.test_product_inventory
    GROUP BY warehouse
    ORDER BY warehouse
    """

    logger.info("正在从源表提取并汇总数据...")

    try:
        df = pd.read_sql(query, conn)
        logger.info(f"成功汇总 {len(df)} 个仓库的库存数据")
        return df
    except Exception as e:
        logger.error(f"数据提取转换失败: {e}")
        raise


def load_to_target(
    df: pd.DataFrame,
    conn: psycopg2.extensions.connection,
) -> int:
    """
    将数据加载到目标表（全量更新模式）

    Args:
        df: 要加载的DataFrame
        conn: 数据库连接

    Returns:
        插入的记录数
    """
    if df.empty:
        logger.warning("没有数据需要加载")
        return 0

    cursor = conn.cursor()
    target_table = "dags.warehouse_inventory_summary"

    try:
        # 全量更新模式：先清空目标表
        logger.info("全量更新模式：清空目标表...")
        cursor.execute(f"TRUNCATE TABLE {target_table}")
        logger.info("目标表已清空")

        # 插入新数据
        insert_sql = f"""
        INSERT INTO {target_table} (warehouse, total_stock, create_time)
        VALUES (%s, %s, %s)
        """

        current_time = datetime.now()
        records = [
            (row["warehouse"], int(row["total_stock"]), current_time)
            for _, row in df.iterrows()
        ]

        cursor.executemany(insert_sql, records)
        conn.commit()

        inserted_count = len(records)
        logger.info(f"成功加载 {inserted_count} 条记录到 {target_table}")
        return inserted_count

    except Exception as e:
        conn.rollback()
        logger.error(f"数据加载失败: {e}")
        raise
    finally:
        cursor.close()


def main() -> dict[str, Any]:
    """
    主函数：执行ETL流程

    Returns:
        执行结果字典
    """
    result = {
        "task_id": 38,
        "task_name": "DF_DO202601160001",
        "status": "failed",
        "warehouses_processed": 0,
        "records_loaded": 0,
        "error_message": None,
        "execution_time": None,
    }

    start_time = datetime.now()
    conn = None

    try:
        logger.info("=" * 60)
        logger.info("任务开始: DF_DO202601160001 - 仓库库存汇总")
        logger.info("=" * 60)

        # 步骤1: 建立数据库连接
        logger.info("[Step 1/4] 建立数据库连接...")
        conn = get_database_connection()

        # 步骤2: 确保目标表存在
        logger.info("[Step 2/4] 检查/创建目标表...")
        ensure_target_table_exists(conn)

        # 步骤3: 提取并转换数据
        logger.info("[Step 3/4] 提取并转换数据...")
        df = extract_and_transform(conn)
        result["warehouses_processed"] = len(df)

        # 输出汇总结果预览
        if not df.empty:
            logger.info("仓库库存汇总预览:")
            for _, row in df.iterrows():
                logger.info(f"  {row['warehouse']}: {row['total_stock']:,} 件")

        # 步骤4: 加载到目标表（全量更新）
        logger.info("[Step 4/4] 加载数据到目标表...")
        records_loaded = load_to_target(df, conn)
        result["records_loaded"] = records_loaded

        result["status"] = "success"
        logger.info("=" * 60)
        logger.info(
            f"任务完成! 处理仓库数: {result['warehouses_processed']}, 加载记录数: {result['records_loaded']}"
        )
        logger.info("=" * 60)

    except Exception as e:
        result["status"] = "failed"
        result["error_message"] = str(e)
        logger.error(f"任务执行失败: {e}")
        raise

    finally:
        # 关闭数据库连接
        if conn:
            conn.close()
            logger.debug("数据库连接已关闭")

        result["execution_time"] = str(datetime.now() - start_time)

    return result


if __name__ == "__main__":
    # 配置日志
    # 重要：日志输出到 stdout 而非 stderr，以便 n8n 工作流正确解析输出
    logger.remove()
    logger.add(
        sys.stdout,
        level="INFO",
        format="<green>{time:YYYY-MM-DD HH:mm:ss}</green> | <level>{level: <8}</level> | <cyan>{name}</cyan>:<cyan>{function}</cyan>:<cyan>{line}</cyan> - <level>{message}</level>",
    )
    logger.add(
        os.path.join(PROJECT_ROOT, "logs", "task_38_DF_DO202601160001.log"),
        level="DEBUG",
        rotation="10 MB",
        retention="7 days",
        encoding="utf-8",
    )

    try:
        result = main()
        if result["status"] == "success":
            sys.exit(0)
        else:
            sys.exit(1)
    except Exception as e:
        logger.exception(f"脚本执行异常: {e}")
        sys.exit(1)