CREATE TABLE IF NOT EXISTS po_purchase_order_sales_order (
    id BIGINT PRIMARY KEY AUTO_INCREMENT,
    purchase_order_id BIGINT NOT NULL,
    sales_order_id BIGINT NOT NULL,
    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
    updated_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
    UNIQUE KEY uq_po_so_link (purchase_order_id, sales_order_id),
    KEY idx_po_so_link_so (sales_order_id),
    CONSTRAINT fk_po_so_link_po FOREIGN KEY (purchase_order_id) REFERENCES po_purchase_order(id) ON DELETE CASCADE,
    CONSTRAINT fk_po_so_link_so FOREIGN KEY (sales_order_id) REFERENCES so_sales_order(id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

SET @idx_wh_stock_lot_item_lot_no_exists := (
  SELECT COUNT(*)
  FROM information_schema.STATISTICS
  WHERE TABLE_SCHEMA = DATABASE()
    AND TABLE_NAME = 'wh_stock_lot'
    AND INDEX_NAME = 'idx_wh_stock_lot_item_lot_no'
);
SET @idx_wh_stock_lot_item_lot_no_sql := IF(
  @idx_wh_stock_lot_item_lot_no_exists = 0,
  'ALTER TABLE wh_stock_lot ADD INDEX idx_wh_stock_lot_item_lot_no (item_id, lot_no)',
  'SELECT ''idx_wh_stock_lot_item_lot_no already exists'''
);
PREPARE idx_wh_stock_lot_item_lot_no_stmt FROM @idx_wh_stock_lot_item_lot_no_sql;
EXECUTE idx_wh_stock_lot_item_lot_no_stmt;
DEALLOCATE PREPARE idx_wh_stock_lot_item_lot_no_stmt;

SET @duplicate_stock_lot_no_groups := (
  SELECT COUNT(*)
  FROM (
    SELECT lot_no
    FROM wh_stock_lot
    WHERE lot_no IS NOT NULL
    GROUP BY lot_no
    HAVING COUNT(*) > 1
  ) duplicated_lots
);
SET @uq_wh_stock_lot_lot_no_sql := (
  SELECT IF(
    @duplicate_stock_lot_no_groups > 0,
    CONCAT('SIGNAL SQLSTATE ''45000'' SET MESSAGE_TEXT = ''wh_stock_lot.lot_no存在重复，重复批次号组数=', @duplicate_stock_lot_no_groups, '，请先清理后再执行迁移'''),
    IF(
      NOT EXISTS (
      SELECT 1
      FROM (
        SELECT INDEX_NAME
        FROM information_schema.STATISTICS
        WHERE TABLE_SCHEMA = DATABASE()
          AND TABLE_NAME = 'wh_stock_lot'
        GROUP BY INDEX_NAME
        HAVING MAX(NON_UNIQUE) = 0
           AND COUNT(*) = 1
          AND SUM(CASE WHEN COLUMN_NAME = 'lot_no' THEN 1 ELSE 0 END) = 1
      ) existing_unique_lot_no_indexes
      ),
      'ALTER TABLE wh_stock_lot ADD UNIQUE KEY uq_wh_stock_lot_lot_no (lot_no)',
      'SELECT ''uq_wh_stock_lot_lot_no already exists'''
    )
  )
);
PREPARE uq_wh_stock_lot_lot_no_stmt FROM @uq_wh_stock_lot_lot_no_sql;
EXECUTE uq_wh_stock_lot_lot_no_stmt;
DEALLOCATE PREPARE uq_wh_stock_lot_lot_no_stmt;

SET @idx_pp_issue_source_lot_exists := (
  SELECT COUNT(DISTINCT INDEX_NAME)
  FROM information_schema.STATISTICS
  WHERE TABLE_SCHEMA = DATABASE()
    AND TABLE_NAME = 'pp_work_order_material_issue'
    AND COLUMN_NAME = 'source_lot_id'
);
SET @idx_pp_issue_source_lot_sql := IF(
  @idx_pp_issue_source_lot_exists = 0,
  'ALTER TABLE pp_work_order_material_issue ADD INDEX idx_pp_issue_source_lot (source_lot_id)',
  'SELECT ''source_lot_id index already exists on pp_work_order_material_issue'''
);
PREPARE idx_pp_issue_source_lot_stmt FROM @idx_pp_issue_source_lot_sql;
EXECUTE idx_pp_issue_source_lot_stmt;
DEALLOCATE PREPARE idx_pp_issue_source_lot_stmt;

SET @uk_material_sub_batch_no_exists := (
  SELECT COUNT(*)
  FROM information_schema.STATISTICS
  WHERE TABLE_SCHEMA = DATABASE()
    AND TABLE_NAME = 'pp_work_order_material_issue'
    AND INDEX_NAME = 'uk_material_sub_batch_no'
);
SET @drop_uk_material_sub_batch_no_sql := IF(
  @uk_material_sub_batch_no_exists > 0,
  'ALTER TABLE pp_work_order_material_issue DROP INDEX uk_material_sub_batch_no',
  'SELECT ''uk_material_sub_batch_no already absent on pp_work_order_material_issue'''
);
PREPARE drop_uk_material_sub_batch_no_stmt FROM @drop_uk_material_sub_batch_no_sql;
EXECUTE drop_uk_material_sub_batch_no_stmt;
DEALLOCATE PREPARE drop_uk_material_sub_batch_no_stmt;

INSERT INTO po_purchase_order_sales_order (purchase_order_id, sales_order_id, created_at, updated_at)
SELECT DISTINCT po.id, so.id, NOW(), NOW()
FROM po_purchase_order po
JOIN po_purchase_order_item poi ON poi.purchase_order_id = po.id
JOIN mrp_material_demand md ON md.id = poi.source_demand_id
JOIN so_sales_order_item soi ON soi.id = md.sales_order_item_id
JOIN so_sales_order so ON so.id = soi.sales_order_id
WHERE NOT EXISTS (
      SELECT 1
      FROM po_purchase_order_sales_order existing
      WHERE existing.purchase_order_id = po.id
        AND existing.sales_order_id = so.id
  );

UPDATE pp_work_order_material_issue issue
JOIN wh_stock_lot lot ON lot.id = issue.source_lot_id
SET issue.material_sub_batch_no = lot.lot_no
WHERE issue.material_sub_batch_no IS NULL
   OR issue.material_sub_batch_no <> lot.lot_no;