import lombok.Data;

@Data
public class CompanyRetainedInfo {
    private String companyName;   // 公司名稱
    private Long retainedId;      // 需保留的公司ID（del_flag=0的記錄）
    private String retainedName;  // 需保留的公司名稱（與companyName一致）
}

public class TableConfig {
    private String tableName;    // 表名（如contract_draft）
    private String idColumn;     // 外鍵ID字段（如purchaser_id）
    private String nameColumn;  // 名稱字段（如purchaser_name，可能為null）

    // 構(gòu)造器 + Getter/Setter
    public TableConfig(String tableName, String idColumn, String nameColumn) {
        this.tableName = tableName;
        this.idColumn = idColumn;
        this.nameColumn = nameColumn;
    }
}

@Mapper
public interface CompanyCleanMapper {
    // 查詢需保留的公司信息（del_flag=0）
    List<CompanyRetainedInfo> selectRetainedCompanies();

    // 根據(jù)公司名查詢待刪除的ID列表（del_flag!=0）
    List<Long> selectIdsToDelete(String companyName);

    // 更新關(guān)聯(lián)表的外鍵引用
    void updateForeignKeys(
        @Param("config") TableConfig config,
        @Param("retainedId") Long retainedId,
        @Param("retainedName") String retainedName,
        @Param("ids") List<Long> ids
    );

    // 刪除冗余公司記錄
    void deleteCompanies(@Param("ids") List<Long> ids);
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" 
    "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.mapper.CompanyCleanMapper">

    <!-- 查詢需保留的公司 -->
    <select id="selectRetainedCompanies" resultType="CompanyRetainedInfo">
        SELECT 
            company_name AS companyName, 
            id AS retainedId, 
            company_name AS retainedName
        FROM sys_company
        WHERE del_flag = 0
          AND company_name IN (
            SELECT company_name
            FROM sys_company
            GROUP BY company_name
            HAVING COUNT(*) > 1 AND SUM(del_flag = 0) = 1
          )
    </select>

    <!-- 查詢待刪除的ID列表 -->
    <select id="selectIdsToDelete" resultType="long">
        SELECT id
        FROM sys_company
        WHERE company_name = #{companyName}
          AND del_flag != 0
    </select>

    <!-- 動(dòng)態(tài)更新外鍵引用 -->
    <update id="updateForeignKeys">
        UPDATE ${config.tableName}
        SET
            <choose>
                <when test="config.nameColumn != null">
                    <!-- 同時(shí)更新ID和名稱字段 -->
                    ${config.idColumn} = #{retainedId},
                    ${config.nameColumn} = #{retainedName}
                </when>
                <otherwise>
                    <!-- 僅更新ID字段 -->
                    ${config.idColumn} = #{retainedId}
                </otherwise>
            </choose>
        WHERE
            ${config.idColumn} IN
            <foreach item="id" collection="ids" open="(" separator="," close=")">
                #{id}
            </foreach>
    </update>

    <!-- 批量刪除公司記錄 -->
    <delete id="deleteCompanies">
        DELETE FROM sys_company
        WHERE id IN
        <foreach item="id" collection="ids" open="(" separator="," close=")">
            #{id}
        </foreach>
    </delete>

</mapper>

@Service
@RequiredArgsConstructor
public class CompanyCleanService {
    private final CompanyCleanMapper companyCleanMapper;

    // 配置需要處理的表和字段
    private static final List<TableConfig> TABLE_CONFIGS = Arrays.asList(
        new TableConfig("contract_draft", "purchaser_id", "purchaser_name"),
        new TableConfig("invoice", "company_id", "company_name")
        // 按需添加其他表...
    );

    @Transactional
    public void cleanDuplicateCompanies() {
        // 1. 查詢所有需保留的公司
        List<CompanyRetainedInfo> retainedCompanies = companyCleanMapper.selectRetainedCompanies();
        
        for (CompanyRetainedInfo info : retainedCompanies) {
            // 2. 查詢待刪除的ID列表
            List<Long> idsToDelete = companyCleanMapper.selectIdsToDelete(info.getCompanyName());
            
            if (!idsToDelete.isEmpty()) {
                // 3. 更新所有關(guān)聯(lián)表的外鍵引用
                TABLE_CONFIGS.forEach(config -> 
                    companyCleanMapper.updateForeignKeys(
                        config, 
                        info.getRetainedId(), 
                        info.getRetainedName(), 
                        idsToDelete
                    )
                );
                
                // 4. 刪除冗余公司記錄
                companyCleanMapper.deleteCompanies(idsToDelete);
            }
        }
    }
}