package com.battery.business.report;

import java.sql.Timestamp;
import java.util.List;
import javax.sql.DataSource;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.support.GeneratedKeyHolder;
import org.springframework.stereotype.Repository;
import com.ruoyi.common.exception.ServiceException;

/** 报表身份和版本存储；重读只访问报表表，不联查来源测试。 */
@Repository
public class CompareReportRepository
{
    private final JdbcTemplate jdbc;

    public CompareReportRepository(DataSource dataSource) { jdbc = new JdbcTemplate(dataSource); }

    public record Summary(long id, String name, String creator, long createdAt) { }
    public record Version(Summary report, int versionNo, String snapshotJson, String operatorName, long versionCreatedAt, String changeSummary) { }
    public record History(int versionNo, String operatorName, long createdAt, String changeSummary) { }

    /** 查询所有已保存报表摘要，允许授权用户跨创建人查看。 */
    public List<Summary> list()
    {
        return jdbc.query("select report_id, report_name, creator_name, created_at_utc from t_compare_report order by created_at_utc desc, report_id desc",
                (rs, index) -> new Summary(rs.getLong(1), rs.getString(2), rs.getString(3), rs.getTimestamp(4).getTime()));
    }

    /** 重读最新完整版本；来源不存在不影响结果。 */
    public Version get(long id)
    { return get(id, null); }

    /** 读取指定历史版，版本号为空时读取最新版本。 */
    public Version get(long id, Integer versionNo)
    {
        var rows = jdbc.query("select r.report_id, r.report_name, r.creator_name, r.created_at_utc, v.version_no, v.snapshot_json, v.operator_name, v.created_at_utc, v.change_summary "
                + "from t_compare_report r join t_compare_report_version v on v.report_id=r.report_id where r.report_id=? "
                + (versionNo == null ? "and v.version_no=(select max(v2.version_no) from t_compare_report_version v2 where v2.report_id=r.report_id)" : "and v.version_no=?"),
                (rs, index) -> new Version(new Summary(rs.getLong(1), rs.getString(2), rs.getString(3), rs.getTimestamp(4).getTime()),
                        rs.getInt(5), rs.getString(6), rs.getString(7), rs.getTimestamp(8).getTime(), rs.getString(9)),
                versionNo == null ? new Object[] { id } : new Object[] { id, versionNo });
        if (rows.isEmpty()) throw new ServiceException("对比报表或版本不存在");
        return rows.get(0);
    }

    /** 历史摘要只来自正式版本，不返回测量快照。 */
    public List<History> history(long id)
    {
        return jdbc.query("select version_no,operator_name,created_at_utc,change_summary from t_compare_report_version where report_id=? order by version_no desc",
                (rs, index) -> new History(rs.getInt(1), rs.getString(2), rs.getTimestamp(3).getTime(), rs.getString(4)), id);
    }

    /** 业务事务内锁定报表，版本号分配与旧基准拒绝共用此锁。 */
    public void lock(long id)
    {
        if (jdbc.queryForList("select report_id from t_compare_report where report_id=? for update", Long.class, id).isEmpty())
            throw new ServiceException("对比报表不存在");
    }

    /** 只追加版本并更新列表名称；业务事务保证两步同时成功。 */
    public void append(long id, int versionNo, String name, String snapshot, long operatorId, String operatorName, String summary)
    {
        jdbc.update("insert into t_compare_report_version(report_id,version_no,snapshot_json,operator_id,operator_name,created_at_utc,change_summary) values(?,?,?,?,?,?,?)",
                id, versionNo, snapshot, operatorId, operatorName, new Timestamp(System.currentTimeMillis()), summary);
        jdbc.update("update t_compare_report set report_name=? where report_id=?", name, id);
    }

    /** 由业务事务调用，身份与首个版本任一写入失败必须一起回滚。 */
    public long insert(String name, String snapshot, long operatorId, String operatorName, long createdAt)
    {
        var keys = new GeneratedKeyHolder();
        jdbc.update(connection -> {
            var statement = connection.prepareStatement("insert into t_compare_report(report_name,creator_id,creator_name,created_at_utc) values(?,?,?,?)", java.sql.Statement.RETURN_GENERATED_KEYS);
            statement.setString(1, name); statement.setLong(2, operatorId); statement.setString(3, operatorName);
            statement.setTimestamp(4, new Timestamp(createdAt));
            return statement;
        }, keys);
        long id = keys.getKey().longValue();
        jdbc.update("insert into t_compare_report_version(report_id,version_no,snapshot_json,operator_id,operator_name,created_at_utc,change_summary) values(?,1,?,?,?,?,?)",
                id, snapshot, operatorId, operatorName, new Timestamp(createdAt), "首次保存对比报表");
        return id;
    }
}