package jnpf.dmsService.recordprint;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import jnpf.exception.DataException;
import lombok.RequiredArgsConstructor;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Component;

import java.util.Arrays;

/**
 * 使用 Redis 保存短期打印预占，避免预览阶段写入业务表。
 */
@Component
@RequiredArgsConstructor
public class RedisDmsRecordPrintReservationStore
        implements DmsRecordPrintReservationStore {

    private static final String KEY_PREFIX = "dms:record-print:reservation:";

    private static final DefaultRedisScript<Long> CREATE_SCRIPT =
            new DefaultRedisScript<>(
                    "if redis.call('exists', KEYS[1]) == 1 then return 0 end "
                            + "redis.call('psetex', KEYS[1], ARGV[1], ARGV[2]) "
                            + "redis.call('psetex', KEYS[2], ARGV[1], ARGV[3]) "
                            + "return 1",
                    Long.class);

    private static final DefaultRedisScript<Long> CONFIRM_SCRIPT =
            new DefaultRedisScript<>(
                    "redis.call('psetex', KEYS[1], ARGV[1], ARGV[2]) "
                            + "redis.call('psetex', KEYS[2], ARGV[1], ARGV[3]) "
                            + "return 1",
                    Long.class);

    private final StringRedisTemplate redisTemplate;
    private final ObjectMapper objectMapper;

    @Override
    public DmsRecordPrintReservation findByPrintItem(String tenantId, String printItemId)
            throws DataException {
        try {
            String itemKey = itemKey(tenantId, printItemId);
            String reservationId = redisTemplate.opsForValue().get(itemKey);
            if (reservationId == null || reservationId.trim().isEmpty()) {
                return null;
            }
            DmsRecordPrintReservation reservation = read(
                    redisTemplate.opsForValue().get(idKey(tenantId, reservationId)));
            if (reservation == null) {
                redisTemplate.delete(itemKey);
            }
            return reservation;
        } catch (RuntimeException exception) {
            throw new DataException("读取打印流水号预占失败");
        }
    }

    @Override
    public DmsRecordPrintReservation findById(String tenantId, String reservationId)
            throws DataException {
        try {
            return read(redisTemplate.opsForValue().get(idKey(tenantId, reservationId)));
        } catch (RuntimeException exception) {
            throw new DataException("读取打印流水号预占失败");
        }
    }

    @Override
    public void create(DmsRecordPrintReservation reservation, long ttlMillis)
            throws DataException {
        try {
            String json = objectMapper.writeValueAsString(reservation);
            Long created = redisTemplate.execute(CREATE_SCRIPT,
                    Arrays.asList(itemKey(reservation.getTenantId(), reservation.getPrintItemId()),
                            idKey(reservation.getTenantId(), reservation.getReservationId())),
                    String.valueOf(ttlMillis), reservation.getReservationId(), json);
            if (!Long.valueOf(1L).equals(created)) {
                throw new DataException("该打印申请已经存在有效预占，请刷新后重试");
            }
        } catch (JsonProcessingException exception) {
            throw new DataException("保存打印流水号预占失败");
        } catch (RuntimeException exception) {
            if (exception instanceof DataException) {
                throw exception;
            }
            throw new DataException("保存打印流水号预占失败");
        }
    }

    @Override
    public void markConfirmed(DmsRecordPrintReservation reservation, long ttlMillis)
            throws DataException {
        try {
            String json = objectMapper.writeValueAsString(reservation);
            redisTemplate.execute(CONFIRM_SCRIPT,
                    Arrays.asList(itemKey(reservation.getTenantId(), reservation.getPrintItemId()),
                            idKey(reservation.getTenantId(), reservation.getReservationId())),
                    String.valueOf(ttlMillis), reservation.getReservationId(), json);
        } catch (JsonProcessingException | RuntimeException exception) {
            throw new DataException("更新打印流水号预占状态失败");
        }
    }

    private DmsRecordPrintReservation read(String json) throws DataException {
        if (json == null || json.trim().isEmpty()) {
            return null;
        }
        try {
            return objectMapper.readValue(json, DmsRecordPrintReservation.class);
        } catch (JsonProcessingException exception) {
            throw new DataException("打印流水号预占数据格式无效");
        }
    }

    private String itemKey(String tenantId, String printItemId) {
        return KEY_PREFIX + "item:{" + tenantId + "}:" + printItemId;
    }

    private String idKey(String tenantId, String reservationId) {
        return KEY_PREFIX + "id:{" + tenantId + "}:" + reservationId;
    }
}