package com.ruoyi.production.utils;

import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

/**
 * <br>
 * 单位转换工具类
 * </br>
 *
 * @author deslrey
 * @version 1.0
 * @since 2026/03/30 15:07
 */
public class UnitUtils {

    private static final Set<String> WEIGHT_UNITS = new HashSet<>(Arrays.asList(
            "千克", "公斤", "kg", "KG", "kG",
            "克", "g", "G",
            "吨", "t", "T"
    ));

    private static final Set<String> KG_UNITS = new HashSet<>(Arrays.asList("千克", "公斤", "kg", "KG", "kG"));
    private static final Set<String> G_UNITS = new HashSet<>(Arrays.asList("克", "g", "G"));
    private static final Set<String> TON_UNITS = new HashSet<>(Arrays.asList("吨", "t", "T"));

    /**
     * 判断是否为重量单位
     */
    public static boolean isWeightUnit(String unit) {
        return unit != null && WEIGHT_UNITS.contains(unit.trim());
    }

    /**
     * 如果是重量单位，统一返回“吨”，否则返回原单位
     */
    public static String normalizeUnit(String unit) {
        if (isWeightUnit(unit)) {
            return "吨";
        }
        return unit != null ? unit.trim() : "未知单位";
    }

    /**
     * 如果是重量单位，折算为“吨”，否则返回原值
     */
    public static BigDecimal convertValueToTon(BigDecimal value, String unit) {
        if (value == null || unit == null) {
            return value != null ? value : BigDecimal.ZERO;
        }

        String trimmedUnit = unit.trim();
        if (KG_UNITS.contains(trimmedUnit)) {
            return value.divide(new BigDecimal("1000"), 6, RoundingMode.HALF_UP);
        } else if (G_UNITS.contains(trimmedUnit)) {
            return value.divide(new BigDecimal("1000000"), 6, RoundingMode.HALF_UP);
        } else if (TON_UNITS.contains(trimmedUnit)) {
            return value;
        }

        return value;
    }
}