package cn.iocoder.yudao.framework.common.util.json.databind;

import tools.jackson.core.JacksonException;
import tools.jackson.core.JsonParser;
import tools.jackson.core.JsonToken;
import tools.jackson.databind.DeserializationContext;
import tools.jackson.databind.ValueDeserializer;

import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;

/**
 * 基于时间戳的 LocalDateTime 反序列化器
 *
 * @author 老五
 */
public class TimestampLocalDateTimeDeserializer extends ValueDeserializer<LocalDateTime> {

    public static final TimestampLocalDateTimeDeserializer INSTANCE = new TimestampLocalDateTimeDeserializer();

    private static final DateTimeFormatter DATE_TIME_FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    private static final DateTimeFormatter DATE_FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd");

    @Override
    public LocalDateTime deserialize(JsonParser p, DeserializationContext ctxt) throws JacksonException {
        // 数字类型：作为时间戳处理
        if (p.currentToken() == JsonToken.VALUE_NUMBER_INT) {
            return LocalDateTime.ofInstant(Instant.ofEpochMilli(p.getValueAsLong()), ZoneId.systemDefault());
        }
        // 字符串类型：先尝试作为时间戳解析，再按日期格式解析
        String text = p.getValueAsString();
        try {
            long millis = Long.parseLong(text);
            return LocalDateTime.ofInstant(Instant.ofEpochMilli(millis), ZoneId.systemDefault());
        } catch (NumberFormatException e) {
            // 不是纯数字，按日期格式解析
        }
        // 纯日期格式（如 "2026-07-29"），补全为当天 00:00:00
        if (text.length() == 10) {
            return LocalDate.parse(text, DATE_FORMATTER).atStartOfDay();
        }
        return LocalDateTime.parse(text, DATE_TIME_FORMATTER);
    }

}