package com.vincent.rsf.openApi.entity.params;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;

/**
 * 支持时间戳（秒/毫秒）与字符串 "yyyy-MM-dd HH:mm:ss" 的 Date 反序列化，与 @JsonFormat 配合使用。
 */
public class FlexibleDateDeserializer extends JsonDeserializer<Date> {

    private static final long MS_THRESHOLD = 10_000_000_000L; // 大于此为毫秒
    private static final String PATTERN = "yyyy-MM-dd HH:mm:ss";
    private static final TimeZone DEFAULT_TZ = TimeZone.getTimeZone("GMT+8");

    @Override
    public Date deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
        JsonToken t = p.getCurrentToken();
        if (t == JsonToken.VALUE_NUMBER_INT || t == JsonToken.VALUE_NUMBER_FLOAT) {
            long v = p.getLongValue();
            long ms = v >= MS_THRESHOLD ? v : v * 1000;
            return new Date(ms);
        }
        if (t == JsonToken.VALUE_STRING) {
            String s = p.getText().trim();
            if (s.isEmpty()) return null;
            try {
                long v = Long.parseLong(s);
                long ms = v >= MS_THRESHOLD ? v : v * 1000;
                return new Date(ms);
            } catch (NumberFormatException ignored) {
            }
            try {
                SimpleDateFormat sdf = new SimpleDateFormat(PATTERN);
                sdf.setTimeZone(DEFAULT_TZ);
                sdf.setLenient(false);
                return sdf.parse(s);
            } catch (Exception ignored) {
            }
            if (s.length() >= 10 && s.charAt(4) == '-' && s.charAt(7) == '-') {
                try {
                    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
                    sdf.setTimeZone(DEFAULT_TZ);
                    sdf.setLenient(false);
                    return sdf.parse(s.substring(0, 10));
                } catch (Exception ignored) {
                }
            }
            return null;
        }
        if (t == JsonToken.VALUE_NULL) return null;
        return (Date) ctxt.handleUnexpectedToken(Date.class, p);
    }
}