"use client";

import { useEffect, useMemo, useState } from "react";
import {
  formatLunarLabel,
  formatSolarLabel,
  lunarToSolarYmd,
  solarYmdToLunarParts,
  todayLunarParts,
  todaySolarYmd,
  type LunarDateParts,
} from "@/lib/calc/lunar-date";

interface LunarBirthPickerProps {
  solarDate: string;
  time: string;
  onSolarDateChange: (solarYmd: string) => void;
  onTimeChange: (time: string) => void;
  label?: string;
  timeDisabled?: boolean;
}

const inputClass =
  "rounded-md border bg-background px-3 py-2 text-sm disabled:opacity-50";

export default function LunarBirthPicker({
  solarDate,
  time,
  onSolarDateChange,
  onTimeChange,
  label = "出生日期 / 时间",
  timeDisabled = false,
}: LunarBirthPickerProps) {
  const [lunar, setLunar] = useState<LunarDateParts>(() => {
    return solarYmdToLunarParts(solarDate) ?? todayLunarParts();
  });

  useEffect(() => {
    const parsed = solarYmdToLunarParts(solarDate);
    if (parsed) {
      setLunar(parsed);
    }
  }, [solarDate]);

  const solarYmd = useMemo(() => lunarToSolarYmd(lunar), [lunar]);
  const lunarLabel = useMemo(() => formatLunarLabel(lunar), [lunar]);
  const solarLabel = useMemo(
    () => (solarYmd ? formatSolarLabel(solarYmd) : null),
    [solarYmd],
  );

  useEffect(() => {
    if (solarYmd && solarYmd !== solarDate) {
      onSolarDateChange(solarYmd);
    }
  }, [solarYmd, solarDate, onSolarDateChange]);

  function updateLunar(patch: Partial<LunarDateParts>) {
    setLunar((prev) => ({ ...prev, ...patch }));
  }

  return (
    <div className="space-y-2">
      <label className="text-sm font-medium">{label}</label>
      <p className="text-xs text-muted-foreground">请按农历（阴历）填写出生日期</p>

      <div className="grid grid-cols-3 gap-2">
        <div className="space-y-1">
          <span className="text-xs text-muted-foreground">农历年</span>
          <input
            type="number"
            className={inputClass + " w-full"}
            min={1900}
            max={2100}
            value={lunar.year}
            onChange={(e) => updateLunar({ year: Number(e.target.value) })}
          />
        </div>
        <div className="space-y-1">
          <span className="text-xs text-muted-foreground">农历月</span>
          <input
            type="number"
            className={inputClass + " w-full"}
            min={1}
            max={12}
            value={lunar.month}
            onChange={(e) => updateLunar({ month: Number(e.target.value) })}
          />
        </div>
        <div className="space-y-1">
          <span className="text-xs text-muted-foreground">农历日</span>
          <input
            type="number"
            className={inputClass + " w-full"}
            min={1}
            max={30}
            value={lunar.day}
            onChange={(e) => updateLunar({ day: Number(e.target.value) })}
          />
        </div>
      </div>

      <label className="flex items-center gap-2 text-xs text-muted-foreground">
        <input
          type="checkbox"
          checked={lunar.isLeapMonth}
          onChange={(e) => updateLunar({ isLeapMonth: e.target.checked })}
        />
        闰月
      </label>

      {lunarLabel && (
        <p className="text-xs text-muted-foreground">农历：{lunarLabel}</p>
      )}

      {solarLabel ? (
        <p className="rounded-md border border-primary/20 bg-primary/5 px-3 py-2 text-sm">
          对应阳历：<span className="font-medium text-foreground">{solarLabel}</span>
          <span className="ml-2 text-xs text-muted-foreground">({solarYmd})</span>
        </p>
      ) : (
        <p className="text-sm text-destructive">农历日期无效，请检查年月日或闰月</p>
      )}

      <div className="space-y-1">
        <span className="text-xs text-muted-foreground">出生时辰</span>
        <input
          type="time"
          className={inputClass + " w-full sm:w-auto"}
          value={time}
          disabled={timeDisabled}
          onChange={(e) => onTimeChange(e.target.value)}
        />
      </div>
    </div>
  );
}

export { todaySolarYmd };