"use client";

import { Minus, Plus } from "lucide-react";
import { useEffect, useState, type KeyboardEvent } from "react";

/** 后台数字步进器：0 是合法值；加减与手输都会提交数字 */
export default function AdminStepper({
  id,
  value,
  onChange,
  min = 0,
  max = 999,
  step = 1,
  unit,
  ariaLabel,
  disabled,
}: {
  id?: string;
  value: number;
  onChange: (n: number) => void;
  min?: number;
  max?: number;
  step?: number;
  unit?: string;
  ariaLabel: string;
  disabled?: boolean;
}) {
  const clamp = (n: number) => Math.min(max, Math.max(min, Math.round(n)));
  const [text, setText] = useState(() => String(value));

  useEffect(() => {
    setText(String(value));
  }, [value]);

  const emit = (n: number) => {
    const next = clamp(Number.isFinite(n) ? n : min);
    onChange(next);
    setText(String(next));
  };

  const onKeyDown = (e: KeyboardEvent<HTMLInputElement>) => {
    if (e.key === "ArrowUp") {
      e.preventDefault();
      emit(value + step);
    } else if (e.key === "ArrowDown") {
      e.preventDefault();
      emit(value - step);
    }
  };

  return (
    <div className={`admin-stepper${disabled ? " is-disabled" : ""}`}>
      <button
        type="button"
        className="admin-stepper-btn"
        onClick={() => emit(value - step)}
        disabled={disabled || value <= min}
        aria-label="减少"
        tabIndex={-1}
      >
        <Minus size={14} />
      </button>
      <input
        id={id}
        className="admin-stepper-input"
        type="text"
        inputMode="numeric"
        value={text}
        aria-label={ariaLabel}
        disabled={disabled}
        onFocus={(e) => e.target.select()}
        onChange={(e) => {
          const raw = e.target.value.replace(/[^\d]/g, "");
          setText(raw);
          if (raw === "") return;
          onChange(clamp(Number(raw)));
        }}
        onBlur={() => emit(text === "" ? min : Number(text))}
        onKeyDown={onKeyDown}
      />
      {unit ? <span className="admin-stepper-unit">{unit}</span> : null}
      <button
        type="button"
        className="admin-stepper-btn"
        onClick={() => emit(value + step)}
        disabled={disabled || value >= max}
        aria-label="增加"
        tabIndex={-1}
      >
        <Plus size={14} />
      </button>
    </div>
  );
}