"use client";

import { useState, type ChangeEvent, type DragEvent, type ReactNode } from "react";

export const VPX_FILE_INPUT_ID = "vpx-file-input";

export interface FileDropZoneProps {
  onFile: (file: File) => void;
  onError: (message: string) => void;
  children: ReactNode;
  className?: string;
}

function validate(file: File | undefined, onFile: (file: File) => void, onError: (m: string) => void) {
  if (!file) return;
  if (!file.name.toLowerCase().endsWith(".vpx")) {
    onError(`"${file.name}" isn't a .vpx file.`);
    return;
  }
  onFile(file);
}

export default function FileDropZone({ onFile, onError, children, className = "" }: FileDropZoneProps) {
  const [isDragging, setIsDragging] = useState(false);

  const handleDrop = (e: DragEvent<HTMLDivElement>) => {
    e.preventDefault();
    setIsDragging(false);
    validate(e.dataTransfer.files[0], onFile, onError);
  };

  const handleInputChange = (e: ChangeEvent<HTMLInputElement>) => {
    validate(e.target.files?.[0], onFile, onError);
    e.target.value = "";
  };

  return (
    <div
      onDragOver={(e) => {
        e.preventDefault();
        setIsDragging(true);
      }}
      onDragLeave={() => setIsDragging(false)}
      onDrop={handleDrop}
      className={`relative ${className}`}
    >
      {children}
      <input
        id={VPX_FILE_INPUT_ID}
        type="file"
        accept=".vpx"
        className="sr-only"
        onChange={handleInputChange}
      />
      {isDragging && (
        <div className="pointer-events-none absolute inset-0 z-20 flex items-center justify-center rounded-lg bg-ink/85 font-display text-3xl tracking-wide text-arc ring-2 ring-arc">
          DROP TO LOAD
        </div>
      )}
    </div>
  );
}