"use client";

import React, { useState, useRef, useCallback } from "react";
import { Button } from "@/components/ui/button";
import { Upload, X, Loader2, FileText, ExternalLink } from "lucide-react";
import { cn } from "@/lib/utils";
import { apiClient } from "@/lib/api/client";
import { toast } from "sonner";

interface PdfUploadProps {
  value?: string;
  onChange?: (value: string) => void;
  tableName?: string;
  recordId?: string;
  columnName?: string;
  height?: string;
  disabled?: boolean;
  className?: string;
}

export function PdfUpload({
  value, onChange, tableName, recordId, columnName,
  height = "h-40", disabled = false, className,
}: PdfUploadProps) {
  const [uploading, setUploading] = useState(false);
  const [dragOver, setDragOver] = useState(false);
  const fileRef = useRef<HTMLInputElement>(null);

  const apiBase = typeof window !== "undefined"
    ? (process.env.NEXT_PUBLIC_API_URL || "").replace(/\/api\/?$/, "")
    : "";
  const pdfUrl = value
    ? (value.startsWith("http") || value.startsWith("/"))
      ? value
      : `${apiBase}/api/files/preview/${value}`
    : null;

  const handleUpload = useCallback(async (file: File) => {
    const isPdf = file.type === "application/pdf" || file.name.toLowerCase().endsWith(".pdf");
    if (!isPdf) {
      toast.error("PDF 파일만 업로드 가능합니다.");
      return;
    }
    if (file.size > 20 * 1024 * 1024) {
      toast.error("파일 크기는 20MB 이하만 가능합니다.");
      return;
    }

    setUploading(true);
    try {
      const formData = new FormData();
      formData.append("files", file);
      formData.append("docType", "PDF");
      formData.append("docTypeName", "도면PDF");
      if (tableName) formData.append("linkedTable", tableName);
      if (recordId) formData.append("recordId", recordId);
      if (columnName) formData.append("columnName", columnName);
      if (tableName && recordId) {
        formData.append("autoLink", "true");
        if (columnName) formData.append("isVirtualFileColumn", "true");
      }

      const res = await apiClient.post("/files/upload", formData, {
        headers: { "Content-Type": "multipart/form-data" },
      });

      if (res.data?.success && (res.data.files?.length > 0 || res.data.data?.length > 0)) {
        const uploaded = res.data.files?.[0] || res.data.data?.[0];
        const objid = uploaded.objid;
        onChange?.(objid);
        toast.success("PDF가 업로드되었습니다.");
      } else {
        toast.error(res.data?.message || "업로드에 실패했습니다.");
      }
    } catch (err: any) {
      console.error("PDF 업로드 실패:", err);
      toast.error(err.response?.data?.message || "업로드에 실패했습니다.");
    } finally {
      setUploading(false);
    }
  }, [tableName, recordId, columnName, onChange]);

  const handleFileChange = (e: React.ChangeEvent<HTMLInputElement>) => {
    const file = e.target.files?.[0];
    if (file) handleUpload(file);
    e.target.value = "";
  };

  const handleDrop = (e: React.DragEvent) => {
    e.preventDefault();
    setDragOver(false);
    const file = e.dataTransfer.files?.[0];
    if (file) handleUpload(file);
  };

  const handleRemove = () => onChange?.("");

  const handleOpen = (e: React.MouseEvent) => {
    e.stopPropagation();
    if (pdfUrl) window.open(pdfUrl, "_blank", "noopener,noreferrer");
  };

  return (
    <div className={cn("relative", className)}>
      <div
        className={cn(
          "border-2 border-dashed rounded-lg flex flex-col items-center justify-center cursor-pointer transition-colors overflow-hidden",
          height,
          dragOver ? "border-primary bg-primary/5" : pdfUrl ? "border-primary/40 bg-muted/20" : "border-muted-foreground/25 hover:border-primary hover:bg-muted/50",
          disabled && "opacity-50 cursor-not-allowed",
        )}
        onClick={() => !disabled && !uploading && fileRef.current?.click()}
        onDragOver={(e) => { e.preventDefault(); if (!disabled) setDragOver(true); }}
        onDragLeave={() => setDragOver(false)}
        onDrop={!disabled ? handleDrop : undefined}
      >
        {uploading ? (
          <div className="flex flex-col items-center gap-2">
            <Loader2 className="h-8 w-8 animate-spin text-muted-foreground" />
            <span className="text-xs text-muted-foreground">업로드 중...</span>
          </div>
        ) : pdfUrl ? (
          <div className="flex flex-col items-center gap-2">
            <FileText className="h-10 w-10 text-primary" />
            <span className="text-xs text-foreground font-medium">PDF 업로드됨</span>
            <Button variant="outline" size="sm" className="h-7 text-xs" onClick={handleOpen}>
              <ExternalLink className="h-3 w-3 mr-1" /> 새 탭에서 열기
            </Button>
          </div>
        ) : (
          <div className="flex flex-col items-center gap-2">
            <Upload className="h-8 w-8 text-muted-foreground/50" />
            <span className="text-xs text-muted-foreground">PDF 클릭 또는 드래그하여 업로드</span>
          </div>
        )}
      </div>

      {pdfUrl && !disabled && (
        <Button variant="destructive" size="sm" className="absolute top-1 right-1 h-6 w-6 p-0 rounded-full"
          onClick={(e) => { e.stopPropagation(); handleRemove(); }}>
          <X className="h-3 w-3" />
        </Button>
      )}

      <input ref={fileRef} type="file" accept="application/pdf,.pdf" onChange={handleFileChange} className="hidden" />
    </div>
  );
}