import { useState, useCallback, useRef } from "react";
import { Upload, FileArchive, X, AlertCircle, Package } from "lucide-react";

interface ZipUploaderProps {
  onFilesReady: (files: File[], zipName: string) => void;
  disabled?: boolean;
}

export function ZipUploader({ onFilesReady, disabled }: ZipUploaderProps) {
  const [dragActive, setDragActive] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [zipInfo, setZipInfo] = useState<{ name: string; size: string } | null>(null);
  const fileInputRef = useRef<HTMLInputElement>(null);

  const processZip = useCallback(
    async (file: File) => {
      if (!file.name.toLowerCase().endsWith(".zip")) {
        setError("Please upload a .zip file containing car images.");
        return;
      }

      setError(null);
      setZipInfo({
        name: file.name,
        size: `${(file.size / 1024 / 1024).toFixed(2)} MB`,
      });

      const JSZip = (await import("jszip")).default;
      const zip = await JSZip.loadAsync(file);

      const imageFiles: File[] = [];
      const IMAGE_EXTS = /\.(jpe?g|png|webp|gif|bmp)$/i;

      const entries = Object.entries(zip.files).filter(
        ([name, entry]) => !entry.dir && IMAGE_EXTS.test(name)
      );

      if (entries.length === 0) {
        setError("No image files found inside the ZIP archive.");
        setZipInfo(null);
        return;
      }

      for (const [name, entry] of entries) {
        const blob = await entry.async("blob");
        const basename = name.split("/").pop() ?? name;
        const ext = basename.split(".").pop()?.toLowerCase() ?? "jpg";
        const mimeMap: Record<string, string> = {
          jpg: "image/jpeg",
          jpeg: "image/jpeg",
          png: "image/png",
          webp: "image/webp",
          gif: "image/gif",
          bmp: "image/bmp",
        };
        const imgFile = new File([blob], basename, {
          type: mimeMap[ext] ?? "image/jpeg",
        });
        imageFiles.push(imgFile);
      }

      onFilesReady(imageFiles, file.name);
    },
    [onFilesReady]
  );

  const handleDrop = useCallback(
    (e: React.DragEvent) => {
      e.preventDefault();
      setDragActive(false);
      const file = e.dataTransfer.files[0];
      if (file) processZip(file);
    },
    [processZip]
  );

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

  const clearSelection = () => {
    setZipInfo(null);
    setError(null);
  };

  return (
    <div className="w-full">
      {/* Drop Zone */}
      <div
        onClick={() => !disabled && fileInputRef.current?.click()}
        onDragOver={(e) => { e.preventDefault(); if (!disabled) setDragActive(true); }}
        onDragLeave={() => setDragActive(false)}
        onDrop={disabled ? undefined : handleDrop}
        className={[
          "relative cursor-pointer rounded-2xl border-2 border-dashed transition-all duration-300 overflow-hidden",
          "group select-none",
          disabled
            ? "opacity-50 cursor-not-allowed border-surface-500"
            : dragActive
            ? "border-brand-500 bg-brand-500/10 scale-[1.01] shadow-[0_0_40px_rgba(26,107,255,0.2)]"
            : zipInfo
            ? "border-emerald-500/60 bg-emerald-500/5 hover:border-emerald-400"
            : "border-surface-500 hover:border-brand-500/60 hover:bg-brand-500/5",
        ].join(" ")}
      >
        {/* Animated background grid */}
        <div className="absolute inset-0 bg-grid-pattern bg-[size:32px_32px] opacity-20 pointer-events-none" />

        <div className="relative z-10 flex flex-col items-center justify-center py-16 px-8 text-center gap-6">
          {zipInfo ? (
            <>
              <div className="relative">
                <div className="w-20 h-20 rounded-2xl bg-emerald-500/20 border border-emerald-500/30 flex items-center justify-center">
                  <FileArchive className="w-10 h-10 text-emerald-400" />
                </div>
                <div className="absolute -top-2 -right-2 w-6 h-6 rounded-full bg-emerald-500 flex items-center justify-center">
                  <span className="text-white text-xs font-bold">✓</span>
                </div>
              </div>
              <div>
                <p className="text-white font-semibold text-lg">{zipInfo.name}</p>
                <p className="text-slate-400 text-sm mt-1">{zipInfo.size} · Ready to classify</p>
              </div>
              <p className="text-emerald-400 text-sm font-medium">
                Click to replace with a different ZIP
              </p>
            </>
          ) : (
            <>
              <div
                className={[
                  "w-24 h-24 rounded-2xl flex items-center justify-center transition-all duration-300",
                  "bg-surface-600 border border-surface-500",
                  "group-hover:bg-brand-500/20 group-hover:border-brand-500/40",
                  dragActive ? "bg-brand-500/20 border-brand-500/40 scale-110" : "",
                ].join(" ")}
              >
                {dragActive ? (
                  <Package className="w-12 h-12 text-brand-400 animate-bounce-subtle" />
                ) : (
                  <Upload className="w-12 h-12 text-slate-400 group-hover:text-brand-400 transition-colors" />
                )}
              </div>

              <div className="space-y-2">
                <h3 className="text-2xl font-bold text-white">
                  {dragActive ? "Drop your ZIP here" : "Upload Car Photos ZIP"}
                </h3>
                <p className="text-slate-400 text-base max-w-md">
                  Drag & drop a <span className="text-brand-400 font-semibold">.zip archive</span> containing
                  car photos, or <span className="text-brand-400 font-semibold">click to browse</span>
                </p>
              </div>

              <div className="flex items-center gap-6 text-sm text-slate-500">
                <div className="flex items-center gap-2">
                  <div className="w-1.5 h-1.5 rounded-full bg-brand-500" />
                  <span>JPG, PNG, WEBP supported</span>
                </div>
                <div className="flex items-center gap-2">
                  <div className="w-1.5 h-1.5 rounded-full bg-brand-500" />
                  <span>Multiple images in one ZIP</span>
                </div>
                <div className="flex items-center gap-2">
                  <div className="w-1.5 h-1.5 rounded-full bg-brand-500" />
                  <span>Detects 8 car angles</span>
                </div>
              </div>
            </>
          )}
        </div>

        <input
          ref={fileInputRef}
          type="file"
          accept=".zip"
          onChange={handleFileSelect}
          className="hidden"
          disabled={disabled}
        />
      </div>

      {/* Error */}
      {error && (
        <div className="mt-4 flex items-center gap-3 p-4 rounded-xl bg-red-500/10 border border-red-500/30 text-red-400 animate-fade-in">
          <AlertCircle className="w-5 h-5 flex-shrink-0" />
          <span className="text-sm">{error}</span>
          <button
            onClick={clearSelection}
            className="ml-auto hover:text-red-300 transition-colors"
          >
            <X className="w-4 h-4" />
          </button>
        </div>
      )}
    </div>
  );
}