"use client";

import { useCallback, useRef, useState } from "react";
import {
  Upload,
  ImageIcon,
  Link2,
  Check,
  Loader2,
  X,
  Copy,
} from "lucide-react";

interface UploadedPhoto {
  id: string;
  url: string;
  originalName: string;
}

export function UploadZone() {
  const [isDragging, setIsDragging] = useState(false);
  const [isUploading, setIsUploading] = useState(false);
  const [uploaded, setUploaded] = useState<UploadedPhoto | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [copied, setCopied] = useState(false);
  const inputRef = useRef<HTMLInputElement>(null);

  const uploadFile = useCallback(async (file: File) => {
    if (!file.type.startsWith("image/")) {
      setError("Можно загружать только изображения");
      return;
    }

    if (file.size > 10 * 1024 * 1024) {
      setError("Максимальный размер файла — 10 МБ");
      return;
    }

    setError(null);
    setIsUploading(true);
    setUploaded(null);

    const formData = new FormData();
    formData.append("file", file);

    try {
      const res = await fetch("/api/upload", {
        method: "POST",
        body: formData,
      });

      if (!res.ok) {
        const data = await res.json();
        throw new Error(data.error || "Ошибка загрузки");
      }

      const photo = await res.json();
      setUploaded(photo);
      window.dispatchEvent(new CustomEvent("photo-uploaded", { detail: photo }));
    } catch (err) {
      setError(err instanceof Error ? err.message : "Ошибка загрузки");
    } finally {
      setIsUploading(false);
    }
  }, []);

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

  const handleCopy = async () => {
    if (!uploaded) return;
    const fullUrl = `${window.location.origin}${uploaded.url}`;
    await navigator.clipboard.writeText(fullUrl);
    setCopied(true);
    setTimeout(() => setCopied(false), 2000);
  };

  const reset = () => {
    setUploaded(null);
    setError(null);
    setCopied(false);
  };

  return (
    <section id="upload" className="px-6 py-16">
      <div className="mx-auto max-w-2xl">
        <div
          onDragOver={(e) => {
            e.preventDefault();
            setIsDragging(true);
          }}
          onDragLeave={() => setIsDragging(false)}
          onDrop={handleDrop}
          onClick={() => !isUploading && !uploaded && inputRef.current?.click()}
          className={`group relative cursor-pointer rounded-3xl border-2 border-dashed p-12 text-center transition-all duration-300 ${
            isDragging
              ? "border-indigo-400 bg-indigo-500/10 glow"
              : "border-border hover:border-indigo-500/50 hover:bg-surface/50"
          } ${uploaded ? "cursor-default border-emerald-500/30 bg-emerald-500/5" : ""}`}
        >
          <input
            ref={inputRef}
            type="file"
            accept="image/*"
            className="hidden"
            onChange={(e) => {
              const file = e.target.files?.[0];
              if (file) uploadFile(file);
              e.target.value = "";
            }}
          />

          {isUploading ? (
            <div className="flex flex-col items-center gap-4">
              <Loader2 className="h-12 w-12 animate-spin text-indigo-400" />
              <p className="text-lg font-medium">Загрузка...</p>
            </div>
          ) : uploaded ? (
            <div className="flex flex-col items-center gap-5">
              <div className="flex h-16 w-16 items-center justify-center rounded-2xl bg-emerald-500/20">
                <Check className="h-8 w-8 text-emerald-400" />
              </div>
              <div>
                <p className="text-lg font-medium text-emerald-400">
                  Фото загружено!
                </p>
                <p className="mt-1 text-sm text-muted">{uploaded.originalName}</p>
              </div>
              <div className="flex w-full max-w-md items-center gap-2 rounded-xl bg-surface p-3">
                <Link2 className="h-4 w-4 shrink-0 text-muted" />
                <input
                  readOnly
                  value={`${typeof window !== "undefined" ? window.location.origin : ""}${uploaded.url}`}
                  className="flex-1 bg-transparent text-sm outline-none"
                />
                <button
                  onClick={(e) => {
                    e.stopPropagation();
                    handleCopy();
                  }}
                  className="shrink-0 rounded-lg bg-indigo-500/20 p-2 transition-colors hover:bg-indigo-500/30"
                >
                  {copied ? (
                    <Check className="h-4 w-4 text-emerald-400" />
                  ) : (
                    <Copy className="h-4 w-4 text-indigo-400" />
                  )}
                </button>
              </div>
              <button
                onClick={(e) => {
                  e.stopPropagation();
                  reset();
                }}
                className="text-sm text-muted transition-colors hover:text-foreground"
              >
                Загрузить ещё
              </button>
            </div>
          ) : (
            <div className="flex flex-col items-center gap-4">
              <div className="flex h-16 w-16 items-center justify-center rounded-2xl bg-indigo-500/10 transition-transform group-hover:scale-110">
                <Upload className="h-8 w-8 text-indigo-400" />
              </div>
              <div>
                <p className="text-lg font-medium">
                  Перетащите фото сюда
                </p>
                <p className="mt-1 text-sm text-muted">
                  или нажмите для выбора файла
                </p>
              </div>
              <div className="mt-2 flex items-center gap-4 text-xs text-muted">
                <span className="flex items-center gap-1">
                  <ImageIcon className="h-3.5 w-3.5" />
                  JPG, PNG, GIF, WebP
                </span>
                <span>до 10 МБ</span>
              </div>
            </div>
          )}
        </div>

        {error && (
          <div className="mt-4 flex items-center gap-2 rounded-xl border border-red-500/20 bg-red-500/10 px-4 py-3 text-sm text-red-400">
            <X className="h-4 w-4 shrink-0" />
            {error}
          </div>
        )}
      </div>
    </section>
  );
}