import { useCallback, useState } from "react";
import { FileItem, UploadStatus } from "../types";

export function useFileUpload() {
  const [files, setFiles] = useState<FileItem[]>([]);
  const [isUploading, setIsUploading] = useState(false);

  // ✅ App.tsx + FileUploader truyền FileItem[]
  const addFiles = useCallback((items: FileItem[]) => {
    setFiles((prev) => [...prev, ...items]);
  }, []);

  const removeFile = useCallback((id: string) => {
    setFiles((prev) => prev.filter((f) => f.id !== id));
  }, []);

  const updateFilePath = useCallback((id: string, path: string) => {
    setFiles((prev) =>
      prev.map((f) => (f.id === id ? { ...f, path } : f))
    );
  }, []);

  const uploadOne = useCallback((item: FileItem) => {
    return new Promise<void>((resolve, reject) => {
      const form = new FormData();
      form.append("file", item.file);
      form.append("path", item.path);

      const xhr = new XMLHttpRequest();
      xhr.open("POST", "/api/upload");

      xhr.upload.onprogress = (e) => {
        if (!e.lengthComputable) return;
        const percent = Math.round((e.loaded / e.total) * 100);

        setFiles((prev) =>
          prev.map((f) =>
            f.id === item.id
              ? {
                  ...f,
                  progress: percent,
                  status: UploadStatus.UPLOADING,
                }
              : f
          )
        );
      };

      xhr.onload = () => {
        if (xhr.status >= 200 && xhr.status < 300) {
          const res = JSON.parse(xhr.responseText);
          setFiles((prev) =>
            prev.map((f) =>
              f.id === item.id
                ? {
                    ...f,
                    progress: 100,
                    status: UploadStatus.SUCCESS,
                    url: res.url,
                  }
                : f
            )
          );
          resolve();
        } else {
          setFiles((prev) =>
            prev.map((f) =>
              f.id === item.id
                ? { ...f, status: UploadStatus.ERROR }
                : f
            )
          );
          reject(new Error("Upload failed"));
        }
      };

      xhr.onerror = () => {
        setFiles((prev) =>
          prev.map((f) =>
            f.id === item.id
              ? { ...f, status: UploadStatus.ERROR }
              : f
          )
        );
        reject(new Error("Network error"));
      };

      xhr.send(form);
    });
  }, []);

  const startUpload = useCallback(async () => {
    if (isUploading) return;
    setIsUploading(true);

    try {
      for (const f of files) {
        if (
          f.status === UploadStatus.IDLE ||
          f.status === UploadStatus.ERROR
        ) {
          await uploadOne(f);
        }
      }
    } finally {
      setIsUploading(false);
    }
  }, [files, uploadOne, isUploading]);

  return {
    files,
    isUploading,
    addFiles,
    removeFile,
    updateFilePath,
    startUpload,
  };
}