/*
 * MIT License
 *
 * Copyright (c) 2020-present Cloudogu GmbH and Contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
import React, { FC, useEffect, useState } from "react";
import DiffFile from "./DiffFile";
import { DiffObjectProps, FileControlFactory } from "./DiffTypes";
import { FileDiff } from "@scm-manager/ui-types";
import { getAnchorSelector, getFileNameFromHash } from "./diffs";
import Notification from "../Notification";
import { useTranslation } from "react-i18next";
import { useLocation } from "react-router-dom";
import useScrollToElement from "../useScrollToElement";
import { getAnchorId } from "./diff/helpers";

type Props = DiffObjectProps & {
  diff: FileDiff[];
  fileControlFactory?: FileControlFactory;
  ignoreWhitespace?: string;
  fetchNextPage?: () => void;
  isFetchingNextPage?: boolean;
  isDataPartial?: boolean;
};

const createKey = (file: FileDiff, ignoreWhitespace?: string) => {
  // we need to include the information about hidden whitespace in the key, because otherwise the diff might not be
  // rendered correctly, if the user toggles the ignore whitespace button
  return `${file.oldPath}@${file.oldRevision}/${file.newPath}@${file.newRevision}?${ignoreWhitespace}`;
};

const getFile = (files: FileDiff[] | undefined, path: string): FileDiff | undefined => {
  return files?.find((e) => (e.type !== "delete" && e.newPath === path) || (e.type === "delete" && e.oldPath === path));
};

const selectFromHash = (hash: string) => {
  const fileName = getFileNameFromHash(hash);
  return fileName ? getAnchorSelector(fileName) : undefined;
};

const jumpToBottom = () => {
  window.scrollTo(0, document.body.scrollHeight);
};

const Diff: FC<Props> = ({
  diff,
  ignoreWhitespace,
  fetchNextPage,
  isFetchingNextPage,
  isDataPartial,
  ...fileProps
}) => {
  const [t] = useTranslation("repos");
  const [contentRef, setContentRef] = useState<HTMLElement | null>();
  const { hash } = useLocation();

  useEffect(() => {
    if (isFetchingNextPage) {
      jumpToBottom();
    }
  }, [isFetchingNextPage]);

  useScrollToElement(
    contentRef,
    () => {
      if (isFetchingNextPage === undefined || isDataPartial === undefined || fetchNextPage === undefined) {
        return selectFromHash(hash);
      }

      const encodedFileName = getFileNameFromHash(hash);
      if (!encodedFileName) {
        return;
      }

      const selectedFile = getFile(diff, decodeURIComponent(encodedFileName));
      if (selectedFile) {
        return getAnchorSelector(getAnchorId(selectedFile));
      }

      if (isDataPartial && !isFetchingNextPage) {
        fetchNextPage();
      }
    },
    [hash]
  );

  return (
    <div ref={setContentRef}>
      {diff.length === 0 ? (
        <Notification type="info">{t("diff.noDiffFound")}</Notification>
      ) : (
        diff.map((file) => <DiffFile key={createKey(file, ignoreWhitespace)} file={file} {...fileProps} />)
      )}
    </div>
  );
};

Diff.defaultProps = {
  sideBySide: false,
};

export default Diff;