import { type MouseEvent as ReactMouseEvent, useEffect } from "react";

import Icon from "../../components/common/Icon";
import type {
  ScriptItem,
  WorkspaceDirectory,
} from "~/services/api";

export type WorkspaceTreeTarget = {
  kind: "root" | "directory" | "file";
  path: string;
  script?: ScriptItem;
};

type WorkspaceTreeProps = {
  title: string;
  scripts: ScriptItem[];
  directories: WorkspaceDirectory[];
  selectedId: string | null;
  onSelect: (id: string) => void;
  onContextMenu?: (
    event: ReactMouseEvent,
    target: WorkspaceTreeTarget,
  ) => void;
  readOnly?: boolean;
  // 唯一标识此 group（通常 `__group__<owner_user_id>`），让多个 owner 的 group 各自独立展开。
  groupKey: string;
  expandedPaths: Set<string>;
  onToggle: (path: string, loadPath?: string) => void;
  loadingChildrenPaths: Set<string>;
};

type WorkspaceTreeItemsProps = Omit<WorkspaceTreeProps, "title" | "readOnly"> & {
  path: string;
  depth: number;
};

function formatTime(value: string) {
  return new Intl.DateTimeFormat("zh-CN", {
    month: "2-digit",
    day: "2-digit",
    hour: "2-digit",
    minute: "2-digit",
    hour12: false,
  }).format(new Date(value));
}

export function scriptIcon(item: ScriptItem) {
  return item.script_type === "notebook" ? "notebook" : "python";
}

function ownedScriptPath(item: ScriptItem) {
  return item.relative_path.replaceAll("\\", "/").split("/").slice(2).join("/");
}

function parentOf(path: string) {
  const parts = path.split("/");
  parts.pop();
  return parts.join("/");
}

export function WorkspaceTreeGroup({
  title,
  scripts,
  directories,
  selectedId,
  onSelect,
  onContextMenu,
  readOnly = false,
  groupKey,
  expandedPaths,
  onToggle,
  loadingChildrenPaths,
}: WorkspaceTreeProps) {
  const open = expandedPaths.has(groupKey);
  // 首次挂载自动展开（保留原本 useState(true) 的默认展开行为）。
  // toggleExpanded 内识别 `__group__` 前缀，不会触发 loadChildren。
  useEffect(() => {
    if (!expandedPaths.has(groupKey)) {
      void onToggle(groupKey);
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [groupKey]);
  return (
    <div className="tree-group">
      <button
        className={`tree-group__title${open ? " is-open" : ""}`}
        type="button"
        aria-expanded={open}
        onClick={() => onToggle(groupKey)}
        onContextMenu={onContextMenu
          ? (event) => onContextMenu(event, { kind: "root", path: "" })
          : undefined}
      >
        <Icon name="chevron" size={14} />
        <Icon name="folder" size={17} />
        <span>{title}</span>
        <em>{scripts.length}</em>
      </button>
      {open && (
        <div className="tree-group__items">
          <WorkspaceTreeItems
            groupKey={groupKey}
            path=""
            depth={0}
            scripts={scripts}
            directories={directories}
            selectedId={selectedId}
            onSelect={onSelect}
            onContextMenu={onContextMenu}
            expandedPaths={expandedPaths}
            onToggle={onToggle}
            loadingChildrenPaths={loadingChildrenPaths}
          />
          {scripts.length === 0 && directories.length === 0 && (
            <p className="tree-group__empty">
              {readOnly ? "暂无文件" : "右键此目录即可新建或上传"}
            </p>
          )}
        </div>
      )}
    </div>
  );
}

function WorkspaceTreeItems({
  groupKey,
  path,
  depth,
  scripts,
  directories,
  selectedId,
  onSelect,
  onContextMenu,
  expandedPaths,
  onToggle,
  loadingChildrenPaths,
}: WorkspaceTreeItemsProps) {
  const childDirectories = directories.filter(
    (item) => item.parent_path === path,
  );
  const childScripts = scripts.filter(
    (item) => parentOf(ownedScriptPath(item)) === path,
  );
  return (
    <>
      {childDirectories.map((directory) => (
        <DirectoryBranch
          key={directory.path}
          groupKey={groupKey}
          directory={directory}
          depth={depth}
          scripts={scripts}
          directories={directories}
          selectedId={selectedId}
          onSelect={onSelect}
          onContextMenu={onContextMenu}
          expandedPaths={expandedPaths}
          onToggle={onToggle}
          loadingChildrenPaths={loadingChildrenPaths}
        />
      ))}
      {childScripts.map((item) => (
        <button
          className={`script-row${
            selectedId === item.script_id ? " script-row--active" : ""
          }`}
          style={{ paddingLeft: 20 + depth * 16 }}
          key={item.script_id}
          type="button"
          onClick={() => onSelect(item.script_id)}
          onContextMenu={onContextMenu
            ? (event) => onContextMenu(event, {
              kind: "file",
              path: ownedScriptPath(item),
              script: item,
            })
            : undefined}
        >
            <span className={`file-icon file-icon--${item.script_type}`}>
              <Icon name={scriptIcon(item)} size={17} />
            </span>
            <span className="script-row__copy">
              <strong title={item.script_name}>{item.script_name}</strong>
              <small>{formatTime(item.updated_at)}</small>
            </span>
            {item.is_locked && (
              <span className="lock-badge" title="已锁定">
                <Icon name="lock" size={12} />
              </span>
            )}
            {item.visibility !== "private" && (
              <span className="visibility-dot" title="Workspace 可见" />
            )}
        </button>
      ))}
    </>
  );
}

function DirectoryBranch({
  groupKey,
  directory,
  depth,
  scripts,
  directories,
  selectedId,
  onSelect,
  onContextMenu,
  expandedPaths,
  onToggle,
  loadingChildrenPaths,
}: Omit<WorkspaceTreeItemsProps, "path"> & {
  directory: WorkspaceDirectory;
}) {
  const expandKey = `${groupKey}/${directory.path}`;
  const open = expandedPaths.has(expandKey);
  const childrenLoading = loadingChildrenPaths.has(directory.path);
  return (
    <div className="directory-branch">
      <button
        className="directory-row"
        style={{ paddingLeft: 10 + depth * 16 }}
        type="button"
        onClick={() => onToggle(expandKey, directory.path)}
        onContextMenu={onContextMenu
          ? (event) => onContextMenu(event, {
            kind: "directory",
            path: directory.path,
          })
          : undefined}
      >
        <span className={`directory-row__chevron${open ? " is-open" : ""}`}>
          <Icon name="chevron" size={13} />
        </span>
        <Icon name="folder" size={17} />
        <strong title={directory.path}>{directory.name}</strong>
        {childrenLoading && <span className="loading-spinner" />}
      </button>
      {open && (
        <WorkspaceTreeItems
          groupKey={groupKey}
          path={directory.path}
          depth={depth + 1}
          scripts={scripts}
          directories={directories}
          selectedId={selectedId}
          onSelect={onSelect}
          onContextMenu={onContextMenu}
          expandedPaths={expandedPaths}
          onToggle={onToggle}
          loadingChildrenPaths={loadingChildrenPaths}
        />
      )}
    </div>
  );
}