import { type ChangeEvent, type MouseEvent as ReactMouseEvent, type RefObject, useMemo } from "react";
import Icon from "../common/Icon";
import { WorkspaceTreeGroup } from "~/features/platform/WorkspaceTree";
import { useScriptWorkspaceStore } from "~/features/platform/state/scriptWorkspaceStore";
import type { ScriptItem, WorkspaceDirectory } from "~/services/api";
import { type AuthUser } from "~/context/AuthContext";
import type { ResourceItem } from "~/services/api";

type ScriptExplorerProps = {
  scripts: ScriptItem[];
  filteredScripts: ScriptItem[];
  directories: WorkspaceDirectory[];
  dataResources: ResourceItem[];
  user: AuthUser | null;
  selectedId: string | null;
  loading: boolean;
  refreshing: boolean;
  uploading: boolean;
  keyword: string;
  onKeywordChange: (keyword: string) => void;
  onRefresh: () => void;
  onUpload: () => void;
  onOpenCreateDialog: (parentPath?: string, scriptType?: "notebook" | "python") => void;
  onOpenFolderDialog: (parentPath?: string) => void;
  onChooseUpload: (parentPath?: string) => void;
  onContextMenu: (
    event: ReactMouseEvent,
    target: { kind: "root" | "directory" | "file"; path: string; script?: ScriptItem }
  ) => void;
  onSelect: (scriptId: string) => void;
  onCopyResourcePath: (jupyterPath: string) => void;
  uploadInputRef: RefObject<HTMLInputElement | null>;
  onHandleUpload: (event: ChangeEvent<HTMLInputElement>) => void;
};

export function ScriptExplorer({
  scripts,
  filteredScripts,
  directories,
  dataResources,
  user,
  selectedId,
  loading,
  refreshing,
  uploading,
  keyword,
  onKeywordChange,
  onRefresh,
  onUpload,
  onOpenCreateDialog,
  onOpenFolderDialog,
  onChooseUpload,
  onContextMenu,
  onSelect,
  onCopyResourcePath,
  uploadInputRef,
  onHandleUpload,
}: ScriptExplorerProps) {
  const expandedPaths = useScriptWorkspaceStore((s) => s.expandedPaths);
  const loadingChildrenPaths = useScriptWorkspaceStore(
    (s) => s.loadingChildrenPaths,
  );
  const onToggle = useScriptWorkspaceStore((s) => s.toggleExpanded);

  const dataByOwner = useMemo(() => {
    const map = new Map<string, ResourceItem[]>();
    for (const r of dataResources) {
      const list = map.get(r.owner_user_id) ?? [];
      list.push(r);
      map.set(r.owner_user_id, list);
    }
    return map;
  }, [dataResources]);

  const memberScriptGroups = useMemo(() => {
    const visibleScripts =
      user?.is_system_admin === true
        ? filteredScripts
        : filteredScripts.filter(
            (item) =>
              item.owner_user_id === user?.user_id ||
              item.visibility === "workspace" ||
              item.visibility === "public",
          );

    const byOwner = new Map<string, ScriptItem[]>();
    // 当前用户的目录树即使没有脚本也要渲染，所以预置空组。
    if (user?.user_id) {
      byOwner.set(user.user_id, []);
    }
    for (const item of visibleScripts) {
      const list = byOwner.get(item.owner_user_id) ?? [];
      list.push(item);
      byOwner.set(item.owner_user_id, list);
    }

    // data-only owner(只有数据资源、没有 scripts 的用户)也要出现在分组里,
    // 因为 data resources 与 scripts 共享同一棵目录树。
    for (const ownerUserId of dataByOwner.keys()) {
      if (!byOwner.has(ownerUserId)) {
        byOwner.set(ownerUserId, []);
      }
    }

    const groups: {
      user: AuthUser | null;
      scripts: ScriptItem[];
      directories: WorkspaceDirectory[];
      dataResources: ResourceItem[];
    }[] = [];
    for (const [ownerUserId, groupScripts] of byOwner.entries()) {
      const groupDataResources = dataByOwner.get(ownerUserId) ?? [];
      // data-only owner（没有 scripts 的用户）回退到 data resources 的
      // owner_display_name，否则 data-only owner 前端只能显示 userId 末 6 位。
      const displayName =
        groupScripts[0]?.owner_display_name ??
        groupDataResources[0]?.owner_display_name ??
        (ownerUserId === user?.user_id ? user?.display_name : null) ??
        `${ownerUserId.slice(-6)}…`;
      const groupUser =
        ownerUserId === user?.user_id
          ? user
          : ({
              user_id: ownerUserId,
              username: ownerUserId,
              display_name: displayName,
              email: null,
              status: "unknown",
              role_code: null,
              is_system_admin: false,
            } as AuthUser);
      const inferred = inferredDirectories(groupScripts);
      groups.push({
        user: groupUser,
        scripts: groupScripts,
        directories:
          ownerUserId === user?.user_id
            ? mergeDirectories(directories, inferred)
            : inferred,
        dataResources: groupDataResources,
      });
    }

    groups.sort((a, b) => {
      if (a.user?.user_id === user?.user_id) return -1;
      if (b.user?.user_id === user?.user_id) return 1;
      return (a.user?.user_id ?? "").localeCompare(b.user?.user_id ?? "");
    });

    return groups;
  }, [filteredScripts, directories, user, dataByOwner]);

  return (
    <aside className="explorer">
      <div className="explorer__header">
        <div>
          <h2>脚本目录</h2>
          <span>{scripts.length + dataResources.length} 个工作副本</span>
        </div>
        <div className="explorer__actions">
          <button
            className="text-button"
            type="button"
            disabled={uploading}
            onClick={onUpload}
          >
            <Icon name="upload" size={15} />
            {uploading ? "上传中…" : "上传"}
          </button>
          <input
            ref={uploadInputRef}
            className="visually-hidden"
            type="file"
            accept=".py,.ipynb,.csv,.xlsx,.xls,.tsv,.json,.parquet,.txt"
            multiple
            onChange={onHandleUpload}
          />
          <button
            className="text-button"
            type="button"
            onClick={() => onOpenCreateDialog()}
          >
            <Icon name="plus" size={16} />
            新建
          </button>
        </div>
      </div>

      <div className="search-box">
        <Icon name="search" size={17} />
        <input
          aria-label="搜索脚本"
          placeholder="搜索脚本名称"
          value={keyword}
          onChange={(event) => onKeywordChange(event.target.value)}
        />
        <button
          className={refreshing ? "is-spinning" : ""}
          type="button"
          aria-label="刷新脚本"
          onClick={onRefresh}
        >
          <Icon name="refresh" size={16} />
        </button>
      </div>

      <div className="tree-scroll">
        {loading ? (
          <div className="tree-skeleton">
            <span /><span /><span /><span />
          </div>
        ) : (
          <>
            {memberScriptGroups.map((group) => {
              const ownerKey = group.user?.user_id ?? "anon";
              return (
                <WorkspaceTreeGroup
                  key={ownerKey}
                  groupKey={`__group__${ownerKey}`}
                  title={`${group.user?.display_name}`}
                  scripts={group.scripts}
                  directories={group.directories}
                  dataResources={group.dataResources}
                  selectedId={selectedId}
                  onSelect={onSelect}
                  onContextMenu={
                    group.user?.user_id === user?.user_id
                      ? onContextMenu
                      : undefined
                  }
                  readOnly={group.user?.user_id !== user?.user_id}
                  expandedPaths={expandedPaths}
                  onToggle={onToggle}
                  loadingChildrenPaths={loadingChildrenPaths}
                  onCopyResourcePath={onCopyResourcePath}
                />
              );
            })}
            {filteredScripts.length === 0 && directories.length === 0 && (
              <div className="tree-empty">
                <span className="tree-empty__icon">
                  <Icon name="script" size={24} />
                </span>
                <strong>{keyword ? "没有匹配脚本" : "还没有构建脚本"}</strong>
                <p>
                  {keyword
                    ? "换个关键词试试"
                    : "新建 Notebook 或 Python 脚本开始实验"}
                </p>
                {!keyword && (
                  <button type="button" onClick={() => onOpenCreateDialog()}>
                    <Icon name="plus" size={15} />
                    新建脚本
                  </button>
                )}
              </div>
            )}
          </>
        )}
      </div>
    </aside>
  );
}

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

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

function inferredDirectories(items: ScriptItem[]): WorkspaceDirectory[] {
  const result = new Map<string, WorkspaceDirectory>();
  for (const item of items) {
    const parts = parentOf(ownedScriptPath(item)).split("/").filter(Boolean);
    let parentPath = "";
    for (const name of parts) {
      const path = parentPath ? `${parentPath}/${name}` : name;
      result.set(path, { path, name, parent_path: parentPath });
      parentPath = path;
    }
  }
  return [...result.values()];
}

function mergeDirectories(
  left: WorkspaceDirectory[],
  right: WorkspaceDirectory[],
): WorkspaceDirectory[] {
  return [...new Map(
    [...left, ...right].map((item) => [item.path, item]),
  ).values()];
}