kandev/apps/web/components/task/file-editor-panel.tsx

"use client";

import { memo, useCallback, useEffect, useMemo, useRef } from "react";
import { PanelRoot, PanelBody } from "./panel-primitives";
import { FileEditorContent, type FileEditorContentProps } from "./file-editor-content";
import { FileImageViewer } from "./file-image-viewer";
import { FileBinaryViewer } from "./file-binary-viewer";
import { useAppStore } from "@/components/state-provider";
import { useDockviewStore, type FileEditorState } from "@/lib/state/dockview-store";
import { useFileEditors } from "@/hooks/use-file-editors";
import { useSessionGitStatus } from "@/hooks/domains/session/use-session-git-status";
import { getFileCategory, getFilePreviewKind } from "@/lib/utils/file-types";
import { getWebSocketClient } from "@/lib/ws/connection";
import { requestFileContent } from "@/lib/ws/workspace-files";
import { calculateHash } from "@/lib/utils/file-diff";
import { panelPortalManager } from "@/lib/layout/panel-portal-manager";
import { syncOpenFileFromWorkspace } from "@/hooks/file-editors-sync";
import { buildRepoScopedItemId } from "@/lib/state/dockview-panel-actions";
import { FileViewerDownloadButton, FileViewerExternalLink } from "./file-viewer-header";
import { triggerFileDownload } from "@/lib/utils/file-download";
import { getSessionWorkspacePath } from "@/lib/session-workspace-path";
import { useTranslation } from "react-i18next";

type FileCategory = "image" | "binary" | "text";

function resolveFileCategory(isBinary: boolean, path: string): FileCategory {
  if (!isBinary) return "text";
  return getFileCategory(path) === "image" ? "image" : "binary";
}

function ImagePanel({
  fileKey,
  path,
  worktreePath,
  headerActions,
}: {
  fileKey: string;
  path: string;
  worktreePath: string | undefined;
  headerActions?: React.ReactNode;
}) {
  const isSymlink = useDockviewStore((s) => !!s.openFiles.get(fileKey)?.resolvedPath);
  const content = useDockviewStore((s) => s.openFiles.get(fileKey)?.content ?? "");
  return (
    <PanelRoot>
      <PanelBody padding={false} scroll={false}>
        <FileImageViewer
          isSymlink={isSymlink}
          path={path}
          content={content}
          worktreePath={worktreePath}
          headerActions={headerActions}
        />
      </PanelBody>
    </PanelRoot>
  );
}

type StaticFilePanelProps = {
  category: Exclude<FileCategory, "text">;
  fileKey: string;
  path: string;
  worktreePath?: string;
  sessionId: string | null;
  taskId: string | null;
  repositoryId?: string;
  repositoryName?: string;
};

/**
 * Download the open file from the copy already in the dockview store.
 *
 * The viewer only renders after `useFileLoader` resolves, so the bytes are
 * always in hand here and no refetch is needed. Binary content is base64,
 * matching the `workspace.file.get` contract `triggerFileDownload` expects.
 */
function useOpenFileDownload(fileKey: string, path: string): (() => void) | undefined {
  const hasFile = useDockviewStore((s) => s.openFiles.has(fileKey));
  const content = useDockviewStore((s) => s.openFiles.get(fileKey)?.content ?? "");
  const isBinary = useDockviewStore((s) => s.openFiles.get(fileKey)?.isBinary ?? false);

  return useMemo(() => {
    if (!hasFile) return undefined;
    return () => triggerFileDownload({ fileName: path, content, isBinary });
  }, [hasFile, path, content, isBinary]);
}

function useLoadedFileDownload(
  hasFile: boolean,
  originalHash: string,
  path: string,
  content: string,
  isBinary: boolean,
): (() => void) | undefined {
  return useMemo(
    () =>
      hasFile && originalHash
        ? () => triggerFileDownload({ fileName: path, content, isBinary })
        : undefined,
    [hasFile, originalHash, path, content, isBinary],
  );
}

function useLoadedFileDownloadForBuffer(
  file: Pick<
    ReturnType<typeof useFileEditorBuffer>,
    "hasFile" | "originalHash" | "content" | "isBinary"
  >,
  path: string,
) {
  return useLoadedFileDownload(file.hasFile, file.originalHash, path, file.content, file.isBinary);
}

type FileEditorPanelActions = Pick<
  ReturnType<typeof useFileEditors>,
  "handleFileChange" | "saveFile" | "deleteFile" | "applyRemoteUpdate"
>;

function useFileEditorPanelActions({
  path,
  repo,
  fileKey,
  renderedPreview,
  updateFileState,
  actions,
}: {
  path: string;
  repo: string | undefined;
  fileKey: string;
  renderedPreview: boolean;
  updateFileState: (path: string, updates: Partial<FileEditorState>) => void;
  actions: FileEditorPanelActions;
}) {
  const { handleFileChange, saveFile, deleteFile, applyRemoteUpdate } = actions;
  const onChange = useCallback(
    (newContent: string) => handleFileChange(path, newContent, repo),
    [handleFileChange, path, repo],
  );
  const onSave = useCallback(() => saveFile(path, repo), [saveFile, path, repo]);
  const onReloadFromAgent = useCallback(
    () => applyRemoteUpdate(path, repo),
    [applyRemoteUpdate, path, repo],
  );
  const onDelete = useCallback(() => deleteFile(path, repo), [deleteFile, path, repo]);
  const onTogglePreview = useCallback(
    () => updateFileState(fileKey, { renderedPreview: !renderedPreview }),
    [updateFileState, fileKey, renderedPreview],
  );
  return { onChange, onSave, onReloadFromAgent, onDelete, onTogglePreview };
}

function StaticFilePanel({
  category,
  fileKey,
  path,
  worktreePath,
  sessionId,
  taskId,
  repositoryId,
  repositoryName,
}: StaticFilePanelProps) {
  const isSymlink = useDockviewStore((s) => !!s.openFiles.get(fileKey)?.resolvedPath);
  const onDownload = useOpenFileDownload(fileKey, path);
  const headerActions = (
    <>
      <FileViewerExternalLink
        path={path}
        sessionId={sessionId}
        taskId={taskId}
        repositoryId={repositoryId}
        repositoryName={repositoryName}
      />
      <FileViewerDownloadButton onDownload={onDownload} />
    </>
  );
  if (category === "image") {
    return (
      <ImagePanel
        fileKey={fileKey}
        path={path}
        worktreePath={worktreePath}
        headerActions={headerActions}
      />
    );
  }
  return (
    <PanelRoot>
      <PanelBody padding={false} scroll={false}>
        <FileBinaryViewer
          isSymlink={isSymlink}
          path={path}
          worktreePath={worktreePath}
          headerActions={headerActions}
        />
      </PanelBody>
    </PanelRoot>
  );
}

type FileLoaderArgs = {
  hasFile: boolean;
  activeSessionId: string | null;
  fileKey: string;
  path: string;
  setFileState: (path: string, state: FileEditorState) => void;
  repo?: string;
};

function useFileLoader({
  hasFile,
  activeSessionId,
  fileKey,
  path,
  setFileState,
  repo,
}: FileLoaderArgs) {
  // Key the in-flight guard by session+path+repo. If any of them changes while
  // a fetch is running, the new effect run starts a fresh fetch (rather than
  // being silently blocked) and the stale response is dropped on arrival — so
  // content from the wrong session/repo can never land in the buffer.
  const inFlightKeyRef = useRef<string | null>(null);
  useEffect(() => {
    if (hasFile || !activeSessionId) return;
    const key = `${activeSessionId}\0${path}\0${repo ?? ""}`;
    if (inFlightKeyRef.current === key) return;
    inFlightKeyRef.current = key;
    const client = getWebSocketClient();
    if (!client) {
      inFlightKeyRef.current = null;
      return;
    }
    requestFileContent(client, activeSessionId, path, repo)
      .then(async (response) => {
        if (inFlightKeyRef.current !== key) return;
        const hash = await calculateHash(response.content);
        const name = path.split("/").pop() || path;
        const state: FileEditorState = {
          path,
          repo,
          name,
          content: response.content,
          originalContent: response.content,
          originalHash: hash,
          isDirty: false,
          isBinary: response.is_binary,
          resolvedPath: response.resolved_path,
        };
        setFileState(fileKey, state);
      })
      .catch(() => {
        /* stays on loading state */
      })
      .finally(() => {
        if (inFlightKeyRef.current === key) inFlightKeyRef.current = null;
      });
  }, [hasFile, activeSessionId, fileKey, path, setFileState, repo]);
}

/**
 * Force a workspace sync whenever the panel becomes the active dockview tab.
 *
 * Background: `useOpenFileWorkspaceSync` (mounted at the parent useFileEditors
 * level) refetches file content when gitStatus signatures change. That signal
 * arrives via the backend's workspace_tracker poll loop, which can be in
 * `PollModeSlow` (30s interval) until the gateway's focus signal upgrades it
 * to `PollModeFast` — there are two documented races in
 * `manager_subscription.go:FlushSessionMode` where the focus signal can miss
 * the mode upgrade for a brief window. When the missed window lines up with a
 * file edit, the editor shows stale content until the next slow-poll cycle.
 *
 * Tab activation is a deterministic, user-driven signal that the editor's
 * content is about to be looked at. Forcing a sync on activation closes the
 * WS-event-miss gap without depending on git polling cadence.
 *
 * Safe by construction: syncOpenFileFromWorkspace is dirty-buffer aware —
 * clean buffers get their content replaced, dirty buffers surface a Reload
 * affordance via `hasRemoteUpdate` rather than clobbering edits.
 */
type ResyncOnTabActivateArgs = {
  panelId: string;
  hasFile: boolean;
  activeSessionId: string | null;
  fileKey: string;
  path: string;
  repo: string | undefined;
  updateFileState: (path: string, updates: Partial<FileEditorState>) => void;
};

function useResyncOnTabActivate({
  panelId,
  hasFile,
  activeSessionId,
  fileKey,
  path,
  repo,
  updateFileState,
}: ResyncOnTabActivateArgs) {
  useEffect(() => {
    if (!hasFile || !activeSessionId) return;
    // panelPortalManager.acquire() runs in usePortalSlot's mount effect (the
    // dockview-side slot), which fires before child portals' effects, so the
    // entry is virtually always present here. There is one acceptable miss:
    // a fromJSON layout restore can swap `entry.api` for the same panelId
    // without remounting this component, which would silently leave the
    // subscription pointing at a disposed api. fromJSON is rare and
    // `useOpenFileWorkspaceSync` still covers the common polling gap, so we
    // accept that edge case rather than wiring a manager-level subscription.
    const entry = panelPortalManager.get(panelId);
    if (!entry?.api) return;
    const syncNow = () => {
      const client = getWebSocketClient();
      if (!client) return;
      void syncOpenFileFromWorkspace({
        client,
        sessionId: activeSessionId,
        fileKey,
        path,
        repo,
        updateFileState,
      });
    };
    // If the panel is already the active tab when this effect first runs,
    // onDidActiveChange won't fire (no transition), but the user is already
    // looking at the editor — sync immediately so the initial open path
    // benefits from the same WS-event-miss recovery as later activations.
    if (entry.api.isActive) syncNow();
    const disposable = entry.api.onDidActiveChange((event) => {
      if (event.isActive) syncNow();
    });
    return () => disposable.dispose();
  }, [panelId, hasFile, activeSessionId, fileKey, path, repo, updateFileState]);
}

type FileEditorPanelProps = {
  panelId: string;
  params: Record<string, unknown>;
};

function useFileEditorBuffer(fileKey: string) {
  const hasFile = useDockviewStore((s) => s.openFiles.has(fileKey));
  const isSymlink = useDockviewStore((s) => !!s.openFiles.get(fileKey)?.resolvedPath);
  const content = useDockviewStore((s) => s.openFiles.get(fileKey)?.content ?? "");
  const isDirty = useDockviewStore((s) => s.openFiles.get(fileKey)?.isDirty ?? false);
  const hasRemoteUpdate = useDockviewStore(
    (s) => s.openFiles.get(fileKey)?.hasRemoteUpdate ?? false,
  );
  const isBinary = useDockviewStore((s) => s.openFiles.get(fileKey)?.isBinary ?? false);
  const originalContent = useDockviewStore((s) => s.openFiles.get(fileKey)?.originalContent ?? "");
  const originalHash = useDockviewStore((s) => s.openFiles.get(fileKey)?.originalHash ?? "");
  const renderedPreview = useDockviewStore(
    (s) => s.openFiles.get(fileKey)?.renderedPreview ?? false,
  );
  return {
    hasFile,
    isSymlink,
    content,
    isDirty,
    hasRemoteUpdate,
    isBinary,
    originalContent,
    originalHash,
    renderedPreview,
  };
}

function LoadingFilePanel() {
  const { t } = useTranslation();
  return (
    <PanelRoot>
      <PanelBody
        padding={false}
        scroll={false}
        className="flex items-center justify-center text-muted-foreground text-sm"
      >
        {t("task:loadingFile")}
      </PanelBody>
    </PanelRoot>
  );
}

type LoadedFilePanelProps = {
  category: FileCategory;
  fileKey: string;
  path: string;
  worktreePath: string | undefined;
  sessionId: string | null;
  taskId: string | null;
  repositoryId: string | undefined;
  repositoryName: string | undefined;
  editorProps: FileEditorContentProps;
};

function LoadedFilePanel({
  category,
  fileKey,
  path,
  worktreePath,
  sessionId,
  taskId,
  repositoryId,
  repositoryName,
  editorProps,
}: LoadedFilePanelProps) {
  if (category !== "text") {
    return (
      <StaticFilePanel
        category={category}
        fileKey={fileKey}
        path={path}
        worktreePath={worktreePath}
        sessionId={sessionId}
        taskId={taskId}
        repositoryId={repositoryId}
        repositoryName={repositoryName}
      />
    );
  }
  return (
    <PanelRoot>
      <PanelBody padding={false} scroll={false}>
        <FileEditorContent {...editorProps} />
      </PanelBody>
    </PanelRoot>
  );
}

function resolveFileEditorPanelState({
  path,
  repo,
  isBinary,
  activeSession,
  activeSessionId,
  activeTaskId,
}: {
  path: string;
  repo: string | undefined;
  isBinary: boolean;
  activeSession: {
    workspace_path?: string | null;
    worktree_path?: string | null;
    repository_id?: string | null;
  } | null;
  activeSessionId: string | null;
  activeTaskId: string | null;
}) {
  return {
    category: resolveFileCategory(isBinary, path),
    previewKind: getFilePreviewKind(path, isBinary),
    panelProps: {
      worktreePath: getSessionWorkspacePath(activeSession),
      sessionId: activeSessionId,
      taskId: activeTaskId,
      repositoryId: activeSession?.repository_id ?? undefined,
      repositoryName: repo,
    },
  };
}

type LoadedFileEditorPanelProps = {
  category: FileCategory;
  fileKey: string;
  panelProps: Pick<
    LoadedFilePanelProps,
    "worktreePath" | "sessionId" | "taskId" | "repositoryId" | "repositoryName"
  >;
  buffer: Pick<
    FileEditorContentProps,
    "isSymlink" | "path" | "content" | "originalContent" | "isDirty" | "hasRemoteUpdate" | "vcsDiff"
  >;
  options: Pick<
    FileEditorContentProps,
    | "isSaving"
    | "sessionId"
    | "taskId"
    | "repositoryId"
    | "worktreePath"
    | "repo"
    | "enableComments"
    | "previewKind"
    | "renderedPreview"
    | "onTogglePreview"
  >;
  actions: Pick<
    FileEditorContentProps,
    "onChange" | "onSave" | "onReloadFromAgent" | "onDelete" | "onDownload"
  >;
};

function LoadedFileEditorPanel({
  category,
  fileKey,
  panelProps,
  buffer,
  options,
  actions,
}: LoadedFileEditorPanelProps) {
  return (
    <LoadedFilePanel
      category={category}
      fileKey={fileKey}
      path={buffer.path}
      {...panelProps}
      editorProps={{ ...buffer, ...options, ...actions }}
    />
  );
}

export const FileEditorPanel = memo(function FileEditorPanel({
  panelId,
  params,
}: FileEditorPanelProps) {
  const path = params.path as string;
  const repo = params.repo as string | undefined;
  const fileKey = buildRepoScopedItemId(path, repo);

  const file = useFileEditorBuffer(fileKey);
  const setFileState = useDockviewStore((s) => s.setFileState);
  const updateFileState = useDockviewStore((s) => s.updateFileState);

  const activeSessionId = useAppStore((state) => state.tasks.activeSessionId);
  const activeTaskId = useAppStore((state) => state.tasks.activeTaskId);
  const activeSession = useAppStore((state) =>
    activeSessionId ? (state.taskSessions.items[activeSessionId] ?? null) : null,
  );
  const gitStatus = useSessionGitStatus(activeSessionId);
  const vcsDiff = gitStatus?.files?.[path]?.diff;
  const { savingFiles, handleFileChange, saveFile, deleteFile, applyRemoteUpdate } =
    useFileEditors();
  useFileLoader({ hasFile: file.hasFile, activeSessionId, fileKey, path, setFileState, repo });
  useResyncOnTabActivate({
    panelId,
    hasFile: file.hasFile,
    activeSessionId,
    fileKey,
    path,
    repo,
    updateFileState,
  });

  const { onChange, onSave, onReloadFromAgent, onDelete, onTogglePreview } =
    useFileEditorPanelActions({
      path,
      repo,
      fileKey,
      renderedPreview: file.renderedPreview,
      updateFileState,
      actions: {
        handleFileChange,
        saveFile,
        deleteFile,
        applyRemoteUpdate,
      },
    });
  const onDownload = useLoadedFileDownloadForBuffer(file, path);

  if (!file.hasFile || !file.originalHash) {
    return <LoadingFilePanel />;
  }

  const { category, previewKind, panelProps } = resolveFileEditorPanelState({
    path,
    repo,
    isBinary: file.isBinary,
    activeSession,
    activeSessionId,
    activeTaskId,
  });

  return (
    <LoadedFileEditorPanel
      category={category}
      fileKey={fileKey}
      panelProps={panelProps}
      buffer={{
        isSymlink: file.isSymlink,
        path,
        content: file.content,
        originalContent: file.originalContent,
        isDirty: file.isDirty,
        hasRemoteUpdate: file.hasRemoteUpdate,
        vcsDiff,
      }}
      options={{
        isSaving: savingFiles.has(fileKey),
        sessionId: activeSessionId || undefined,
        taskId: activeTaskId,
        repositoryId: panelProps.repositoryId,
        worktreePath: panelProps.worktreePath,
        repo,
        enableComments: !!activeSessionId,
        previewKind,
        renderedPreview: previewKind !== "none" && file.renderedPreview,
        onTogglePreview: previewKind === "markdown" ? onTogglePreview : undefined,
      }}
      actions={{
        onChange,
        onSave,
        onReloadFromAgent,
        onDelete,
        onDownload,
      }}
    />
  );
});