import { useMemo } from 'react';
import { useSearchParams } from 'react-router';
import { ChatPanelWrapper, ChatHeader } from 'officerdev';

/**
 * A chat, sitting under the message you are reading.
 *
 * ── Why the panel is ours ──
 *
 * `PluginScreen` renders the workspace with `appTypes={{ allowed, fallback: allowed[0] }}` where `allowed`
 * is this plugin's own panel keys, so a layout naming `officerdev/chat` silently renders the fallback
 * instead. That is deliberate — a persisted layout must not be able to mount another plugin's panel here.
 * So the panel is ours and the chat inside it is the platform's; `ChatPanelWrapper` is exported from
 * `officerdev` for exactly this, and carries the composer, transcript, queue, model picker, session
 * persistence and the agent identity bar with no second implementation to fall behind the first.
 *
 * ── What these chats are told, and where it lives ──
 *
 * `chat/CLAUDE.md`, in this plugin. The platform writes it into the directory these chats run in, and
 * Claude Code reads it from its own cwd at session start.
 *
 * There WAS a `promptPrefix` here and it is gone. A prefix rides every message: paid per turn forever,
 * invisible as a design artefact because it lives in a TypeScript constant, and visible in the one place
 * it should not be — three words sent, and a paragraph of preamble going out attached to them. The file
 * costs nothing per turn and can be opened by the person it is about.
 */

/**
 * Which mailbox this chat is about.
 *
 * `context: 'email'` resolves server-side to the ACCOUNT's own directory — the one holding `emails.db` —
 * rather than to a chats folder. That is the whole point: the agent starts beside the database it is meant
 * to answer from, and its brief can say so.
 *
 * This panel declared no context at all until now, and it did not need to while email was part of the
 * platform: `ChatPanelWrapper` recognised the screen by `workspace.id === 'email'` and supplied it. A
 * plugin's workspace key is `screens/plugin/email`, so that id became `plugin/email` and the branch
 * stopped matching the day email was extracted — every email chat since has run somewhere with no mailbox
 * near it. Declaring it here is what that branch's own comment asked for, and it carries the mailbox too,
 * which a hardcoded screen id never could.
 *
 * `all` is the list's sentinel for the unified view and is NOT an address. Sending it would name a mailbox
 * that does not exist, so it is dropped here and the server picks the most recently synced account.
 *
 * Memoised because it is passed to hooks that key on it. An object rebuilt every render is the trap that
 * silently broke playback reporting in the Jellyfin player for days; it costs one line to not repeat.
 */
const useEmailChatContext = () => {
  const [searchParams] = useSearchParams();
  const account = searchParams.get('account');
  const mailbox = account && account !== 'all' ? account : undefined;
  return useMemo(() => ({ context: 'email', ...(mailbox ? { contextId: mailbox } : {}) }), [mailbox]);
};

export const EmailChatPanel = ({ panelId }: { panelId: string }) => {
  const chatContext = useEmailChatContext();

  return (
    <div className="flex h-full min-h-0 flex-col">
      <ChatPanelWrapper panelId={panelId} chatContext={chatContext} />
    </div>
  );
};

/**
 * The panel's header: the conversation picker, scoped to this mailbox's directory.
 *
 * A registry `header` is mounted with `{ panelId }` only, so the context is bound here rather than passed —
 * which is the whole reason this wrapper exists.
 */
export const EmailChatPanelHeader = ({ panelId }: { panelId: string }) => {
  const chatContext = useEmailChatContext();

  return <ChatHeader panelId={panelId} chatContext={chatContext} commanderLabel="Email" />;
};