import type { ModuleUiHostContext } from "@ekklesia/module-ui-sdk";
import { EkklesiaUiStyles, EmptyState, Tabs } from "@ekklesia/ui";
import { type ReactElement, useMemo, useState } from "react";
import { DesktopOnly } from "../browser/desktop-gate.js";
import { createSignageApi } from "./api.js";
import { useResource } from "./hooks.js";
import { DisplaysPanel } from "./panels/DisplaysPanel.js";
import { ImagesPanel } from "./panels/ImagesPanel.js";
import { PlaybackPanel } from "./panels/PlaybackPanel.js";
import { ProvidersPanel } from "./panels/ProvidersPanel.js";
import { renderLoadable } from "./panels/shared.js";
import { TimelinesPanel } from "./panels/TimelinesPanel.js";
import type { ChannelGroupView, SettingsResponse } from "./types.js";

/**
 * The Signage management screen.
 *
 * Host-neutral by construction: every value comes from the host context, and nothing here hardcodes
 * a URL, an origin, or a global. Presentation is entirely the platform's shared elements plus
 * Signage's own stylesheet, so this looks like the rest of Ekklesia without copying a colour.
 *
 * Permission checks here decide what an operator is *offered*. The server decides what happens: a
 * hidden button is a courtesy, and every route is enforced regardless of what this believes.
 */
export function SignageDashboard({
  context,
}: {
  readonly context: ModuleUiHostContext;
}): ReactElement {
  const api = useMemo(() => createSignageApi(context.api), [context.api]);
  // Read before the resources below, so a viewer who may not see Signage at all asks for nothing.
  // A hidden screen is a usability choice; the server is what actually refuses, and making a
  // request it will certainly refuse is noise in a log rather than security.
  const mayView = context.permissions.has("signage.view");
  const settings = useResource(
    () => (mayView ? api.get<SettingsResponse>("settings") : Promise.resolve(undefined)),
    [mayView],
  );
  const groups = useResource(
    () =>
      mayView
        ? api.get<{ groups: readonly ChannelGroupView[] }>("channel-groups")
        : Promise.resolve(undefined),
    [mayView],
  );
  const [tab, setTab] = useState("playback");
  const [groupId, setGroupId] = useState<string | undefined>(undefined);

  const mayManageAssets = context.permissions.has("signage.assets.manage");
  const mayManageTimelines = context.permissions.has("signage.timelines.manage");
  const mayControl = context.permissions.has("signage.playback.control");
  const mayManageDisplays = context.permissions.has("signage.displays.manage");

  if (!mayView) {
    return (
      <EmptyState
        description="Ask an administrator for the signage.view permission."
        title="No access to Signage"
      />
    );
  }

  const selectedGroupId =
    groupId ?? (groups.state.status === "ready" ? groups.state.value?.groups[0]?.id : undefined);
  const selectedGroup =
    groups.state.status === "ready"
      ? groups.state.value?.groups.find((candidate) => candidate.id === selectedGroupId)
      : undefined;

  return (
    <>
      <EkklesiaUiStyles />
      <DesktopOnly>
        {renderLoadable(
          settings.state,
          (loaded) =>
            loaded === undefined ? undefined : (
              <Tabs
                label="Signage sections"
                onSelect={setTab}
                selectedId={tab}
                tabs={[
                  {
                    content: (
                      <PlaybackPanel
                        api={api}
                        canControl={mayControl}
                        context={context}
                        groupId={selectedGroupId}
                        onGroupChange={setGroupId}
                        settings={loaded}
                      />
                    ),
                    id: "playback",
                    label: "Playback",
                  },
                  {
                    content: (
                      <TimelinesPanel
                        {...(selectedGroup
                          ? {
                              activeGroupName: selectedGroup.name,
                              activeTimelineId: selectedGroup.playback.activeTimelineId,
                            }
                          : {})}
                        api={api}
                        canManage={mayManageTimelines}
                        onActivate={
                          mayControl && selectedGroupId !== undefined
                            ? async (timelineId) => {
                                await api.send("POST", `playback/${selectedGroupId}/activate`, {
                                  timelineId,
                                  when: "now",
                                });
                                groups.reload();
                                setTab("playback");
                              }
                            : undefined
                        }
                        settings={loaded}
                      />
                    ),
                    id: "timelines",
                    label: "Timelines",
                  },
                  {
                    content: (
                      <ImagesPanel api={api} canManage={mayManageAssets} settings={loaded} />
                    ),
                    id: "images",
                    label: "Images",
                  },
                  {
                    content: <DisplaysPanel api={api} canManage={mayManageDisplays} />,
                    id: "displays",
                    label: "Displays",
                  },
                  {
                    content: <ProvidersPanel api={api} context={context} settings={loaded} />,
                    id: "providers",
                    label: "Providers",
                  },
                ]}
              />
            ),
          { label: "Loading Signage…", onRetry: settings.reload },
        )}
      </DesktopOnly>
    </>
  );
}