/**
 * Renders a user's profile page, which is also where the signed-in user edits
 * their own profile.
 *
 * @module
 */

import { useLocation, useNavigate, useParams } from "react-router";
import { Trans } from "@lingui/react/macro";

import { API_URL } from "../config/api.ts";
import type { Invitee } from "../../shared/user.ts";
import type { Wire } from "../../shared/api.ts";
import {
  FOLLOW_VIEWS,
  type FollowView,
  PROFILE_TABS,
  type ProfileTab,
  userPath,
} from "../../shared/paths.ts";
import { deserializeInvitee } from "../utils/shared/deserialize.ts";
import { dataOr } from "../utils/shared/api.ts";
import { can } from "../utils/auth/permissions.ts";
import { useAuth } from "../hooks/auth/useAuth.ts";
import { useDocumentTitle } from "../hooks/shared/useDocumentTitle.ts";
import { useFetchState } from "../hooks/shared/useFetchState.ts";
import { useTabParam } from "../hooks/shared/useTabParam.ts";
import { useCanonicalPath } from "../hooks/shared/useCanonicalPath.ts";
import { useProfile } from "../hooks/profile/useProfile.ts";
import { PageShell } from "../components/layout/PageShell.tsx";
import { PageError } from "../components/layout/PageError.tsx";
import { TabBar } from "../components/shared/TabBar.tsx";
import { ProfileHeader } from "../components/profile/ProfileHeader.tsx";
import { ProfileDescription } from "../components/profile/ProfileDescription.tsx";
import { ProfileOverviewTab } from "../components/profile/ProfileOverviewTab.tsx";
import { ProfileDumpsTab } from "../components/profile/ProfileDumpsTab.tsx";
import { ProfilePlaylistsTab } from "../components/profile/ProfilePlaylistsTab.tsx";
import { ProfileFollowTab } from "../components/profile/ProfileFollowTab.tsx";
import { ProfileInviteesTab } from "../components/profile/ProfileInviteesTab.tsx";
import { ProfileManageTab } from "../components/profile/ProfileManageTab.tsx";
import { NotFound } from "./NotFound.tsx";

/** The overview, the bare `/@name`, which no path segment names. */
const OVERVIEW = "overview";
type Tab = ProfileTab | typeof OVERVIEW;
const TABS: readonly Tab[] = [OVERVIEW, ...PROFILE_TABS];

/**
 * Renders `/@:username` and its tabs, `/@:username/:tab`, and the follow
 * tab's view `/@:username/follow/playlists`, for anyone. `useProfile` loads
 * the user, by a former name or another case too, and the URL then takes the
 * current one; each tab loads its own lists, by the user's id, when shown.
 * On their own profile, users edit their avatar, description and email, and
 * create invites. The "manage" tab, another user's role and name, is for those
 * who hold `user:manage`. A tab or view the profile hasn't is `NotFound`.
 */
export function UserPublicProfile(): React.JSX.Element {
  const { handle = "" } = useParams();
  const username = handle.slice(1);
  const { pathname } = useLocation();
  const navigate = useNavigate();
  const { user: me, logout } = useAuth();
  const { state, isOwnProfile, setUser } = useProfile(username);
  const user = state.status === "loaded" ? state.data : null;

  useDocumentTitle(
    user ? user.username : state.status === "error" ? null : undefined,
  );

  // The base is the path's own first segment, however it spells the name.
  const base = `/${pathname.split("/")[1]}`;
  const [tab, setTab] = useTabParam<Tab>(base, TABS, OVERVIEW);
  useCanonicalPath(
    user && `${userPath(user.username)}${pathname.slice(base.length)}`,
  );

  // Only the follow tab has a view, one segment further.
  const extra = pathname.slice(base.length).split("/").filter(Boolean).slice(1);
  const view: FollowView | null = extra.length === 0
    ? "users"
    : tab === "follow" && extra.length === 1 && extra[0] !== FOLLOW_VIEWS[0] &&
        (FOLLOW_VIEWS as readonly string[]).includes(extra[0])
    ? extra[0] as FollowView
    : null;

  const canManageUsers = can(me, "user:manage");
  const showManageTab = !isOwnProfile && canManageUsers;

  const invitees = useFetchState<Invitee[]>(
    user?.id,
    (signal) =>
      fetch(`${API_URL}/api/users/${user!.id}/invitees`, { signal })
        .then((res) => dataOr<Wire<Invitee>[]>(res, []))
        .then((entries) => entries.map(deserializeInvitee)),
    { enabled: tab === "invitees" },
  );

  if (!tab || !view || (tab === "manage" && user && !showManageTab)) {
    return <NotFound />;
  }

  if (state.status === "loading") {
    return (
      <PageShell>
        <p className="page-loading">
          <Trans>Loading profile…</Trans>
        </p>
      </PageShell>
    );
  }

  if (state.status === "error") {
    return (
      <PageError
        message={state.error}
        actions={
          <>
            <button
              className="btn-border"
              type="button"
              onClick={() => navigate("/")}
            >
              <Trans>← Back</Trans>
            </button>
            {me && (
              <button
                className="btn-border btn-border--danger"
                type="button"
                onClick={logout}
              >
                <Trans>Log out</Trans>
              </button>
            )}
          </>
        }
      />
    );
  }

  const profileUser = state.data;

  return (
    <PageShell>
      <ProfileHeader
        user={profileUser}
        isOwnProfile={isOwnProfile}
        onUserChange={(u) => setUser(() => u)}
      />
      <ProfileDescription
        description={profileUser.description}
        isOwnProfile={isOwnProfile}
        onSaved={(description) => setUser((u) => ({ ...u, description }))}
      />

      <TabBar
        tabs={[
          { key: OVERVIEW as Tab, label: <Trans>Overview</Trans> },
          { key: "dumps" as Tab, label: <Trans>Dumps</Trans> },
          { key: "upvoted" as Tab, label: <Trans>Upvoted</Trans> },
          { key: "playlists" as Tab, label: <Trans>Playlists</Trans> },
          { key: "follow" as Tab, label: <Trans>Followed</Trans> },
          { key: "invitees" as Tab, label: <Trans>Invitees</Trans> },
          ...(showManageTab
            ? [{ key: "manage" as Tab, label: <Trans>Manage</Trans> }]
            : []),
        ]}
        activeTab={tab}
        onChange={(key) => setTab(key)}
        className="profile-tabs-scroller"
        innerClassName="profile-tabs"
      />

      {tab === OVERVIEW && (
        <ProfileOverviewTab user={profileUser} isOwnProfile={isOwnProfile} />
      )}
      {(tab === "dumps" || tab === "upvoted") && (
        <ProfileDumpsTab
          key={tab}
          user={profileUser}
          list={tab}
          isOwnProfile={isOwnProfile}
        />
      )}
      {tab === "playlists" && (
        <ProfilePlaylistsTab user={profileUser} isOwnProfile={isOwnProfile} />
      )}
      {tab === "follow" && <ProfileFollowTab user={profileUser} view={view} />}
      {tab === "invitees" && (
        <ProfileInviteesTab userId={profileUser.id} state={invitees.state} />
      )}
      {tab === "manage" && (
        <ProfileManageTab
          user={profileUser}
          onUserSaved={(u) => setUser(() => u)}
        />
      )}
    </PageShell>
  );
}