import type { Metadata } from "next";
import Link from "next/link";
import { redirect } from "next/navigation";
import { caseKinds } from "@/components/cases";
import { ActionForm, SubmitButton } from "@/components/forms";
import { PageHeader } from "@/components/status";
import { DateTime } from "@/components/time";
import { buttonVariants } from "@/components/ui/button";
import { Card, CardContent } from "@/components/ui/card";
import { api, getMe, unwrap, type NotificationEntry } from "@/lib/api";
import { cn } from "@/lib/utils";
import { markAllRead } from "../console/cases/actions";

export const metadata: Metadata = { title: "Notifications" };

export default async function Notifications({ searchParams }: { searchParams: Promise<{ before?: string | string[] }> }) {
  const me = await getMe();
  if (!me) redirect("/signin?next=/notifications");
  const raw = (await searchParams).before;
  const before = typeof raw === "string" && /^\d+$/.test(raw) ? Number(raw) : undefined;
  const data = unwrap(await api.notifications.get({ query: before ? { before } : {} }));

  return (
    <>
      <div className="flex flex-wrap items-start justify-between gap-4">
        <PageHeader title="Notifications">
          {data.unread > 0 ? `${data.unread} unread.` : "You're up to date."}
        </PageHeader>
        {data.unread > 0 && (
          <ActionForm action={markAllRead}>
            <SubmitButton variant="outline" pendingLabel="Marking…">
              Mark all as read
            </SubmitButton>
          </ActionForm>
        )}
      </div>
      <Card>
        <CardContent>
          {data.notifications.length === 0 ? (
            <p className="text-sm text-muted-foreground">Nothing yet.</p>
          ) : (
            <ul className="divide-y">
              {data.notifications.map((n) => {
                const { text, href } = describe(n);
                return (
                  <li key={n.id} className={cn("flex flex-wrap items-baseline gap-x-3 gap-y-1 py-3 first:pt-0 last:pb-0", n.read && "text-muted-foreground")}>
                    {!n.read && <span className="size-2 shrink-0 self-center rounded-full bg-foreground" aria-label="Unread" />}
                    <span className="min-w-0 flex-1 text-sm">
                      {href ? (
                        <Link href={href} className="underline-offset-4 hover:underline">
                          {text}
                        </Link>
                      ) : (
                        text
                      )}
                    </span>
                    <span className="text-xs text-muted-foreground">
                      <DateTime iso={n.at} />
                    </span>
                  </li>
                );
              })}
            </ul>
          )}
        </CardContent>
      </Card>
      {data.before && (
        <div className="mt-4">
          <Link href={`/notifications?before=${data.before}`} className={buttonVariants({ variant: "outline" })}>
            Older
          </Link>
        </div>
      )}
    </>
  );
}

/** A notification in words, and where it leads. */
function describe(n: NotificationEntry): { text: string; href?: string } {
  const d = n.data as Record<string, unknown>;
  const s = (k: string) => (typeof d[k] === "string" ? (d[k] as string) : "");
  const why = s("reason") ? `: “${s("reason")}”` : "";
  switch (n.type) {
    case "product_edited": {
      const what =
        s("kind") === "lock"
          ? "changed the locks on"
          : s("kind") === "revert"
            ? "undid a change to"
            : `changed the ${(d.fields as string[] | undefined)?.join(", ") ?? "info"} of`;
      return { text: `${s("by") || "A moderator"} ${what} ${s("name")}${why}`, href: `/products/${s("product")}/edit` };
    }
    case "product_removed":
      return { text: `Moderation removed ${s("name")}${why}. You can appeal it from your audit log.`, href: `/console/audit?product=${s("product")}` };
    case "product_restored":
      return { text: `Moderation restored ${s("name")}${why}`, href: `/products/${s("product")}` };
    case "case_decided": {
      const status = s("status") === "resolved" ? "resolved" : "declined";
      const res = s("resolution") ? `: “${s("resolution")}”` : "";
      return { text: `Your ${caseKinds[s("kind")]?.toLowerCase() ?? "case"} was ${status}${res}`, href: `/console/cases/${d.case}` };
    }
    case "case_note":
      return { text: `${s("by") || "Someone"} replied on your ${caseKinds[s("kind")]?.toLowerCase() ?? "case"}`, href: `/console/cases/${d.case}` };
    case "membership_decided": {
      const status = s("status");
      const text =
        status === "member"
          ? `You're a member of ${s("name")}`
          : status === "banned"
            ? `${s("name")} banned you`
            : `${s("name")} declined your request to join`;
      return { text, href: `/catalogs/${s("catalog")}` };
    }
    default:
      return { text: n.type };
  }
}