import config from "@payload-config";
import { getPayload } from "payload";
import Link from "next/link";
import { headers as nextHeaders } from "next/headers";
import type { Award, Media } from "@/payload-types";
import { AwardWithGrantButton } from "@/components/frontend/account/AwardWithGrantButton";
import { Item, ItemContent, ItemHeader, ItemTitle } from "@/components/ui/item";
import { Button } from "@/components/ui/button";
import { MedalIcon } from "lucide-react";
import hasRoles from "@/utils/access-control/hasRoles";
import { isPayloadUser } from "@/utils/access-control/isPayloadUser";

export const metadata = {
  title: "Awards",
  description:
    "Browse every medal and ribbon that can be granted to a member of Polaris Task Force.",
};

const TYPE_LABEL: Record<"ribbon" | "medal", string> = {
  ribbon: "Ribbons",
  medal: "Medals",
};

type AwardCatalogItem =
  | { readonly kind: "award"; readonly award: Award }
  | {
      readonly kind: "advancement";
      readonly seriesKey: string;
      readonly familyName: string;
    };

function buildRibbonCatalogItems(ribbons: Award[]): AwardCatalogItem[] {
  const awardsBySeries = new Map<string, Award[]>();
  for (const award of ribbons) {
    const seriesKey = award.advancement?.seriesKey;
    if (seriesKey == null) continue;

    const seriesAwards = awardsBySeries.get(seriesKey);
    if (seriesAwards) seriesAwards.push(award);
    else awardsBySeries.set(seriesKey, [award]);
  }

  const groupedSeriesKeys = new Set(
    [...awardsBySeries.entries()]
      .filter(([, seriesAwards]) => seriesAwards.length > 1)
      .map(([seriesKey]) => seriesKey),
  );
  const emittedSeriesKeys = new Set<string>();
  const items: AwardCatalogItem[] = [];

  for (const award of ribbons) {
    const seriesKey = award.advancement?.seriesKey;
    if (seriesKey == null || !groupedSeriesKeys.has(seriesKey)) {
      items.push({ kind: "award", award });
      continue;
    }
    if (emittedSeriesKeys.has(seriesKey)) continue;

    const seriesAwards = [...(awardsBySeries.get(seriesKey) ?? [])].sort((first, second) => {
      const tierDifference =
        (first.advancement?.tier ?? Number.POSITIVE_INFINITY) -
        (second.advancement?.tier ?? Number.POSITIVE_INFINITY);
      if (tierDifference !== 0) return tierDifference;
      if (first.name !== second.name) return first.name < second.name ? -1 : 1;
      return first.id - second.id;
    });
    const familyAward =
      seriesAwards.find((seriesAward) => seriesAward.advancement?.tier === 1) ?? seriesAwards[0];
    if (!familyAward) continue;

    items.push({
      kind: "advancement",
      seriesKey,
      familyName: familyAward.name,
    });
    for (const seriesAward of seriesAwards) {
      items.push({ kind: "award", award: seriesAward });
    }
    emittedSeriesKeys.add(seriesKey);
  }

  return items;
}

export default async function AwardsPage() {
  const headers = await nextHeaders();
  const payloadConfig = await config;
  const payload = await getPayload({ config: payloadConfig });
  const { user: authUser } = await payload.auth({ headers, canSetHeaders: false });
  const user = isPayloadUser(authUser) ? authUser : null;
  const canReview = hasRoles(["admin", "developer"], user);

  const res = await payload.find({
    collection: "awards",
    where: {
      type: { in: ["ribbon", "medal"] },
    },
    sort: "name",
    limit: 100,
    depth: 1,
    overrideAccess: true,
  });

  const pendingCount = canReview
    ? (
        await payload.count({
          collection: "ribbon-submissions",
          where: { status: { equals: "pending" } },
          overrideAccess: true,
        })
      ).totalDocs
    : 0;

  const awards: Award[] = res.docs;
  const ribbons = awards.filter((a) => a.type === "ribbon");
  const medals = awards.filter((a) => a.type === "medal");

  const catalogSections: { title: string; items: AwardCatalogItem[] }[] = [];
  if (medals.length > 0) {
    catalogSections.push({
      title: TYPE_LABEL.medal,
      items: medals.map((award) => ({ kind: "award", award })),
    });
  }
  if (ribbons.length > 0) {
    catalogSections.push({
      title: TYPE_LABEL.ribbon,
      items: buildRibbonCatalogItems(ribbons),
    });
  }

  return (
    <div className="p-5 flex flex-col gap-6 max-w-7xl">
      <div className="flex flex-col gap-3 sm:flex-row sm:items-start sm:justify-between">
        <div className="flex flex-col gap-1.5">
          <div className="flex items-center gap-2">
            <MedalIcon className="size-4 text-muted-foreground" />
            <h1 className="text-2xl font-bold tracking-tight uppercase">Awards</h1>
          </div>
          <p className="text-sm text-muted-foreground max-w-2xl">
            A reference of every medal and ribbon that can be earned by a member of Polaris Task
            Force. Review the requirements for each award and its artwork. Commendations are granted
            on the fly and are not catalogued here.
          </p>
        </div>
        <div className="flex flex-wrap items-center gap-2">
          <Button asChild size="sm">
            <Link href="/awards/design">Design a ribbon</Link>
          </Button>
          {canReview && (
            <Button asChild size="sm" variant="outline">
              <Link href="/awards/review">Review queue ({pendingCount})</Link>
            </Button>
          )}
        </div>
      </div>

      {awards.length === 0 ? (
        <Item variant="muted">
          <ItemHeader>
            <ItemTitle>No awards defined</ItemTitle>
          </ItemHeader>
          <ItemContent>
            <p className="text-sm text-muted-foreground italic">
              No medals or ribbons have been catalogued yet. Check back soon.
            </p>
          </ItemContent>
        </Item>
      ) : (
        catalogSections.map((section) => (
          <section key={section.title} className="flex flex-col gap-3">
            <h2 className="text-sm font-semibold uppercase tracking-wider text-muted-foreground">
              {section.title}
            </h2>
            <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
              {section.items.map((item) => {
                switch (item.kind) {
                  case "advancement":
                    return (
                      <div
                        key={`advancement-${item.seriesKey}`}
                        className="col-span-full flex items-center gap-2 border-b border-border pb-1 text-xs font-medium text-muted-foreground"
                      >
                        <span className="shrink-0">Advancement: {item.familyName}</span>
                        <div className="h-px flex-1 bg-border" aria-hidden />
                      </div>
                    );
                  case "award": {
                    const { award } = item;
                    const awardImage =
                      typeof award.image === "object" && award.image
                        ? (award.image as Media)
                        : null;
                    const backgroundImage =
                      typeof award.backgroundImage === "object" && award.backgroundImage
                        ? (award.backgroundImage as Media)
                        : null;
                    return (
                      <AwardWithGrantButton
                        key={award.id}
                        award={award}
                        awardImage={awardImage}
                        backgroundImage={backgroundImage}
                      />
                    );
                  }
                  default: {
                    const exhaustiveItem: never = item;
                    return exhaustiveItem;
                  }
                }
              })}
            </div>
          </section>
        ))
      )}
    </div>
  );
}