"use client";

import { useCallback, useEffect, useMemo, useState } from "react";
import { useRouter, useSearchParams } from "next/navigation";
import AddBusinessModal from "@/components/AddBusinessModal";
import BusinessCardList from "@/components/BusinessCardList";
import ConfirmDialog from "@/components/ConfirmDialog";
import MakeSpecialModal from "@/components/MakeSpecialModal";
import {
  deleteMarketplaceBusiness,
  listBusinesses,
  updateMarketplaceBusiness,
} from "@/services/marketplace";
import {
  getBusinessProfile,
  getMeshkeeBusiness,
} from "@/services/meshkee-businesses";
import {
  searchMeshkeeCategories,
  type MeshkeeCategory,
} from "@/services/meshkee-categories";
import type { BusinessStatus, MarketplaceBusiness } from "@/types/business";
import styles from "./BusinessesPage.module.css";

type FilterKey = "all" | BusinessStatus;

const FILTERS: { key: FilterKey; label: string }[] = [
  { key: "all", label: "All" },
  { key: "pending_review", label: "Pending" },
  { key: "published", label: "Published" },
  { key: "draft", label: "Draft" },
  { key: "hidden", label: "Hidden" },
  { key: "rejected", label: "Rejected" },
];

function categoryAncestors(
  categoryId: string | undefined,
  byId: Map<string, MeshkeeCategory>,
): string[] {
  if (!categoryId) return [];
  const names: string[] = [];
  const seen = new Set<string>();
  let current = byId.get(categoryId);
  while (current && !seen.has(current.id)) {
    seen.add(current.id);
    names.unshift(current.name);
    current = current.parentId ? byId.get(current.parentId) : undefined;
  }
  return names;
}

function lastTwoCategoryLevels(trail: string[]) {
  if (trail.length === 0) return undefined;
  return trail.slice(-2).join(" / ");
}

async function enrichListings(
  items: MarketplaceBusiness[],
): Promise<MarketplaceBusiness[]> {
  const categories = await searchMeshkeeCategories("").catch(
    () => [] as MeshkeeCategory[],
  );
  const byId = new Map(categories.map((category) => [category.id, category]));

  return Promise.all(
    items.map(async (item) => {
      try {
        const id = String(item.meshkeeBusinessId);
        const [meshkee, profile] = await Promise.all([
          getMeshkeeBusiness(id),
          getBusinessProfile(id),
        ]);
        const primaryCategoryId =
          profile.profile.categoryIds[0] ?? meshkee.categories[0]?.id;
        const trail = categoryAncestors(primaryCategoryId, byId);
        return {
          ...item,
          name: meshkee.name,
          categoryName: trail[trail.length - 1] ?? meshkee.categories[0]?.name,
          categoryTrail: lastTwoCategoryLevels(trail),
          logoUrl: profile.profile.logoUrl ?? meshkee.logoUrl ?? undefined,
          bannerUrl:
            profile.profile.bannerUrl ?? meshkee.bannerUrl ?? undefined,
        };
      } catch {
        return { ...item, name: item.slug };
      }
    }),
  );
}

function isFilterKey(value: string | null): value is FilterKey {
  if (!value) return false;
  return FILTERS.some((item) => item.key === value);
}

export default function BusinessesPage() {
  const router = useRouter();
  const searchParams = useSearchParams();
  const initialFilter = isFilterKey(searchParams.get("status"))
    ? (searchParams.get("status") as FilterKey)
    : "all";

  const [filter, setFilter] = useState<FilterKey>(initialFilter);
  const [items, setItems] = useState<MarketplaceBusiness[]>([]);
  const [total, setTotal] = useState(0);
  const [error, setError] = useState("");
  const [loading, setLoading] = useState(true);
  const [modalOpen, setModalOpen] = useState(false);
  const [removing, setRemoving] = useState<MarketplaceBusiness | null>(null);
  const [rejecting, setRejecting] = useState<MarketplaceBusiness | null>(null);
  const [makingSpecial, setMakingSpecial] =
    useState<MarketplaceBusiness | null>(null);
  const [busyId, setBusyId] = useState<string | null>(null);

  const reload = useCallback(async () => {
    setLoading(true);
    setError("");
    try {
      const data = await listBusinesses({ status: "all", limit: 100 });
      const enriched = await enrichListings(data.items);
      setItems(enriched);
      setTotal(data.total);
    } catch (err) {
      setError(
        err instanceof Error
          ? err.message
          : "Could not load businesses from the API.",
      );
      setItems([]);
      setTotal(0);
    } finally {
      setLoading(false);
    }
  }, []);

  useEffect(() => {
    void reload();
  }, [reload]);

  useEffect(() => {
    const next = isFilterKey(searchParams.get("status"))
      ? (searchParams.get("status") as FilterKey)
      : "all";
    setFilter(next);
  }, [searchParams]);

  const counts = useMemo(() => {
    const next: Record<FilterKey, number> = {
      all: items.length,
      draft: 0,
      pending_review: 0,
      published: 0,
      hidden: 0,
      rejected: 0,
    };
    for (const item of items) {
      next[item.status] += 1;
    }
    return next;
  }, [items]);

  const visible = useMemo(() => {
    if (filter === "all") return items;
    return items.filter((item) => item.status === filter);
  }, [items, filter]);

  function selectFilter(next: FilterKey) {
    setFilter(next);
    const url = new URL(window.location.href);
    if (next === "all") url.searchParams.delete("status");
    else url.searchParams.set("status", next);
    router.replace(`${url.pathname}${url.search}`);
  }

  async function setStatus(business: MarketplaceBusiness, status: BusinessStatus) {
    setBusyId(business.id);
    setError("");
    try {
      await updateMarketplaceBusiness(business.id, { status });
      await reload();
    } catch (err) {
      setError(
        err instanceof Error
          ? err.message
          : "Could not update listing status.",
      );
    } finally {
      setBusyId(null);
    }
  }

  const removingBusy = Boolean(removing && busyId === removing.id);
  const rejectingBusy = Boolean(rejecting && busyId === rejecting.id);
  const removingName = removing?.name || removing?.slug || "this business";
  const rejectingName = rejecting?.name || rejecting?.slug || "this business";

  return (
    <div className={styles.page}>
      <header className={styles.head}>
        <div>
          <nav className={styles.breadcrumb} aria-label="Breadcrumb">
            <a href="/">Home</a>
            <span className={styles.breadcrumbSep} aria-hidden>
              /
            </span>
            <span className={styles.breadcrumbCurrent}>Businesses</span>
          </nav>
          <h1 className={styles.title}>Businesses</h1>
          <p className={styles.lead}>
            Review submissions, publish listings, and manage the marketplace
            gate.
          </p>
        </div>
        <div className={styles.headActions}>
          <p className={styles.count}>
            {loading
              ? "Loading…"
              : filter === "all"
                ? `${total} total`
                : `${visible.length} shown · ${total} total`}
          </p>
          <button
            type="button"
            className={styles.addBtn}
            aria-label="Add business"
            onClick={() => setModalOpen(true)}
          >
            <img src="/images/icons/add.svg" alt="" width={18} height={18} />
          </button>
        </div>
      </header>

      <div className={styles.filters} role="tablist" aria-label="Listing status">
        {FILTERS.map((item) => {
          const active = filter === item.key;
          const count = counts[item.key];
          return (
            <button
              key={item.key}
              type="button"
              role="tab"
              aria-selected={active}
              className={`${styles.filter} ${active ? styles.filterActive : ""}`}
              onClick={() => selectFilter(item.key)}
            >
              <span>{item.label}</span>
              <em>{loading ? "—" : count}</em>
            </button>
          );
        })}
      </div>

      {error ? (
        <div className={styles.error} role="alert">
          <p className={styles.errorTitle}>API unavailable</p>
          <p className={styles.errorCopy}>{error}</p>
          <p className={styles.errorHint}>
            Start the marketplace backend on port 3001, then refresh.
          </p>
        </div>
      ) : loading ? (
        <div className={styles.loading}>Loading businesses…</div>
      ) : (
        <BusinessCardList
          items={visible}
          busyId={busyId}
          emptyTitle={
            filter === "pending_review"
              ? "No pending submissions"
              : "No businesses in this view"
          }
          emptyCopy={
            filter === "pending_review"
              ? "New shop registrations will appear here for approval."
              : "Try another filter, or add a Meshkee business to the marketplace."
          }
          onApprove={(business) => void setStatus(business, "published")}
          onReject={setRejecting}
          onDisable={async (business) => {
            const nextStatus =
              business.status === "hidden" ? "published" : "hidden";
            await setStatus(business, nextStatus);
          }}
          onRemove={setRemoving}
          onMakeSpecial={setMakingSpecial}
          onMetaTag={(business) => {
            const lines = [
              `Name: ${business.name || business.slug}`,
              `Slug: /${business.slug}`,
              `Category: ${business.categoryName || "Uncategorized"}`,
              `Status: ${business.status}`,
              `Featured: ${business.isFeatured ? "yes" : "no"}`,
            ].join("\n");
            window.alert(lines);
          }}
        />
      )}

      <AddBusinessModal
        open={modalOpen}
        onClose={() => setModalOpen(false)}
        onConnected={() => {
          void reload();
        }}
      />

      <MakeSpecialModal
        open={Boolean(makingSpecial)}
        business={makingSpecial}
        onClose={() => setMakingSpecial(null)}
      />

      <ConfirmDialog
        open={Boolean(rejecting)}
        kicker="Reject submission"
        title={`Reject ${rejectingName}?`}
        message="The Meshkee shop stays intact. The listing will be marked rejected and stay off the public site."
        confirmLabel="Reject"
        cancelLabel="Keep pending"
        danger
        busy={rejectingBusy}
        onClose={() => {
          if (!rejectingBusy) setRejecting(null);
        }}
        onConfirm={async () => {
          if (!rejecting) return;
          await setStatus(rejecting, "rejected");
          setRejecting(null);
        }}
      />

      <ConfirmDialog
        open={Boolean(removing)}
        kicker="Remove listing"
        title={`Remove ${removingName}?`}
        message="This unlists the business from the marketplace. The Meshkee business stays intact."
        confirmLabel="Remove"
        cancelLabel="Keep"
        danger
        busy={removingBusy}
        onClose={() => {
          if (!removingBusy) setRemoving(null);
        }}
        onConfirm={async () => {
          if (!removing) return;
          setBusyId(removing.id);
          setError("");
          try {
            await deleteMarketplaceBusiness(removing.id);
            setRemoving(null);
            await reload();
          } catch (err) {
            setError(
              err instanceof Error
                ? err.message
                : "Could not remove listing.",
            );
          } finally {
            setBusyId(null);
          }
        }}
      />
    </div>
  );
}