import type { SubscriptionGroup, SubscriptionOverviewItem, SubscriptionSort } from "@umt/contracts";
import {
  CalendarClock,
  CalendarDays,
  ChevronDown,
  LayoutGrid,
  List,
  ListChecks,
  Pause,
  Play,
  Plus,
  Search,
  Trash2,
  X,
} from "lucide-react";
import { useEffect, useMemo, useState } from "react";
import { Link } from "react-router";
import { useSiteOptions } from "~/api/instances.ts";
import { useRuleGroups } from "~/api/rules.ts";
import { type OverviewFilters, useSubscriptionOverview } from "~/api/subscriptions.ts";
import { EmptyState, ErrorState, LoadingState } from "~/components/console/empty-state.tsx";
import { FilterBar, FilterSelect } from "~/components/console/filter-bar.tsx";
import { consolePath } from "~/components/console/nav.ts";
import { PageHeader } from "~/components/console/page-header.tsx";
import { useListPagination } from "~/components/console/use-list-pagination.ts";
import { useQueryState } from "~/components/console/use-query-state.ts";
import { opts, SUB_ORIGIN } from "~/components/library/labels.ts";
import { DeleteSubscriptionsDialog, useSubscriptionOps } from "~/components/subscriptions/actions.tsx";
import { SubscriptionCalendarView } from "~/components/subscriptions/calendar.tsx";
import { GROUP_LABEL, GROUP_ORDER, SUB_KIND_LABEL } from "~/components/subscriptions/model.ts";
import { SubscriptionCard, SubscriptionRow } from "~/components/subscriptions/overview-item.tsx";
import { SubscriptionFormDialog } from "~/components/subscriptions/subscription-form.tsx";
import { Button } from "~/components/ui/button.tsx";
import { Pagination } from "~/components/ui/pagination.tsx";
import { cn } from "~/lib/utils.ts";
import { legacyRedirectLoader } from "./redirects.ts";

// 订阅总览(FE-5,docs/design/subscriptions.md §1):类型页签 → 五组分段(计数来自 counts)→ 卡片 / 列表。
// 筛选、分组、视图都进 URL;组内按上次更新倒序(服务端 sort=lastUpdated)。

export const meta = () => [{ title: "订阅 · UHD 媒体自动化控制台" }];

// 旧的 ?tab=policies 跳到收录策略
export const clientLoader = legacyRedirectLoader;

const SORT_LABEL: Record<SubscriptionSort, string> = {
  lastUpdated: "上次更新",
  nextSearch: "下次搜索",
  missing: "缺集数",
  created: "添加时间",
  name: "名称",
};

const VIEW_KEY = "umt.subscriptions.view";

function useDebounced(v: string, ms = 300) {
  const [d, setD] = useState(v);
  useEffect(() => {
    const t = setTimeout(() => setD(v), ms);
    return () => clearTimeout(t);
  }, [v, ms]);
  return d;
}

function Pills<T extends string>({
  label,
  value,
  onChange,
  items,
}: {
  label: string;
  value: T | "";
  onChange: (v: T | "") => void;
  items: { value: T | ""; label: string; count?: number }[];
}) {
  return (
    <div role="tablist" aria-label={label} className="flex min-w-0 gap-1 overflow-x-auto scroll-bleed">
      {items.map((it) => (
        <button
          key={it.value || "all"}
          type="button"
          role="tab"
          aria-selected={value === it.value}
          onClick={() => onChange(it.value)}
          className={cn(
            "inline-flex h-8 shrink-0 cursor-pointer items-center gap-1.5 rounded-full border px-3 text-sm font-medium whitespace-nowrap transition-colors duration-micro",
            value === it.value
              ? "pill-selected text-foreground"
              : "border-transparent text-muted-foreground hover:bg-foreground/[0.06] hover:text-foreground",
          )}
        >
          {it.label}
          {it.count !== undefined ? (
            <span className="text-meta text-muted-foreground tabular-nums">{it.count}</span>
          ) : null}
        </button>
      ))}
    </div>
  );
}

export default function SubscriptionsPage() {
  const f = useQueryState(["kind", "group", "q", "site", "rg", "origin", "up", "sort", "view", "month"] as const);
  const v = f.values;
  const [q, setQ] = useState(v.q);
  const dq = useDebounced(q.trim());
  useEffect(() => {
    if (dq !== v.q) f.set("q", dq);
  }, [dq, v.q, f.set]);
  const [view, setViewState] = useState<"card" | "list">("card");
  useEffect(() => {
    try {
      if (localStorage.getItem(VIEW_KEY) === "list") setViewState("list");
    } catch {
      /* 无存储时用卡片 */
    }
  }, []);
  const calendar = v.view === "calendar";
  const setView = (x: "card" | "list") => {
    if (calendar) f.set("view", "");
    setViewState(x);
    try {
      localStorage.setItem(VIEW_KEY, x);
    } catch {
      /* 忽略 */
    }
  };
  const [creating, setCreating] = useState(false);
  const [editing, setEditing] = useState<SubscriptionOverviewItem | null>(null);
  const [selecting, setSelecting] = useState(false);
  const [sel, setSel] = useState<Set<string>>(new Set());
  const [confirmDelete, setConfirmDelete] = useState(false);
  const [collapsed, setCollapsed] = useState<Set<SubscriptionGroup>>(new Set());
  const ops = useSubscriptionOps();

  const filters: OverviewFilters = {
    mediaKind: (v.kind || undefined) as OverviewFilters["mediaKind"],
    group: (v.group || undefined) as OverviewFilters["group"],
    q: v.q || undefined,
    siteId: v.site || undefined,
    ruleGroupId: v.rg || undefined,
    origin: (v.origin || undefined) as OverviewFilters["origin"],
    upgrading: (v.up || undefined) as OverviewFilters["upgrading"],
    sort: (v.sort || undefined) as OverviewFilters["sort"],
  };
  const query = useSubscriptionOverview(filters);
  const items = useMemo(() => query.data?.pages.flatMap((p) => p.items) ?? [], [query.data]);
  const paged = useListPagination(items, {
    hasMore: query.hasNextPage,
    onLoadMore: () => query.fetchNextPage(),
    loadingMore: query.isFetchingNextPage,
    error: query.error,
    resetKey: JSON.stringify(filters),
  });
  const visible = paged.items ?? [];
  const first = query.data?.pages[0];
  const counts = first?.counts;
  const allCount = counts ? GROUP_ORDER.reduce((n, g) => n + (counts[g] ?? 0), 0) : undefined;
  const sites = useSiteOptions();
  const groups = useRuleGroups({});
  const filtered = !!(v.q || v.site || v.rg || v.origin || v.up);
  const grouped = !v.group && !v.sort;

  const toggle = (id: string, on: boolean) =>
    setSel((s) => {
      const n = new Set(s);
      if (on) n.add(id);
      else n.delete(id);
      return n;
    });
  const selIds = [...sel].filter((id) => items.some((x) => x.id === id));
  const exitSelect = () => {
    setSelecting(false);
    setSel(new Set());
  };

  const renderItems = (list: SubscriptionOverviewItem[]) =>
    view === "card" ? (
      <div className="grid gap-3 sm:grid-cols-2 xl:grid-cols-3 2xl:grid-cols-4">
        {list.map((x) => (
          <SubscriptionCard
            key={x.id}
            x={x}
            onEdit={() => setEditing(x)}
            selected={sel.has(x.id)}
            onSelect={selecting ? (on) => toggle(x.id, on) : undefined}
          />
        ))}
      </div>
    ) : (
      <ul className="pg-slab divide-y divide-border/60 overflow-hidden rounded-xl">
        {list.map((x) => (
          <SubscriptionRow
            key={x.id}
            x={x}
            onEdit={() => setEditing(x)}
            selected={sel.has(x.id)}
            onSelect={selecting ? (on) => toggle(x.id, on) : undefined}
          />
        ))}
      </ul>
    );

  return (
    <>
      <PageHeader
        title="订阅"
        actions={
          <>
            <Button asChild variant="ghost" size="sm">
              <Link to={consolePath("rules")}>
                <ListChecks />
                规则
              </Link>
            </Button>
            <Button onClick={() => setCreating(true)}>
              <Plus />
              新建订阅
            </Button>
          </>
        }
      />
      <div className="mb-3 flex flex-wrap items-center justify-between gap-2">
        <Pills
          label="类型"
          value={v.kind as "" | "series" | "movie" | "variety"}
          onChange={(x) => f.set("kind", x)}
          items={[
            { value: "", label: "全部" },
            { value: "series", label: SUB_KIND_LABEL.series },
            { value: "movie", label: SUB_KIND_LABEL.movie },
            { value: "variety", label: SUB_KIND_LABEL.variety },
          ]}
        />
        <div className="flex items-center gap-1">
          {calendar ? null : (
            <Button
              variant={selecting ? "secondary" : "ghost"}
              size="sm"
              onClick={() => (selecting ? exitSelect() : setSelecting(true))}
            >
              {selecting ? <X /> : null}
              {selecting ? "退出批量" : "批量"}
            </Button>
          )}
          <fieldset className="m-0 flex rounded-full border border-border p-0.5" aria-label="视图">
            <Button
              variant="ghost"
              size="icon-sm"
              aria-label="卡片视图"
              aria-pressed={!calendar && view === "card"}
              className={cn("rounded-full", !calendar && view === "card" && "bg-foreground/[0.08]")}
              onClick={() => setView("card")}
            >
              <LayoutGrid />
            </Button>
            <Button
              variant="ghost"
              size="icon-sm"
              aria-label="列表视图"
              aria-pressed={!calendar && view === "list"}
              className={cn("rounded-full", !calendar && view === "list" && "bg-foreground/[0.08]")}
              onClick={() => setView("list")}
            >
              <List />
            </Button>
            <Button
              variant="ghost"
              size="icon-sm"
              aria-label="日历"
              aria-pressed={calendar}
              className={cn("rounded-full", calendar && "bg-foreground/[0.08]")}
              onClick={() => f.set("view", "calendar")}
            >
              <CalendarDays />
            </Button>
          </fieldset>
        </div>
      </div>
      {calendar ? (
        <SubscriptionCalendarView
          month={v.month}
          onMonth={(m) => f.set("month", m)}
          mediaKind={(v.kind || undefined) as "series" | "movie" | "variety" | undefined}
        />
      ) : (
        <>
          {/* 一条订阅都没有时只留空态和「新建订阅」,不铺筛选 */}
          {allCount === 0 && !filtered && !v.group && !v.kind ? null : (
            <>
              <div className="mb-3">
                <Pills
                  label="分组"
                  value={v.group as SubscriptionGroup | ""}
                  onChange={(x) => f.set("group", x)}
                  items={[
                    { value: "", label: "全部", count: allCount },
                    ...GROUP_ORDER.map((g) => ({ value: g, label: GROUP_LABEL[g], count: counts?.[g] })),
                  ]}
                />
              </div>
              <FilterBar
                search={{ value: q, onChange: setQ, placeholder: "作品标题 / 别名 / 检索词" }}
                onReset={
                  filtered
                    ? () => {
                        setQ("");
                        for (const k of ["q", "site", "rg", "origin", "up"] as const) f.set(k, "");
                      }
                    : undefined
                }
              >
                <FilterSelect
                  label="站点"
                  value={v.site}
                  onChange={(x) => f.set("site", x)}
                  options={(sites.data?.items ?? []).map((s) => ({ value: s.id, label: s.name }))}
                />
                <FilterSelect
                  label="规则组"
                  value={v.rg}
                  onChange={(x) => f.set("rg", x)}
                  options={(groups.data?.items ?? []).map((g) => ({ value: g.id, label: g.name }))}
                />
                <FilterSelect
                  label="来源"
                  value={v.origin}
                  onChange={(x) => f.set("origin", x)}
                  options={opts(SUB_ORIGIN)}
                />
                <FilterSelect
                  label="洗版"
                  value={v.up}
                  onChange={(x) => f.set("up", x)}
                  options={[
                    { value: "true", label: "洗版中" },
                    { value: "false", label: "未洗版" },
                  ]}
                />
                <FilterSelect
                  label="排序"
                  value={v.sort}
                  onChange={(x) => f.set("sort", x)}
                  allLabel="按分组"
                  options={opts(SORT_LABEL)}
                />
              </FilterBar>
            </>
          )}

          {selecting ? (
            <div className="pg-slab sticky top-2 z-20 mb-3 flex flex-wrap items-center gap-2 rounded-xl px-3 py-2">
              <span className="text-sm text-foreground tabular-nums">已选 {selIds.length}</span>
              <Button
                variant="ghost"
                size="sm"
                onClick={() =>
                  setSel((previous) => {
                    const next = new Set(previous);
                    const selected = visible.every((x) => previous.has(x.id));
                    for (const x of visible) {
                      if (selected) next.delete(x.id);
                      else next.add(x.id);
                    }
                    return next;
                  })
                }
              >
                {visible.length > 0 && visible.every((x) => sel.has(x.id)) ? "取消本页全选" : "全选本页"}
              </Button>
              <span className="ml-auto flex flex-wrap gap-2">
                <Button
                  size="sm"
                  variant="outline"
                  disabled={!selIds.length || ops.pending}
                  onClick={() => ops.batch(selIds, "search")}
                >
                  <Search />
                  立即搜索
                </Button>
                <Button
                  size="sm"
                  variant="outline"
                  disabled={!selIds.length || ops.pending}
                  onClick={() => ops.batch(selIds, "pause")}
                >
                  <Pause />
                  暂停
                </Button>
                <Button
                  size="sm"
                  variant="outline"
                  disabled={!selIds.length || ops.pending}
                  onClick={() => ops.batch(selIds, "resume")}
                >
                  <Play />
                  恢复
                </Button>
                <Button
                  size="sm"
                  variant="destructive"
                  disabled={!selIds.length}
                  onClick={() => setConfirmDelete(true)}
                >
                  <Trash2 />
                  删除
                </Button>
              </span>
            </div>
          ) : null}

          {query.isPending ? (
            <LoadingState rows={4} />
          ) : query.isError ? (
            <ErrorState error={query.error} onRetry={() => query.refetch()} />
          ) : items.length === 0 ? (
            <EmptyState
              icon={CalendarClock}
              title={filtered || v.group || v.kind ? "没有符合条件的订阅" : "还没有订阅"}
              description={
                filtered || v.group || v.kind ? undefined : "在搜索或媒体库里点「订阅」，或点右上角「新建订阅」。"
              }
            />
          ) : grouped ? (
            <div className="space-y-6">
              {GROUP_ORDER.map((g) => {
                const list = visible.filter((x) => x.group === g);
                if (!list.length) return null;
                const closed = collapsed.has(g);
                return (
                  <section key={g} aria-labelledby={`grp-${g}`}>
                    <button
                      type="button"
                      id={`grp-${g}`}
                      aria-expanded={!closed}
                      onClick={() =>
                        setCollapsed((s) => {
                          const n = new Set(s);
                          if (closed) n.delete(g);
                          else n.add(g);
                          return n;
                        })
                      }
                      className="mb-2 flex cursor-pointer items-center gap-1.5 text-body font-semibold text-foreground"
                    >
                      <ChevronDown
                        className={cn("h-4 w-4 text-muted-foreground transition-transform", closed && "-rotate-90")}
                      />
                      {GROUP_LABEL[g]}
                      <span className="text-meta font-normal text-muted-foreground tabular-nums">
                        {counts?.[g] ?? list.length}
                      </span>
                    </button>
                    {closed ? null : renderItems(list)}
                  </section>
                );
              })}
            </div>
          ) : (
            renderItems(visible)
          )}
          {items.length > 0 || query.hasNextPage ? <Pagination {...paged.pagination} /> : null}
        </>
      )}

      {creating ? <SubscriptionFormDialog onClose={() => setCreating(false)} /> : null}
      {editing ? (
        <SubscriptionFormDialog
          sub={editing}
          title={editing.mediaEntityTitle ?? editing.titleQuery ?? undefined}
          onClose={() => setEditing(null)}
        />
      ) : null}
      <DeleteSubscriptionsDialog
        open={confirmDelete}
        onOpenChange={setConfirmDelete}
        ids={selIds}
        onDone={exitSelect}
      />
    </>
  );
}