import { useQueryClient } from "@tanstack/react-query";
import type { DownloadBoardState } from "@umt/contracts";
import { EventType } from "@umt/contracts";
import { RefreshCw } from "lucide-react";
import { useMemo, useState } from "react";
import { Link } from "react-router";
import { useDownloadBoard } from "~/api/downloads.ts";
import { DataTable } from "~/components/console/data-table.tsx";
import { DetailSheet } from "~/components/console/detail-sheet.tsx";
import { consolePath } from "~/components/console/nav.ts";
import { PageHeader } from "~/components/console/page-header.tsx";
import { readBoardState, writeBoardState } from "~/components/downloads/board-format.ts";
import { CacheVolumes } from "~/components/downloads/cache-volumes.tsx";
import {
  activeColumns,
  BOARD_EMPTY,
  BoardSegments,
  completedColumns,
  TransferLine,
} from "~/components/downloads/download-board.tsx";
import { DownloadDetail } from "~/components/downloads/download-detail.tsx";
import { DownloadsTabs } from "~/components/downloads/downloads-tabs.tsx";
import { Button } from "~/components/ui/button.tsx";
import { useSse } from "~/lib/sse.ts";

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

// DL-2:默认只看进行中;已完成单独一段(本浏览器记住选择)。页面可见时每 4 秒刷新速度,切到后台停。

export default function DownloadsPage() {
  // SPA 模式:路由组件只在浏览器渲染,可直接读本地记住的分段
  const [state, setStateRaw] = useState<DownloadBoardState>(readBoardState);
  const setState = (s: DownloadBoardState) => {
    setStateRaw(s);
    writeBoardState(s);
  };
  const [openId, setOpenId] = useState<string | null>(null);
  const qc = useQueryClient();
  const board = useDownloadBoard(state);

  // 状态变化、阈值事件到达时立即刷新(速度靠轮询)
  useSse(
    [
      EventType.downloadProgress,
      EventType.downloadStatusChanged,
      EventType.downloadSubmitted,
      EventType.downloadThreshold,
    ],
    () => void qc.invalidateQueries({ queryKey: ["downloads"] }),
  );

  const pages = board.data?.pages;
  const rows = pages?.flatMap((p) => p.items);
  const first = pages?.[0];
  const open = rows?.find((t) => t.id === openId) ?? null;
  const columns = useMemo(() => (state === "active" ? activeColumns() : completedColumns()), [state]);
  const empty = BOARD_EMPTY[state];

  return (
    <>
      <PageHeader
        title="下载面板"
        actions={
          <Button variant="outline" size="sm" onClick={() => void qc.invalidateQueries({ queryKey: ["downloads"] })}>
            <RefreshCw className={board.isFetching ? "animate-spin" : undefined} />
            刷新
          </Button>
        }
      />
      <DownloadsTabs />
      <CacheVolumes />
      <div className="mb-3 flex flex-wrap items-center justify-between gap-x-4 gap-y-2">
        <BoardSegments value={state} counts={first?.counts} onChange={setState} />
        <TransferLine transfer={first?.transfer} />
      </div>
      <DataTable
        columns={columns}
        rows={rows}
        rowKey={(t) => t.id}
        loading={board.isPending}
        error={board.error}
        onRetry={() => void board.refetch()}
        onRowClick={(t) => setOpenId(t.id)}
        selectedKey={openId}
        hasMore={board.hasNextPage}
        onLoadMore={() => void board.fetchNextPage()}
        loadingMore={board.isFetchingNextPage}
        empty={empty}
      />

      <DetailSheet
        open={!!open}
        onOpenChange={(o) => !o && setOpenId(null)}
        width="lg"
        title={open?.name ?? ""}
        footer={
          open ? (
            <Button asChild variant="outline" size="sm">
              <Link to={consolePath("downloads", open.id)}>打开详情页</Link>
            </Button>
          ) : null
        }
      >
        {open ? <DownloadDetail task={open} live={open.live} /> : null}
      </DetailSheet>
    </>
  );
}