"use client";

import { Check, ChevronDown, Search } from "lucide-react";
import Link from "next/link";
import { useCallback, useEffect, useState } from "react";
import { useRouter, useSearchParams } from "next/navigation";
import { useTranslation } from "react-i18next";
import { toast } from "sonner";

import { getSettlementPeriods, type SettlementPeriodRow } from "@/api/admin-agent-settlement";
import { getAdminIntegrationSites } from "@/api/admin-integration-sites";
import { AdminLoadingState } from "@/components/admin/admin-loading-state";
import { AdminPageGuide } from "@/components/admin/admin-page-guide";
import { ADMIN_DOC_LINKS } from "@/lib/admin-doc-links";
import { AdminNoIntegrationSiteState } from "@/components/admin/admin-no-integration-site-state";
import { AgentBillDetail } from "@/modules/settlement/agent-bill-detail";
import { SettlementCenterPeriodDetail } from "@/modules/settlement/settlement-center-period-detail";
import {
  parseSettlementCenterView,
  settlementCenterListHref,
  settlementPeriodViewHref,
  type SettlementPeriodView,
} from "@/modules/settlement/settlement-center-nav";
import { SettlementPeriodWorkbench } from "@/modules/settlement/settlement-period-workbench";
import { formatAdminSiteLabel } from "@/lib/admin-site-display";
import { adminHasAnyPermission } from "@/lib/admin-permissions";
import { PRD_SETTLEMENT_AGENT_MANAGE } from "@/lib/admin-prd";
import {
  Dialog,
  DialogContent,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog";
import { Button, buttonVariants } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Popover, PopoverContent, PopoverTrigger } from "@/components/ui/popover";
import { ScrollArea } from "@/components/ui/scroll-area";
import { cn } from "@/lib/utils";
import { useAdminProfile } from "@/stores/admin-session";

type SiteOption = { id: number; label: string; code: string; currency_code: string };

export function SettlementCenterShell(): React.ReactElement {
  const { t } = useTranslation(["settlementCenter", "common"]);
  const router = useRouter();
  const searchParams = useSearchParams();
  const profile = useAdminProfile();
  const boundAgent = profile?.agent ?? null;

  const { siteId: siteFromUrl, periodId: activePeriodId, view: activeView } = parseSettlementCenterView(
    searchParams.get("site"),
    searchParams.get("period"),
    searchParams.get("view"),
  );

  const canOperateBills =
    profile?.is_super_admin === true ||
    adminHasAnyPermission(profile?.permissions, [PRD_SETTLEMENT_AGENT_MANAGE]);
  const canManagePeriods = canOperateBills && boundAgent === null;
  const canFinanceAdjustments = canOperateBills && boundAgent === null;

  const [siteOptions, setSiteOptions] = useState<SiteOption[]>([]);
  const [sitesReady, setSitesReady] = useState(() => boundAgent?.admin_site_id != null);
  const [adminSiteId, setAdminSiteId] = useState<number | null>(null);
  const [sitePickerOpen, setSitePickerOpen] = useState(false);
  const [siteKeyword, setSiteKeyword] = useState("");
  const [periods, setPeriods] = useState<SettlementPeriodRow[]>([]);
  const [periodsReady, setPeriodsReady] = useState(false);
  const [detailBillId, setDetailBillId] = useState<number | null>(null);
  const [refreshKey, setRefreshKey] = useState(0);
  const [periodLookupDone, setPeriodLookupDone] = useState(false);

  useEffect(() => {
    if (boundAgent?.admin_site_id) {
      const label = formatAdminSiteLabel(
        boundAgent.admin_site_name,
        boundAgent.site_code ?? boundAgent.code,
      );
      setSiteOptions([{
        id: boundAgent.admin_site_id,
        label,
        code: boundAgent.site_code ?? boundAgent.code ?? "",
        currency_code: "NPR",
      }]);
      setAdminSiteId(boundAgent.admin_site_id);
      setSitesReady(true);
      return;
    }

    setSitesReady(false);
    void getAdminIntegrationSites()
      .then((sites) => {
        const options = (sites.items ?? []).map((site) => ({
          id: site.id,
          label: formatAdminSiteLabel(site.name, site.code),
          code: site.code,
          currency_code: site.currency_code ?? "NPR",
        }));
        setSiteOptions(options);
        setAdminSiteId((current) => {
          if (siteFromUrl !== null && options.some((site) => site.id === siteFromUrl)) {
            return siteFromUrl;
          }
          if (current !== null && options.some((site) => site.id === current)) {
            return current;
          }
          return options[0]?.id ?? null;
        });
      })
      .catch(() => {
        setSiteOptions([]);
      })
      .finally(() => {
        setSitesReady(true);
      });
  }, [boundAgent, siteFromUrl]);

  const siteId = adminSiteId ?? siteOptions[0]?.id ?? null;
  const selectedSite = siteOptions.find((s) => s.id === siteId) ?? null;
  const siteLabel = selectedSite?.label ?? null;
  const currency = siteOptions.find((s) => s.id === siteId)?.currency_code ?? "NPR";
  const filteredSites = siteKeyword.trim().toLowerCase()
    ? siteOptions.filter((site) => site.label.toLowerCase().includes(siteKeyword.trim().toLowerCase()))
    : siteOptions;

  const boundAgentIdentity =
    boundAgent !== null ? (
      <p className="text-xs text-muted-foreground">
        {t("boundAgentIdentity", {
          defaultValue: "经营身份：{{agent}} · 账号 {{username}}",
          agent: boundAgent.name || boundAgent.code,
          username: profile?.username ?? "—",
        })}
      </p>
    ) : null;

  const siteSelector =
    siteOptions.length > 0 && siteId !== null ? (
      <Popover open={sitePickerOpen} onOpenChange={setSitePickerOpen}>
        <PopoverTrigger
          render={
            <Button
              type="button"
              variant="outline"
              size="sm"
              className="h-9 w-[240px] justify-between gap-2 bg-background px-3 font-normal"
            />
          }
        >
          <span className="min-w-0 flex-1 truncate text-left">{siteLabel ?? "—"}</span>
          <span className="shrink-0 text-xs text-muted-foreground">
            {selectedSite?.code ?? ""}
          </span>
          <ChevronDown className="size-4 shrink-0 text-muted-foreground" />
        </PopoverTrigger>
        <PopoverContent align="end" className="w-[320px] p-0">
          <div className="border-b border-border/60 p-3">
            <div className="relative">
              <Search className="pointer-events-none absolute left-3 top-1/2 size-4 -translate-y-1/2 text-muted-foreground" />
              <Input
                value={siteKeyword}
                onChange={(event) => setSiteKeyword(event.target.value)}
                placeholder={t("siteSearch", { defaultValue: "搜索站点名称" })}
                className="pl-9"
              />
            </div>
          </div>
          <ScrollArea className="max-h-72">
            <div className="p-2">
              {filteredSites.map((site) => {
                const active = site.id === siteId;

                return (
                  <button
                    key={site.id}
                    type="button"
                    className={cn(
                      "flex w-full items-center gap-3 rounded-md px-3 py-2 text-left transition-colors",
                      active ? "bg-primary/10 text-primary" : "hover:bg-muted/70",
                    )}
                    onClick={() => {
                      setAdminSiteId(site.id);
                      setSitePickerOpen(false);
                      setSiteKeyword("");
                      router.replace(settlementCenterListHref(site.id));
                    }}
                  >
                    <div className="min-w-0 flex-1">
                      <div className="truncate text-sm font-medium text-foreground">{site.label}</div>
                      <div className="truncate text-xs text-muted-foreground">{site.code}</div>
                    </div>
                    {active ? <Check className="size-4 shrink-0" /> : null}
                  </button>
                );
              })}
              {filteredSites.length === 0 ? (
                <div className="px-3 py-6 text-center text-sm text-muted-foreground">
                  {t("common:states.empty", { defaultValue: "暂无数据" })}
                </div>
              ) : null}
            </div>
          </ScrollArea>
        </PopoverContent>
      </Popover>
    ) : null;

  const headerActions =
    siteSelector !== null || boundAgentIdentity !== null ? (
      <div className="flex flex-col items-end gap-1">
        {siteSelector}
        {boundAgentIdentity}
      </div>
    ) : null;

  const loadPeriods = useCallback(async (): Promise<SettlementPeriodRow[]> => {
    if (siteId === null) {
      return [];
    }
    try {
      const data = await getSettlementPeriods({ admin_site_id: siteId });
      const items = data.items ?? [];
      setPeriods(items);
      setPeriodsReady(true);
      return items;
    } catch {
      setPeriods([]);
      setPeriodsReady(true);
      toast.error(t("periods.loadFailed", { defaultValue: "账期加载失败" }));
      return [];
    }
  }, [siteId, t]);

  useEffect(() => {
    setPeriodsReady(false);
    void loadPeriods();
  }, [loadPeriods]);

  const activePeriod =
    activePeriodId !== null ? (periods.find((row) => row.id === activePeriodId) ?? null) : null;

  const openPeriodView = (periodId: number, view: SettlementPeriodView): void => {
    router.push(settlementPeriodViewHref(periodId, view, siteId));
  };

  const isListMode = activePeriodId === null;

  useEffect(() => {
    if (boundAgent !== null || siteId === null) {
      return;
    }
    if (isListMode) {
      if (siteFromUrl === siteId) {
        return;
      }
      router.replace(settlementCenterListHref(siteId));
      return;
    }
    if (activePeriodId !== null && siteFromUrl !== siteId) {
      router.replace(settlementPeriodViewHref(activePeriodId, activeView, siteId));
    }
  }, [activePeriodId, activeView, boundAgent, isListMode, router, siteFromUrl, siteId]);

  useEffect(() => {
    setPeriodLookupDone(false);
  }, [activePeriodId, siteId]);

  useEffect(() => {
    if (!periodsReady || activePeriodId === null || siteId === null) {
      return;
    }

    if (activePeriod !== null) {
      setPeriodLookupDone(true);
      return;
    }

    let cancelled = false;
    void getSettlementPeriods().then((data) => {
      if (cancelled) {
        return;
      }

      const match = (data.items ?? []).find((row) => row.id === activePeriodId);
      if (match?.admin_site_id && match.admin_site_id !== siteId) {
        setAdminSiteId(match.admin_site_id);
        router.replace(settlementPeriodViewHref(activePeriodId, activeView, match.admin_site_id));
        return;
      }

      setPeriodLookupDone(true);
    });

    return () => {
      cancelled = true;
    };
  }, [activePeriod, activePeriodId, activeView, periodsReady, router, siteId]);

  const shellBootstrapping =
    !sitesReady || (siteId !== null && !periodsReady);

  return (
    <div className="mx-auto flex w-full max-w-7xl flex-col gap-4">
      <AdminPageGuide guide={t("pageGuide")} docHref={ADMIN_DOC_LINKS.settlementCenter} />
      {shellBootstrapping ? (
        <AdminLoadingState />
      ) : siteId === null && siteOptions.length === 0 && boundAgent === null ? (
        <AdminNoIntegrationSiteState canCreate={profile?.is_super_admin === true} />
      ) : siteId === null ? (
        <p className="text-sm text-muted-foreground">{t("empty.noSite", { defaultValue: "请选择站点。" })}</p>
      ) : isListMode ? (
        <SettlementPeriodWorkbench
          adminSiteId={siteId}
          currencyCode={currency}
          canManage={canManagePeriods}
          periods={periods}
          headerActions={headerActions}
          onViewDetail={(id) => openPeriodView(id, "bills")}
          onReloadPeriods={loadPeriods}
          onPeriodOpened={() => {
            setRefreshKey((n) => n + 1);
          }}
          onPeriodClosed={(result) => {
            setRefreshKey((n) => n + 1);
            const n = result?.unsettled_ticket_count ?? 0;
            if (n > 0) {
              toast.warning(
                t("toast.periodClosedUnsettled", {
                  defaultValue: "已关账，仍有 {{count}} 笔注单未结算。",
                  count: n,
                }),
              );
            }
          }}
        />
      ) : activePeriod === null ? (
        !periodLookupDone ? (
          <AdminLoadingState />
        ) : (
        <div className="flex flex-col gap-3">
          <p className="text-sm text-muted-foreground">
            {t("periodDetail.notFound", { defaultValue: "账期不存在或已切换站点，请返回列表。" })}
          </p>
          <Link
            href={settlementCenterListHref(siteId)}
            className={cn(buttonVariants({ variant: "outline", size: "sm" }), "w-fit")}
          >
            {t("periodDetail.back", { defaultValue: "返回账期列表" })}
          </Link>
        </div>
        )
      ) : (
        <SettlementCenterPeriodDetail
          period={activePeriod}
          view={activeView}
          adminSiteId={siteId}
          currencyCode={currency}
          canOperateBills={canOperateBills}
          boundAgentId={boundAgent?.id ?? null}
          refreshKey={refreshKey}
          onOpenBillDetail={setDetailBillId}
        />
      )}

      <Dialog open={detailBillId !== null} onOpenChange={(open) => !open && setDetailBillId(null)}>
        <DialogContent
          className="grid !h-[min(92vh,980px)] !w-[calc(100vw-2rem)] !max-w-none sm:!w-[min(640px,calc(100vw-2rem))] sm:!max-w-[640px] grid-rows-[auto,minmax(0,1fr)] overflow-hidden p-0"
        >
          <DialogHeader className="border-b px-6 py-4">
            <DialogTitle>{t("actions.billDetail", { defaultValue: "账单详情" })}</DialogTitle>
          </DialogHeader>
          {detailBillId !== null ? (
            <div className="min-h-0 overflow-y-auto px-6 py-5">
              <AgentBillDetail
                billId={detailBillId}
                currencyCode={currency}
                canManage={canOperateBills}
                boundAgent={boundAgent}
                canFinanceAdjustments={canFinanceAdjustments}
                onUpdated={() => {
                  void loadPeriods();
                  setRefreshKey((n) => n + 1);
                }}
              />
            </div>
          ) : null}
        </DialogContent>
      </Dialog>
    </div>
  );
}