import { useState } from "react";
import { useTranslation } from "react-i18next";
import { keepPreviousData, useQuery } from "@tanstack/react-query";

import { api, type AdminQuotaRow } from "../lib/api";
import { sinceOf } from "../lib/activityUrlState";
import { formatNumber, quotaActionLabel } from "../lib/format";
import { qk } from "../lib/queryKeys";
import type { Shared } from "./ActivityRuns";
import { Pressable } from "./ui/Pressable";
import { LoadingState, StateMessage } from "./ui/QueryState";
import { SURFACE } from "./ui/surfaces";

// Activity → Quota: the shared YouTube API budget's spend over the page's time range — per day
// (Pacific days, as the budget resets), then per account, each opening to its actions. The
// account filter narrows both to one account; the text filter has nothing to match here.

export default function ActivityQuota({ shared }: { shared: Shared }) {
  const { t, i18n } = useTranslation();
  const lang = i18n.language;
  const q = useQuery({
    queryKey: qk.adminQuota({ window: shared.window, user: shared.user }),
    queryFn: () => api.adminQuota(sinceOf(shared.window), shared.user),
    placeholderData: keepPreviousData,
  });
  const data = q.data;
  const maxDaily = Math.max(1, ...(data?.daily ?? []).map((d) => d.total));
  const grandTotal = (data?.rows ?? []).reduce((s, r) => s + r.total, 0);

  return (
    <div className={q.isPlaceholderData ? "opacity-60" : ""} aria-busy={q.isPlaceholderData}>
      <p className="text-xs text-muted mb-3 leading-relaxed">
        {t("stats.introBefore")}
        <b className="text-fg/80">{t("stats.introSystem")}</b>
        {t("stats.introAfter")}
      </p>
      {q.isError && !data ? (
        <StateMessage tone="error" onRetry={() => void q.refetch()}>
          {t("common.loadError")}
        </StateMessage>
      ) : q.isLoading || !data ? (
        <LoadingState label={t("stats.loading")} />
      ) : (
        <>
          {q.isError && (
            <StateMessage tone="error" compact onRetry={() => void q.refetch()} className="mb-3">
              {t("activity.stale")}
            </StateMessage>
          )}
          <div className={`${SURFACE.card} p-3 mb-4`}>
            <div className="text-xs text-muted mb-2">
              {t(shared.window === "all" ? "activity.quota.totalAll" : "activity.quota.total", {
                count: grandTotal,
                window: t(`activity.windows.${shared.window}`),
                units: formatNumber(grandTotal, lang),
              })}
            </div>
            {data.daily.length === 0 ? (
              <div className="text-muted text-sm">{t("stats.noUsageInRange")}</div>
            ) : (
              // Each day's figure is in its bar's text too (read out, not shown): the tooltip only
              // reaches a pointer.
              <div
                className="flex items-end gap-0.5 h-24"
                role="list"
                aria-label={t("activity.quota.daily")}
              >
                {data.daily.map((d) => (
                  <div
                    key={d.day}
                    role="listitem"
                    // The day under the pointer is lit by the B3 layer over its whole column, not by
                    // dimming the bar: an opacity dim reads as "disabled".
                    className="flex-1 h-full flex items-end bg-card/50 rounded-t state-layer"
                    title={t("stats.dailyTooltip", {
                      count: d.total,
                      day: d.day,
                      units: formatNumber(d.total, lang),
                    })}
                  >
                    <span className="sr-only">
                      {t("stats.dailyTooltip", {
                        count: d.total,
                        day: d.day,
                        units: formatNumber(d.total, lang),
                      })}
                    </span>
                    <div
                      className="w-full bg-accent rounded-t"
                      style={{ height: `${Math.max(3, (d.total / maxDaily) * 100)}%` }}
                    />
                  </div>
                ))}
              </div>
            )}
          </div>

          <div className="flex flex-col gap-1.5">
            {data.rows.length === 0 ? (
              <div className="text-muted py-4">{t("stats.noUsageInRange")}</div>
            ) : (
              data.rows.map((r) => (
                <UserRow key={r.user_id ?? "system"} row={r} max={data.rows[0]?.total || 1} />
              ))
            )}
          </div>
        </>
      )}
    </div>
  );
}

function UserRow({ row, max }: { row: AdminQuotaRow; max: number }) {
  const { t, i18n } = useTranslation();
  const lang = i18n.language;
  const [open, setOpen] = useState(false);
  const actions = Object.entries(row.by_action).sort((a, b) => b[1] - a[1]);
  const isSystem = row.user_id === null;
  return (
    <div className={`${SURFACE.card} p-3`}>
      <Pressable
        selectable
        onClick={() => setOpen((o) => !o)}
        aria-expanded={open}
        className="w-full flex items-center gap-3"
      >
        <span className={`text-sm font-medium truncate flex-1 ${isSystem ? "text-muted" : ""}`}>
          {isSystem ? t("stats.system") : row.email}
        </span>
        <span className="text-sm font-semibold tabular-nums shrink-0">
          {formatNumber(row.total, lang)}
        </span>
      </Pressable>
      {/* Proportion bar */}
      <div className="mt-2 h-1.5 bg-border/40 rounded-full overflow-hidden">
        <div
          className="h-full bg-accent rounded-full"
          style={{ width: `${Math.max(2, (row.total / max) * 100)}%` }}
        />
      </div>
      {open && actions.length > 0 && (
        <div className="mt-2 space-y-1 text-xs text-muted">
          {actions.map(([action, units]) => (
            <div key={action} className="flex items-center justify-between gap-2">
              <span>{quotaActionLabel(t, action)}</span>
              <span className="tabular-nums">{formatNumber(units, lang)}</span>
            </div>
          ))}
        </div>
      )}
    </div>
  );
}