"use client";

import { useEffect, useRef, useState } from "react";
import { ChevronDown, Clock3, Loader2, UserCircle } from "lucide-react";
import type { AuthUser } from "@/lib/auth/session";
import {
  USAGE_PRESET_OPTIONS,
  type PersonalUsageReport,
  type UsagePreset
} from "@/lib/usage";

export function AccountUsageMenu({ user }: { user: AuthUser }) {
  const [open, setOpen] = useState(false);
  const [preset, setPreset] = useState<UsagePreset>("month");
  const [report, setReport] = useState<PersonalUsageReport | null>(null);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const containerRef = useRef<HTMLDivElement | null>(null);

  useEffect(() => {
    if (!open) return;
    const onPointerDown = (event: PointerEvent) => {
      if (!containerRef.current?.contains(event.target as Node)) setOpen(false);
    };
    const onKeyDown = (event: KeyboardEvent) => {
      if (event.key === "Escape") setOpen(false);
    };
    document.addEventListener("pointerdown", onPointerDown);
    document.addEventListener("keydown", onKeyDown);
    return () => {
      document.removeEventListener("pointerdown", onPointerDown);
      document.removeEventListener("keydown", onKeyDown);
    };
  }, [open]);

  useEffect(() => {
    if (!open) return;
    const controller = new AbortController();
    setLoading(true);
    setError(null);
    fetch(`/api/usage?preset=${preset}`, { cache: "no-store", signal: controller.signal })
      .then(async (response) => {
        const payload = await response.json() as PersonalUsageReport & { error?: string };
        if (!response.ok) throw new Error(payload.error || "读取用量失败");
        setReport(payload);
      })
      .catch((nextError) => {
        if (nextError instanceof DOMException && nextError.name === "AbortError") return;
        setError(nextError instanceof Error ? nextError.message : String(nextError));
      })
      .finally(() => {
        if (!controller.signal.aborted) setLoading(false);
      });
    return () => controller.abort();
  }, [open, preset]);

  return (
    <div className="account-usage-menu" ref={containerRef}>
      <button
        className="account-chip account-chip-button"
        type="button"
        aria-haspopup="dialog"
        aria-expanded={open}
        aria-controls="account-usage-popover"
        title={`${user.username || user.subject} · 查看用量`}
        onClick={() => setOpen((current) => !current)}
      >
        <UserCircle aria-hidden="true" />
        <span>{user.displayName}</span>
        <ChevronDown className={open ? "account-chevron open" : "account-chevron"} aria-hidden="true" />
      </button>

      {open ? (
        <section
          className="account-usage-popover"
          id="account-usage-popover"
          role="dialog"
          aria-label="我的用量"
        >
          <header className="account-usage-head">
            <div>
              <span>我的用量</span>
              <strong>{user.displayName}</strong>
            </div>
            <small>{user.username || user.subject}</small>
          </header>

          <div className="segmented account-usage-tabs" aria-label="用量周期">
            {USAGE_PRESET_OPTIONS.map((option) => (
              <button
                className={preset === option.value ? "active" : ""}
                type="button"
                aria-pressed={preset === option.value}
                key={option.value}
                onClick={() => setPreset(option.value)}
              >
                {option.label}
              </button>
            ))}
          </div>

          {error ? <div className="account-usage-error" role="alert">{error}</div> : null}
          {loading && !report ? (
            <div className="account-usage-loading"><Loader2 className="spin" />正在读取用量</div>
          ) : report ? (
            <div className={loading ? "account-usage-content refreshing" : "account-usage-content"}>
              <div className="account-usage-total">
                <span>{report.range.label}</span>
                <strong>{report.total}</strong>
                <small>次成功任务</small>
              </div>

              <div className="account-usage-breakdown" aria-label="按功能分类">
                {report.byCapability.map((item) => (
                  <div key={item.key}>
                    <span>{item.label}</span>
                    <strong>{item.count}</strong>
                  </div>
                ))}
              </div>

              <div className="account-usage-recent">
                <div className="account-usage-section-title">
                  <Clock3 aria-hidden="true" />
                  <strong>最近记录</strong>
                </div>
                {report.recent.length ? report.recent.map((record) => (
                  <div className="account-usage-record" key={record.id}>
                    <div>
                      <strong>{record.capabilityLabel}</strong>
                      <small>{record.providerLabel}{record.reqKey ? ` · ${record.reqKey}` : ""}</small>
                    </div>
                    <time dateTime={record.createdAt}>{formatUsageTime(record.createdAt)}</time>
                  </div>
                )) : (
                  <div className="account-usage-empty">当前周期暂无真实任务用量</div>
                )}
              </div>
            </div>
          ) : null}
        </section>
      ) : null}
    </div>
  );
}

function formatUsageTime(value: string): string {
  return new Intl.DateTimeFormat("zh-CN", {
    timeZone: "Asia/Shanghai",
    month: "2-digit",
    day: "2-digit",
    hour: "2-digit",
    minute: "2-digit",
    hour12: false
  }).format(new Date(value));
}