import {
  ArrowLeft,
  CheckCircle2,
  Coins,
  Gift,
  Search,
  Sparkles,
  Users,
} from "lucide-react";
import {
  useCallback,
  useEffect,
  useMemo,
  useRef,
  useState,
  type FormEvent,
} from "react";
import { useSearchParams } from "react-router-dom";
import { toast } from "sonner";
import { adminApi, ApiError } from "../../api/client";
import type {
  LedgerQuery,
  SortOrder,
  UserDetail,
  UsersQuery,
  UserSummary,
  UserUsageAggregate,
} from "../../api/types";
import { DataTable, type DataColumn } from "../../components/data-table";
import { DateRangeControl } from "../../components/date-range-control";
import { FilterControl } from "../../components/filter-control";
import {
  Badge,
  Button,
  Card,
  Dialog,
  ErrorState,
  Input,
  LoadingState,
  PageHeader,
  Textarea,
} from "../../components/primitives";
import { TableToolbar } from "../../components/table-toolbar";
import { useCursorPage } from "../../hooks/use-cursor-page";
import {
  createIdempotencyKey,
  formatDateTime,
  formatNumber,
  statusLabel,
  usageTypeLabel,
} from "../../lib/format";
import { useAuth } from "../auth/auth-context";
import { LedgerFilters } from "../credits/ledger-filters";
import { LedgerTable } from "../credits/ledger-table";
import { useLedgerFilters } from "../credits/use-ledger-filters";

export function UsersPage() {
  const { auth } = useAuth();
  const [searchParams, setSearchParams] = useSearchParams();
  const role = auth.status === "authenticated" ? auth.role : "ANALYST";
  const selectedUserId = searchParams.get("userId") ?? undefined;

  function selectUser(userId?: string) {
    setSearchParams((current) => {
      const params = new URLSearchParams(current);
      if (userId) params.set("userId", userId);
      else params.delete("userId");
      return params;
    });
  }

  return selectedUserId ? (
    <UserDetailView
      userId={selectedUserId}
      canGrant={role === "SUPER_ADMIN"}
      onBack={() => selectUser()}
    />
  ) : (
    <UserList onSelect={selectUser} />
  );
}

function UserList({ onSelect }: { onSelect: (userId: string) => void }) {
  const [searchParams, setSearchParams] = useSearchParams();
  const initialQuery = searchParams.get("q") ?? "";
  const [query, setQuery] = useState(initialQuery);
  const [activeQuery, setActiveQuery] = useState(initialQuery);
  const [from, setFrom] = useState(searchParams.get("from") ?? "");
  const [until, setUntil] = useState(searchParams.get("until") ?? "");
  const [status, setStatus] = useState<"" | UserSummary["status"]>(
    (searchParams.get("status") as UserSummary["status"] | null) ?? "",
  );
  const [order, setOrder] = useState<SortOrder>(
    searchParams.get("order") === "asc" ? "asc" : "desc",
  );
  const usersQuery = useMemo<UsersQuery>(
    () => ({
      q: activeQuery || undefined,
      from: from || undefined,
      until: until || undefined,
      status: status || undefined,
      sort: "createdAt",
      order,
      limit: 50,
    }),
    [activeQuery, from, order, status, until],
  );
  const fetchUsers = useCallback((value: UsersQuery) => adminApi.users(value), []);
  const {
    items,
    nextCursor,
    loading,
    loadingMore,
    error,
    loadMore,
    reload,
  } = useCursorPage(usersQuery, fetchUsers);

  useEffect(() => {
    const params = new URLSearchParams();
    if (activeQuery) params.set("q", activeQuery);
    if (from) params.set("from", from);
    if (until) params.set("until", until);
    if (status) params.set("status", status);
    params.set("sort", "createdAt");
    params.set("order", order);
    setSearchParams(params, { replace: true });
  }, [activeQuery, from, order, setSearchParams, status, until]);

  function submit(event: FormEvent<HTMLFormElement>) {
    event.preventDefault();
    const search = query.trim();
    setActiveQuery(search);
  }

  const columns = useMemo<DataColumn<UserSummary>[]>(
    () => [
      {
        id: "user",
        header: "用户",
        cell: ({ row }) => (
          <button
            className="group/user max-w-64 text-left"
            type="button"
            onClick={() => onSelect(row.original.userId)}
          >
            <span className="block font-semibold transition group-hover/user:text-primary">
              {row.original.displayName || "未命名用户"}
            </span>
            <span className="mt-1 block truncate font-mono text-[11px] text-muted">
              {row.original.userId}
            </span>
          </button>
        ),
      },
      {
        accessorKey: "status",
        header: "状态",
        cell: ({ getValue }) => <UserStatus status={String(getValue())} />,
      },
      {
        accessorKey: "consumedCredits",
        header: "累计使用",
        cell: ({ getValue }) => (
          <span className="tabular-nums">{formatNumber(Number(getValue()))}</span>
        ),
      },
      {
        accessorKey: "creditBalance",
        header: "当前积分",
        cell: ({ getValue }) => (
          <span className="font-semibold tabular-nums">{formatNumber(Number(getValue()))}</span>
        ),
      },
      {
        accessorKey: "createdAt",
        header: "注册时间",
        cell: ({ getValue }) => (
          <span className="whitespace-nowrap text-xs text-muted">
            {formatDateTime(String(getValue()))}
          </span>
        ),
      },
      {
        id: "actions",
        header: "操作",
        cell: ({ row }) => (
          <Button size="sm" variant="secondary" onClick={() => onSelect(row.original.userId)}>
            查看详情
          </Button>
        ),
      },
    ],
    [onSelect],
  );

  return (
    <div className="space-y-6">
      <PageHeader
        eyebrow="账户管理"
        title="用户列表"
        description="按注册时间浏览账户，支持完整或后 8 位内部用户 ID 查询。"
      />
      <Card className="overflow-hidden">
        <div className="border-b border-border p-5 sm:p-6">
          <form className="flex max-w-2xl flex-col gap-3 sm:flex-row" onSubmit={submit}>
            <label className="relative flex-1">
              <span className="sr-only">内部用户 ID</span>
              <Search
                className="pointer-events-none absolute left-3.5 top-1/2 size-4 -translate-y-1/2 text-muted"
                aria-hidden
              />
              <Input
                className="pl-10"
                value={query}
                onChange={(event) => setQuery(event.target.value)}
                type="search"
                placeholder="输入完整或后 8 位用户 ID"
                maxLength={36}
                autoComplete="off"
              />
            </label>
            <Button type="submit">
              <Search className="size-4" aria-hidden />
              搜索用户
            </Button>
          </form>
        </div>
        <TableToolbar
          active={Boolean(activeQuery || from || until || status || order !== "desc")}
          onClear={() => {
            setQuery("");
            setActiveQuery("");
            setFrom("");
            setUntil("");
            setStatus("");
            setOrder("desc");
          }}
        >
          <DateRangeControl
            value={{ from: from || undefined, until: until || undefined }}
            onChange={(value) => {
              setFrom(value.from ?? "");
              setUntil(value.until ?? "");
            }}
          />
          <FilterControl
            label="账户状态"
            value={status}
            options={[
              { value: "", label: "全部状态" },
              { value: "active", label: "正常" },
              { value: "suspended", label: "已暂停" },
            ]}
            onChange={setStatus}
          />
        </TableToolbar>
        <div className="flex items-center gap-2 border-b border-border bg-surface-muted/35 px-5 py-3 text-xs text-muted sm:px-6">
          <Users className="size-4 text-primary" aria-hidden />
          {activeQuery ? "查询结果" : "全部用户"}
          <span aria-hidden>·</span>
          <strong className="text-foreground">{formatNumber(items.length)} 位</strong>
        </div>
        {error ? (
          <div className="p-6">
            <ErrorState error={error} retry={reload} />
          </div>
        ) : loading ? (
          <LoadingState label="加载用户列表" />
        ) : (
          <DataTable
            data={items}
            columns={columns}
            caption={activeQuery ? "用户查询结果" : "全部用户"}
            emptyTitle={
              activeQuery || from || until || status
                ? "没有符合当前筛选条件的用户"
                : "暂无用户"
            }
            sort={{ key: "createdAt", order }}
            sortableColumns={{ createdAt: "createdAt" }}
            onSortChange={(_, nextOrder) => setOrder(nextOrder)}
            footer={
              nextCursor ? (
                <div className="flex justify-center border-t border-border p-5">
                  <Button variant="secondary" onClick={() => void loadMore()} loading={loadingMore}>
                    加载更多用户
                  </Button>
                </div>
              ) : null
            }
          />
        )}
      </Card>
    </div>
  );
}

function UserDetailView({
  userId,
  canGrant,
  onBack,
}: {
  userId: string;
  canGrant: boolean;
  onBack: () => void;
}) {
  const [user, setUser] = useState<UserDetail>();
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<unknown>();
  const [grantOpen, setGrantOpen] = useState(false);
  const filters = useLedgerFilters("ledger");
  const requestVersion = useRef(0);
  const fetchLedger = useCallback(
    (value: LedgerQuery) => adminApi.ledger(userId, value),
    [userId],
  );
  const ledgerPage = useCursorPage(filters.query, fetchLedger);

  const load = useCallback(async () => {
    const version = ++requestVersion.current;
    setLoading(true);
    setError(undefined);
    try {
      const detail = await adminApi.user(userId);
      if (requestVersion.current !== version) return;
      setUser(detail);
    } catch (requestError) {
      if (requestVersion.current === version) setError(requestError);
    } finally {
      if (requestVersion.current === version) setLoading(false);
    }
  }, [userId]);

  useEffect(() => {
    void load();
  }, [load]);

  if (error || ledgerPage.error) {
    return (
      <ErrorState
        error={error ?? ledgerPage.error}
        retry={() => {
          void load();
          ledgerPage.reload();
        }}
      />
    );
  }
  if (loading || ledgerPage.loading || !user) return <LoadingState label="加载用户详情" />;

  const usage = user.usage ?? [];
  const requests = usage.reduce((total, item) => total + item.requests, 0);
  const chargedCredits = usage.reduce((total, item) => total + item.chargedCredits, 0);
  const inviterUserId = user.referral?.inviterUserId ?? user.referredByUserId;
  const qualifiedUsage = user.qualifiedUsage || requests > 0;

  return (
    <div className="space-y-6">
      <div>
        <Button className="-ml-3 mb-4" variant="ghost" onClick={onBack}>
          <ArrowLeft className="size-4" aria-hidden />
          返回用户列表
        </Button>
        <PageHeader
          eyebrow="用户详情"
          title={user.displayName || "未命名用户"}
          description={user.userId}
          actions={
            canGrant ? (
              <Button onClick={() => setGrantOpen(true)}>
                <Gift className="size-4" aria-hidden />
                人工赠送积分
              </Button>
            ) : undefined
          }
        />
      </div>

      <section className="grid gap-6 xl:grid-cols-[340px_minmax(0,1fr)]">
        <Card className="h-fit overflow-hidden">
          <div className="bg-gradient-to-br from-primary-soft to-violet-soft/40 p-6">
            <div className="flex items-center gap-4">
              <span className="grid size-14 place-items-center rounded-2xl bg-surface text-xl font-bold text-primary shadow-sm">
                {(user.displayName || "用").slice(0, 1)}
              </span>
              <div className="min-w-0">
                <strong className="block truncate">{user.displayName || "未命名用户"}</strong>
                <div className="mt-2">
                  <UserStatus status={user.status} />
                </div>
              </div>
            </div>
          </div>
          <div className="p-6">
            <p className="text-xs font-medium text-muted">当前积分</p>
            <strong className="mt-2 block text-4xl font-bold tracking-[-0.06em] tabular-nums">
              {formatNumber(user.creditBalance)}
            </strong>
            <dl className="mt-6 divide-y divide-border">
              <DetailRow label="注册时间" value={formatDateTime(user.createdAt)} />
              <DetailRow label="最近活跃" value={formatDateTime(user.lastActiveAt)} />
              <DetailRow
                label="有效使用"
                value={qualifiedUsage ? `已达成 · ${formatNumber(requests)} 次` : "未达成"}
              />
              <DetailRow label="累计消耗" value={`${formatNumber(chargedCredits)} 积分`} />
              <DetailRow label="邀请码" value={user.referralCode || "—"} mono />
              <DetailRow label="邀请来源" value={inviterUserId || "—"} mono />
              {user.referral ? (
                <DetailRow
                  label="邀请成效"
                  value={`${formatNumber(user.referral.rewardedInvites)} / ${formatNumber(user.referral.invitedUsers)} 已奖励`}
                />
              ) : null}
            </dl>
          </div>
        </Card>

        <div className="space-y-6">
          <Card className="overflow-hidden">
            <SectionHeading
              icon={Coins}
              title="积分流水"
              description="所有变动均来自不可变账本"
            />
            <LedgerFilters
              value={filters.state}
              onChange={filters.update}
              onClear={filters.clear}
            />
            <LedgerTable
              entries={ledgerPage.items}
              caption={`${user.displayName || user.userId} 的积分流水`}
              emptyTitle={
                filters.state.from ||
                filters.state.until ||
                filters.state.type ||
                filters.state.entryType ||
                filters.state.usageType ||
                filters.state.referenceId
                  ? "没有符合当前筛选条件的流水"
                  : "暂无积分流水"
              }
              sort={filters.state.sort}
              order={filters.state.order}
              onSortChange={(sort, order) => filters.update({ sort, order })}
              onReferenceFilter={(referenceId) => filters.update({ referenceId })}
              footer={
                ledgerPage.nextCursor ? (
                  <div className="flex justify-center border-t border-border p-5">
                    <Button
                      variant="secondary"
                      onClick={() => void ledgerPage.loadMore()}
                      loading={ledgerPage.loadingMore}
                    >
                      加载更多流水
                    </Button>
                  </div>
                ) : null
              }
            />
          </Card>

          {usage.length > 0 ? <UsagePanel usage={usage} /> : null}
        </div>
      </section>

      {canGrant ? (
        <GrantDialog
          open={grantOpen}
          user={user}
          onOpenChange={setGrantOpen}
          onSuccess={async () => {
            await load();
            ledgerPage.reload();
          }}
        />
      ) : null}
    </div>
  );
}

export function GrantDialog({
  open,
  user,
  onOpenChange,
  onSuccess,
}: {
  open: boolean;
  user: UserDetail;
  onOpenChange: (open: boolean) => void;
  onSuccess: () => Promise<void>;
}) {
  const [step, setStep] = useState<"input" | "confirm">("input");
  const [amount, setAmount] = useState("");
  const [reason, setReason] = useState("");
  const [error, setError] = useState("");
  const [submitting, setSubmitting] = useState(false);
  const [outcomeUnknown, setOutcomeUnknown] = useState(false);
  const [idempotencyKey, setIdempotencyKey] = useState(createIdempotencyKey);

  function reset() {
    setStep("input");
    setAmount("");
    setReason("");
    setError("");
    setSubmitting(false);
    setOutcomeUnknown(false);
    setIdempotencyKey(createIdempotencyKey());
  }

  function handleOpenChange(nextOpen: boolean) {
    if (!nextOpen && outcomeUnknown) {
      setError("赠送结果尚未确认，请在当前窗口使用同一请求安全重试");
      return;
    }
    onOpenChange(nextOpen);
    if (!nextOpen) reset();
  }

  function review() {
    const numericAmount = Number(amount);
    if (!Number.isSafeInteger(numericAmount) || numericAmount < 1 || numericAmount > 100_000) {
      setError("积分必须是 1 至 100,000 的整数");
      return;
    }
    if (reason.trim().length < 4) {
      setError("请填写至少 4 个字符的赠送原因");
      return;
    }
    setError("");
    setStep("confirm");
  }

  async function submit() {
    setSubmitting(true);
    setError("");
    try {
      await adminApi.grantCredits({
        userId: user.userId,
        amount: Number(amount),
        reason: reason.trim(),
        idempotencyKey,
      });
      onOpenChange(false);
      reset();
      toast.success("积分赠送成功，账本已更新");
      await onSuccess();
    } catch (requestError) {
      const unknown =
        !(requestError instanceof ApiError) ||
        requestError.status === 0 ||
        requestError.status >= 500;
      setOutcomeUnknown(unknown);
      setError(
        unknown
          ? "赠送结果尚未确认；重试会复用同一请求，不会重复到账"
          : requestError instanceof ApiError
            ? requestError.message
            : "赠送失败，请重试",
      );
      setSubmitting(false);
    }
  }

  return (
    <Dialog
      open={open}
      onOpenChange={handleOpenChange}
      title={step === "input" ? "人工赠送积分" : "确认赠送"}
      description="赠送将写入不可变账本，并记录完整管理员审计日志。"
      preventClose={outcomeUnknown}
    >
      {step === "input" ? (
        <div className="space-y-5">
          <Field label="用户 ID">
            <Input value={user.userId} disabled />
          </Field>
          <Field label="赠送积分">
            <Input
              value={amount}
              onChange={(event) => setAmount(event.target.value)}
              type="number"
              min={1}
              max={100000}
              step={1}
              inputMode="numeric"
            />
          </Field>
          <Field label="赠送原因">
            <Textarea
              value={reason}
              onChange={(event) => setReason(event.target.value)}
              minLength={4}
              maxLength={200}
              placeholder="填写可审计的业务原因"
            />
          </Field>
          <p className="min-h-5 text-sm text-danger" role="alert">
            {error}
          </p>
          <div className="flex justify-end gap-3">
            <Button variant="secondary" onClick={() => handleOpenChange(false)}>
              取消
            </Button>
            <Button onClick={review}>下一步</Button>
          </div>
        </div>
      ) : (
        <div>
          <div className="rounded-2xl border border-danger/15 bg-danger-soft/60 p-5">
            <p className="text-sm text-muted">即将向以下用户赠送积分</p>
            <strong className="mt-2 block text-2xl font-bold tabular-nums">
              {formatNumber(Number(amount))} 积分
            </strong>
            <p className="mt-3 text-sm">{user.displayName || user.userId}</p>
            <p className="mt-2 rounded-xl bg-surface/70 p-3 text-xs leading-5 text-muted">
              原因：{reason.trim()}
            </p>
          </div>
          <p className="mt-4 min-h-5 text-sm text-danger" role="alert">
            {error}
          </p>
          <div className="mt-5 flex justify-end gap-3">
            <Button
              variant="secondary"
              disabled={outcomeUnknown || submitting}
              onClick={() => setStep("input")}
            >
              返回修改
            </Button>
            <Button variant="danger" loading={submitting} onClick={() => void submit()}>
              确认赠送
            </Button>
          </div>
        </div>
      )}
    </Dialog>
  );
}

function UsagePanel({ usage }: { usage: UserUsageAggregate[] }) {
  const columns = useMemo<DataColumn<UserUsageAggregate>[]>(
    () => [
      {
        accessorKey: "kind",
        header: "类型",
        cell: ({ getValue }) => <Badge tone="violet">{usageTypeLabel(String(getValue()))}</Badge>,
      },
      {
        accessorKey: "requests",
        header: "请求",
        cell: ({ getValue }) => formatNumber(Number(getValue())),
      },
      {
        accessorKey: "chargedCredits",
        header: "消耗积分",
        cell: ({ getValue }) => formatNumber(Number(getValue())),
      },
      {
        accessorKey: "asrMillis",
        header: "语音毫秒",
        cell: ({ getValue }) => formatNumber(Number(getValue())),
      },
      {
        accessorKey: "inputTokens",
        header: "输入 Token",
        cell: ({ getValue }) => formatNumber(Number(getValue())),
      },
      {
        accessorKey: "outputTokens",
        header: "输出 Token",
        cell: ({ getValue }) => formatNumber(Number(getValue())),
      },
    ],
    [],
  );
  return (
    <Card className="overflow-hidden">
      <SectionHeading
        icon={Sparkles}
        title="使用统计"
        description="按使用类型汇总，不包含任何用户内容"
      />
      <DataTable data={usage} columns={columns} caption="用户使用统计" />
    </Card>
  );
}

function SectionHeading({
  icon: Icon,
  title,
  description,
}: {
  icon: typeof Coins;
  title: string;
  description: string;
}) {
  return (
    <div className="flex items-center justify-between border-b border-border px-5 py-5 sm:px-6">
      <div>
        <h2 className="text-base font-bold">{title}</h2>
        <p className="mt-1 text-xs text-muted">{description}</p>
      </div>
      <span className="grid size-10 place-items-center rounded-2xl bg-primary-soft text-primary">
        <Icon className="size-4" aria-hidden />
      </span>
    </div>
  );
}

function DetailRow({
  label,
  value,
  mono,
}: {
  label: string;
  value: string;
  mono?: boolean;
}) {
  return (
    <div className="flex items-start justify-between gap-4 py-3 text-xs">
      <dt className="shrink-0 text-muted">{label}</dt>
      <dd
        className={`m-0 max-w-[190px] break-all text-right font-medium ${mono ? "font-mono text-[11px]" : ""}`}
      >
        {value}
      </dd>
    </div>
  );
}

function UserStatus({ status }: { status: string }) {
  const tone = status === "active" ? "success" : status === "suspended" ? "danger" : "neutral";
  return (
    <Badge tone={tone}>
      {status === "active" ? <CheckCircle2 className="size-3" aria-hidden /> : null}
      {statusLabel(status)}
    </Badge>
  );
}

function Field({ label, children }: { label: string; children: React.ReactNode }) {
  return (
    <label className="block">
      <span className="mb-2 block text-sm font-semibold">{label}</span>
      {children}
    </label>
  );
}