import { useState } from 'react';
import { Plus, Upload, Download, FileText } from 'lucide-react';
import { useSearchParams } from 'react-router-dom';
import { userApi } from '@/api/user';
import { toast } from '@/hooks/useToast';
import { ConfirmDialog } from '@/components/ConfirmDialog';
import { useQueryState, asString, asNumber } from '@/hooks/useQueryState';
import { useUsersList } from '@/features/rbac/hooks/useUsersList';
import { useUserSelection } from '@/features/rbac/hooks/useUserSelection';
import { exportUsersToCSV } from '@/features/rbac/utils';
import type { BatchActionKey } from '@/features/rbac/constants';
import type { UserItem } from '@/features/rbac/types';
import { UserFilters } from '@/features/rbac/components/UserFilters';
import { BatchActionBar } from '@/features/rbac/components/BatchActionBar';
import { UserTable } from '@/features/rbac/components/UserTable';
import { CreateUserModal } from '@/features/rbac/components/CreateUserModal';
import { EditUserModal } from '@/features/rbac/components/EditUserModal';
import { ResetPasswordModal } from '@/features/rbac/components/ResetPasswordModal';
import { UserDetailModal } from '@/features/rbac/components/UserDetailModal';
import { BatchImportModal } from '@/features/rbac/components/BatchImportModal';

/* ───────── 用户管理页(编排:筛选/表格/弹窗均拆分至 features/rbac) ───────── */

const PAGE_SIZE = 20;

/** 列表接口参与的筛选键(空态「清除筛选条件」仅清这三项,保留来源与页码) */
const LIST_FILTER_KEYS = ['q', 'role', 'status'] as const;

export default function UsersPage() {
  // 筛选/分页状态迁移到 URL query:刷新、分享链接、回退均可恢复
  const [search, setSearch] = useQueryState('q', '', asString);
  const [roleFilter, setRoleFilter] = useQueryState('role', '', asString);
  const [statusFilter, setStatusFilter] = useQueryState('status', '', asString);
  const [sourceFilter, setSourceFilter] = useQueryState('source', '', asString);
  const [page, setPage] = useQueryState('page', 1, asNumber);
  // 注意:react-router 的 setSearchParams 函数式更新基于渲染期快照,
  // 同一事件内多次调用会互相覆盖,批量重置必须合并为一次导航
  const [, setSearchParams] = useSearchParams();

  const [showCreate, setShowCreate] = useState(false);
  const [showDetail, setShowDetail] = useState<UserItem | null>(null);
  const [showEdit, setShowEdit] = useState<UserItem | null>(null);
  const [showResetPwd, setShowResetPwd] = useState<UserItem | null>(null);
  const [showImport, setShowImport] = useState(false);
  const [deleteConfirm, setDeleteConfirm] = useState<{msg: string; onConfirm: () => void} | null>(null);

  const { users, total, loading, fetchUsers } = useUsersList({
    page, pageSize: PAGE_SIZE, search, roleFilter, statusFilter,
  });

  // 来源筛选在前端执行(不参与列表请求,保持原行为)
  const filtered = users.filter(u => {
    if (sourceFilter && u.auth_source !== sourceFilter) return false;
    return true;
  });

  const { selectedIds, setSelectedIds, allSelected, toggleSelectAll, toggleSelect } = useUserSelection(filtered);

  /* ───────── 筛选重置(单次导航,等价于原「清空全部筛选并回到第 1 页」) ───────── */
  const resetFilters = () => setSearchParams({}, { replace: true });

  /* ───────── 空态「清除筛选条件」:仅清关键字/角色/状态,保留来源与页码 ───────── */
  const clearListFilters = () => setSearchParams(prev => {
    const params = new URLSearchParams(prev);
    LIST_FILTER_KEYS.forEach(key => params.delete(key));
    return params;
  }, { replace: true });

  const handleToggleActive = async (user: UserItem) => {
    try {
      await userApi.update(user.id, { is_active: !user.is_active });
      toast('success', `用户已${!user.is_active ? '启用' : '禁用'}`);
      fetchUsers();
    } catch { toast('error', '操作失败'); }
  };

  const handleDelete = (id: number) => {
    setDeleteConfirm({msg: '确定删除该用户？此操作不可恢复。', onConfirm: async () => {
      try {
        await userApi.delete(id);
        setSelectedIds(prev => { const n = new Set(prev); n.delete(id); return n; });
        toast('success', '用户已删除');
        fetchUsers();
      } catch { toast('error', '删除失败'); }
    }});
  };

  const handleBatchAction = async (action: BatchActionKey) => {
    const ids = Array.from(selectedIds);
    if (ids.length === 0) return;
    if (action === 'delete') {
      setDeleteConfirm({
        msg: `确定删除选中的 ${ids.length} 个用户？此操作不可恢复。`,
        onConfirm: async () => {
          try {
            await Promise.all(ids.map(id => userApi.delete(id)));
            toast('success', `已删除 ${ids.length} 个用户`);
            setSelectedIds(new Set());
            fetchUsers();
          } catch { toast('error', '批量删除失败'); }
        },
      });
      return;
    }
    try {
      if (action === 'enable') {
        await Promise.all(ids.map(id => userApi.update(id, { is_active: true })));
        toast('success', `已启用 ${ids.length} 个用户`);
      } else if (action === 'disable') {
        await Promise.all(ids.map(id => userApi.update(id, { is_active: false })));
        toast('success', `已禁用 ${ids.length} 个用户`);
      }
      setSelectedIds(new Set());
      fetchUsers();
    } catch { toast('error', '批量操作失败'); }
  };

  const handleDownloadTemplate = async () => {
    try {
      const blob = await userApi.downloadTemplate() as any;
      const url = URL.createObjectURL(new Blob([blob], { type: 'text/csv' }));
      const a = document.createElement('a');
      a.href = url;
      a.download = 'users_import_template.csv';
      a.click();
      URL.revokeObjectURL(url);
    } catch { toast('error', '下载模板失败'); }
  };

  return (
    <div className="space-y-5">
      {/* Header */}
      <div className="flex items-center justify-between">
        <div>
          <h1 className="text-2xl font-semibold">用户管理</h1>
          <p className="text-sm text-[var(--dg-text-secondary)] mt-1">管理系统用户，分配角色和数据库访问权限</p>
        </div>
        <div className="flex items-center gap-2">
          <button
            onClick={handleDownloadTemplate}
            className="flex items-center gap-2 px-4 py-2.5 bg-[var(--dg-bg-tertiary)] border border-[var(--dg-border)] rounded-lg text-sm font-medium text-[var(--dg-text-primary)] hover:bg-[var(--dg-bg-hover)] transition-all"
          >
            <FileText className="w-4 h-4" /> 模板
          </button>
          <button
            onClick={() => setShowImport(true)}
            className="flex items-center gap-2 px-4 py-2.5 bg-[var(--dg-bg-tertiary)] border border-[var(--dg-border)] rounded-lg text-sm font-medium text-[var(--dg-text-primary)] hover:bg-[var(--dg-bg-hover)] transition-all"
          >
            <Upload className="w-4 h-4" /> 导入
          </button>
          <button
            onClick={() => exportUsersToCSV(filtered)}
            className="flex items-center gap-2 px-4 py-2.5 bg-[var(--dg-bg-tertiary)] border border-[var(--dg-border)] rounded-lg text-sm font-medium text-[var(--dg-text-primary)] hover:bg-[var(--dg-bg-hover)] transition-all"
          >
            <Download className="w-4 h-4" /> 导出
          </button>
          <button
            onClick={() => setShowCreate(true)}
            className="flex items-center gap-2 px-4 py-2.5 bg-[var(--dg-blue)] rounded-lg text-sm font-medium text-white hover:opacity-90 transition-opacity"
          >
            <Plus className="w-4 h-4" /> 新建用户
          </button>
        </div>
      </div>

      {/* Filters */}
      <UserFilters
        search={search}
        roleFilter={roleFilter}
        statusFilter={statusFilter}
        sourceFilter={sourceFilter}
        onSearchChange={setSearch}
        onRoleFilterChange={setRoleFilter}
        onStatusFilterChange={setStatusFilter}
        onSourceFilterChange={setSourceFilter}
        onReset={resetFilters}
      />

      {/* Batch Actions Bar */}
      {selectedIds.size > 0 && (
        <BatchActionBar selectedCount={selectedIds.size} onAction={handleBatchAction} />
      )}

      {/* User Table */}
      <UserTable
        users={filtered}
        loading={loading}
        total={total}
        page={page}
        pageSize={PAGE_SIZE}
        selectedIds={selectedIds}
        allSelected={allSelected}
        showClearFilters={!!(search || roleFilter || statusFilter)}
        onToggleSelectAll={toggleSelectAll}
        onToggleSelect={toggleSelect}
        onShowDetail={setShowDetail}
        onShowEdit={setShowEdit}
        onShowResetPassword={setShowResetPwd}
        onToggleActive={handleToggleActive}
        onDelete={handleDelete}
        onClearFilters={clearListFilters}
        onPageChange={setPage}
      />

      {/* Create Modal */}
      {showCreate && (
        <CreateUserModal onClose={() => setShowCreate(false)} onCreated={() => { setShowCreate(false); fetchUsers(); }} />
      )}

      {/* Detail Modal */}
      {showDetail && (
        <UserDetailModal user={showDetail} onClose={() => setShowDetail(null)} />
      )}

      {/* Edit Modal */}
      {showEdit && (
        <EditUserModal user={showEdit} onClose={() => setShowEdit(null)} onUpdated={() => { setShowEdit(null); fetchUsers(); }} />
      )}

      {/* Reset Password Modal */}
      {showResetPwd && (
        <ResetPasswordModal user={showResetPwd} onClose={() => setShowResetPwd(null)} />
      )}

      {/* Batch Import Modal */}
      {showImport && (
        <BatchImportModal onClose={() => setShowImport(false)} onImported={() => { setShowImport(false); fetchUsers(); }} />
      )}
      <ConfirmDialog
        open={!!deleteConfirm}
        title={deleteConfirm?.msg || '确认操作'}
        variant="danger"
        confirmText="确定"
        onConfirm={() => { deleteConfirm?.onConfirm(); setDeleteConfirm(null); }}
        onCancel={() => setDeleteConfirm(null)}
      />
    </div>
  );
}