type TypedClient = {
  from: (table: string) => any;
};

interface WorkspaceMembershipRow {
  workspace_id: string;
  is_default: boolean;
  workspaces:
    | {
        id: string;
        name: string;
        type: "personal" | "team";
        icon_url: string | null;
      }
    | Array<{
        id: string;
        name: string;
        type: "personal" | "team";
        icon_url: string | null;
      }>
    | null;
}

export interface WorkspaceSummary {
  id: string;
  name: string;
  type: "personal" | "team";
  iconUrl: string | null;
  memberCount: number;
  isDefault: boolean;
}

export async function ensureDefaultWorkspace(client: TypedClient, userId: string, fallbackName: string): Promise<void> {
  const { data: memberships, error } = await client
    .from("workspace_members")
    .select("workspace_id")
    .eq("user_id", userId)
    .limit(1);

  if (error) {
    throw new Error(`获取工作空间成员信息失败：${error.message}`);
  }

  if (memberships && memberships.length > 0) {
    return;
  }

  const workspaceName = fallbackName.trim() ? `${fallbackName.trim()} 的空间` : "我的空间";

  const { data: workspace, error: workspaceError } = await client
    .from("workspaces")
    .insert({
      name: workspaceName,
      type: "personal",
      created_by: userId,
    })
    .select("id")
    .single();

  if (workspaceError || !workspace) {
    throw new Error(`创建默认工作空间失败：${workspaceError?.message ?? "未知错误"}`);
  }

  const { error: memberError } = await client.from("workspace_members").insert({
    workspace_id: workspace.id,
    user_id: userId,
    role: "owner",
    is_default: true,
  });

  if (memberError) {
    throw new Error(`创建工作空间成员失败：${memberError.message}`);
  }
}

export async function fetchWorkspaceSummaries(
  client: TypedClient,
  userId: string,
): Promise<{ workspaces: WorkspaceSummary[]; activeWorkspaceId: string }> {
  const { data: memberRows, error } = await client
    .from("workspace_members")
    .select("workspace_id,is_default,workspaces(id,name,type,icon_url)")
    .eq("user_id", userId)
    .order("created_at", { ascending: true });

  if (error) {
    throw new Error(`拉取工作空间列表失败：${error.message}`);
  }

  const rows: WorkspaceMembershipRow[] = (memberRows ?? []) as any;
  const workspaceIds = rows.map((row) => row.workspace_id);

  const memberCountMap: Record<string, number> = {};
  if (workspaceIds.length > 0) {
    const { data: memberCounts, error: countError } = await client
      .from("workspace_members")
      .select("workspace_id")
      .in("workspace_id", workspaceIds);

    if (countError) {
      throw new Error(`统计成员数失败：${countError.message}`);
    }

    const countRows = (memberCounts ?? []) as Array<{ workspace_id: string }>;
    countRows.forEach((item) => {
      const workspaceId = item.workspace_id;
      memberCountMap[workspaceId] = (memberCountMap[workspaceId] ?? 0) + 1;
    });
  }

  const summaries: WorkspaceSummary[] = rows
    .map((row) => {
      const workspace = Array.isArray(row.workspaces) ? row.workspaces[0] : row.workspaces;
      if (!workspace) {
        return null;
      }
      return {
        id: workspace.id,
        name: workspace.name,
        type: workspace.type,
        iconUrl: workspace.icon_url,
        memberCount: memberCountMap[workspace.id] ?? 1,
        isDefault: row.is_default,
      } satisfies WorkspaceSummary;
    })
    .filter(Boolean) as WorkspaceSummary[];

  const defaultWorkspace = summaries.find((workspace) => workspace.isDefault);
  const activeWorkspaceId = defaultWorkspace?.id ?? summaries[0]?.id ?? "";

  return {
    workspaces: summaries,
    activeWorkspaceId,
  };
}

export async function resolveActiveWorkspaceId(client: TypedClient, userId: string): Promise<string> {
  const { data, error } = await client
    .from("workspace_members")
    .select("workspace_id,is_default")
    .eq("user_id", userId)
    .order("is_default", { ascending: false })
    .order("created_at", { ascending: true })
    .limit(1);

  if (error) {
    throw new Error(`获取当前工作空间失败：${error.message}`);
  }

  return data?.[0]?.workspace_id ?? "";
}