-module(identity_policy_ets).
-include("policy.hrl").

-export([init/0]).
-export([get_policies/1, insert/1, delete/1, update/2]).

init() ->
    ets:new(identity_policy, [named_table, bag, public, {keypos, 2}, {read_concurrency, true}]).

-spec get_policies(IdentityId :: integer()) -> [PolicyId :: integer()].
get_policies(IdentityId) when is_integer(IdentityId) ->
    Records = ets:lookup(identity_policy, IdentityId),
    lists:map(fun(#identity_policy{policy_id = PolicyId}) -> PolicyId end, Records).

insert(#{<<"identity_id">> := IdentityId, <<"policy_id">> := PolicyId}) ->
    insert(#identity_policy{identity_id = IdentityId, policy_id = PolicyId});
insert(IdentityPolicy=#identity_policy{}) ->
    true = ets:insert(identity_policy, IdentityPolicy).

delete(#{<<"identity_id">> := IdentityId, <<"policy_id">> := PolicyId}) ->
    ets:delete_object(identity_policy, #identity_policy{identity_id = IdentityId, policy_id = PolicyId});
delete(IdentityPolicy = #identity_policy{}) ->
    true = ets:delete_object(identity_policy, IdentityPolicy).

update(NewData=#{<<"identity_id">> := IdentityId, <<"policy_id">> := PolicyId}, OldData) ->
    %% 清理老的数据
    #{<<"identity_id">> := OldIdentityId, <<"policy_id">> := OldPolicyId} = maps:merge(NewData, OldData),
    ets:delete_object(identity_policy, #identity_policy{identity_id = OldIdentityId, policy_id = OldPolicyId}),
    ets:insert(identity_policy, #identity_policy{identity_id = IdentityId, policy_id = PolicyId}).