From 69a0fafd6bb12f7399427b4fb7d9d49387a9c197 Mon Sep 17 00:00:00 2001
From: zhanghongtong <rory-z@outlook.com>
Date: Tue, 10 Aug 2021 15:59:58 +0800
Subject: [PATCH] feat(authz api): get api support paging

Signed-off-by: zhanghongtong <rory-z@outlook.com>
---
 apps/emqx_authz/src/emqx_authz_api.erl        | 45 ++++++++++++++++---
 apps/emqx_authz/test/emqx_authz_api_SUITE.erl | 29 +++++++-----
 2 files changed, 55 insertions(+), 19 deletions(-)

diff --git a/apps/emqx_authz/src/emqx_authz_api.erl b/apps/emqx_authz/src/emqx_authz_api.erl
index 245384774..cacca761d 100644
--- a/apps/emqx_authz/src/emqx_authz_api.erl
+++ b/apps/emqx_authz/src/emqx_authz_api.erl
@@ -45,17 +45,34 @@
         ]).
 
 api_spec() ->
-    {[ authorization_api(),
-       authorization_api2()
+    {[ api(),
+       once_api()
      ], definitions()}.
 
 definitions() -> emqx_authz_api_schema:definitions().
 
-authorization_api() ->
+api() ->
     Metadata = #{
         get => #{
             description => "List authorization rules",
-            parameters => [],
+            parameters => [
+                #{
+                    name => page,
+                    in => query,
+                    schema => #{
+                       type => integer
+                    },
+                    required => false
+                },
+                #{
+                    name => limit,
+                    in => query,
+                    schema => #{
+                       type => integer
+                    },
+                    required => false
+                }
+            ],
             responses => #{
                 <<"200">> => #{
                     description => <<"OK">>,
@@ -128,7 +145,7 @@ authorization_api() ->
     },
     {"/authorization", Metadata, authorization}.
 
-authorization_api2() ->
+once_api() ->
     Metadata = #{
         get => #{
             description => "List authorization rules",
@@ -210,7 +227,7 @@ authorization_api2() ->
     },
     {"/authorization/:id", Metadata, authorization_once}.
 
-authorization(get, _Request) ->
+authorization(get, Request) ->
     Rules = lists:foldl(fun (#{type := _Type, enable := true, annotations := #{id := Id} = Annotations} = Rule, AccIn) ->
                                 NRule = case emqx_resource:health_check(Id) of
                                     ok ->
@@ -222,7 +239,21 @@ authorization(get, _Request) ->
                             (Rule, AccIn) ->
                                 lists:append(AccIn, [Rule])
                         end, [], emqx_authz:lookup()),
-    {200, #{rules => Rules}};
+    Query = cowboy_req:parse_qs(Request),
+    case lists:keymember(<<"page">>, 1, Query) andalso lists:keymember(<<"limit">>, 1, Query) of
+        true ->
+            {<<"page">>, Page} = lists:keyfind(<<"page">>, 1, Query),
+            {<<"limit">>, Limit} = lists:keyfind(<<"limit">>, 1, Query),
+            Index = (binary_to_integer(Page) - 1) * binary_to_integer(Limit),
+            {_, Rules1} = lists:split(Index, Rules),
+            case binary_to_integer(Limit) < length(Rules1) of
+                true ->
+                    {Rules2, _} = lists:split(binary_to_integer(Limit), Rules1),
+                    {200, #{rules => Rules2}};
+                false -> {200, #{rules => Rules1}}
+            end;
+        false -> {200, #{rules => Rules}}
+    end;
 authorization(post, Request) ->
     {ok, Body, _} = cowboy_req:read_body(Request),
     RawConfig = jsx:decode(Body, [return_maps]),
diff --git a/apps/emqx_authz/test/emqx_authz_api_SUITE.erl b/apps/emqx_authz/test/emqx_authz_api_SUITE.erl
index af8c9013d..d065a8adf 100644
--- a/apps/emqx_authz/test/emqx_authz_api_SUITE.erl
+++ b/apps/emqx_authz/test/emqx_authz_api_SUITE.erl
@@ -75,28 +75,33 @@ t_post(_) ->
     {ok, 200, Result1} = request(get, uri(["authorization"]), []),
     ?assertEqual([], get_rules(Result1)),
 
-    {ok, 201, _} = request(post, uri(["authorization"]),
-                           #{<<"action">> => <<"all">>, <<"permission">> => <<"deny">>,
-                             <<"principal">> => <<"all">>, <<"topics">> => [<<"#">>]}),
-    {ok, 201, _} = request(post, uri(["authorization"]),
-                           #{<<"action">> => <<"all">>, <<"permission">> => <<"deny">>,
-                             <<"principal">> => <<"all">>, <<"topics">> => [<<"#">>]}),
-    {ok, 201, _} = request(post, uri(["authorization"]),
-                           #{<<"action">> => <<"all">>, <<"permission">> => <<"deny">>,
-                             <<"principal">> => <<"all">>, <<"topics">> => [<<"#">>]}),
+    lists:foreach(fun(_) ->
+                        {ok, 201, _} = request(post, uri(["authorization"]),
+                                         #{<<"action">> => <<"all">>,
+                                           <<"permission">> => <<"deny">>,
+                                           <<"principal">> => <<"all">>,
+                                           <<"topics">> => [<<"#">>]}
+                                        )
+                  end, lists:seq(1, 20)),
     {ok, 200, Result2} = request(get, uri(["authorization"]), []),
-    ?assertEqual(3, length(get_rules(Result2))),
+    ?assertEqual(20, length(get_rules(Result2))),
+
+    lists:foreach(fun(Page) ->
+                          Query = "?page=" ++ integer_to_list(Page) ++ "&&limit=10",
+                          Url = uri(["authorization" ++ Query]),
+                          {ok, 200, Result} = request(get, Url, []),
+                          ?assertEqual(10, length(get_rules(Result)))
+                  end, lists:seq(1, 2)),
 
     {ok, 204, _} = request(put, uri(["authorization"]),
                            [ #{<<"action">> => <<"all">>, <<"permission">> => <<"allow">>, <<"principal">> => <<"all">>, <<"topics">> => [<<"#">>]}
                            , #{<<"action">> => <<"all">>, <<"permission">> => <<"allow">>, <<"principal">> => <<"all">>, <<"topics">> => [<<"#">>]}
                            , #{<<"action">> => <<"all">>, <<"permission">> => <<"allow">>, <<"principal">> => <<"all">>, <<"topics">> => [<<"#">>]}
-                           , #{<<"action">> => <<"all">>, <<"permission">> => <<"allow">>, <<"principal">> => <<"all">>, <<"topics">> => [<<"#">>]}
                            ]),
 
     {ok, 200, Result3} = request(get, uri(["authorization"]), []),
     Rules = get_rules(Result3),
-    ?assertEqual(4, length(Rules)),
+    ?assertEqual(3, length(Rules)),
 
     lists:foreach(fun(#{<<"permission">> := Allow}) ->
                           ?assertEqual(<<"allow">>, Allow)