1 // Copyright 2020 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "cast/streaming/sender_message.h"
6
7 #include <utility>
8
9 #include "absl/strings/ascii.h"
10 #include "cast/streaming/message_fields.h"
11 #include "util/base64.h"
12 #include "util/enum_name_table.h"
13 #include "util/json/json_helpers.h"
14 #include "util/json/json_serialization.h"
15
16 namespace openscreen {
17 namespace cast {
18
19 namespace {
20
21 EnumNameTable<SenderMessage::Type, 4> kMessageTypeNames{
22 {{kMessageTypeOffer, SenderMessage::Type::kOffer},
23 {"GET_CAPABILITIES", SenderMessage::Type::kGetCapabilities},
24 {"RPC", SenderMessage::Type::kRpc}}};
25
GetMessageType(const Json::Value & root)26 SenderMessage::Type GetMessageType(const Json::Value& root) {
27 std::string type;
28 if (!json::TryParseString(root[kMessageType], &type)) {
29 return SenderMessage::Type::kUnknown;
30 }
31
32 absl::AsciiStrToUpper(&type);
33 ErrorOr<SenderMessage::Type> parsed = GetEnum(kMessageTypeNames, type);
34
35 return parsed.value(SenderMessage::Type::kUnknown);
36 }
37
38 } // namespace
39
40 // static
Parse(const Json::Value & value)41 ErrorOr<SenderMessage> SenderMessage::Parse(const Json::Value& value) {
42 if (!value) {
43 return Error(Error::Code::kParameterInvalid, "Empty JSON");
44 }
45
46 SenderMessage message;
47 if (!json::TryParseInt(value[kSequenceNumber], &(message.sequence_number))) {
48 message.sequence_number = -1;
49 }
50
51 message.type = GetMessageType(value);
52 switch (message.type) {
53 case Type::kOffer: {
54 Offer offer;
55 if (Offer::TryParse(value[kOfferMessageBody], &offer).ok()) {
56 message.body = std::move(offer);
57 message.valid = true;
58 }
59 } break;
60
61 case Type::kRpc: {
62 std::string rpc_body;
63 std::vector<uint8_t> rpc;
64 if (json::TryParseString(value[kRpcMessageBody], &rpc_body) &&
65 base64::Decode(rpc_body, &rpc)) {
66 message.body = rpc;
67 message.valid = true;
68 }
69 } break;
70
71 case Type::kGetCapabilities:
72 message.valid = true;
73 break;
74
75 default:
76 break;
77 }
78
79 return message;
80 }
81
ToJson() const82 ErrorOr<Json::Value> SenderMessage::ToJson() const {
83 OSP_CHECK(type != SenderMessage::Type::kUnknown)
84 << "Trying to send an unknown message is a developer error";
85
86 Json::Value root;
87 ErrorOr<const char*> message_type = GetEnumName(kMessageTypeNames, type);
88 root[kMessageType] = message_type.value();
89 if (sequence_number >= 0) {
90 root[kSequenceNumber] = sequence_number;
91 }
92
93 switch (type) {
94 case SenderMessage::Type::kOffer:
95 root[kOfferMessageBody] = absl::get<Offer>(body).ToJson();
96 break;
97
98 case SenderMessage::Type::kRpc:
99 root[kRpcMessageBody] =
100 base64::Encode(absl::get<std::vector<uint8_t>>(body));
101 break;
102
103 case SenderMessage::Type::kGetCapabilities:
104 break;
105
106 default:
107 OSP_NOTREACHED();
108 }
109 return root;
110 }
111
112 } // namespace cast
113 } // namespace openscreen
114