feat: add initial experimental Twitch Eventsub support (#5837)

Co-authored-by: nerix <nerixdev@outlook.de>

lib/twitch-eventsub-ws/ast/lib/templates/enum-definition.tmpl

@@ -0,0 +1,2 @@
+boost::json::result_for<{{enum.full_name}}, boost::json::value>::type tag_invoke(
+    boost::json::try_value_to_tag<{{enum.full_name}}>, const boost::json::value &jvRoot);

lib/twitch-eventsub-ws/ast/lib/templates/enum-implementation.tmpl

@@ -0,0 +1,21 @@
+boost::json::result_for<{{enum.full_name}}, boost::json::value>::type tag_invoke(
+    boost::json::try_value_to_tag<{{enum.full_name}}>, const boost::json::value &jvRoot)
+{
+    if (!jvRoot.is_string())
+    {
+        static const error::ApplicationErrorCategory errorMustBeString{"{{enum.full_name}} must be a string"};
+        return boost::system::error_code{129, errorMustBeString};
+    }
+    std::string_view eString(jvRoot.get_string());
+
+    using namespace std::string_view_literals;
+
+{%- for constant in enum.constants %}
+    if (eString == "{{constant.json_name}}"sv) {
+        return {{enum.full_name}}::{{constant.name}};
+    }
+{%- endfor %}
+
+    static const error::ApplicationErrorCategory errorEnumNameDidNotExist{"{{enum.full_name}} did not have a constant that matched this string"};
+    return boost::system::error_code{129, errorEnumNameDidNotExist};
+}

lib/twitch-eventsub-ws/ast/lib/templates/error-failed-to-deserialize.tmpl

@@ -0,0 +1 @@
+return {{field.name}}.error();

lib/twitch-eventsub-ws/ast/lib/templates/error-missing-field.tmpl

@@ -0,0 +1,2 @@
+static const error::ApplicationErrorCategory error_missing_field_{{field.name}}{"Missing required key {{field.json_name}}"};
+return boost::system::error_code{129, error_missing_field_{{field.name}}};

lib/twitch-eventsub-ws/ast/lib/templates/field-basic.tmpl

@@ -0,0 +1,15 @@
+const auto *jv{{field.name}} = root.if_contains("{{field.json_name}}");
+if (jv{{field.name}} == nullptr)
+{
+    {% include 'error-missing-field.tmpl' indent content %}
+}
+{% if field.tag %}
+auto {{field.name}} = boost::json::try_value_to<{{field.type_name}}>(*jv{{field.name}}, {{field.tag}}());
+{% else %}
+auto {{field.name}} = boost::json::try_value_to<{{field.type_name}}>(*jv{{field.name}});
+{% endif %}
+if ({{field.name}}.has_error())
+{
+    {% include 'error-failed-to-deserialize.tmpl' indent content %}
+}
+

lib/twitch-eventsub-ws/ast/lib/templates/field-optional-vector.tmpl

@@ -0,0 +1 @@
+assert(false && "OPTIONAL VECTOR FIELD UNIMPLEMENTED");

lib/twitch-eventsub-ws/ast/lib/templates/field-optional.tmpl

@@ -0,0 +1,27 @@
+std::optional<{{field.type_name}}> {{field.name}} = std::nullopt;
+const auto *jv{{field.name}} = root.if_contains("{{field.json_name}}");
+if (jv{{field.name}} != nullptr && !jv{{field.name}}->is_null())
+{
+    {% if field.tag %}
+    auto t{{field.name}} = boost::json::try_value_to<{{field.type_name}}>(*jv{{field.name}}, {{field.tag}}());
+    {% else %}
+    auto t{{field.name}} = boost::json::try_value_to<{{field.type_name}}>(*jv{{field.name}});
+    {% endif %}
+    {% if field.dont_fail_on_deserialization %}
+    if (t{{field.name}}.has_error())
+    {
+        // TODO: report error in some way?
+    }
+    else
+    {
+        {{field.name}} = t{{field.name}}.value();
+    }
+    {% else %}
+    if (t{{field.name}}.has_error())
+    {
+        return t{{field.name}}.error();
+    }
+    {{field.name}} = std::move(t{{field.name}}.value());
+    {% endif %}
+}
+

lib/twitch-eventsub-ws/ast/lib/templates/field-vector.tmpl

@@ -0,0 +1,14 @@
+{% if field.tag -%}
+static_assert(false && "JSON tag support is not implemented for vectors");
+{%- endif %}
+const auto *jv{{field.name}} = root.if_contains("{{field.json_name}}");
+if (jv{{field.name}} == nullptr)
+{
+    {% include 'error-missing-field.tmpl' indent content %}
+}
+const auto {{field.name}} = boost::json::try_value_to<std::vector<{{field.type_name}}>>(*jv{{field.name}});
+if ({{field.name}}.has_error())
+{
+    {% include 'error-failed-to-deserialize.tmpl' indent content %}
+}
+

lib/twitch-eventsub-ws/ast/lib/templates/initializer-basic.tmpl

@@ -0,0 +1 @@
+.{{field.name}} = std::move({{field.name}}.value()),

lib/twitch-eventsub-ws/ast/lib/templates/initializer-optional-vector.tmpl

@@ -0,0 +1 @@
+assert(false && "OPTIONAL VECTOR INITIALIZER UNIMPLEMENTED");

lib/twitch-eventsub-ws/ast/lib/templates/initializer-optional.tmpl

@@ -0,0 +1 @@
+.{{field.name}} = std::move({{field.name}}),

lib/twitch-eventsub-ws/ast/lib/templates/initializer-vector.tmpl

@@ -0,0 +1 @@
+.{{field.name}} = {{field.name}}.value(),

lib/twitch-eventsub-ws/ast/lib/templates/struct-definition.tmpl

@@ -0,0 +1,2 @@
+boost::json::result_for<{{struct.full_name}}, boost::json::value>::type tag_invoke(
+    boost::json::try_value_to_tag<{{struct.full_name}}>, const boost::json::value &jvRoot);

lib/twitch-eventsub-ws/ast/lib/templates/struct-implementation.tmpl

@@ -0,0 +1,58 @@
+boost::json::result_for<{{struct.full_name}}, boost::json::value>::type tag_invoke(
+    boost::json::try_value_to_tag<{{struct.full_name}}>, const boost::json::value &jvRoot)
+{
+    {% if struct.inner_root %}
+    if (!jvRoot.is_object())
+    {
+        static const error::ApplicationErrorCategory errorMustBeObject{"{{struct.full_name}} must be an object"};
+        return boost::system::error_code{129, errorMustBeObject};
+    }
+    const auto &outerRoot = jvRoot.get_object();
+
+    const auto *jvInnerRoot = outerRoot.if_contains("{{struct.inner_root}}");
+    if (jvInnerRoot == nullptr)
+    {
+        static const error::ApplicationErrorCategory errorMissing{"{{struct.full_name}}'s key {{struct.inner_root}} is missing"};
+        return boost::system::error_code{129, errorMissing};
+    }
+    if (!jvInnerRoot->is_object())
+    {
+        static const error::ApplicationErrorCategory errorMustBeObject{"{{struct.full_name}}'s {{struct.inner_root}} must be an object"};
+        return boost::system::error_code{129, errorMustBeObject};
+    }
+    const auto &root = jvInnerRoot->get_object();
+    {% else %}
+    if (!jvRoot.is_object())
+    {
+        static const error::ApplicationErrorCategory errorMustBeObject{"{{struct.full_name}} must be an object"};
+        return boost::system::error_code{129, errorMustBeObject};
+    }
+    const auto &root = jvRoot.get_object();
+    {% endif %}
+
+{% for field in struct.members %}
+    {% if field.member_type == MemberType.BASIC -%}
+    {% include 'field-basic.tmpl' indent content %}
+    {%- elif field.member_type == MemberType.VECTOR -%}
+    {% include 'field-vector.tmpl' indent content %}
+    {%- elif field.member_type == MemberType.OPTIONAL -%}
+    {% include 'field-optional.tmpl' indent content %}
+    {%- elif field.member_type == MemberType.OPTIONAL_VECTOR -%}
+    {% include 'field-optional-vector.tmpl' indent content %}
+    {%- endif -%}
+{% endfor %}
+
+    return {{struct.full_name}}{
+{%- for field in struct.members %}
+        {% if field.member_type == MemberType.BASIC -%}
+        {% include 'initializer-basic.tmpl' indent content %}
+        {%- elif field.member_type == MemberType.VECTOR -%}
+        {% include 'initializer-vector.tmpl' indent content %}
+        {%- elif field.member_type == MemberType.OPTIONAL -%}
+        {% include 'initializer-optional.tmpl' indent content %}
+        {%- elif field.member_type == MemberType.OPTIONAL_VECTOR -%}
+        {% include 'initializer-optional-vector.tmpl' indent content %}
+        {%- endif -%}
+{% endfor %}
+    };
+}