LibWeb: Generate PseudoClass metadata

The usual to/from-string functions, and metadata about whether the
pseudo-class is a a function or not, and what type of parameter it
takes.

Meta/Lagom/Tools/CodeGenerators/LibWeb/GenerateCSSPseudoClass.cpp

@@ -0,0 +1,205 @@
+/*
+ * Copyright (c) 2022-2023, Sam Atkins <atkinssj@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "GeneratorUtil.h"
+#include <AK/SourceGenerator.h>
+#include <LibCore/ArgsParser.h>
+#include <LibMain/Main.h>
+
+ErrorOr<void> generate_header_file(JsonObject& pseudo_classes_data, Core::File& file);
+ErrorOr<void> generate_implementation_file(JsonObject& pseudo_classes_data, Core::File& file);
+
+ErrorOr<int> serenity_main(Main::Arguments arguments)
+{
+    StringView generated_header_path;
+    StringView generated_implementation_path;
+    StringView identifiers_json_path;
+
+    Core::ArgsParser args_parser;
+    args_parser.add_option(generated_header_path, "Path to the PseudoClasses header file to generate", "generated-header-path", 'h', "generated-header-path");
+    args_parser.add_option(generated_implementation_path, "Path to the PseudoClasses implementation file to generate", "generated-implementation-path", 'c', "generated-implementation-path");
+    args_parser.add_option(identifiers_json_path, "Path to the JSON file to read from", "json-path", 'j', "json-path");
+    args_parser.parse(arguments);
+
+    auto json = TRY(read_entire_file_as_json(identifiers_json_path));
+    VERIFY(json.is_object());
+    auto data = json.as_object();
+
+    auto generated_header_file = TRY(Core::File::open(generated_header_path, Core::File::OpenMode::Write));
+    auto generated_implementation_file = TRY(Core::File::open(generated_implementation_path, Core::File::OpenMode::Write));
+
+    TRY(generate_header_file(data, *generated_header_file));
+    TRY(generate_implementation_file(data, *generated_implementation_file));
+
+    return 0;
+}
+
+ErrorOr<void> generate_header_file(JsonObject& pseudo_classes_data, Core::File& file)
+{
+    StringBuilder builder;
+    SourceGenerator generator { builder };
+
+    TRY(generator.try_append(R"~~~(
+#pragma once
+
+#include <AK/Optional.h>
+#include <AK/StringView.h>
+
+namespace Web::CSS {
+
+enum class PseudoClass {
+)~~~"));
+
+    TRY(pseudo_classes_data.try_for_each_member([&](auto& name, auto&) -> ErrorOr<void> {
+        auto member_generator = TRY(generator.fork());
+        TRY(member_generator.set("name:titlecase", TRY(title_casify(name))));
+
+        TRY(member_generator.try_appendln("    @name:titlecase@,"));
+        return {};
+    }));
+    TRY(generator.try_append(R"~~~(
+};
+
+Optional<PseudoClass> pseudo_class_from_string(StringView);
+StringView pseudo_class_name(PseudoClass);
+
+struct PseudoClassMetadata {
+    enum class ParameterType {
+        None,
+        ANPlusB,
+        ANPlusBOf,
+        ForgivingSelectorList,
+        LanguageRanges,
+        SelectorList,
+    } parameter_type;
+    bool is_valid_as_function;
+    bool is_valid_as_identifier;
+};
+PseudoClassMetadata pseudo_class_metadata(PseudoClass);
+
+}
+)~~~"));
+
+    TRY(file.write_until_depleted(generator.as_string_view().bytes()));
+    return {};
+}
+
+ErrorOr<void> generate_implementation_file(JsonObject& pseudo_classes_data, Core::File& file)
+{
+    StringBuilder builder;
+    SourceGenerator generator { builder };
+
+    TRY(generator.try_append(R"~~~(
+#include <LibWeb/CSS/PseudoClass.h>
+
+namespace Web::CSS {
+
+Optional<PseudoClass> pseudo_class_from_string(StringView string)
+{
+)~~~"));
+
+    TRY(pseudo_classes_data.try_for_each_member([&](auto& name, auto&) -> ErrorOr<void> {
+        auto member_generator = TRY(generator.fork());
+        TRY(member_generator.set("name", TRY(String::from_deprecated_string(name))));
+        TRY(member_generator.set("name:titlecase", TRY(title_casify(name))));
+
+        TRY(member_generator.try_append(R"~~~(
+    if (string.equals_ignoring_ascii_case("@name@"sv))
+        return PseudoClass::@name:titlecase@;
+)~~~"));
+        return {};
+    }));
+
+    TRY(generator.try_append(R"~~~(
+
+    return {};
+}
+
+StringView pseudo_class_name(PseudoClass pseudo_class)
+{
+    switch (pseudo_class) {
+)~~~"));
+
+    TRY(pseudo_classes_data.try_for_each_member([&](auto& name, auto&) -> ErrorOr<void> {
+        auto member_generator = TRY(generator.fork());
+        TRY(member_generator.set("name", TRY(String::from_deprecated_string(name))));
+        TRY(member_generator.set("name:titlecase", TRY(title_casify(name))));
+
+        TRY(member_generator.try_append(R"~~~(
+    case PseudoClass::@name:titlecase@:
+        return "@name@"sv;
+)~~~"));
+        return {};
+    }));
+
+    TRY(generator.try_append(R"~~~(
+    }
+    VERIFY_NOT_REACHED();
+}
+
+PseudoClassMetadata pseudo_class_metadata(PseudoClass pseudo_class)
+{
+    switch (pseudo_class) {
+)~~~"));
+
+    TRY(pseudo_classes_data.try_for_each_member([&](auto& name, JsonValue const& value) -> ErrorOr<void> {
+        auto member_generator = TRY(generator.fork());
+        auto& pseudo_class = value.as_object();
+        auto argument_string = pseudo_class.get_deprecated_string("argument"sv).value();
+
+        bool is_valid_as_identifier = argument_string.is_empty();
+        bool is_valid_as_function = !argument_string.is_empty();
+
+        if (argument_string.ends_with('?')) {
+            is_valid_as_identifier = true;
+            argument_string = argument_string.substring(0, argument_string.length() - 1);
+        }
+
+        String parameter_type = "None"_string;
+        if (is_valid_as_function) {
+            if (argument_string == "<an+b>"sv) {
+                parameter_type = "ANPlusB"_string;
+            } else if (argument_string == "<an+b-of>"sv) {
+                parameter_type = "ANPlusBOf"_string;
+            } else if (argument_string == "<forgiving-selector-list>"sv) {
+                parameter_type = "ForgivingSelectorList"_string;
+            } else if (argument_string == "<language-ranges>"sv) {
+                parameter_type = "LanguageRanges"_string;
+            } else if (argument_string == "<selector-list>"sv) {
+                parameter_type = "SelectorList"_string;
+            } else {
+                warnln("Unrecognized pseudo-class argument type: `{}`", argument_string);
+                VERIFY_NOT_REACHED();
+            }
+        }
+
+        TRY(member_generator.set("name:titlecase", TRY(title_casify(name))));
+        TRY(member_generator.set("parameter_type", parameter_type));
+        TRY(member_generator.set("is_valid_as_function", is_valid_as_function ? "true"_string : "false"_string));
+        TRY(member_generator.set("is_valid_as_identifier", is_valid_as_identifier ? "true"_string : "false"_string));
+
+        TRY(member_generator.try_append(R"~~~(
+    case PseudoClass::@name:titlecase@:
+        return {
+            .parameter_type = PseudoClassMetadata::ParameterType::@parameter_type@,
+            .is_valid_as_function = @is_valid_as_function@,
+            .is_valid_as_identifier = @is_valid_as_identifier@,
+        };
+)~~~"));
+        return {};
+    }));
+
+    TRY(generator.try_append(R"~~~(
+    }
+    VERIFY_NOT_REACHED();
+}
+
+}
+)~~~"));
+
+    TRY(file.write_until_depleted(generator.as_string_view().bytes()));
+    return {};
+}