// Copyright 2021 The Dawn Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

{% set impl_dir = metadata.impl_dir + "/" if metadata.impl_dir else "" %}
{% set namespace_name = Name(metadata.native_namespace) %}
{% set native_namespace = namespace_name.namespace_case() %}
{% set native_dir = impl_dir + namespace_name.Dirs() %}
#include "{{native_dir}}/ChainUtils_autogen.h"

#include <unordered_set>

namespace {{native_namespace}} {

{% set namespace = metadata.namespace %}
MaybeError ValidateSTypes(const ChainedStruct* chain,
                          std::vector<std::vector<{{namespace}}::SType>> oneOfConstraints) {
    std::unordered_set<{{namespace}}::SType> allSTypes;
    for (; chain; chain = chain->nextInChain) {
        DAWN_INVALID_IF(allSTypes.find(chain->sType) != allSTypes.end(),
            "Extension chain has duplicate sType %s.", chain->sType);
        allSTypes.insert(chain->sType);
    }

    for (const auto& oneOfConstraint : oneOfConstraints) {
        bool satisfied = false;
        for ({{namespace}}::SType oneOfSType : oneOfConstraint) {
            if (allSTypes.find(oneOfSType) != allSTypes.end()) {
                DAWN_INVALID_IF(satisfied,
                    "sType %s is part of a group of exclusive sTypes that is already present.",
                    oneOfSType);
                satisfied = true;
                allSTypes.erase(oneOfSType);
            }
        }
    }

    DAWN_INVALID_IF(!allSTypes.empty(), "Unsupported sType %s.", *allSTypes.begin());
    return {};
}

MaybeError ValidateSTypes(const ChainedStructOut* chain,
                          std::vector<std::vector<{{namespace}}::SType>> oneOfConstraints) {
    std::unordered_set<{{namespace}}::SType> allSTypes;
    for (; chain; chain = chain->nextInChain) {
        DAWN_INVALID_IF(allSTypes.find(chain->sType) != allSTypes.end(),
            "Extension chain has duplicate sType %s.", chain->sType);
        allSTypes.insert(chain->sType);
    }

    for (const auto& oneOfConstraint : oneOfConstraints) {
        bool satisfied = false;
        for ({{namespace}}::SType oneOfSType : oneOfConstraint) {
            if (allSTypes.find(oneOfSType) != allSTypes.end()) {
                DAWN_INVALID_IF(satisfied,
                    "sType %s is part of a group of exclusive sTypes that is already present.",
                    oneOfSType);
                satisfied = true;
                allSTypes.erase(oneOfSType);
            }
        }
    }

    DAWN_INVALID_IF(!allSTypes.empty(), "Unsupported sType %s.", *allSTypes.begin());
    return {};
}

}  // namespace {{native_namespace}}