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** Copyright (C) 2016 The Qt Company Ltd.
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#pragma once

#include "stringcache.h"

#include <clang/Basic/SourceManager.h>
#include <clang/Lex/MacroInfo.h>
#include <clang/Lex/HeaderSearch.h>
#include <clang/Lex/PPCallbacks.h>
#include <clang/Lex/Preprocessor.h>

#include <utils/smallstringvector.h>

#include <algorithm>

namespace ClangBackEnd {

class CollectIncludesPreprocessorCallbacks final : public clang::PPCallbacks
{
public:
    CollectIncludesPreprocessorCallbacks(clang::HeaderSearch &headerSearch,
                                         std::vector<uint> &includeIds,
                                         StringCache<Utils::SmallString> &filePathCache,
                                         const std::vector<uint> &excludedIncludeUID,
                                         std::vector<uint>  &alreadyIncludedFileUIDs)
        : m_headerSearch(headerSearch),
          m_includeIds(includeIds),
          m_filePathCache(filePathCache),
          m_excludedIncludeUID(excludedIncludeUID),
          m_alreadyIncludedFileUIDs(alreadyIncludedFileUIDs)
    {}

    void InclusionDirective(clang::SourceLocation /*hashLocation*/,
                            const clang::Token &/*includeToken*/,
                            llvm::StringRef fileName,
                            bool /*isAngled*/,
                            clang::CharSourceRange /*fileNameRange*/,
                            const clang::FileEntry *file,
                            llvm::StringRef /*searchPath*/,
                            llvm::StringRef /*relativePath*/,
                            const clang::Module * /*imported*/) override
    {
        if (file) {
            auto fileUID = file->getUID();

            flagIncludeAlreadyRead(file);

            if (isNotInExcludedIncludeUID(fileUID)) {
                auto notAlreadyIncluded = isNotAlreadyIncluded(fileUID);
                if (notAlreadyIncluded.first) {
                    m_alreadyIncludedFileUIDs.insert(notAlreadyIncluded.second, fileUID);
                    uint includeId = m_filePathCache.stringId({fileName.data(), fileName.size()});
                    m_includeIds.emplace_back(includeId);
                }
            }
        }
    }

    bool isNotInExcludedIncludeUID(uint uid) const
    {
        return !std::binary_search(m_excludedIncludeUID.begin(),
                                   m_excludedIncludeUID.end(),
                                   uid);
    }

    std::pair<bool, std::vector<uint>::iterator> isNotAlreadyIncluded(uint uid) const
    {
        auto range = std::equal_range(m_alreadyIncludedFileUIDs.begin(),
                                      m_alreadyIncludedFileUIDs.end(),
                                      uid);

        return {range.first == range.second, range.first};
    }

    void flagIncludeAlreadyRead(const clang::FileEntry *file)
    {
        auto &headerFileInfo = m_headerSearch.getFileInfo(file);

        headerFileInfo.isImport = true;
        ++headerFileInfo.NumIncludes;

    }

private:
    clang::HeaderSearch &m_headerSearch;
    std::vector<uint> &m_includeIds;
    StringCache<Utils::SmallString> &m_filePathCache;
    const std::vector<uint> &m_excludedIncludeUID;
    std::vector<uint> &m_alreadyIncludedFileUIDs;
};

} // namespace ClangBackEnd