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#include "codecompleter.h"

#include "clangfilepath.h"
#include "clangcodecompleteresults.h"
#include "clangstring.h"
#include "cursor.h"
#include "codecompletefailedexception.h"
#include "codecompletionsextractor.h"
#include "sourcelocation.h"
#include "unsavedfile.h"
#include "clangtranslationunit.h"
#include "sourcerange.h"

#include <clang-c/Index.h>

namespace ClangBackEnd {

namespace {

CodeCompletions toCodeCompletions(const ClangCodeCompleteResults &results)
{
    if (results.isNull())
        return CodeCompletions();

    CodeCompletionsExtractor extractor(results.data());
    CodeCompletions codeCompletions = extractor.extractAll();

    return codeCompletions;
}

} // anonymous namespace

CodeCompleter::CodeCompleter(TranslationUnit translationUnit)
    : translationUnit(std::move(translationUnit))
{
}

CodeCompletions CodeCompleter::complete(uint line, uint column)
{
    neededCorrection_ = CompletionCorrection::NoCorrection;

    ClangCodeCompleteResults results = complete(line,
                                                column,
                                                translationUnit.cxUnsavedFiles(),
                                                translationUnit.unsavedFilesCount());

    tryDotArrowCorrectionIfNoResults(results, line, column);

    return toCodeCompletions(results);
}

CompletionCorrection CodeCompleter::neededCorrection() const
{
    return neededCorrection_;
}

ClangCodeCompleteResults CodeCompleter::complete(uint line,
                                                 uint column,
                                                 CXUnsavedFile *unsavedFiles,
                                                 unsigned unsavedFileCount)
{
    const Utf8String nativeFilePath = FilePath::toNativeSeparators(translationUnit.filePath());

    return clang_codeCompleteAt(translationUnit.cxTranslationUnitWithoutReparsing(),
                                nativeFilePath.constData(),
                                line,
                                column,
                                unsavedFiles,
                                unsavedFileCount,
                                defaultOptions());
}

uint CodeCompleter::defaultOptions() const
{
    uint options = CXCodeComplete_IncludeMacros
                 | CXCodeComplete_IncludeCodePatterns;

    if (translationUnit.defaultOptions() & CXTranslationUnit_IncludeBriefCommentsInCodeCompletion)
        options |= CXCodeComplete_IncludeBriefComments;

    return options;
}

void CodeCompleter::tryDotArrowCorrectionIfNoResults(ClangCodeCompleteResults &results,
                                                     uint line,
                                                     uint column)
{
    if (results.hasNoResultsForDotCompletion()) {
        const UnsavedFile &unsavedFile = translationUnit.unsavedFile();
        bool positionIsOk = false;
        const uint dotPosition = unsavedFile.toUtf8Position(line, column - 1, &positionIsOk);
        if (positionIsOk && unsavedFile.hasCharacterAt(dotPosition, '.'))
            results = completeWithArrowInsteadOfDot(line, column, dotPosition);
    }
}

ClangCodeCompleteResults CodeCompleter::completeWithArrowInsteadOfDot(uint line,
                                                                      uint column,
                                                                      uint dotPosition)
{
    ClangCodeCompleteResults results;
    const bool replaced = translationUnit.unsavedFile().replaceAt(dotPosition,
                                                                  1,
                                                                  Utf8StringLiteral("->"));

    if (replaced) {
        results = complete(line,
                           column + 1,
                           translationUnit.cxUnsavedFiles(),
                           translationUnit.unsavedFilesCount());

        if (results.hasResults())
            neededCorrection_ = CompletionCorrection::DotToArrowCorrection;
    }

    return results;
}

Utf8String CodeCompleter::filePath() const
{
    return translationUnit.filePath();
}

void CodeCompleter::checkCodeCompleteResult(CXCodeCompleteResults *completeResults)
{
    if (!completeResults)
        throw CodeCompleteFailedException();
}

} // namespace ClangBackEnd