// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0

#pragma once

#include "texteditor_global.h"

#include "fontsettings.h"

#include <QHash>
#include <QFuture>
#include <QTextCharFormat>

#include <functional>
#include <utility>

QT_BEGIN_NAMESPACE
class QTextBlock;
QT_END_NAMESPACE

namespace TextEditor {

class SyntaxHighlighter;

class TEXTEDITOR_EXPORT HighlightingResult
{
public:
    int line = 0; // 1-based
    int column = 0; // 1-based
    int length = 0;
    TextStyles textStyles;
    int kind = 0; /// The various highlighters can define their own kind of results.
    bool useTextSyles = false;

    bool isValid() const
    { return line != 0; }

    bool isInvalid() const
    { return line == 0; }

    HighlightingResult() = default;

    HighlightingResult(int line, int column, int length, int kind)
        : line(line), column(column), length(length), kind(kind), useTextSyles(false)
    {}

    HighlightingResult(int line, int column, int length, TextStyles textStyles)
        : line(line), column(column), length(length), textStyles(textStyles), useTextSyles(true)
    {}

    bool operator==(const HighlightingResult& other) const
    {
        return line == other.line
                && column == other.column
                && length == other.length
                && kind == other.kind;
    }
    bool operator!=(const HighlightingResult& other) const { return !(*this == other); }
};

using HighlightingResults = QList<HighlightingResult>;

namespace SemanticHighlighter {

using Splitter = std::function<const QList<std::pair<HighlightingResult, QTextBlock>>
        (const HighlightingResult &, const QTextBlock &)>;

// Applies the future results [from, to) and applies the extra formats
// indicated by Result::kind and kindToFormat to the correct location using
// SyntaxHighlighter::setExtraAdditionalFormats.
// It is incremental in the sense that it clears the extra additional formats
// from all lines that have no results between the (from-1).line result and
// the (to-1).line result.
// Requires that results of the Future are ordered by line.
void TEXTEDITOR_EXPORT
incrementalApplyExtraAdditionalFormats(SyntaxHighlighter *highlighter,
                                       const QFuture<HighlightingResult> &future,
                                       int from,
                                       int to,
                                       const QHash<int, QTextCharFormat> &kindToFormat,
                                       const Splitter &splitter = {});

// Clears all extra highlights and applies the extra formats
// indicated by Result::kind and kindToFormat to the correct location using
// SyntaxHighlighter::setExtraFormats. In contrast to
// incrementalApplyExtraAdditionalFormats the results do not have to be ordered by line.
void TEXTEDITOR_EXPORT setExtraAdditionalFormats(SyntaxHighlighter *highlighter,
                                                 const HighlightingResults &results,
                                                 const QHash<int, QTextCharFormat> &kindToFormat);

// Cleans the extra additional formats after the last result of the Future
// until the end of the document.
// Requires that results of the Future are ordered by line.
void TEXTEDITOR_EXPORT clearExtraAdditionalFormatsUntilEnd(
    SyntaxHighlighter *highlighter, const QFuture<HighlightingResult> &future);

} // namespace SemanticHighlighter
} // namespace TextEditor