// Copyright (C) 2019 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0

#include <QTest>
#include <QTextDocument>
#include <QTextCursor>
#include <QTextBlock>
#include <QTextList>
#include <QTextTable>
#include <QBuffer>
#include <QDebug>
#include <QFontInfo>
#include <QLoggingCategory>

#include <private/qtextmarkdownwriter_p.h>

Q_LOGGING_CATEGORY(lcTests, "qt.text.tests")

// #define DEBUG_WRITE_OUTPUT

class tst_QTextMarkdownWriter : public QObject
{
    Q_OBJECT
public slots:
    void init();
    void cleanup();

private slots:
    void testWriteParagraph_data();
    void testWriteParagraph();
    void testWriteList();
    void testWriteEmptyList();
    void testWriteCheckboxListItemEndingWithCode();
    void testWriteNestedBulletLists_data();
    void testWriteNestedBulletLists();
    void testWriteNestedNumericLists();
    void testWriteTable();
    void rewriteDocument_data();
    void rewriteDocument();
    void fromHtml_data();
    void fromHtml();

private:
    bool isMainFontFixed();
    bool isFixedFontProportional();
    QString documentToUnixMarkdown();

private:
    QTextDocument *document;
};

void tst_QTextMarkdownWriter::init()
{
    document = new QTextDocument();
}

void tst_QTextMarkdownWriter::cleanup()
{
    delete document;
}

bool tst_QTextMarkdownWriter::isMainFontFixed()
{
    bool ret = QFontInfo(QGuiApplication::font()).fixedPitch();
    if (ret) {
        qCWarning(lcTests) << "QFontDatabase::GeneralFont is monospaced: markdown writing is likely to use too many backticks"
                           << QFontDatabase::systemFont(QFontDatabase::GeneralFont);
    }
    return ret;
}

bool tst_QTextMarkdownWriter::isFixedFontProportional()
{
    bool ret = !QFontInfo(QFontDatabase::systemFont(QFontDatabase::FixedFont)).fixedPitch();
    if (ret) {
        qCWarning(lcTests) << "QFontDatabase::FixedFont is NOT monospaced: markdown writing is likely to use too few backticks"
                           << QFontDatabase::systemFont(QFontDatabase::FixedFont);
    }
    return ret;
}

QString tst_QTextMarkdownWriter::documentToUnixMarkdown()
{
    QString ret;
    QTextStream ts(&ret, QIODevice::WriteOnly);
    QTextMarkdownWriter writer(ts, QTextDocument::MarkdownDialectGitHub);
    writer.writeAll(document);
    return ret;
}

void tst_QTextMarkdownWriter::testWriteParagraph_data()
{
    QTest::addColumn<QString>("input");
    QTest::addColumn<QString>("expectedOutput");

    QTest::newRow("empty") << "" <<
        "";
    QTest::newRow("spaces") << "foobar   word" <<
        "foobar   word\n\n";
    QTest::newRow("starting spaces") << "  starting spaces" <<
        "  starting spaces\n\n";
    QTest::newRow("trailing spaces") << "trailing spaces  " <<
        "trailing spaces  \n\n";
    QTest::newRow("tab") << "word\ttab x" <<
        "word\ttab x\n\n";
    QTest::newRow("tab2") << "word\t\ttab\tx" <<
        "word\t\ttab\tx\n\n";
    QTest::newRow("misc") << "foobar   word\ttab x" <<
        "foobar   word\ttab x\n\n";
    QTest::newRow("misc2") << "\t     \tFoo" <<
        "\t     \tFoo\n\n";
}

void tst_QTextMarkdownWriter::testWriteParagraph()
{
    QFETCH(QString, input);
    QFETCH(QString, expectedOutput);

    QTextCursor cursor(document);
    cursor.insertText(input);

    const QString output = documentToUnixMarkdown();
    if (output != expectedOutput && isMainFontFixed())
        QEXPECT_FAIL("", "fixed-pitch main font (QTBUG-103484)", Continue);
    QCOMPARE(output, expectedOutput);
}

void tst_QTextMarkdownWriter::testWriteList()
{
    QTextCursor cursor(document);
    QTextList *list = cursor.createList(QTextListFormat::ListDisc);
    cursor.insertText("ListItem 1");
    list->add(cursor.block());
    cursor.insertBlock();
    cursor.insertText("ListItem 2");
    list->add(cursor.block());

    const QString output = documentToUnixMarkdown();
    const QString expected = QString::fromLatin1("- ListItem 1\n- ListItem 2\n");
    if (output != expected && isMainFontFixed())
        QEXPECT_FAIL("", "fixed-pitch main font (QTBUG-103484)", Continue);
    QCOMPARE(output, expected);
}

void tst_QTextMarkdownWriter::testWriteEmptyList()
{
    QTextCursor cursor(document);
    cursor.createList(QTextListFormat::ListDisc);

    QCOMPARE(documentToUnixMarkdown(), QString::fromLatin1("- \n"));
}

void tst_QTextMarkdownWriter::testWriteCheckboxListItemEndingWithCode()
{
    QTextCursor cursor(document);
    QTextList *list = cursor.createList(QTextListFormat::ListDisc);
    cursor.insertText("Image.originalSize property (not necessary; PdfDocument.pagePointSize() substitutes)");
    list->add(cursor.block());
    {
        auto fmt = cursor.block().blockFormat();
        fmt.setMarker(QTextBlockFormat::MarkerType::Unchecked);
        cursor.setBlockFormat(fmt);
    }
    cursor.movePosition(QTextCursor::PreviousWord, QTextCursor::MoveAnchor, 2);
    cursor.movePosition(QTextCursor::Left, QTextCursor::MoveAnchor);
    cursor.movePosition(QTextCursor::PreviousWord, QTextCursor::KeepAnchor, 4);
    QCOMPARE(cursor.selectedText(), QString::fromLatin1("PdfDocument.pagePointSize()"));
    auto fmt = cursor.charFormat();
    fmt.setFontFixedPitch(true);
    cursor.setCharFormat(fmt);
    cursor.movePosition(QTextCursor::PreviousWord, QTextCursor::MoveAnchor, 5);
    cursor.movePosition(QTextCursor::Left, QTextCursor::MoveAnchor);
    cursor.movePosition(QTextCursor::PreviousWord, QTextCursor::KeepAnchor, 4);
    QCOMPARE(cursor.selectedText(), QString::fromLatin1("Image.originalSize"));
    cursor.setCharFormat(fmt);

    const QString output = documentToUnixMarkdown();
    const QString expected = QString::fromLatin1(
                "- [ ] `Image.originalSize` property (not necessary; `PdfDocument.pagePointSize()`\n  substitutes)\n");
    if (output != expected && isMainFontFixed())
        QEXPECT_FAIL("", "fixed-pitch main font (QTBUG-103484)", Continue);
    QCOMPARE(output, expected);
}

void tst_QTextMarkdownWriter::testWriteNestedBulletLists_data()
{
    QTest::addColumn<bool>("checkbox");
    QTest::addColumn<bool>("checked");
    QTest::addColumn<bool>("continuationLine");
    QTest::addColumn<bool>("continuationParagraph");
    QTest::addColumn<QString>("expectedOutput");

    QTest::newRow("plain bullets") << false << false << false << false <<
        "- ListItem 1\n  * ListItem 2\n    + ListItem 3\n- ListItem 4\n  * ListItem 5\n";
    QTest::newRow("bullets with continuation lines") << false << false << true << false <<
        "- ListItem 1\n  * ListItem 2\n    + ListItem 3 with text that won't fit on one line and thus needs a\n      continuation\n- ListItem 4\n  * ListItem 5 with text that won't fit on one line and thus needs a\n    continuation\n";
    QTest::newRow("bullets with continuation paragraphs") << false << false << false << true <<
        "- ListItem 1\n\n  * ListItem 2\n    + ListItem 3\n\n      continuation\n\n- ListItem 4\n\n  * ListItem 5\n\n    continuation\n\n";
    QTest::newRow("unchecked") << true << false << false << false <<
        "- [ ] ListItem 1\n  * [ ] ListItem 2\n    + [ ] ListItem 3\n- [ ] ListItem 4\n  * [ ] ListItem 5\n";
    QTest::newRow("checked") << true << true << false << false <<
        "- [x] ListItem 1\n  * [x] ListItem 2\n    + [x] ListItem 3\n- [x] ListItem 4\n  * [x] ListItem 5\n";
    QTest::newRow("checked with continuation lines") << true << true << true << false <<
        "- [x] ListItem 1\n  * [x] ListItem 2\n    + [x] ListItem 3 with text that won't fit on one line and thus needs a\n      continuation\n- [x] ListItem 4\n  * [x] ListItem 5 with text that won't fit on one line and thus needs a\n    continuation\n";
    QTest::newRow("checked with continuation paragraphs") << true << true << false << true <<
        "- [x] ListItem 1\n\n  * [x] ListItem 2\n    + [x] ListItem 3\n\n      continuation\n\n- [x] ListItem 4\n\n  * [x] ListItem 5\n\n    continuation\n\n";
}

void tst_QTextMarkdownWriter::testWriteNestedBulletLists()
{
    QFETCH(bool, checkbox);
    QFETCH(bool, checked);
    QFETCH(bool, continuationParagraph);
    QFETCH(bool, continuationLine);
    QFETCH(QString, expectedOutput);

    QTextCursor cursor(document);
    QTextBlockFormat blockFmt = cursor.blockFormat();
    if (checkbox) {
        blockFmt.setMarker(checked ? QTextBlockFormat::MarkerType::Checked : QTextBlockFormat::MarkerType::Unchecked);
        cursor.setBlockFormat(blockFmt);
    }

    QTextList *list1 = cursor.createList(QTextListFormat::ListDisc);
    cursor.insertText("ListItem 1");
    list1->add(cursor.block());

    QTextListFormat fmt2;
    fmt2.setStyle(QTextListFormat::ListCircle);
    fmt2.setIndent(2);
    QTextList *list2 = cursor.insertList(fmt2);
    cursor.insertText("ListItem 2");

    QTextListFormat fmt3;
    fmt3.setStyle(QTextListFormat::ListSquare);
    fmt3.setIndent(3);
    cursor.insertList(fmt3);
    cursor.insertText(continuationLine ?
                          "ListItem 3 with text that won't fit on one line and thus needs a continuation" :
                          "ListItem 3");
    if (continuationParagraph) {
        QTextBlockFormat blockFmt;
        blockFmt.setIndent(2);
        cursor.insertBlock(blockFmt);
        cursor.insertText("continuation");
    }

    cursor.insertBlock(blockFmt);
    cursor.insertText("ListItem 4");
    list1->add(cursor.block());

    cursor.insertBlock();
    cursor.insertText(continuationLine ?
                          "ListItem 5 with text that won't fit on one line and thus needs a continuation" :
                          "ListItem 5");
    list2->add(cursor.block());
    if (continuationParagraph) {
        QTextBlockFormat blockFmt;
        blockFmt.setIndent(2);
        cursor.insertBlock(blockFmt);
        cursor.insertText("continuation");
    }

    const QString output = documentToUnixMarkdown();
#ifdef DEBUG_WRITE_OUTPUT
    {
        QFile out("/tmp/" + QLatin1String(QTest::currentDataTag()) + ".md");
        out.open(QFile::WriteOnly);
        out.write(output.toUtf8());
        out.close();
    }
#endif
    if (output != expectedOutput && isMainFontFixed())
        QEXPECT_FAIL("", "fixed-pitch main font (QTBUG-103484)", Continue);
    QCOMPARE(output, expectedOutput);
}

void tst_QTextMarkdownWriter::testWriteNestedNumericLists()
{
    QTextCursor cursor(document);

    QTextList *list1 = cursor.createList(QTextListFormat::ListDecimal);
    cursor.insertText("ListItem 1");
    list1->add(cursor.block());

    QTextListFormat fmt2;
    fmt2.setStyle(QTextListFormat::ListLowerAlpha);
    fmt2.setNumberSuffix(QLatin1String(")"));
    fmt2.setIndent(2);
    QTextList *list2 = cursor.insertList(fmt2);
    cursor.insertText("ListItem 2");

    QTextListFormat fmt3;
    fmt3.setStyle(QTextListFormat::ListDecimal);
    fmt3.setIndent(3);
    cursor.insertList(fmt3);
    cursor.insertText("ListItem 3");

    cursor.insertBlock();
    cursor.insertText("ListItem 4");
    list1->add(cursor.block());

    cursor.insertBlock();
    cursor.insertText("ListItem 5");
    list2->add(cursor.block());

    const QString output = documentToUnixMarkdown();
    // There's no QTextList API to set the starting number so we hard-coded all lists to start at 1 (QTBUG-65384)
    const QString expected = QString::fromLatin1(
                "1.  ListItem 1\n    1)  ListItem 2\n        1.  ListItem 3\n2.  ListItem 4\n    2)  ListItem 5\n");
    if (output != expected && isMainFontFixed())
        QEXPECT_FAIL("", "fixed-pitch main font (QTBUG-103484)", Continue);
    QCOMPARE(output, expected);
}

void tst_QTextMarkdownWriter::testWriteTable()
{
    QTextCursor cursor(document);
    QTextTable * table = cursor.insertTable(4, 3);
    cursor = table->cellAt(0, 0).firstCursorPosition();
    // valid Markdown tables need headers, but QTextTable doesn't make that distinction
    // so QTextMarkdownWriter assumes the first row of any table is a header
    cursor.insertText("one");
    cursor.movePosition(QTextCursor::NextCell);
    cursor.insertText("two");
    cursor.movePosition(QTextCursor::NextCell);
    cursor.insertText("three");
    cursor.movePosition(QTextCursor::NextCell);

    cursor.insertText("alice");
    cursor.movePosition(QTextCursor::NextCell);
    cursor.insertText("bob");
    cursor.movePosition(QTextCursor::NextCell);
    cursor.insertText("carl");
    cursor.movePosition(QTextCursor::NextCell);

    cursor.insertText("dennis");
    cursor.movePosition(QTextCursor::NextCell);
    cursor.insertText("eric");
    cursor.movePosition(QTextCursor::NextCell);
    cursor.insertText("fiona");
    cursor.movePosition(QTextCursor::NextCell);

    cursor.insertText("gina");
    /*
        |one   |two |three|
        |------|----|-----|
        |alice |bob |carl |
        |dennis|eric|fiona|
        |gina  |    |     |
    */

    QString md = documentToUnixMarkdown();

#ifdef DEBUG_WRITE_OUTPUT
    {
        QFile out("/tmp/table.md");
        out.open(QFile::WriteOnly);
        out.write(md.toUtf8());
        out.close();
    }
#endif

    QString expected = QString::fromLatin1(
        "\n|one   |two |three|\n|------|----|-----|\n|alice |bob |carl |\n|dennis|eric|fiona|\n|gina  |    |     |\n\n");
    if (md != expected && isMainFontFixed())
        QEXPECT_FAIL("", "fixed-pitch main font (QTBUG-103484)", Continue);
    QCOMPARE(md, expected);

    // create table with merged cells
    document->clear();
    cursor = QTextCursor(document);
    table = cursor.insertTable(3, 3);
    table->mergeCells(0, 0, 1, 2);
    table->mergeCells(1, 1, 1, 2);
    cursor = table->cellAt(0, 0).firstCursorPosition();
    cursor.insertText("a");
    cursor.movePosition(QTextCursor::NextCell);
    cursor.insertText("b");
    cursor.movePosition(QTextCursor::NextCell);
    cursor.insertText("c");
    cursor.movePosition(QTextCursor::NextCell);
    cursor.insertText("d");
    cursor.movePosition(QTextCursor::NextCell);
    cursor.insertText("e");
    cursor.movePosition(QTextCursor::NextCell);
    cursor.insertText("f");
    /*
      +---+-+
      |a  |b|
      +---+-+
      |c|  d|
      +-+-+-+
      |e|f| |
      +-+-+-+

      generates

      |a ||b|
      |-|-|-|
      |c|d ||
      |e|f| |

    */

    md = documentToUnixMarkdown();

#ifdef DEBUG_WRITE_OUTPUT
    {
        QFile out("/tmp/table-merged-cells.md");
        out.open(QFile::WriteOnly);
        out.write(md.toUtf8());
        out.close();
    }
#endif

    expected = QString::fromLatin1("\n|a ||b|\n|-|-|-|\n|c|d ||\n|e|f| |\n\n");
    if (md != expected && isMainFontFixed())
        QEXPECT_FAIL("", "fixed-pitch main font (QTBUG-103484)", Continue);
    QCOMPARE(md, expected);
}

void tst_QTextMarkdownWriter::rewriteDocument_data()
{
    QTest::addColumn<QString>("inputFile");

    QTest::newRow("block quotes") << "blockquotes.md";
    QTest::newRow("example") << "example.md";
    QTest::newRow("list items after headings") << "headingsAndLists.md";
    QTest::newRow("word wrap") << "wordWrap.md";
    QTest::newRow("links") << "links.md";
    QTest::newRow("lists and code blocks") << "listsAndCodeBlocks.md";
}

void tst_QTextMarkdownWriter::rewriteDocument()
{
    QFETCH(QString, inputFile);
    QTextDocument doc;
    QFile f(QFINDTESTDATA("data/" + inputFile));
    QVERIFY(f.open(QFile::ReadOnly | QIODevice::Text));
    QString orig = QString::fromUtf8(f.readAll());
    f.close();
    doc.setMarkdown(orig);
    QString md = doc.toMarkdown();

#ifdef DEBUG_WRITE_OUTPUT
    QFile out("/tmp/rewrite-" + inputFile);
    out.open(QFile::WriteOnly);
    out.write(md.toUtf8());
    out.close();
#endif

    if (md != orig && isMainFontFixed())
        QEXPECT_FAIL("", "fixed-pitch main font (QTBUG-103484)", Continue);
    QCOMPARE(md, orig);
}

void tst_QTextMarkdownWriter::fromHtml_data()
{
    QTest::addColumn<QString>("input");
    QTest::addColumn<QString>("expectedOutput");

    QTest::newRow("long URL") <<
        "<span style=\"font-style:italic;\">https://www.example.com/dir/subdir/subsubdir/subsubsubdir/subsubsubsubdir/subsubsubsubsubdir/</span>" <<
        "*https://www.example.com/dir/subdir/subsubdir/subsubsubdir/subsubsubsubdir/subsubsubsubsubdir/*\n\n";
    QTest::newRow("non-emphasis inline asterisk") << "3 * 4" << "3 * 4\n\n";
    QTest::newRow("arithmetic") << "(2 * a * x + b)^2 = b^2 - 4 * a * c" << "(2 * a * x + b)^2 = b^2 - 4 * a * c\n\n";
    QTest::newRow("escaped asterisk after newline") <<
        "The first sentence of this paragraph holds 80 characters, then there's a star. * This is wrapped, but is <em>not</em> a bullet point." <<
        "The first sentence of this paragraph holds 80 characters, then there's a star.\n\\* This is wrapped, but is *not* a bullet point.\n\n";
    QTest::newRow("escaped plus after newline") <<
        "The first sentence of this paragraph holds 80 characters, then there's a plus. + This is wrapped, but is <em>not</em> a bullet point." <<
        "The first sentence of this paragraph holds 80 characters, then there's a plus.\n\\+ This is wrapped, but is *not* a bullet point.\n\n";
    QTest::newRow("escaped hyphen after newline") <<
        "The first sentence of this paragraph holds 80 characters, then there's a minus. - This is wrapped, but is <em>not</em> a bullet point." <<
        "The first sentence of this paragraph holds 80 characters, then there's a minus.\n\\- This is wrapped, but is *not* a bullet point.\n\n";
    QTest::newRow("list items with indented continuations") <<
        "<ul><li>bullet<p>continuation paragraph</p></li><li>another bullet<br/>continuation line</li></ul>" <<
        "- bullet\n\n  continuation paragraph\n\n- another bullet\n  continuation line\n";
    QTest::newRow("nested list items with continuations") <<
        "<ul><li>bullet<p>continuation paragraph</p></li><li>another bullet<br/>continuation line</li><ul><li>bullet<p>continuation paragraph</p></li><li>another bullet<br/>continuation line</li></ul></ul>" <<
        "- bullet\n\n  continuation paragraph\n\n- another bullet\n  continuation line\n\n  - bullet\n\n    continuation paragraph\n\n  - another bullet\n    continuation line\n";
    QTest::newRow("nested ordered list items with continuations") <<
        "<ol><li>item<p>continuation paragraph</p></li><li>another item<br/>continuation line</li><ol><li>item<p>continuation paragraph</p></li><li>another item<br/>continuation line</li></ol><li>another</li><li>another</li></ol>" <<
        "1.  item\n\n    continuation paragraph\n\n2.  another item\n    continuation line\n\n    1.  item\n\n        continuation paragraph\n\n    2.  another item\n        continuation line\n\n3.  another\n4.  another\n";
    QTest::newRow("thematic break") <<
        "something<hr/>something else" <<
        "something\n\n- - -\nsomething else\n\n";
    QTest::newRow("block quote") <<
        "<p>In 1958, Mahatma Gandhi was quoted as follows:</p><blockquote>The Earth provides enough to satisfy every man's need but not for every man's greed.</blockquote>" <<
        "In 1958, Mahatma Gandhi was quoted as follows:\n\n> The Earth provides enough to satisfy every man's need but not for every man's\n> greed.\n\n";
    QTest::newRow("image") <<
        "<img src=\"/url\" alt=\"foo\" title=\"title\"/>" <<
        "![foo](/url \"title\")\n\n";
    QTest::newRow("code") <<
        "<pre class=\"language-pseudocode\">\n#include \"foo.h\"\n\nblock {\n    statement();\n}\n\n</pre>" <<
        "```pseudocode\n#include \"foo.h\"\n\nblock {\n    statement();\n}\n\n```\n\n";
    // TODO
//    QTest::newRow("escaped number and paren after double newline") <<
//        "<p>(The first sentence of this paragraph is a line, the next paragraph has a number</p>13) but that's not part of an ordered list" <<
//        "(The first sentence of this paragraph is a line, the next paragraph has a number\n\n13\\) but that's not part of an ordered list\n\n";
    QTest::newRow("preformats with embedded backticks") <<
        "<pre>none `one` ``two``</pre>plain<pre>```three``` ````four````</pre>plain" <<
        "```\nnone `one` ``two``\n\n```\nplain\n\n```\n```three``` ````four````\n\n```\nplain\n\n";
    QTest::newRow("list items with and without checkboxes") <<
        "<ul><li>bullet</li><li class=\"unchecked\">unchecked item</li><li class=\"checked\">checked item</li></ul>" <<
        "- bullet\n- [ ] unchecked item\n- [x] checked item\n";
}

void tst_QTextMarkdownWriter::fromHtml()
{
    QFETCH(QString, input);
    QFETCH(QString, expectedOutput);

    document->setHtml(input);
    QString output = documentToUnixMarkdown();

#ifdef DEBUG_WRITE_OUTPUT
    {
        QFile out("/tmp/" + QLatin1String(QTest::currentDataTag()) + ".md");
        out.open(QFile::WriteOnly);
        out.write(output.toUtf8());
        out.close();
    }
#endif

    if (output != expectedOutput && (isMainFontFixed() || isFixedFontProportional()))
        QEXPECT_FAIL("", "fixed main font or proportional fixed font (QTBUG-103484)", Continue);
    QCOMPARE(output, expectedOutput);
}

QTEST_MAIN(tst_QTextMarkdownWriter)
#include "tst_qtextmarkdownwriter.moc"