/*

    Copyright (c) 2017, Lukas Holecek <hluk@email.cz>

    This file is part of CopyQ.

    CopyQ is free software: you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by

    the Free Software Foundation, either version 3 of the License, or

    (at your option) any later version.

    CopyQ is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License

    along with CopyQ.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "commandedit.h"

#include "ui_commandedit.h"

#include "gui/commandsyntaxhighlighter.h"

#include "gui/commandcompleter.h"

#include <QScriptEngine>

#include <QTextBlock>

#include <QTextCursor>

#include <QTextDocument>

CommandEdit::CommandEdit(QWidget *parent)

    : QWidget(parent)

    , ui(new Ui::CommandEdit)

{

    ui->setupUi(this);

    ui->labelErrors->hide();

    ui->plainTextEditCommand->document()->setDefaultFont(commandFont());

    setFocusProxy(ui->plainTextEditCommand);

    installCommandSyntaxHighlighter(ui->plainTextEditCommand);

    new CommandCompleter(ui->plainTextEditCommand);

}

CommandEdit::~CommandEdit()

{

    delete ui;

}

void CommandEdit::setCommand(const QString &command) const

{

    ui->plainTextEditCommand->setPlainText(command);

}

QString CommandEdit::command() const

{

    return ui->plainTextEditCommand->toPlainText();

}

bool CommandEdit::isEmpty() const

{

    return ui->plainTextEditCommand->document()->characterCount() == 0;

}

QFont CommandEdit::commandFont() const

{

    QFont font("Monospace");

    font.setStyleHint(QFont::TypeWriter);

    font.setPointSize(10);

    return font;

}

void CommandEdit::resizeEvent(QResizeEvent *event)

{

    QWidget::resizeEvent(event);

    updateCommandEditSize();

}

void CommandEdit::on_plainTextEditCommand_textChanged()

{

    updateCommandEditSize();

    emit changed();

    QString errors;

    QList<QTextEdit::ExtraSelection> selections;

    QString command = ui->plainTextEditCommand->toPlainText();

    QRegExp scriptPrefix("(^|\\b)copyq:");

    const int pos = command.indexOf(scriptPrefix);

    if (pos != -1) {

        const int scriptStartPos = pos + scriptPrefix.matchedLength();

        command.remove(0, scriptStartPos);

        const QScriptSyntaxCheckResult result = QScriptEngine::checkSyntax(command);

        if (result.state() == QScriptSyntaxCheckResult::Error) {

            errors = result.errorMessage();

            if (errors.isEmpty())

                errors = "Syntax error";

            const int line = result.errorLineNumber() - 1;

            const int column = result.errorColumnNumber() - 1;

            QTextDocument *doc = ui->plainTextEditCommand->document();

            const int firstBlockNumber = doc->findBlock(pos).blockNumber();

            QTextBlock block = doc->findBlockByNumber(firstBlockNumber + line);

            const int blockStartPos = line == 0 ? scriptStartPos : block.position();

            const int errorPosition = column + blockStartPos;

            QTextCursor cursor = ui->plainTextEditCommand->textCursor();

            cursor.setPosition(errorPosition);

            cursor.movePosition(QTextCursor::NextCharacter, QTextCursor::KeepAnchor);

            QTextEdit::ExtraSelection selection;

            selection.cursor = cursor;

            selection.format = cursor.blockCharFormat();

            selection.format.setUnderlineColor(Qt::red);

            selection.format.setUnderlineStyle(QTextCharFormat::SpellCheckUnderline);

            selections.append(selection);

        }

    }

    ui->plainTextEditCommand->setExtraSelections(selections);

    ui->labelErrors->setVisible(!errors.isEmpty());

    ui->labelErrors->setText(errors);

}

void CommandEdit::updateCommandEditSize()

{

    const QFontMetrics fm( ui->plainTextEditCommand->document()->defaultFont() );

    const auto height = static_cast<int>( ui->plainTextEditCommand->document()->size().height() );

    const int lines = height + 2;

    const int visibleLines = qBound(3, lines, 20);

    const int h = visibleLines * fm.lineSpacing();

    ui->plainTextEditCommand->setMinimumHeight(h);

}