#include "qpconsole.h"

#include <QApplication>
#include <QTextBlock>
#include <QTextDocument>
#include <QTextCursor>
#include <QClipboard>

QPConsole::QPConsole(QWidget *parent) :
  QPlainTextEdit(parent),
  mHistoryPos(-1),
  mCommandLineReady(false)
{
  QPalette p = palette();
  p.setColor(QPalette::Active, QPalette::Base, Qt::black);
  p.setColor(QPalette::Inactive, QPalette::Base, Qt::black);
  p.setColor(QPalette::Active, QPalette::Text, Qt::white);
  p.setColor(QPalette::Inactive, QPalette::Text, Qt::white);
  setPalette(p);

  QFont f;
#ifdef Q_OS_LINUX
  f.setFamily("Monospace");
  f.setPointSize(10);
#else
  f.setFamily("Lucida Console");
  f.setPointSize(10);
#endif
  f.setFixedPitch(true);
  setFont(f);

  setCursorWidth(QFontMetrics(font()).width(QChar('x')));
  setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);
  setHorizontalScrollBarPolicy(Qt::ScrollBarAsNeeded);
  setUndoRedoEnabled(false);
  setLineWrapMode(QPlainTextEdit::NoWrap);
  setWordWrapMode(QTextOption::NoWrap);
  setBackgroundVisible(false);
  setFrameStyle(QFrame::NoFrame);
  setTabStopWidth(40);
  setAcceptDrops(false);
  setPrefix("terminal> ");
  setPrefixColor(QColor(140, 255, 50));
  f.setBold(true);
  setPrefixFont(f);

  prepareCommandLine();
}

void QPConsole::setPrefix(const QString &prefix)
{
  mPrefix = prefix;
}

void QPConsole::setPrefixColor(const QColor &color)
{
  mPrefixColor = color;
}

void QPConsole::setPrefixFont(const QFont &font)
{
  mPrefixFont = font;
}

bool QPConsole::inCommandLine() const
{
  return mCommandLineReady && document()->blockCount()-1 == textCursor().blockNumber() && textCursor().positionInBlock() >= mPrefix.length();
}

void QPConsole::processCommand()
{
  QString inputString = document()->lastBlock().text();
  if (inputString.startsWith(mPrefix))
    inputString.remove(0, mPrefix.length());
  if (!inputString.trimmed().isEmpty())
    mHistory.append(inputString);
  mHistoryPos = -1;
  inputString = inputString.trimmed();

  QStringList params;
  QString cmd;
  int p = inputString.indexOf(' ');
  if (p > -1)
  {
    cmd = inputString.mid(0, p);
    params = getParams(inputString.mid(p+1));
  } else
    cmd = inputString;

  QTextCursor cur(document()->lastBlock());
  cur.movePosition(QTextCursor::EndOfBlock);
  cur.insertBlock();
  setTextCursor(cur);
  mCommandLineReady = false;
  emit command(cmd, params);
}

QStringList QPConsole::getParams(QString str)
{
  QStringList result;
  str = str.trimmed();
  if (str.isEmpty())
    return result;

  bool escaped = false;
  bool quoted = false;
  QString param;
  int i = 0;
  while (i < str.size())
  {
    if (escaped)
    {
      escaped = false;
      param += str[i];
    } else if (str[i] == '\\')
    {
      escaped = true;
    } else if (str[i] == '"')
    {
      quoted = !quoted;
      if (!param.isEmpty() && !(i+1>=str.size() || str[i+1]==' ')) // only add quote if not first and last, embracing a parameter
        param += str[i];
    } else if (str[i] == ' ')
    {
      if (quoted)
      {
        param += str[i];
      } else if (!param.isEmpty())
      {
        result.append(param);
        param.clear();
      }
    } else
    {
      param += str[i];
    }
    ++i;
  }
  if (!param.isEmpty())
  {
    result.append(param);
    param.clear();
  }
  return result;
}

void QPConsole::keyPressEvent(QKeyEvent *event)
{
  if (inCommandLine())
  {
    // clear selection that spans multiple blocks (or prefix characters) (would overwrite previous command lines):
    QTextCursor cur = textCursor();
    if (cur.hasSelection())
    {
      if (document()->findBlock(cur.selectionStart()) != document()->findBlock(cur.selectionEnd()) || // spans multiple blocks (including command line)
          cur.selectionStart()-cur.block().position() < mPrefix.length() || // spans prefix
          cur.selectionEnd()-cur.block().position() < mPrefix.length() ) // spans prefix
      {
        cur.clearSelection();
        if (cur.positionInBlock() < mPrefix.length())
          cur.setPosition(cur.block().position()+mPrefix.length());
        setTextCursor(cur);
      }
    }
    if (cur.positionInBlock() == mPrefix.length())
    {
      cur.setCharFormat(QTextCharFormat()); // make sure we don't pick up format from prefix
      setTextCursor(cur);
    }
    // react to keystroke:
    if (event->matches(QKeySequence::MoveToPreviousLine)) // history up
    {
      if (mHistory.isEmpty() || mHistoryPos >= mHistory.size()-1)
        return;
      ++mHistoryPos;
      int index = mHistory.size()-mHistoryPos-1;
      QTextCursor cur(document()->lastBlock());
      cur.movePosition(QTextCursor::NextCharacter, QTextCursor::MoveAnchor, mPrefix.length());
      cur.movePosition(QTextCursor::EndOfBlock, QTextCursor::KeepAnchor);
      cur.removeSelectedText();
      cur.setCharFormat(QTextCharFormat());
      cur.insertText(mHistory.at(index));
      setTextCursor(cur);
    } else if (event->matches(QKeySequence::MoveToNextLine)) // history down
    {
      if (mHistory.isEmpty() || mHistoryPos <= 0)
        return;
      --mHistoryPos;
      int index = mHistory.size()-mHistoryPos-1;
      QTextCursor cur(document()->lastBlock());
      cur.movePosition(QTextCursor::NextCharacter, QTextCursor::MoveAnchor, mPrefix.length());
      cur.movePosition(QTextCursor::EndOfBlock, QTextCursor::KeepAnchor);
      cur.removeSelectedText();
      cur.setCharFormat(QTextCharFormat());
      cur.insertText(mHistory.at(index));
      setTextCursor(cur);
    } else if (event->matches(QKeySequence::Paste)) // paste text, do it manually to remove text char formatting and newlines
    {
      QString pasteText = QApplication::clipboard()->text();
      pasteText.replace("\n", "").replace("\r", "");
      cur.setCharFormat(QTextCharFormat());
      cur.insertText(pasteText);
      setTextCursor(cur);
    } else if (event->key() == Qt::Key_Return) // process command
    {
      processCommand();
    } else if (event->key() == Qt::Key_Backspace) // only allow backspace if we wouldn't delete last char of prefix
    {
      if (cur.positionInBlock() > mPrefix.length())
        QPlainTextEdit::keyPressEvent(event);
    } else if (!event->matches(QKeySequence::Close) &&
               !event->matches(QKeySequence::New) &&
               !event->matches(QKeySequence::Open) &&
               !event->matches(QKeySequence::Preferences) &&
               !event->matches(QKeySequence::Bold) &&
               !event->matches(QKeySequence::Italic) &&
               !event->matches(QKeySequence::InsertLineSeparator) &&
               !event->matches(QKeySequence::InsertParagraphSeparator) &&
               !event->matches(QKeySequence::Redo) &&
               !event->matches(QKeySequence::Undo) &&
               !event->matches(QKeySequence::DeleteStartOfWord))
    {
      QPlainTextEdit::keyPressEvent(event);
    }
  } else // cursor position not in command line
  {
    if (event->matches(QKeySequence::MoveToEndOfDocument) ||
        event->matches(QKeySequence::MoveToEndOfBlock) ||
        event->matches(QKeySequence::MoveToEndOfLine) ||
        event->matches(QKeySequence::MoveToStartOfDocument) ||
        event->matches(QKeySequence::MoveToStartOfBlock) ||
        event->matches(QKeySequence::MoveToStartOfLine) ||
        event->matches(QKeySequence::MoveToNextLine) ||
        event->matches(QKeySequence::MoveToNextWord) ||
        event->matches(QKeySequence::MoveToNextChar) ||
        event->matches(QKeySequence::MoveToPreviousLine) ||
        event->matches(QKeySequence::MoveToPreviousWord) ||
        event->matches(QKeySequence::MoveToPreviousChar) ||
        event->matches(QKeySequence::SelectAll) ||
        event->matches(QKeySequence::SelectEndOfDocument) ||
        event->matches(QKeySequence::SelectEndOfBlock) ||
        event->matches(QKeySequence::SelectEndOfLine) ||
        event->matches(QKeySequence::SelectStartOfDocument) ||
        event->matches(QKeySequence::SelectStartOfBlock) ||
        event->matches(QKeySequence::SelectStartOfLine) ||
        event->matches(QKeySequence::SelectNextLine) ||
        event->matches(QKeySequence::SelectNextWord) ||
        event->matches(QKeySequence::SelectNextChar) ||
        event->matches(QKeySequence::SelectPreviousLine) ||
        event->matches(QKeySequence::SelectPreviousWord) ||
        event->matches(QKeySequence::SelectPreviousChar) ||
        event->matches(QKeySequence::Copy) )
      QPlainTextEdit::keyPressEvent(event);
  }
}

void QPConsole::print(QString str)
{
  QTextCursor cur(document()->lastBlock());
  cur.setCharFormat(QTextCharFormat());
  cur.insertText(str);
  cur.movePosition(QTextCursor::EndOfBlock);
  cur.insertBlock();
  setTextCursor(cur);
  mCommandLineReady = false;
}

void QPConsole::prepareCommandLine()
{
  QTextCursor cur(document()->lastBlock());
  if (!document()->lastBlock().text().isEmpty())
  {
    cur.movePosition(QTextCursor::EndOfBlock);
    cur.insertBlock();
  }
  QTextCharFormat fmt;
  fmt.setForeground(QBrush(mPrefixColor));
  fmt.setFont(mPrefixFont);
  cur.setCharFormat(fmt);
  cur.insertText(mPrefix);
  cur.setCharFormat(QTextCharFormat());
  setTextCursor(cur);
  mCommandLineReady = true;
}