#include "toonzqt/expressionfield.h"

#include "texpression.h"

#include "tparser.h"

#include "tconvert.h"

#include <qsyntaxhighlighter></qsyntaxhighlighter>

#include <qcompleter></qcompleter>

#include <qkeyevent></qkeyevent>

#include <qabstractitemview></qabstractitemview>

#include <qscrollbar></qscrollbar>

#include <qstringlistmodel></qstringlistmodel>

#include <qstandarditemmodel></qstandarditemmodel>

#include <qstandarditem></qstandarditem>

#include <qtooltip></qtooltip>

#include <qlistview></qlistview>

#include <qlabel></qlabel>

using namespace DVGui;

using namespace TSyntax;

//=============================================================================

class ExpressionField::SyntaxHighlighter final : public QSyntaxHighlighter {

  const Grammar *m_grammar;

public:

  bool m_open;

  SyntaxHighlighter(QTextDocument *parent)

      : QSyntaxHighlighter(parent), m_grammar(0), m_open(true) {}

  ~SyntaxHighlighter() {}

  void setGrammar(const Grammar *grammar) { m_grammar = grammar; }

  void highlightBlock(const QString &text) override {

    Parser parser(m_grammar);

    std::vector<syntaxtoken> tokens;</syntaxtoken>

    Parser::SyntaxStatus status =

        parser.checkSyntax(tokens, text.toStdString());

    int nextPos = 0;

    for (int i = 0; i < (int)tokens.size(); i++) {

      QTextCharFormat fmt;

      int pos    = tokens[i].m_pos;

      int length = tokens[i].m_length;

      int type   = tokens[i].m_type;

      nextPos    = pos + length;

      switch (type) {

      case TSyntax::Unknown:

        fmt.setForeground(Qt::black);

        break;

      case TSyntax::Number:

        fmt.setForeground(QColor(0x50, 0x7d, 0x0));

        break;  // number

      case TSyntax::Constant:

        fmt.setForeground(QColor(0x50, 0x7d, 0x0));

        break;  // constant

      case TSyntax::Variable:

        fmt.setForeground(QColor(0x0, 0x88, 0xc8));

        break;  // var

      case TSyntax::Operator:

        fmt.setForeground(QColor(50, 0, 255));

        break;  // infix

      case TSyntax::Parenthesis:

        fmt.setForeground(QColor(50, 50, 255));

        break;  // braket

      case TSyntax::Function:

        fmt.setForeground(QColor(0x0, 0x50, 0x7d));

        break;  // fname

      case TSyntax::Comma:

        fmt.setForeground(QColor(50, 20, 255));

        break;  // f ;

      case TSyntax::UnexpectedToken:

        fmt.setForeground(QColor(0xdc, 0x0, 0x0));

        break;  // expression not found

      case TSyntax::Eos:

        fmt.setForeground(QColor(255, 127, 0));

        break;  //  EOS

      case TSyntax::Mismatch:

        fmt.setForeground(QColor(255, 0, 0));

        break;  // token mismatch

      default:

        fmt.setForeground(QColor(127, 127, 255));

        break;

      }

      if (type == 4) fmt.setToolTip("Infix");

      if (length == 0) length = 1;

      setFormat(pos, length, fmt);

    }

  }

};

//=============================================================================

class MyListView final : public QListView {

  QLabel *m_tooltip;

public:

  MyListView() : QListView() {

    setObjectName("SuggestionPopup");

    setStyleSheet(

        "#SuggestionPopup {background-color:#FFFFFF; border:1px solid black; "

        "color: black;}");

    setWindowFlags(Qt::Popup);

    setMouseTracking(true);

    m_tooltip = new QLabel(0, Qt::ToolTip);

    // Stesso stile del popuop che lo contiene.

    m_tooltip->hide();

    m_tooltip->setObjectName("helpTooltip");

    m_tooltip->setAlignment(Qt::AlignLeft);

    m_tooltip->setIndent(1);

    m_tooltip->setWordWrap(false);

  }

  void showEvent(QShowEvent *) override { showToolTip(currentIndex()); }

  void hideEvent(QHideEvent *) override { m_tooltip->hide(); }

  void currentChanged(const QModelIndex ¤t,

                      const QModelIndex &previous) override {

    showToolTip(current);

    QListView::currentChanged(current, previous);

  }

  void showToolTip(const QModelIndex &index) {

    if (!index.isValid()) {

      m_tooltip->hide();

      return;

    }

    QVariant data = model()->data(index, Qt::ToolTipRole);

    if (!data.isValid()) {

      m_tooltip->hide();

      return;

    }

    QRect rect = visualRect(index);

    m_tooltip->setText(data.toString());

    QPoint pos = viewport()->mapToGlobal(

        QPoint(-m_tooltip->sizeHint().width(), rect.top()));

    m_tooltip->setGeometry(QRect(pos, m_tooltip->sizeHint()));

    m_tooltip->show();

  }

protected:

  void resizeEvent(QResizeEvent *e) override {

    QListView::resizeEvent(e);

    if (m_tooltip->isVisible()) showToolTip(currentIndex());

  }

};

//=============================================================================

ExpressionField::ExpressionField(QWidget *parent)

    : QTextEdit(parent)

    , m_editing(false)

    , m_grammar(0)

    , m_syntaxHighlighter(0)

    , m_completerPopup(0)

    , m_completerStartPos(0) {

  setFrameStyle(QFrame::StyledPanel);

  setObjectName("ExpressionField");

  setLineWrapMode(NoWrap);

  setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

  setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

  setTabChangesFocus(true);

  // setSizePolicy(QSizePolicy(QSizePolicy::Expanding,QSizePolicy::Fixed));

  connect(this, SIGNAL(textChanged()), this, SLOT(onTextChanged()));

#ifdef MACOSX

  setFixedHeight(23);

#else

  setFixedHeight(20);  // +40);

#endif

  m_completerPopup          = new MyListView();

  QStandardItemModel *model = new QStandardItemModel();

  m_completerPopup->setModel(model);

  m_completerPopup->setFocusPolicy(Qt::NoFocus);

  m_completerPopup->setFocusProxy(this);

  m_completerPopup->installEventFilter(this);

  connect(m_completerPopup, SIGNAL(clicked(const QModelIndex &)), this,

          SLOT(insertCompletion(const QModelIndex &)));

  m_syntaxHighlighter = new SyntaxHighlighter(document());

}

ExpressionField::~ExpressionField() { delete m_syntaxHighlighter; }

void ExpressionField::showEvent(QShowEvent *e) { QTextEdit::showEvent(e); }

void ExpressionField::hideEvent(QHideEvent *e) { QTextEdit::hideEvent(e); }

void ExpressionField::setExpression(std::string expression) {

  setPlainText(QString::fromStdString(expression));

}

std::string ExpressionField::getExpression() const {

  return toPlainText().toStdString();

}

bool ExpressionField::event(QEvent *e) {

  if (e->type() == QEvent::ToolTip) {

    QHelpEvent *helpEvent = static_cast<qhelpevent *="">(e);</qhelpevent>

    // openCompletionPopup();

  } else if (e->type() == QEvent::ShortcutOverride) {

    e->accept();

    return true;

  }

  // else

  return QTextEdit::event(e);

}

void ExpressionField::keyPressEvent(QKeyEvent *e) {

  // setStyleSheet("background-color: cyan");

  if (e->key() == Qt::Key_Return || e->key() == Qt::Key_Enter) {

    m_editing = false;

    emit expressionChanged();

  } else if (e->key() == Qt::Key_F10) {

    setAutoFillBackground(true);

    QPalette p = palette();

    p.setColor(QPalette::Base, Qt::cyan);

    p.setColor(QPalette::Background, Qt::cyan);

    setPalette(p);

    update();

    setStyleSheet("#ExpressionField {background-color:cyan;}");

  } else if (e->key() == Qt::Key_F11) {

    m_completerPopup->installEventFilter(this);

    QRect cr = cursorRect();

    QSize size(100, 200);

    QPoint pos = mapToGlobal(QPoint(cr.left(), cr.top() - size.height()));

    m_completerPopup->setGeometry(QRect(pos, size));

    m_completerPopup->show();

    QTextEdit::keyPressEvent(e);

  } else {

    QTextEdit::keyPressEvent(e);

    if (m_completerPopup->isVisible()) {

      updateCompleterPopup();

    } else if (Qt::Key_A <= e->key() && e->key() <= Qt::Key_Z ||

               std::string("+&|!*/=?,:-").find(e->key()) != std::string::npos) {

      openCompleterPopup();

    }

    setFocus();

  }

}

bool ExpressionField::eventFilter(QObject *obj, QEvent *e) {

  if (e->type() == QEvent::KeyPress) {

    QKeyEvent *keyEvent = static_cast<qkeyevent *="">(e);</qkeyevent>

    switch (keyEvent->key()) {

    case Qt::Key_Return:

    case Qt::Key_Enter:

      insertCompletion(m_completerPopup->currentIndex());

      return true;

    case Qt::Key_Left:

    case Qt::Key_Right:

      event(keyEvent);

      m_completerPopup->hide();

      return true;

    case Qt::Key_Escape:

      m_completerPopup->hide();

      return true;

    case Qt::Key_Down:

    case Qt::Key_Up:

      return false;

    default:

      event(e);

      return true;

    }

  } else if (e->type() == QEvent::MouseButtonPress) {

    m_completerPopup->hide();

    event(e);

    return true;

  } else if (e->type() == QEvent::ShortcutOverride) {

    e->accept();

    return true;

  }

  return QObject::eventFilter(obj, e);

}

void ExpressionField::onTextChanged() {

  if (!m_editing) {

    m_editing = true;

    // setStyleSheet("background: rgb(250,200,200)");

  }

}

void ExpressionField::focusInEvent(QFocusEvent *e) {

  m_syntaxHighlighter->m_open = true;

  m_syntaxHighlighter->rehighlight();

  QTextEdit::focusInEvent(e);

}

void ExpressionField::focusOutEvent(QFocusEvent *e) {

  m_syntaxHighlighter->m_open = false;

  m_syntaxHighlighter->rehighlight();

  QTextEdit::focusOutEvent(e);

}

void ExpressionField::onCursorPositionChanged() {}

void ExpressionField::openCompleterPopup() {

  int n = computeSuggestions();

  if (n < 2) return;

  if (updateCompleterPopup()) m_completerPopup->show();

}

bool ExpressionField::updateCompleterPopup() {

  int start        = m_completerStartPos;

  int pos          = textCursor().position();

  std::string text = getExpression();

  if (m_suggestions.empty() || start < 0 || start > pos ||

      pos > (int)text.length()) {

    if (m_completerPopup->isVisible()) m_completerPopup->hide();

    return false;

  }

  QStandardItemModel *model = new QStandardItemModel();

  std::string prefix        = toLower(text.substr(start, pos - start));

  int prefixLength          = prefix.length();

  int count                 = 0;

  for (int i = 0; i < (int)m_suggestions.size(); i++) {

    std::string item = m_suggestions[i].first;

    if ((int)item.length() >= prefixLength &&

        toLower(item.substr(0, prefixLength)) == prefix) {

      QStandardItem *item = new QStandardItem();

      item->setData(QString::fromStdString(m_suggestions[i].first),

                    Qt::EditRole);

      if (m_suggestions[i].second != "")

        item->setData(QString::fromStdString(m_suggestions[i].second),

                      Qt::ToolTipRole);

      model->appendRow(item);

      count++;

    }

  }

  if (count == 0) {

    if (m_completerPopup->isVisible()) m_completerPopup->hide();

    return false;

  }

  m_completerPopup->setModel(model);

  m_completerPopup->setCurrentIndex(model->index(0, 0));

  QTextCursor cursor(textCursor());

  cursor.setPosition(m_completerStartPos);

  QRect cr = cursorRect(cursor);

  int w = m_completerPopup->sizeHintForColumn(0) +

          m_completerPopup->verticalScrollBar()->sizeHint().width() + 5;

  int h =

      (m_completerPopup->sizeHintForRow(0) * std::min(7, model->rowCount()) + 3) +

      3;

  QSize size(w, h);

  QPoint popupPos = mapToGlobal(QPoint(cr.left(), cr.bottom() + 3));

  m_completerPopup->setGeometry(QRect(popupPos, size));

  return true;

}

int ExpressionField::computeSuggestions() {

  m_completerStartPos = -1;

  m_suggestions.clear();

  std::string text = getExpression();

  int pos          = textCursor().position();

  int start        = pos;

  if (start > 0) {

    start--;

    while (start > 0) {

      char c = text[start - 1];

      if (isascii(c) && isalpha(c) || c == '_' ||

          c == '.' && (start - 2 < 0 ||

                       isascii(text[start - 2]) && isalpha(text[start - 2]))) {

      } else

        break;

      start--;

    }

  }

  if (start >= (int)text.length()) return 0;

  m_completerStartPos = start;

  text                = text.substr(0, start);

  TSyntax::Parser parser(m_grammar);

  parser.getSuggestions(m_suggestions, text);

  return (int)m_suggestions.size();

}

void ExpressionField::insertCompletion() {

  if (!m_completerPopup->isVisible()) return;

  QModelIndex index = m_completerPopup->currentIndex();

  if (!index.isValid()) return;

  QString item =

      m_completerPopup->model()->data(index, Qt::EditRole).toString();

  QTextCursor tc = textCursor();

  int pos        = tc.position();

  // tc.movePosition(m_completionStartPos, QTextCursor::KeepAnchor);

  tc.insertText(item);

  m_completerPopup->hide();

}

void ExpressionField::insertCompletion(const QModelIndex &index) {

  if (index.isValid()) {

    QString item =

        m_completerPopup->model()->data(index, Qt::EditRole).toString();

    QTextCursor tc = textCursor();

    int pos        = tc.position();

    if (pos - m_completerStartPos >= 1)

      tc.movePosition(QTextCursor::Left, QTextCursor::KeepAnchor,

                      pos - m_completerStartPos);

    tc.insertText(item);

  }

  m_completerPopup->hide();

}

void ExpressionField::setGrammar(const Grammar *grammar) {

  m_grammar = grammar;

  m_syntaxHighlighter->setGrammar(grammar);

};