/******************************************************************************
 * The MIT License (MIT)
 *
 * Copyright (c) 2019-2020 Baldur Karlsson
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 ******************************************************************************/

#pragma once

#include <QLabel>
#include <QStyledItemDelegate>
#include <QTreeView>
#include "Code/QRDUtils.h"

class RDTreeView;

typedef QSet<uint> RDTreeViewExpansionState;

class RDTreeViewDelegate : public ForwardingDelegate
{
private:
  Q_OBJECT

  RDTreeView *m_View;

public:
  RDTreeViewDelegate(RDTreeView *view);
  QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const override;
};

class RDTipLabel : public QLabel
{
private:
  Q_OBJECT

  int m_TooltipMargin = 0;
  QWidget *mouseListener;

public:
  explicit RDTipLabel(QWidget *listener = NULL);

  int tipMargin() { return m_TooltipMargin; }
protected:
  void paintEvent(QPaintEvent *);
  void mousePressEvent(QMouseEvent *);
  void mouseReleaseEvent(QMouseEvent *);
  void mouseDoubleClickEvent(QMouseEvent *);
  void resizeEvent(QResizeEvent *);

  void sendListenerEvent(QMouseEvent *e);
};

typedef std::function<uint(QModelIndex, uint)> ExpansionKeyGen;

class RDTreeView : public QTreeView
{
  Q_OBJECT

  Q_PROPERTY(bool customCopyPasteHandler READ customCopyPasteHandler WRITE setCustomCopyPasteHandler)
public:
  explicit RDTreeView(QWidget *parent = 0);
  virtual ~RDTreeView();

  void showBranches() { m_VisibleBranches = true; }
  void hideBranches() { m_VisibleBranches = false; }
  void showGridLines() { m_VisibleGridLines = true; }
  void hideGridLines() { m_VisibleGridLines = false; }
  bool visibleGridLines() { return m_VisibleGridLines; }
  void setTooltipElidedItems(bool tool) { m_TooltipElidedItems = tool; }
  bool tooltipElidedItems() { return m_TooltipElidedItems; }
  void setItemVerticalMargin(int vertical) { m_VertMargin = vertical; }
  int verticalItemMargin() { return m_VertMargin; }
  void setIgnoreIconSize(bool ignore) { m_IgnoreIconSize = ignore; }
  bool ignoreIconSize() { return m_IgnoreIconSize; }
  bool customCopyPasteHandler() { return m_customCopyPaste; }
  void setCustomCopyPasteHandler(bool custom) { m_customCopyPaste = custom; }
  QModelIndex currentHoverIndex() const { return m_currentHoverIndex; }
  void setItemDelegate(QAbstractItemDelegate *delegate);
  QAbstractItemDelegate *itemDelegate() const;

  void setModel(QAbstractItemModel *model) override;

  // state is the storage to save the expansion state into
  // keygen is a function that will take the index of a row and a previous hash, and return the hash
  //   for that row.
  void saveExpansion(RDTreeViewExpansionState &state, const ExpansionKeyGen &keygen);
  void applyExpansion(const RDTreeViewExpansionState &state, const ExpansionKeyGen &keygen);

  // convenience overloads for the simple case of using a single column's data as hash
  void saveExpansion(RDTreeViewExpansionState &state, int keyColumn, int keyRole = Qt::DisplayRole)
  {
    saveExpansion(state, [keyColumn, keyRole](QModelIndex idx, uint seed) {
      return qHash(idx.sibling(idx.row(), keyColumn).data(keyRole).toString(), seed);
    });
  }
  void applyExpansion(const RDTreeViewExpansionState &state, int keyColumn,
                      int keyRole = Qt::DisplayRole)
  {
    applyExpansion(state, [keyColumn, keyRole](QModelIndex idx, uint seed) {
      return qHash(idx.sibling(idx.row(), keyColumn).data(keyRole).toString(), seed);
    });
  }

  // Internally tracked expansions
  RDTreeViewExpansionState &getInternalExpansion(uint expansionID)
  {
    return m_Expansions[expansionID];
  }
  bool hasInternalExpansion(uint expansionID) { return m_Expansions.contains(expansionID); }
  void clearInternalExpansions() { m_Expansions.clear(); }
  virtual void copySelection();

  void expandAll(QModelIndex index);
  void collapseAll(QModelIndex index);
  using QTreeView::expandAll;
  using QTreeView::collapseAll;

signals:
  void leave(QEvent *e);
  void keyPress(QKeyEvent *e);

protected:
  void mouseMoveEvent(QMouseEvent *e) override;
  void wheelEvent(QWheelEvent *e) override;
  void leaveEvent(QEvent *e) override;
  void keyPressEvent(QKeyEvent *e) override;
  bool viewportEvent(QEvent *event) override;
  void contextMenuEvent(QContextMenuEvent *event) override;

  void drawRow(QPainter *painter, const QStyleOptionViewItem &options,
               const QModelIndex &index) const override;
  void drawBranches(QPainter *painter, const QRect &rect, const QModelIndex &index) const override;

  void fillBranchesRect(QPainter *painter, const QRect &rect, const QModelIndex &index) const;
  void enableBranchRectFill(bool fill) { m_fillBranchRect = fill; }
  QModelIndex m_currentHoverIndex;

private slots:
  void modelAboutToBeReset();

private:
  bool m_VisibleBranches = true;
  bool m_VisibleGridLines = true;
  bool m_TooltipElidedItems = true;
  bool m_customCopyPaste = false;

  QMap<uint, RDTreeViewExpansionState> m_Expansions;

  void saveExpansionFromRow(RDTreeViewExpansionState &state, QModelIndex idx, uint seed,
                            const ExpansionKeyGen &keygen);
  void applyExpansionToRow(const RDTreeViewExpansionState &state, QModelIndex idx, uint seed,
                           const ExpansionKeyGen &keygen);

  QAbstractItemDelegate *m_userDelegate = NULL;
  RDTreeViewDelegate *m_delegate;

  RDTipLabel *m_ElidedTooltip;

  int m_VertMargin = 6;
  bool m_IgnoreIconSize = false;

  bool m_fillBranchRect = true;
};