/*
Copyright 2011-2016 Google Inc. All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package com.google.security.zynamics.zylib.gui.zygraph.realizers.KeyBehaviours;

import com.google.security.zynamics.zylib.gui.zygraph.realizers.ECommentPlacement;
import com.google.security.zynamics.zylib.gui.zygraph.realizers.IZyEditableObject;
import com.google.security.zynamics.zylib.gui.zygraph.realizers.ZyLineContent;
import com.google.security.zynamics.zylib.gui.zygraph.realizers.KeyBehaviours.UndoHistroy.CUndoManager;

import java.util.List;


public class CBackspaceKeyBehavior extends CAbstractKeyBehavior {
  private int m_caretX;
  private int m_caretY;

  private boolean m_wasSelection = false;

  private boolean m_isBehindComment = false;
  private boolean m_isAboveComment = false;
  private boolean m_isLabelComment = false;

  private IZyEditableObject m_editableObject = null;
  private IZyEditableObject m_lineModel = null;

  private boolean m_wasEditablePosition = false;

  public CBackspaceKeyBehavior(final CUndoManager undoManager) {
    super(undoManager);
  }

  private void handleLineComments() {
    int x = getCaretEndPosX();
    final int y = getCaretMouseReleasedY();

    final ZyLineContent lineContent = getLineContent(y);

    if (m_editableObject == null) {
      // Caret is not within an editable object
      return;
    }

    final int firstModelLine = getLabelContent().getFirstLineIndexOfModelAt(y);
    final int nonCommentLine = getLabelContent().getNonPureCommentLineIndexOfModelAt(y);
    final int firstCommentLine =
        (nonCommentLine != -1) && m_isBehindComment ? nonCommentLine : firstModelLine;

    final String lineText = lineContent.getText();
    String changedText = "";

    // TODO: Remove debug code left-over
    // System.out.println("Backspace behavior befor: " + lineText.replace("\r",
    // "<cr>").replace("\n", "<br>"));

    if (!isCommentDelimiter(x, y)) {
      // Caret is within a comment line and there is no delimiter on the caret's left hand side.

      if ((lineText.length() > 0) && (lineText.length() == m_editableObject.getEnd())
          && (x == lineText.length())) {
        final char lastChar = lineText.charAt(lineText.length() - 1);

        if ((lastChar == '\n') || (lastChar == '\r')) {
          x = -1;
        }
      }

      changedText =
          String.format("%s%s", lineText.substring(m_editableObject.getStart(), x - 1),
              lineText.substring(x, m_editableObject.getEnd()));

      m_caretY = y;
      m_caretX = x - 1;

      changedText = getMultilineComment(m_caretY, changedText);
    } else {
      // Caret's left hand side or caret itself is within a comment delimiter

      final List<IZyEditableObject> editableObjectList = lineContent.getLineFragmentObjectList();
      m_editableObject = editableObjectList.get(editableObjectList.size() - 1);

      if (firstCommentLine == y) {
        // Caret is within the first comment line

        if (m_editableObject.getLength() == 1) {
          // First comment line consists of exactly one character. So only line break or line feed
          // can be left. Delete line.

          if (y > 0) {
            m_caretY = y - 1;
            final ZyLineContent prevLineContent = getLineContent(m_caretY);
            m_caretX = prevLineContent.getText().length();
          }

          changedText = getMultilineComment(y, changedText);
        } else {
          // First comment has more than one character. Do nothing.

          m_caretX = getCaretEndPosX();
          m_caretY = getCaretMouseReleasedY();

          return;
        }
      } else {
        // Caret is not within the first comment line. Remove this line delimiter and concatenate
        // this line with the previous if existing.

        final ZyLineContent prevLineContent = getLineContent(y - 1);
        final String prevLineText = prevLineContent.getText();

        if (!prevLineText.isEmpty() && !prevLineContent.getLineObject().isPlaceholder()) {
          final IZyEditableObject prevLineFragmentObject =
              prevLineContent.getLineFragmentObjectAt(prevLineText.length() - 1);
          changedText =
              prevLineText.substring(prevLineFragmentObject.getStart(),
                  prevLineFragmentObject.getEnd() - 1);

          m_caretY = y - 1;
          m_caretX = prevLineText.length() - 1;

          changedText = getMultilineComment(m_caretY, changedText);
        } else {
          m_caretY = y - 1;
          m_caretX = 0;
        }
      }
    }

    if (changedText.endsWith("\n")) {
      changedText = changedText.substring(0, changedText.length() - 1) + "\r";
    }

    // TODO: Remove debug code left-over
    // System.out.println("Backspace behavior after: " + changedText.replace("\r",
    // "<cr>").replace("\n", "<br>"));

    if (m_isAboveComment) {
      m_editableObject.updateComment(changedText, ECommentPlacement.ABOVE_LINE);
    } else if (m_isBehindComment) {
      m_editableObject.updateComment(changedText, ECommentPlacement.BEHIND_LINE);
    } else if (m_isLabelComment) {
      m_editableObject.update(changedText);
    }

    getLabelContent().getLineEditor().recreateLabelLines(getLabelContent(),
        m_editableObject.getPersistentModel());
  }

  private void handleTextFragment() {
    throw new RuntimeException("Not implemneted yet");
  }

  private boolean isCommentDelimiter(final int x, final int y) {
    final ZyLineContent lineContent = getLineContent(y);

    final IZyEditableObject fragment = lineContent.getLineFragmentObjectAt(x);
    IZyEditableObject leftNeighbourFragment =
        x > 0 ? leftNeighbourFragment = lineContent.getLineFragmentObjectAt(x - 1) : null;

    return

    ((fragment != null) && fragment.isCommentDelimiter())
        || ((leftNeighbourFragment != null) && leftNeighbourFragment.isCommentDelimiter());
  }

  @Override
  protected void initUndoHistory() {
    final int x = getCaretEndPosX();
    final int y = getCaretMouseReleasedY();

    final ZyLineContent lineContent = getLineContent(y);

    m_editableObject = lineContent.getLineFragmentObjectAt(x);
    m_lineModel = lineContent.getLineObject();

    if (m_editableObject != null) {
      // Caret is within an editable object.

      m_wasEditablePosition = true;

      String text =
          lineContent.getText().substring(m_editableObject.getStart(), m_editableObject.getEnd());

      m_isAboveComment = isAboveLineComment(y);
      m_isBehindComment = isBehindLineComment(x, y);
      m_isLabelComment = isLabelComment(y);

      if (isComment(x, y)) {
        text = getMultiLineComment(y);
      }

      udpateUndolist(getLabelContent(), m_lineModel.getPersistentModel(), m_editableObject, text,
          m_isAboveComment, m_isBehindComment, m_isLabelComment, getCaretStartPosX(),
          getCaretMousePressedX(), getCaretMousePressedY(), getCaretEndPosX(),
          getCaretMouseReleasedX(), getCaretMouseReleasedY());
    }
  }

  @Override
  protected void updateCaret() {
    setCaret(m_caretX, m_caretX, m_caretY, m_caretX, m_caretX, m_caretY);

    m_wasSelection = false;
  }

  @Override
  protected void updateClipboard() {
    // Do nothing
  }

  @Override
  protected void updateLabelContent() {
    m_caretX = getCaretEndPosX();
    m_caretY = getCaretMouseReleasedY();

    if (!m_wasSelection) {
      if (isComment(m_caretX, m_caretY)) {
        // Caret end was within a comment, when key was pressed

        handleLineComments();
      } else if (getLineContent(m_caretY).getLineFragmentObjectAt(m_caretX) != null) {
        // Caret end was within an non comment editable object, when key was pressed

        handleTextFragment();
      }
    }
  }

  @Override
  protected void updateSelection() {
    m_wasSelection = isSelection();

    deleteSelection();
  }

  @Override
  protected void updateUndoHistory() {
    if (!m_wasEditablePosition) {
      return;
    }

    m_wasEditablePosition = false;

    final int x = getCaretEndPosX();
    int y = getCaretMouseReleasedY();

    ZyLineContent lineContent = getLineContent(y);

    String text = "";

    if ((lineContent == null) || (lineContent.getLineObject() == null)
        || (m_lineModel.getPersistentModel() != lineContent.getLineObject().getPersistentModel())) {
      if (!m_isLabelComment) {
        int offset = 0;

        if ((y + 1) < getLabelContent().getLineCount()) {
          offset = 1;
          lineContent = getLineContent(y + offset);
        }

        if ((m_lineModel.getPersistentModel() != lineContent.getLineObject().getPersistentModel())
            && (y > 0)) {
          offset = -1;

          lineContent = getLineContent(y + offset);
        }

        y += offset;
      }
    } else if (isComment(x, y)) {
      text = getMultiLineComment(y);
    }

    udpateUndolist(getLabelContent(), m_lineModel.getPersistentModel(), m_lineModel, text,
        m_isAboveComment, m_isBehindComment, m_isLabelComment, getCaretStartPosX(),
        getCaretMousePressedX(), getCaretMousePressedY(), getCaretEndPosX(),
        getCaretMouseReleasedX(), getCaretMouseReleasedY());
  }
}
