package net.sourceforge.phpdt.internal.compiler.ast;

import net.sourceforge.phpdt.internal.compiler.parser.Outlineable;
import net.sourceforge.phpdt.internal.ui.PHPUiImages;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.text.Position;

import java.util.List;

/**
 * A variable declaration.
 * 
 * @author Matthieu Casanova
 */
public class VariableDeclaration extends Expression implements Outlineable {

  public static final int EQUAL = 0;
  public static final int PLUS_EQUAL = 1;
  public static final int MINUS_EQUAL = 2;
  public static final int STAR_EQUAL = 3;
  public static final int SLASH_EQUAL = 4;
  public static final int AND_EQUAL = 5;
  public static final int OR_EQUAL = 6;
  public static final int XOR_EQUAL = 7;
  public static final int DOT_EQUAL = 8;
  public static final int REM_EQUAL = 9;
  public static final int TILDE_EQUAL = 10;
  public static final int LSHIFT_EQUAL = 11;
  public static final int RSIGNEDSHIFT_EQUAL = 12;

  protected final AbstractVariable variable;

  /** The value for variable initialization. */
  public Expression initialization;

  private Object parent;
  protected boolean reference;

  private Position position;

  private int operator;

  /**
   * Create a variable.
   * 
   * @param variable       the name of the variable
   * @param initialization the initialization
   * @param operator       the assign operator
   * @param sourceStart    the start point
   */
  public VariableDeclaration(final Object parent,
                             final AbstractVariable variable,
                             final Expression initialization,
                             final int operator,
                             final int sourceStart) {
    super(sourceStart, initialization.sourceEnd);
    this.initialization = initialization;
    this.variable = variable;
    this.operator = operator;
    this.parent = parent;
    position = new Position(sourceStart, sourceEnd);
  }

  /**
   * Create a variable.
   * 
   * @param variable    a variable (in case of $$variablename)
   * @param sourceStart the start point
   */
  public VariableDeclaration(final Object parent,
                             final AbstractVariable variable,
                             final int sourceStart,
                             final int sourceEnd) {
    super(sourceStart, sourceEnd);
    this.variable = variable;
    this.parent = parent;
    position = new Position(sourceStart, sourceEnd);
  }

  public final void setReference(final boolean reference) {
    this.reference = reference;
  }

  /**
   * Create a variable.
   * 
   * @param initialization the initialization
   * @param variable       a variable (in case of $$variablename)
   * @param sourceStart    the start point
   */
  public VariableDeclaration(final AbstractVariable variable,
                             final Expression initialization,
                             final int operator,
                             final int sourceStart) {
    super(sourceStart, initialization.sourceEnd);
    this.variable = variable;
    this.initialization = initialization;
    this.operator = operator;
  }

  /**
   * Create a variable.
   * 
   * @param variable    a variable (in case of $$variablename)
   * @param sourceStart the start point
   */
  public VariableDeclaration(final AbstractVariable variable,
                             final int sourceStart) {
    super(sourceStart, variable.sourceEnd);
    this.variable = variable;
  }

  /**
   * Return the operator as String.
   * 
   * @return the operator
   */
  private String operatorToString() {
    switch (operator) {
      case EQUAL:
        return "="; //$NON-NLS-1$
      case PLUS_EQUAL:
        return "+=";   //$NON-NLS-1$
      case MINUS_EQUAL:
        return "-=";   //$NON-NLS-1$
      case STAR_EQUAL:
        return "*="; //$NON-NLS-1$
      case SLASH_EQUAL:
        return "/="; //$NON-NLS-1$
      case AND_EQUAL:
        return "<="; //$NON-NLS-1$
      case OR_EQUAL:
        return "|=";//$NON-NLS-1$
      case XOR_EQUAL:
        return "^=";//$NON-NLS-1$
      case DOT_EQUAL:
        return ".="; //$NON-NLS-1$
      case REM_EQUAL:
        return "%="; //$NON-NLS-1$
      case TILDE_EQUAL:
        return "~="; //$NON-NLS-1$
      case LSHIFT_EQUAL:
        return "<<="; //$NON-NLS-1$
      case RSIGNEDSHIFT_EQUAL:
        return ">>="; //$NON-NLS-1$
    }
    return " unknown operator ";//$NON-NLS-1$
  }

  /**
   * Return the variable into String.
   * 
   * @return a String
   */
  public String toStringExpression() {
    final String variableString = variable.toStringExpression();
    if (initialization == null) {
      if (reference) return '&' + variableString; else return variableString;
    } else {
      final String operatorString = operatorToString();
      final String initString = initialization.toStringExpression();
      final StringBuffer buff = new StringBuffer(variableString.length() +
                                                 operatorString.length() +
                                                 initString.length() +
                                                 1);
      buff.append(variableString);
      buff.append(operatorString); //$NON-NLS-1$
      buff.append(initString);
      return buff.toString();
    }
  }

  public final Object getParent() {
    return parent;
  }

  public final String toString() {
    return toStringExpression();
  }

  /**
   * Get the image of a variable.
   * 
   * @return the image that represents a php variable
   */
  public final ImageDescriptor getImage() {
    return PHPUiImages.DESC_VAR;
  }

  public final Position getPosition() {
    return position;
  }

  /**
   * Get the name of the field as String.
   * 
   * @return the name of the String
   */
  public final String name() {
    return variable.getName();
  }

  /**
   * Get the variables from outside (parameters, globals ...)
   */
  public final void getOutsideVariable(final List list) {
  }

  /**
   * get the modified variables.
   */
  public final void getModifiedVariable(final List list) {
    variable.getUsedVariable(list);
    if (initialization != null) {
      initialization.getModifiedVariable(list);
    }
  }

  /**
   * Get the variables used.
   */
  public final void getUsedVariable(final List list) {
    if (initialization != null) {
      initialization.getUsedVariable(list);
    }
  }
}