/*
 * [The "BSD license"]
 *  Copyright (c) 2010 Terence Parr
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *  1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *      derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 *  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.antlr.tool;

import org.antlr.codegen.CodeGenerator;
import org.antlr.runtime.Token;

import java.util.*;

Track the attributes within a scope.  A named scoped has just its list
 of attributes.  Each rule has potentially 3 scopes: return values,
 parameters, and an implicitly-named scope (i.e., a scope defined in a rule).
 Implicitly-defined scopes are named after the rule; rules and scopes then
 must live in the same name space--no collisions allowed.
/** Track the attributes within a scope.  A named scoped has just its list
 *  of attributes.  Each rule has potentially 3 scopes: return values,
 *  parameters, and an implicitly-named scope (i.e., a scope defined in a rule).
 *  Implicitly-defined scopes are named after the rule; rules and scopes then
 *  must live in the same name space--no collisions allowed.
 */
public class AttributeScope {

	
All token scopes (token labels) share the same fixed scope of
 of predefined attributes.  I keep this out of the runtime.Token
 object to avoid a runtime space burden.
/** All token scopes (token labels) share the same fixed scope of
	 *  of predefined attributes.  I keep this out of the runtime.Token
	 *  object to avoid a runtime space burden.
	 */
	public static final AttributeScope tokenScope = new AttributeScope("Token",null);

	static {
		tokenScope.addAttribute("text", null);
		tokenScope.addAttribute("type", null);
		tokenScope.addAttribute("line", null);
		tokenScope.addAttribute("index", null);
		tokenScope.addAttribute("pos", null);
		tokenScope.addAttribute("channel", null);
		tokenScope.addAttribute("tree", null);
		tokenScope.addAttribute("int", null);
	}

	
This scope is associated with which input token (for error handling)? /** This scope is associated with which input token (for error handling)? */
	public Token derivedFromToken;

	public Grammar grammar;

	
The scope name /** The scope name */
	private String name;

	
Not a rule scope, but visible to all rules "scope symbols { ...}" /** Not a rule scope, but visible to all rules "scope symbols { ...}" */
	public boolean isDynamicGlobalScope;

	
Visible to all rules, but defined in rule "scope { int i; }" /** Visible to all rules, but defined in rule "scope { int i; }" */
	public boolean isDynamicRuleScope;

	public boolean isParameterScope;

	public boolean isReturnScope;

	public boolean isPredefinedRuleScope;

	public boolean isPredefinedLexerRuleScope;

	
The list of Attribute objects /** The list of Attribute objects */
	protected LinkedHashMap<String,Attribute> attributes = new LinkedHashMap<String, Attribute>();

	/* Placeholder for compatibility with the CSharp3 target. */
	public LinkedHashMap<String, GrammarAST> actions = new LinkedHashMap<String, GrammarAST>();

	public AttributeScope(String name, Token derivedFromToken) {
		this(null,name,derivedFromToken);
	}

	public AttributeScope(Grammar grammar, String name, Token derivedFromToken) {
		this.grammar = grammar;
		this.name = name;
		this.derivedFromToken = derivedFromToken;
	}

	public String getName() {
		if ( isParameterScope ) {
			return name+"_parameter";
		}
		else if ( isReturnScope ) {
			return name+"_return";
		}
		return name;
	}

	
From a chunk of text holding the definitions of the attributes,
 pull them apart and create an Attribute for each one.  Add to
 the list of attributes for this scope.  Pass in the character
 that terminates a definition such as ',' or ';'.  For example,
 scope symbols {
 	int n;
 	List names;
 }
 would pass in definitions equal to the text in between {...} and
 separator=';'.  It results in two Attribute objects.
/** From a chunk of text holding the definitions of the attributes,
	 *  pull them apart and create an Attribute for each one.  Add to
	 *  the list of attributes for this scope.  Pass in the character
	 *  that terminates a definition such as ',' or ';'.  For example,
	 *
	 *  scope symbols {
	 *  	int n;
	 *  	List names;
	 *  }
	 *
	 *  would pass in definitions equal to the text in between {...} and
	 *  separator=';'.  It results in two Attribute objects.
	 */
	public void addAttributes(String definitions, int separator) {
		List<String> attrs = new ArrayList<String>();
		CodeGenerator.getListOfArgumentsFromAction(definitions,0,-1,separator,attrs);
		for (String a : attrs) {
			Attribute attr = new Attribute(a);
			if ( !isReturnScope && attr.initValue!=null ) {
				ErrorManager.grammarError(ErrorManager.MSG_ARG_INIT_VALUES_ILLEGAL,
										  grammar,
										  derivedFromToken,
										  attr.name);
				attr.initValue=null; // wipe it out
			}
			attributes.put(attr.name, attr);
		}
	}

	public void addAttribute(String name, String decl) {
		attributes.put(name, new Attribute(name,decl));
	}

	
Given @scope::name {action} define it for this attribute scope. Later,
 the code generator will ask for the actions table.
/** Given @scope::name {action} define it for this attribute scope. Later,
	 *  the code generator will ask for the actions table.
	 */
	public final void defineNamedAction(GrammarAST nameAST, GrammarAST actionAST)
	{
		String actionName = nameAST.getText();
		GrammarAST a = actions.get(actionName);
		if (a != null) {
			ErrorManager.grammarError(ErrorManager.MSG_ACTION_REDEFINITION,
									  grammar,
									  nameAST.getToken(),
									  nameAST.getText());
		} else {
			actions.put(actionName, actionAST);
		}
	}

	public Attribute getAttribute(String name) {
		return attributes.get(name);
	}

	
Used by templates to get all attributes /** Used by templates to get all attributes */
	public List<Attribute> getAttributes() {
		List<Attribute> a = new ArrayList<Attribute>();
		a.addAll(attributes.values());
		return a;
	}

	
Return the set of keys that collide from
 this and other.
/** Return the set of keys that collide from
	 *  this and other.
	 */
	public Set<String> intersection(AttributeScope other) {
		if ( other==null || other.size()==0 || size()==0 ) {
			return null;
		}
		Set<String> inter = new HashSet<String>();
		Set<String> thisKeys = attributes.keySet();
		for (String key : thisKeys) {
			if ( other.attributes.get(key)!=null ) {
				inter.add(key);
			}
		}
		if ( inter.isEmpty() ) {
			return null;
		}
		return inter;
	}

	public int size() {
		return attributes==null?0:attributes.size();
	}

	@Override
	public String toString() {
		return (isDynamicGlobalScope?"global ":"")+getName()+":"+attributes;
	}
}