/*
 * JAME 6.2.1
 * http://jame.sourceforge.net
 *
 * Copyright 2001, 2016 Andrea Medeghini
 *
 * This file is part of JAME.
 *
 * JAME is an application for creating fractals and other graphics artifacts.
 *
 * JAME is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * JAME is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with JAME.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
package net.sf.jame.contextfree.parser;

import java.util.List;

import org.antlr.v4.runtime.Token;

class ASTUserFunction extends ASTExpression {
	private ASTExpression arguments;
	private ASTDefine definition;
	private int nameIndex;
	protected boolean isLet;

	public ASTUserFunction(int nameIndex, ASTExpression arguments, ASTDefine definition, Token location) {
		super(false, false, EExpType.NoType, location);
		this.nameIndex = nameIndex;
		this.definition = definition;
		this.arguments = arguments;
		isLet = false;
	}

	public ASTExpression getArguments() {
		return arguments;
	}

	protected void setArguments(ASTExpression arguments) {
		this.arguments = arguments;
	}

	public ASTDefine getDefinition() {
		return definition;
	}

	public int getNameIndex() {
		return nameIndex;
	}

	public boolean isLet() {
		return isLet;
	}

	@Override
	public int evaluate(double[] result, int length, RTI rti) {
		if (type != EExpType.NumericType) {
			error("Function does not evaluate to a number");
			return -1;
		}
		if (result != null && length < definition.getTupleSize()) {
			return -1;
		}
		if (result == null) {
			return definition.getTupleSize();
		}
		if (rti == null) throw new DeferUntilRuntimeException();
		if (rti.getRequestStop()/*TODO || Render.abortEverything*/) {
			throw new CfdgException("Stopping");
		}
		StackType oldStackType = setupStack(rti);
		definition.getExp().evaluate(result, length, rti);
		cleanupStack(rti, oldStackType);
		return definition.getTupleSize();
	}

	@Override
	public void evaluate(Modification[] result, boolean shapeDest, RTI rti) {
		if (type != EExpType.ModType) {
			error("Function does not evaluate to an adjustment");
			return;
		}
		if (rti == null) throw new DeferUntilRuntimeException();
		if (rti.getRequestStop()/*TODO || Render.abortEverything*/) {
			throw new CfdgException("Stopping");
		}
		StackType oldStackType = setupStack(rti);
		definition.getExp().evaluate(result, shapeDest, rti);
		cleanupStack(rti, oldStackType);
	}

	@Override
	public void entropy(StringBuilder e) {
		if (arguments != null) {
			arguments.entropy(e);
		}
		e.append(definition.getName());
	}

	@Override
	public ASTExpression simplify() {
		if (arguments != null) {
			if (arguments instanceof ASTCons) {
				ASTCons c = (ASTCons)arguments;
				for (ASTExpression e : c.getChildren()) {
					e.simplify();
				}
			} else {
				arguments.simplify();
			}
		}
		return this;
	}

	@Override
	public ASTExpression compile(ECompilePhase ph) {
		switch (ph) {
			case TypeCheck:
				{
	                // Function calls and shape specifications are ambiguous at parse
	                // time so the parser always chooses a function call. During
	                // type check we may need to convert to a shape spec.
					ASTDefine[] def = new ASTDefine[1];
					@SuppressWarnings("unchecked")
					List<ASTParameter>[] p = new List[1];
					String name = Builder.currentBuilder().getTypeInfo(nameIndex, def, p);
					if (def[0] != null && p[0] != null) {
						error("Name matches both a function and a shape");
						return null;
					}
					if (def[0] == null && p[0] == null) {
						error("Name does not match shape name or function name");
						return null;
					}
					if (def[0] != null) {
						if (arguments != null) {
							arguments.compile(ph);
						}
						definition = def[0];
						ASTParameter.checkType(def[0].getParameters(), arguments, false);
						isConstant = false;
						isNatural = definition.isNatural();
						type = definition.getExpType();
						locality = arguments != null ? arguments.getLocality() : ELocality.PureLocal;
						if (definition.getExp() != null && definition.getExp().getLocality() == ELocality.ImpureNonlocal && locality == ELocality.PureNonlocal) {
							locality = ELocality.ImpureNonlocal;
						}
						return null;
					}
					ASTRuleSpecifier r = new ASTRuleSpecifier(nameIndex, name, arguments, null, location);
					r.compile(ph);
					return r;
				}
	
			case Simplify: 
				break;
	
			default:
				break;
		}
		return null;
	}

	@Override
	public StackRule evalArgs(RTI rti, StackRule parent) {
		if (type != EExpType.RuleType) {
			error("Function does not evaluate to a shape");
			return null;
		}
		if (rti == null) throw new DeferUntilRuntimeException();
		if (rti.getRequestStop()/*TODO || Render.abortEverything*/) {
			throw new CfdgException("Stopping");
		}
		StackType oldStackType = setupStack(rti);
		StackRule ret = definition.getExp().evalArgs(rti, parent);
		cleanupStack(rti, oldStackType);
		return ret;
	}
	
	private StackType setupStack(RTI rti) {
		StackType stackType = rti.getLogicalStackTop();
		if (definition.getStackCount() > 0) {
			int size = rti.getCFStack().size();
			rti.getCFStack().get(size).evalArgs(rti, arguments, definition.getParameters(), isLet);
			rti.setLogicalStackTop(new StackType(size));
		}
		return stackType;
	}

	private void cleanupStack(RTI rti, StackType stackType) {
		if (definition.getStackCount() > 0) {
			rti.setLogicalStackTop(stackType);
		}
	}
}