/*
 * Copyright © 2010 Reinier Zwitserloot and Roel Spilker.
 * 
 * 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.
 */
package lombok.javac.handlers;

import lombok.javac.JavacASTAdapter;
import lombok.javac.JavacASTVisitor;
import lombok.javac.JavacNode;
import lombok.javac.JavacResolution;

import org.mangosdk.spi.ProviderFor;

import com.sun.tools.javac.code.Flags;
import com.sun.tools.javac.code.Type;
import com.sun.tools.javac.tree.JCTree;
import com.sun.tools.javac.tree.JCTree.JCEnhancedForLoop;
import com.sun.tools.javac.tree.JCTree.JCExpression;
import com.sun.tools.javac.tree.JCTree.JCVariableDecl;

@ProviderFor(JavacASTVisitor.class)
public class HandleVal extends JavacASTAdapter {
	@Override public boolean isResolutionBased() {
		return true;
	}
	
	@Override public void visitLocal(JavacNode localNode, JCVariableDecl local) {
		if (local.vartype != null && local.vartype.toString().equals("val")) {
			JCExpression rhsOfEnhancedForLoop = null;
			if (local.init == null) {
				JCTree parentRaw = localNode.directUp().get();
				if (parentRaw instanceof JCEnhancedForLoop) {
					JCEnhancedForLoop efl = (JCEnhancedForLoop) parentRaw;
					if (efl.var == local) rhsOfEnhancedForLoop = efl.expr;
				}
			}
			
			if (rhsOfEnhancedForLoop == null && local.init == null) {
				localNode.addError("'val' on a local variable requires an initializer expression");
				return;
			}
			
			local.mods.flags |= Flags.FINAL;
			JCExpression oldVarType = local.vartype;
			local.vartype = JavacResolution.createJavaLangObject(localNode.getTreeMaker(), localNode.getAst());
			
			Type type;
			try {
				if (rhsOfEnhancedForLoop == null) {
					if (local.init.type == null) {
						JavacResolution resolver = new JavacResolution(localNode.getContext());
						type = ((JCExpression) resolver.resolve(localNode).get(local.init)).type;
					} else {
						type = local.init.type;
					}
				} else {
					if (rhsOfEnhancedForLoop.type == null) {
						JavacResolution resolver = new JavacResolution(localNode.getContext());
						type = ((JCExpression) resolver.resolve(localNode.directUp()).get(rhsOfEnhancedForLoop)).type;
					} else {
						type = rhsOfEnhancedForLoop.type;
					}
				}
				
				try {
					JCExpression replacement;
					
					if (rhsOfEnhancedForLoop != null) {
						localNode.addError("For now 'val' cannot be used in enhanced for loops. Fixing this is a high priority lombok issue though!");
						return;
						// TODO: Fix enhanced for loops - then uncomment a bunch of lines in test/transform/resource/*/ValInFor.java
					}
					replacement = JavacResolution.typeToJCTree(type, localNode.getTreeMaker(), localNode.getAst());
					if (replacement != null) local.vartype = replacement;
					else local.vartype = oldVarType;
				} catch (JavacResolution.TypeNotConvertibleException e) {
					localNode.addError("Cannot use 'val' here because initializer expression does not have a representable type: " + e.getMessage());
					local.vartype = oldVarType;
				}
			} catch (RuntimeException e) {
				local.vartype = oldVarType;
				throw e;
			}
		}
		// TODO search for val decls in either kind of for.
	}
}