/*
 * Copyright (C) 2009-2013 The Project Lombok Authors.
 * 
 * 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.eclipse;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.regex.Pattern;

import lombok.core.ClassLiteral;
import lombok.core.FieldSelect;
import org.eclipse.jdt.internal.compiler.ast.ASTNode;
import org.eclipse.jdt.internal.compiler.ast.AbstractMethodDeclaration;
import org.eclipse.jdt.internal.compiler.ast.AbstractVariableDeclaration;
import org.eclipse.jdt.internal.compiler.ast.Annotation;
import org.eclipse.jdt.internal.compiler.ast.ClassLiteralAccess;
import org.eclipse.jdt.internal.compiler.ast.Clinit;
import org.eclipse.jdt.internal.compiler.ast.Expression;
import org.eclipse.jdt.internal.compiler.ast.Literal;
import org.eclipse.jdt.internal.compiler.ast.QualifiedNameReference;
import org.eclipse.jdt.internal.compiler.ast.SingleNameReference;
import org.eclipse.jdt.internal.compiler.ast.TryStatement;
import org.eclipse.jdt.internal.compiler.ast.TypeDeclaration;
import org.eclipse.jdt.internal.compiler.ast.TypeReference;
import org.eclipse.jdt.internal.compiler.ast.UnaryExpression;
import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;
import org.eclipse.jdt.internal.compiler.lookup.TypeIds;

public class Eclipse {
	private static final Annotation[] EMPTY_ANNOTATIONS_ARRAY = new Annotation[0];
	
Eclipse's Parser class is instrumented to not attempt to fill in the body of any method or initializer
or field initialization if this flag is set. Set it on the flag field of
any method, field, or initializer you create!
/**
	 * Eclipse's Parser class is instrumented to not attempt to fill in the body of any method or initializer
	 * or field initialization if this flag is set. Set it on the flag field of
	 * any method, field, or initializer you create!
	 */
	public static final int ECLIPSE_DO_NOT_TOUCH_FLAG = ASTNode.Bit24;
	
	private static final Pattern SPLIT_AT_DOT = Pattern.compile("\\.");
	
	private Eclipse() {
		//Prevent instantiation
	}
	
	
For 'speed' reasons, Eclipse works a lot with char arrays. I have my doubts this was a fruitful exercise,
but we need to deal with it. This turns [[java][lang][String]] into "java.lang.String".
/**
	 * For 'speed' reasons, Eclipse works a lot with char arrays. I have my doubts this was a fruitful exercise,
	 * but we need to deal with it. This turns [[java][lang][String]] into "java.lang.String".
	 */
	public static String toQualifiedName(char[][] typeName) {
		int len = typeName.length - 1; // number of dots
		if (len == 0) return new String(typeName[0]);
		
		for (char[] c : typeName) len += c.length;
		char[] ret = new char[len];
		char[] part = typeName[0];
		System.arraycopy(part, 0, ret, 0, part.length);
		int pos = part.length;
		for (int i = 1; i < typeName.length; i++) {
			ret[pos++] = '.';
			part = typeName[i];
			System.arraycopy(part, 0, ret, pos, part.length);
			pos += part.length;
		}
		return new String(ret);
	}
	
	public static char[][] fromQualifiedName(String typeName) {
		String[] split = SPLIT_AT_DOT.split(typeName);
		char[][] result = new char[split.length][];
		for (int i = 0; i < split.length; i++) {
			result[i] = split[i].toCharArray();
		}
		return result;
	}
	
	public static long pos(ASTNode node) {
		return ((long) node.sourceStart << 32) | (node.sourceEnd & 0xFFFFFFFFL);
	}
	
	public static long[] poss(ASTNode node, int repeat) {
		long p = ((long) node.sourceStart << 32) | (node.sourceEnd & 0xFFFFFFFFL);
		long[] out = new long[repeat];
		Arrays.fill(out, p);
		return out;
	}
	
	
Checks if an eclipse-style array-of-array-of-characters to represent a fully qualified name ('foo.bar.baz'), matches a plain
string containing the same fully qualified name with dots in the string.
/**
	 * Checks if an eclipse-style array-of-array-of-characters to represent a fully qualified name ('foo.bar.baz'), matches a plain
	 * string containing the same fully qualified name with dots in the string.
	 */
	public static boolean nameEquals(char[][] typeName, String string) {
		int pos = 0, len = string.length();
		for (int i = 0; i < typeName.length; i++) {
			char[] t = typeName[i];
			if (i > 0) {
				if (pos == len) return false;
				if (string.charAt(pos++) != '.') return false;
			}
			for (int j = 0; j < t.length; j++) {
				if (pos == len) return false;
				if (string.charAt(pos++) != t[j]) return false;
			}
		}
		
		return true;
	}
	
	public static boolean hasClinit(TypeDeclaration parent) {
		if (parent.methods == null) return false;
		
		for (AbstractMethodDeclaration method : parent.methods) {
			if (method instanceof Clinit) return true;
		}
		return false;
	}
	
	
Searches the given field node for annotations and returns each one that matches the provided regular expression pattern.
Only the simple name is checked - the package and any containing class are ignored.
/**
	 * Searches the given field node for annotations and returns each one that matches the provided regular expression pattern.
	 * 
	 * Only the simple name is checked - the package and any containing class are ignored.
	 */
	public static Annotation[] findAnnotations(AbstractVariableDeclaration field, Pattern namePattern) {
		List<Annotation> result = new ArrayList<Annotation>();
		if (field.annotations == null) return EMPTY_ANNOTATIONS_ARRAY;
		for (Annotation annotation : field.annotations) {
			TypeReference typeRef = annotation.type;
			if (typeRef != null && typeRef.getTypeName() != null) {
				char[][] typeName = typeRef.getTypeName();
				String suspect = new String(typeName[typeName.length - 1]);
				if (namePattern.matcher(suspect).matches()) {
					result.add(annotation);
				}
			}
		}	
		return result.toArray(EMPTY_ANNOTATIONS_ARRAY);
	}
	
	
Matches any of the 8 primitive names, such as boolean. /** Matches any of the 8 primitive names, such as {@code boolean}. */
	private static final Pattern PRIMITIVE_TYPE_NAME_PATTERN = Pattern.compile(
			"^(boolean|byte|short|int|long|float|double|char)$");
	
	
Checks if the given type reference represents a primitive type.
/**
	 * Checks if the given type reference represents a primitive type.
	 */
	public static boolean isPrimitive(TypeReference ref) {
		if (ref.dimensions() > 0) return false;
		return PRIMITIVE_TYPE_NAME_PATTERN.matcher(toQualifiedName(ref.getTypeName())).matches();
	}
	
	
Returns the actual value of the given Literal or Literal-like node.
/**
	 * Returns the actual value of the given Literal or Literal-like node.
	 */
	public static Object calculateValue(Expression e) {
		if (e instanceof Literal) {
			((Literal) e).computeConstant();
			switch (e.constant.typeID()) {
			case TypeIds.T_int: return e.constant.intValue();
			case TypeIds.T_byte: return e.constant.byteValue();
			case TypeIds.T_short: return e.constant.shortValue();
			case TypeIds.T_char: return e.constant.charValue();
			case TypeIds.T_float: return e.constant.floatValue();
			case TypeIds.T_double: return e.constant.doubleValue();
			case TypeIds.T_boolean: return e.constant.booleanValue();
			case TypeIds.T_long: return e.constant.longValue();
			case TypeIds.T_JavaLangString: return e.constant.stringValue();
			default: return null;
			}
		} else if (e instanceof ClassLiteralAccess) {
			return new ClassLiteral(Eclipse.toQualifiedName(((ClassLiteralAccess) e).type.getTypeName()));
		} else if (e instanceof SingleNameReference) {
			return new FieldSelect(new String(((SingleNameReference)e).token));
		} else if (e instanceof QualifiedNameReference) {
			String qName = Eclipse.toQualifiedName(((QualifiedNameReference) e).tokens);
			int idx = qName.lastIndexOf('.');
			return new FieldSelect(idx == -1 ? qName : qName.substring(idx+1));
		} else if (e instanceof UnaryExpression) {
			if ("-".equals(((UnaryExpression) e).operatorToString())) {
				Object inner = calculateValue(((UnaryExpression) e).expression);
				if (inner instanceof Integer) return - ((Integer) inner).intValue();
				if (inner instanceof Byte) return - ((Byte) inner).byteValue();
				if (inner instanceof Short) return - ((Short) inner).shortValue();
				if (inner instanceof Long) return - ((Long) inner).longValue();
				if (inner instanceof Float) return - ((Float) inner).floatValue();
				if (inner instanceof Double) return - ((Double) inner).doubleValue();
				return null;
			}
		}
		
		return null;
	}
	
	private static long latestEcjCompilerVersionConstantCached = 0;
	
	public static long getLatestEcjCompilerVersionConstant() {
		if (latestEcjCompilerVersionConstantCached != 0) return latestEcjCompilerVersionConstantCached;
		
		int highestVersionSoFar = 0;
		for (Field f : ClassFileConstants.class.getDeclaredFields()) {
			try {
				if (f.getName().startsWith("JDK1_")) {
					int thisVersion = Integer.parseInt(f.getName().substring("JDK1_".length()));
					if (thisVersion > highestVersionSoFar) {
						highestVersionSoFar = thisVersion;
						latestEcjCompilerVersionConstantCached = (Long) f.get(null);
					}
				}
			} catch (Exception ignore) {}
		}
		
		if (highestVersionSoFar > 6 && !ecjSupportsJava7Features()) {
			latestEcjCompilerVersionConstantCached = ClassFileConstants.JDK1_6;
		}
		return latestEcjCompilerVersionConstantCached;
	}
	
	private static int ecjCompilerVersionCached = -1;
	public static int getEcjCompilerVersion() {
		if (ecjCompilerVersionCached >= 0) return ecjCompilerVersionCached;
		
		for (Field f : CompilerOptions.class.getDeclaredFields()) {
			try {
				if (f.getName().startsWith("VERSION_1_")) {
					ecjCompilerVersionCached = Math.max(ecjCompilerVersionCached, Integer.parseInt(f.getName().substring("VERSION_1_".length())));
				}
			} catch (Exception ignore) {}
		}
		
		if (ecjCompilerVersionCached < 5) ecjCompilerVersionCached = 5;
		if (!ecjSupportsJava7Features()) ecjCompilerVersionCached = Math.min(6, ecjCompilerVersionCached);
		return ecjCompilerVersionCached;
	}
	
	
Certain ECJ versions that only go up to -source 6 report that they support -source 7 and even fail to error when -source 7 is applied.
We detect this and correctly say that no more than -source 6 is supported. (when this is the case, this method returns false).
/**
	 * Certain ECJ versions that only go up to -source 6 report that they support -source 7 and even fail to error when -source 7 is applied.
	 * We detect this and correctly say that no more than -source 6 is supported. (when this is the case, this method returns false).
	 */
	private static boolean ecjSupportsJava7Features() {
		try {
			TryStatement.class.getDeclaredField("resources");
			return true;
		} catch (NoSuchFieldException e) {
			return false;
		}
	}
}