/*
 * Copyright (C) 2009-2019 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.core;

import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

Library of types, which can be used to look up potential matching types. For example, if you put foo.Spork and bar.Spork into the library, and then ask for all compatible types given the type Spork, you'll get both of them, but you'll only get the one if you ask for compatible types given foo.Spork. 
 When adding foo.Spork, that FQN (Fully Qualified Name) will be returned as an option for any of these queries: 
foo.Spork
Spork
foo.*
/**
 * Library of types, which can be used to look up potential matching types.
 * 
 * For example, if you put {@code foo.Spork} and {@code bar.Spork} into the library, and then ask for
 * all compatible types given the type {@code Spork}, you'll get both of them, but you'll only
 * get the one if you ask for compatible types given {@code foo.Spork}.
 * <p>
 * When adding {@code foo.Spork}, that FQN (Fully Qualified Name) will be returned as an option for any of these queries:
 * <ul><li>foo.Spork</li><li>Spork</li><li>foo.*</li></ul>
 */
public class TypeLibrary {
	private final Map<String, Object> unqualifiedToQualifiedMap; // maps to usually a string, but could be a string array in aliasing cases.
	private final String unqualified, qualified;
	private boolean locked;
	
	public TypeLibrary() {
		unqualifiedToQualifiedMap = new HashMap<String, Object>();
		unqualified = null;
		qualified = null;
	}
	
	public TypeLibrary(TypeLibrary parent) {
		unqualifiedToQualifiedMap = new HashMap<String, Object>();
		unqualified = null;
		qualified = null;
	}
	
	public void lock() {
		this.locked = true;
	}
	
	private TypeLibrary(String fqnSingleton) {
		if (fqnSingleton.indexOf("$") != -1) {
			unqualifiedToQualifiedMap = new HashMap<String, Object>();
			unqualified = null;
			qualified = null;
			addType(fqnSingleton);
		} else {
			unqualifiedToQualifiedMap = null;
			qualified = fqnSingleton;
			int idx = fqnSingleton.lastIndexOf('.');
			if (idx == -1) {
				unqualified = fqnSingleton;
			} else {
				unqualified = fqnSingleton.substring(idx + 1);
			}
		}
		locked = true;
	}
	
	public static TypeLibrary createLibraryForSingleType(String fqnSingleton) {
		if (LombokInternalAliasing.REVERSE_ALIASES.containsKey(fqnSingleton)) {
			// Internal aliasing is a little too complex to handle with the map-less 'efficient' implementation.
			TypeLibrary tl = new TypeLibrary();
			tl.addType(fqnSingleton);
			tl.lock();
			return tl;
		}
		
		return new TypeLibrary(fqnSingleton);
	}
	
	
Add a type to the library.
Params:
fullyQualifiedTypeName – the FQN type name, such as 'java.lang.String'./**
	 * Add a type to the library.
	 * 
	 * @param fullyQualifiedTypeName the FQN type name, such as 'java.lang.String'.
	 */
	public void addType(String fullyQualifiedTypeName) {
		Collection<String> oldNames = LombokInternalAliasing.REVERSE_ALIASES.get(fullyQualifiedTypeName);
		if (oldNames != null) for (String oldName : oldNames) addType(oldName);
		
		String dotBased = fullyQualifiedTypeName.replace("$", ".");
		
		if (locked) throw new IllegalStateException("locked");
		int idx = fullyQualifiedTypeName.lastIndexOf('.');
		if (idx == -1) throw new IllegalArgumentException(
			"Only fully qualified types are allowed (types in the default package cannot be added here either)");
		String unqualified = fullyQualifiedTypeName.substring(idx + 1);
		if (unqualifiedToQualifiedMap == null) throw new IllegalStateException("SingleType library");
		
		put(unqualified.replace("$", "."), dotBased);
		put(unqualified, dotBased);
		put(fullyQualifiedTypeName, dotBased);
		put(dotBased, dotBased);
		
		int idx2 = fullyQualifiedTypeName.indexOf('$', idx + 1);
		while (idx2 != -1) {
			String unq = fullyQualifiedTypeName.substring(idx2 + 1);
			put(unq.replace("$", "."), dotBased);
			put(unq, dotBased);
			idx2 = fullyQualifiedTypeName.indexOf('$', idx2 + 1);
		}
	}
	
	
Translates an unqualified name such as 'String' to 'java.lang.String', _if_ you added 'java.lang.String' to the library via the addType method. Also returns the input if it is equal to a fully qualified name added to this type library. Returns an empty collection if it does not match any type in this type library. /**
	 * Translates an unqualified name such as 'String' to 'java.lang.String', _if_ you added 'java.lang.String' to the library via the {@code addType} method.
	 * Also returns the input if it is equal to a fully qualified name added to this type library.
	 * 
	 * Returns an empty collection if it does not match any type in this type library.
	 */
	public List<String> toQualifieds(String typeReference) {
		if (unqualifiedToQualifiedMap == null) {
			if (typeReference.equals(unqualified) || typeReference.equals(qualified)) return Collections.singletonList(qualified);
			return null;
		}
		
		Object v = unqualifiedToQualifiedMap.get(typeReference);
		if (v == null) return Collections.emptyList();
		if (v instanceof String) return Collections.singletonList((String) v);
		return Arrays.asList((String[]) v);
	}
	
	private void put(String k, String v) {
		Object old = unqualifiedToQualifiedMap.put(k, v);
		if (old == null) return;
		String[] nv;
		if (old instanceof String) {
			if (old.equals(v)) return;
			nv = new String[] {(String) old, v};
		} else {
			String[] s = (String[]) old;
			nv = new String[s.length + 1];
			System.arraycopy(s, 0, nv, 0, s.length);
			nv[s.length] = v;
		}
		unqualifiedToQualifiedMap.put(k, nv);
	}
}