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/*
* Carrot2 project.
*
* Copyright (C) 2002-2020, Dawid Weiss, Stanisław Osiński.
* All rights reserved.
*
* Refer to the full license file "carrot2.LICENSE"
* in the root folder of the repository checkout or at:
* https://www.carrot2.org/carrot2.LICENSE
*/
package org.carrot2.attrs;
import java.util.*;
import java.util.function.Function;
import java.util.stream.Collectors;
import org.carrot2.internal.nanojson.JsonWriter;
/**
* Static utility methods for converting between {@link AcceptingVisitor} and {@link Map}s.
*
* @see #extract(AcceptingVisitor)
* @see #populate(AcceptingVisitor, Map)
* @see #toMap(AcceptingVisitor)
* @see #fromMap(Class, Map, Function)
*/
public final class Attrs {
private static final String KEY_WRAPPED = "@value";
static final String KEY_TYPE = "@type";
private static class Wrapper implements AcceptingVisitor {
AttrObject value =
AttrObject.builder(AcceptingVisitor.class).defaultValue(() -> null);
@Override
public void accept(AttrVisitor visitor) {
visitor.visit(KEY_WRAPPED, value);
}
}
/**
* Convert an instance to a map. The output map will contain the type of the instance and can be
* recreated with {@link #fromMap(Class, Map)}.
*
* This method uses default class name mappings.
*
* @see #fromMap(Class, Map)
*/
public static Map toMap(AcceptingVisitor composite) {
return toMap(composite, AliasMapper.SPI_DEFAULTS::toName);
}
/**
* Convert an instance to a map. The output map will contain the type of the instance and can be
* recreated with {@link #fromMap(Class, Map)}.
*
* @param classToName Class to name mapping provider.
* @see #fromMap(Class, Map, Function)
*/
public static Map toMap(
AcceptingVisitor composite, Function classToName) {
LinkedHashMap map = new LinkedHashMap<>();
Wrapper wrapped = new Wrapper();
wrapped.value.set(composite);
wrapped.accept(new ToMapVisitor(map, classToName));
@SuppressWarnings("unchecked")
Map sub = (Map) map.get(KEY_WRAPPED);
return sub;
}
/**
* Convert a map to an instance of a class.
*
* This method uses default class name mappings.
*
* @see #toMap(AcceptingVisitor)
*/
public static E fromMap(
Class clazz, Map map) {
return fromMap(clazz, map, AliasMapper.SPI_DEFAULTS::fromName);
}
/**
* Convert a map to an instance of a class.
*
* @param nameToClass Name to new class instance supplier.
* @see #toMap(AcceptingVisitor)
*/
public static E fromMap(
Class clazz, Map map, Function nameToClass) {
Wrapper wrapper =
populate(new Wrapper(), Collections.singletonMap(KEY_WRAPPED, map), nameToClass);
return safeCast(wrapper.value.get(), KEY_WRAPPED, clazz);
}
/**
* Extracts just the attributes of an instance (no top-level type information is preserved).
*
* @param classToName Class to name mapping provider.
*/
public static Map extract(
AcceptingVisitor instance, Function classToName) {
Map attrs = toMap(instance, classToName);
attrs.remove(KEY_TYPE);
return attrs;
}
/**
* Extracts just the attributes of an instance (no top-level type information is preserved).
*
* This method uses default class name mappings.
*/
public static Map extract(AcceptingVisitor instance) {
return extract(instance, AliasMapper.SPI_DEFAULTS::toName);
}
/**
* Populates a given instance with the values from the map.
*
* This method uses default class name mappings.
*
* @see #extract(AcceptingVisitor)
*/
public static E populate(E instance, Map map) {
return populate(instance, map, AliasMapper.SPI_DEFAULTS::fromName);
}
/**
* Populates a given instance with the values from the map.
*
* @param nameToClass Name to new class instance supplier.
* @see #extract(AcceptingVisitor, Function)
*/
public static E populate(
E instance, Map map, Function nameToClass) {
FromMapVisitor visitor = new FromMapVisitor(map, nameToClass);
instance.accept(visitor);
visitor.ensureKeysConsumed();
return instance;
}
/**
* Converts an instance (recursively) to JSON.
*
* This method uses default class name mappings.
*/
public static String toJson(AcceptingVisitor composite, ClassNameMapper classNameMapper) {
return toJson(composite, classNameMapper::toName);
}
/**
* Converts an instance (recursively) to JSON.
*
* @param classToName Class to name mapping provider.
*/
public static String toJson(AcceptingVisitor composite, Function classToName) {
Map asMap = toMap(composite, classToName);
return JsonWriter.indent(" ").string().object(asMap).done();
}
private static class FromMapVisitor implements AttrVisitor {
private final Map map;
private final Function classToInstance;
private FromMapVisitor(Map map, Function classToInstance) {
this.map = new LinkedHashMap<>(Objects.requireNonNull(map));
this.classToInstance = classToInstance;
}
@Override
public void visit(String key, AttrInteger attr) {
if (map.containsKey(key)) {
Number value = safeCast(map.remove(key), key, Number.class);
if (value != null) {
if (Double.compare(value.doubleValue(), value.longValue()) != 0) {
throw new IllegalArgumentException(
String.format(
Locale.ROOT,
"Value at key '%s' should be an integer but encountered floating point value: '%s'",
key,
toDebugString(value)));
}
long v = value.longValue();
if ((int) v != v) {
throw new IllegalArgumentException(
String.format(
Locale.ROOT,
"Value at key '%s' should be an integer but is out of integer range: '%s'",
key,
toDebugString(value)));
}
attr.set((int) v);
} else {
attr.set(null);
}
}
}
@Override
public void visit(String key, AttrDouble attr) {
if (map.containsKey(key)) {
Number value = safeCast(map.remove(key), key, Number.class);
attr.set(value == null ? null : value.doubleValue());
}
}
@Override
public void visit(String key, AttrBoolean attr) {
if (map.containsKey(key)) {
attr.set(safeCast(map.remove(key), key, Boolean.class));
}
}
@Override
public void visit(String key, AttrObject attr) {
if (map.containsKey(key)) {
@SuppressWarnings("unchecked")
Map submap = safeCast(this.map.remove(key), key, Map.class);
if (submap == null) {
attr.set(null);
} else {
submap = new LinkedHashMap<>(submap);
T value;
if (submap.containsKey(KEY_TYPE)) {
String valueType = safeCast(submap.remove(KEY_TYPE), KEY_TYPE, String.class);
value = safeCast(classToInstance.apply(valueType), key, attr.getInterfaceClass());
} else {
value = notNull(key, attr.newDefaultValue());
}
FromMapVisitor visitor = new FromMapVisitor(submap, classToInstance);
value.accept(visitor);
visitor.ensureKeysConsumed();
attr.set(value);
}
}
}
@Override
public void visit(String key, AttrObjectArray attr) {
if (map.containsKey(key)) {
Object value = map.remove(key);
if (value == null) {
attr.set(null);
} else {
List array;
if (value instanceof List) {
array = (List) value;
} else if (value instanceof Object[]) {
array = Arrays.asList((Object[]) value);
} else {
throw new IllegalArgumentException(
String.format(
Locale.ROOT,
"Value at key '%s' should be a list or an array of objects of type '%s' but is an instance of '%s': '%s'",
key,
attr.getInterfaceClass().getSimpleName(),
value.getClass().getSimpleName(),
toDebugString(value)));
}
List entries =
array.stream()
.map(
entry -> {
@SuppressWarnings("unchecked")
Map submap = safeCast(entry, key, Map.class);
if (submap == null) {
return null;
} else {
submap = new LinkedHashMap<>(submap);
T entryValue;
if (submap.containsKey(KEY_TYPE)) {
String entryValueType =
safeCast(submap.remove(KEY_TYPE), KEY_TYPE, String.class);
entryValue =
safeCast(
classToInstance.apply(entryValueType),
key,
attr.getInterfaceClass());
} else {
entryValue = notNull(key, attr.newDefaultEntryValue());
}
FromMapVisitor visitor = new FromMapVisitor(submap, classToInstance);
entryValue.accept(visitor);
visitor.ensureKeysConsumed();
return entryValue;
}
})
.collect(Collectors.toList());
attr.set(entries);
}
}
}
@Override
public > void visit(String key, AttrEnum attr) {
if (map.containsKey(key)) {
Object value = map.remove(key);
if (value == null) {
attr.set((T) null);
} else if (value instanceof String) {
try {
attr.set(Enum.valueOf(attr.enumClass(), (String) value));
} catch (IllegalArgumentException e) {
throw new IllegalArgumentException(
String.format(
Locale.ROOT,
"Value at key '%s' should be an enum constant of class '%s', but no such constant exists: '%s' (available constants: %s)",
key,
attr.enumClass().getSimpleName(),
toDebugString(value),
EnumSet.allOf(attr.enumClass())));
}
} else {
attr.set(safeCast(value, key, attr.enumClass()));
}
}
}
@Override
public void visit(String key, AttrStringArray attr) {
if (map.containsKey(key)) {
Object value = map.remove(key);
if (value instanceof List) {
// Attempt to convert List to String[].
attr.set(
((List) value)
.stream().map(ob -> safeCast(ob, key, String.class)).toArray(String[]::new));
} else {
attr.set(safeCast(value, key, String[].class));
}
}
}
@Override
public void visit(String key, AttrString attr) {
if (map.containsKey(key)) {
attr.set(safeCast(map.remove(key), key, String.class));
}
}
private T notNull(String key, T value) {
if (value == null) {
throw new RuntimeException(
String.format(
Locale.ROOT, "Default instance supplier returned null for key: '%s'", key));
}
return value;
}
public void ensureKeysConsumed() {
if (!map.isEmpty()) {
throw new IllegalArgumentException(
String.format(
Locale.ROOT,
"Unrecognized extra attributes with keys: %s",
String.join(", ", map.keySet())));
}
}
}
static T safeCast(Object value, String key, Class clazz) {
if (value == null) {
return null;
} else {
if (!clazz.isInstance(value)) {
throw new IllegalArgumentException(
String.format(
Locale.ROOT,
"Value at key '%s' should be an instance of '%s', but encountered class '%s': '%s'",
key,
clazz.getSimpleName(),
value.getClass().getSimpleName(),
toDebugString(value)));
}
return clazz.cast(value);
}
}
static String toDebugString(Object value) {
if (value == null) {
return "[null]";
} else if (value instanceof Object[]) {
return Arrays.deepToString(((Object[]) value));
} else {
return Objects.toString(value);
}
}
private static class ToMapVisitor implements AttrVisitor {
private final Map map;
private final Function objectToClass;
public ToMapVisitor(Map map, Function objectToClass) {
this.map = map;
this.objectToClass = objectToClass;
}
@Override
public void visit(String key, AttrInteger attr) {
ensureNoExistingKey(map, key);
map.put(key, attr.get());
}
@Override
public void visit(String key, AttrDouble attr) {
ensureNoExistingKey(map, key);
map.put(key, attr.get());
}
@Override
public void visit(String key, AttrBoolean attr) {
ensureNoExistingKey(map, key);
map.put(key, attr.get());
}
@Override
public void visit(String key, AttrObject attr) {
ensureNoExistingKey(map, key);
AcceptingVisitor currentValue = attr.get();
if (currentValue != null) {
Map submap = new LinkedHashMap<>();
if (!attr.isDefaultClass(currentValue)) {
submap.put(KEY_TYPE, objectToClass.apply(currentValue));
}
currentValue.accept(new ToMapVisitor(submap, objectToClass));
map.put(key, submap);
} else {
map.put(key, null);
}
}
@Override
public void visit(String key, AttrObjectArray attr) {
ensureNoExistingKey(map, key);
List values = attr.get();
if (values != null) {
Object[] array =
values.stream()
.map(
currentValue -> {
Map submap = new LinkedHashMap<>();
if (!attr.isDefaultClass(currentValue)) {
submap.put(KEY_TYPE, objectToClass.apply(currentValue));
}
currentValue.accept(new ToMapVisitor(submap, objectToClass));
return submap;
})
.toArray();
map.put(key, array);
} else {
map.put(key, null);
}
}
@Override
public > void visit(String key, AttrEnum attr) {
ensureNoExistingKey(map, key);
map.put(key, attr.get() != null ? attr.get().name() : null);
}
@Override
public void visit(String key, AttrStringArray attr) {
ensureNoExistingKey(map, key);
map.put(key, attr.get());
}
@Override
public void visit(String key, AttrString attr) {
ensureNoExistingKey(map, key);
map.put(key, attr.get());
}
private void ensureNoExistingKey(Map map, String key) {
if (map.containsKey(key)) {
throw new RuntimeException(
String.format(
Locale.ROOT,
"Could not serialize key '%s' because it already exists in the map with value: %s",
key,
map.get(key)));
}
}
}
}