/**
* Copyright (c) 2013 Puppet Labs, Inc. and other contributors, as listed below.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Puppet Labs
*/
package com.puppetlabs.geppetto.forge.util;
import java.io.File;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.puppetlabs.geppetto.forge.FilePosition;
import org.codehaus.jackson.JsonFactory;
import org.codehaus.jackson.JsonLocation;
import org.codehaus.jackson.JsonParseException;
import org.codehaus.jackson.JsonParser;
import org.codehaus.jackson.JsonToken;
public class JsonPositionalParser {
public static class JArray extends JElement {
private final List<JElement> elements;
JArray(Object sourceRef, int[] pos, List<JElement> elements) {
super(sourceRef, pos);
this.elements = elements;
}
@Override
public List<Object> getValue() {
int top = elements.size();
ArrayList<Object> values = new ArrayList<Object>(top);
for(int idx = 0; idx < top; ++idx)
values.add(elements.get(idx).getValue());
return values;
}
public List<JElement> getValues() {
return elements;
}
}
public static abstract class JElement implements FilePosition {
private final int offset;
private final int length;
private final int line;
private final File file;
JElement(Object sourceRef, int[] pos) {
this.file = (File) sourceRef;
this.line = pos[0];
this.offset = pos[1];
this.length = pos[2];
}
public File getFile() {
return file;
}
public int getLength() {
return length;
}
public int getLine() {
return line;
}
public int getOffset() {
return offset;
}
public abstract Object getValue();
public String toStringOrNull() {
return null;
}
}
public static class JEntry extends JElement {
private final String key;
private final JElement value;
JEntry(Object sourceRef, int[] pos, String key, JElement value) {
super(sourceRef, pos);
this.key = key;
this.value = value;
}
public JElement getElement() {
return value;
}
public String getKey() {
return key;
}
@Override
public Object getValue() {
return value == null
? null
: value.getValue();
}
}
public static class JObject extends JElement {
private final List<JEntry> entries;
JObject(Object sourceRef, int[] pos, List<JEntry> entries) {
super(sourceRef, pos);
this.entries = entries;
}
public List<JEntry> getEntries() {
return entries;
}
@Override
public Map<String, Object> getValue() {
int idx = entries.size();
Map<String, Object> map = new HashMap<String, Object>(idx);
while(--idx >= 0) {
JEntry entry = entries.get(idx);
map.put(entry.getKey(), entry.getValue());
}
return map;
}
}
public static class JPrimitive extends JElement {
private final Object value;
JPrimitive(Object sourceRef, int[] pos, Object value) {
super(sourceRef, pos);
this.value = value;
}
@Override
public Object getValue() {
return value;
}
@Override
public String toStringOrNull() {
return value instanceof String
? (String) value
: null;
}
}
static class JsonExtFactory extends JsonFactory {
public JsonParser createJsonParser(File f, Reader reader) throws IOException, JsonParseException {
return _createJsonParser(reader, _createContext(f, true));
}
}
private JsonParser jp;
private String content;
private int[] adjustPosition(int line, int offset, int length) {
int top = content.length();
++length;
while(offset < top) {
char c = content.charAt(offset);
if(!(c == ',' || Character.isWhitespace(c)))
break;
++offset;
--length;
if(c == '\n')
++line;
}
return new int[] { line, offset, length };
}
public JElement parse(File file, String content) throws JsonParseException, IOException {
JsonExtFactory jsonFactory = new JsonExtFactory();
this.content = content;
jp = jsonFactory.createJsonParser(file, new StringReader(content));
JsonToken token = jp.nextToken();
if(token == JsonToken.NOT_AVAILABLE)
return null;
return parseValue(token);
}
private JArray parseArray() throws JsonParseException, IOException {
JsonLocation loc = jp.getTokenLocation();
long startPos = loc.getCharOffset();
int line = loc.getLineNr();
List<JElement> values = new ArrayList<JElement>();
for(;;) {
JsonToken token = jp.nextToken();
if(token == JsonToken.END_ARRAY) {
int[] pos = adjustPosition(
line, (int) startPos, (int) (jp.getCurrentLocation().getCharOffset() - startPos));
return new JArray(loc.getSourceRef(), pos, values);
}
values.add(parseValue(token));
}
}
private JEntry parseField() throws JsonParseException, IOException {
JsonLocation loc = jp.getTokenLocation();
long startPos = loc.getCharOffset();
int line = loc.getLineNr();
String key = jp.getCurrentName();
JElement value = parseValue(jp.nextToken());
// We get weird positions from the parser that includes whitespace etc. We adjust
// that here
int[] pos = adjustPosition(line, (int) startPos, (int) (jp.getCurrentLocation().getCharOffset() - startPos));
return new JEntry(loc.getSourceRef(), pos, key, value);
}
private JObject parseObject() throws JsonParseException, IOException {
JsonLocation loc = jp.getTokenLocation();
long startPos = loc.getCharOffset();
int line = loc.getLineNr();
List<JEntry> entries = new ArrayList<JEntry>();
for(;;) {
switch(jp.nextToken()) {
case END_OBJECT:
int[] pos = adjustPosition(
line, (int) startPos, (int) (jp.getCurrentLocation().getCharOffset() - startPos));
return new JObject(loc.getSourceRef(), pos, entries);
case FIELD_NAME:
entries.add(parseField());
continue;
default:
throw new JsonParseException("Field name expected", jp.getTokenLocation());
}
}
}
private JElement parseValue(JsonToken token) throws JsonParseException, IOException {
JsonLocation loc = jp.getCurrentLocation();
long startPos = loc.getCharOffset();
int line = loc.getLineNr();
switch(token) {
case START_ARRAY:
return parseArray();
case START_OBJECT:
return parseObject();
case VALUE_FALSE:
case VALUE_NULL:
case VALUE_TRUE:
case VALUE_NUMBER_FLOAT:
case VALUE_NUMBER_INT:
case VALUE_STRING:
Object value = null;
switch(token) {
case VALUE_FALSE:
value = Boolean.FALSE;
break;
case VALUE_TRUE:
value = Boolean.TRUE;
break;
case VALUE_NUMBER_FLOAT:
value = jp.getDoubleValue();
break;
case VALUE_NUMBER_INT:
value = jp.getLongValue();
break;
case VALUE_STRING:
value = jp.getText();
}
long endPos = jp.getCurrentLocation().getCharOffset();
int[] pos = adjustPosition(line, (int) startPos, (int) (endPos - startPos));
return new JPrimitive(loc.getSourceRef(), pos, value);
default:
throw new JsonParseException("Value expected", loc);
}
}
}