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// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
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package org.apache.juneau.uon;

import java.lang.reflect.*;
import java.util.*;
import java.util.concurrent.*;

import org.apache.juneau.*;
import org.apache.juneau.annotation.*;
import org.apache.juneau.httppart.*;
import org.apache.juneau.parser.*;

/**
 * Parses UON (a notation for URL-encoded query parameter values) text into POJO models.
 *
 * <h5 class='topic'>Media types</h5>
 *
 * Handles <c>Content-Type</c> types:  <bc>text/uon</bc>
 *
 * <h5 class='topic'>Description</h5>
 *
 * This parser uses a state machine, which makes it very fast and efficient.
 */
@ConfigurableContext
public class UonParser extends ReaderParser implements HttpPartParser, UonMetaProvider, UonCommon {

	//-------------------------------------------------------------------------------------------------------------------
	// Configurable properties
	//-------------------------------------------------------------------------------------------------------------------

	static final String PREFIX = "UonParser";

	/**
	 * Configuration property: Decode <js>"%xx"</js> sequences.
	 *
	 * <h5 class='section'>Property:</h5>
	 * <ul class='spaced-list'>
	 * 	<li><b>ID:</b>  {@link org.apache.juneau.uon.UonParser#UON_decoding UON_decoding}
	 * 	<li><b>Name:</b>  <js>"UonParser.decoding.b"</js>
	 * 	<li><b>Data type:</b>  <jk>boolean</jk>
	 * 	<li><b>System property:</b>  <c>UonParser.decoding</c>
	 * 	<li><b>Environment variable:</b>  <c>UONPARSER_DECODING</c>
	 * 	<li><b>Default:</b>  <jk>false</jk> for {@link org.apache.juneau.uon.UonParser}, <jk>true</jk> for {@link org.apache.juneau.urlencoding.UrlEncodingParser}
	 * 	<li><b>Session property:</b>  <jk>false</jk>
	 * 	<li><b>Annotations:</b>
	 * 		<ul>
	 * 			<li class='ja'>{@link org.apache.juneau.uon.annotation.UonConfig#decoding()}
	 * 		</ul>
	 * 	<li><b>Methods:</b>
	 * 		<ul>
	 * 			<li class='jm'>{@link org.apache.juneau.uon.UonParserBuilder#decoding(boolean)}
	 * 			<li class='jm'>{@link org.apache.juneau.uon.UonParserBuilder#decoding()}
	 * 		</ul>
	 * </ul>
	 *
	 * <h5 class='section'>Description:</h5>
	 * <p>
	 * Specify <jk>true</jk> if URI encoded characters should be decoded, <jk>false</jk> if they've already been decoded
	 * before being passed to this parser.
	 *
	 * <h5 class='section'>Example:</h5>
	 * <p class='bcode w800'>
	 * 	<jc>// Create a decoding UON parser.</jc>
	 * 	ReaderParser p = UonParser.
	 * 		.<jsm>create</jsm>()
	 * 		.decoding()
	 * 		.build();
	 *
	 * 	<jc>// Same, but use property.</jc>
	 * 	ReaderParser p = UonParser.
	 * 		.<jsm>create</jsm>()
	 * 		.set(<jsf>UON_decoding</jsf>, <jk>true</jk>)
	 * 		.build();
	 *
	 *  <jc>// Produces: ["foo bar", "baz quz"].</jc>
	 * 	String[] foo = p.parse(<js>"@(foo%20bar,baz%20qux)"</js>, String[].<jk>class</jk>);
	 * </p>
	 */
	public static final String UON_decoding = PREFIX + ".decoding.b";

	/**
	 * Configuration property:  Validate end.
	 *
	 * <h5 class='section'>Property:</h5>
	 * <ul class='spaced-list'>
	 * 	<li><b>ID:</b>  {@link org.apache.juneau.uon.UonParser#UON_validateEnd UON_validateEnd}
	 * 	<li><b>Name:</b>  <js>"UonParser.validateEnd.b"</js>
	 * 	<li><b>Data type:</b>  <jk>boolean</jk>
	 * 	<li><b>System property:</b>  <c>UonParser.validateEnd</c>
	 * 	<li><b>Environment variable:</b>  <c>UONPARSER_VALIDATEEND</c>
	 * 	<li><b>Default:</b>  <jk>false</jk>
	 * 	<li><b>Session property:</b>  <jk>false</jk>
	 * 	<li><b>Annotations:</b>
	 * 		<ul>
	 * 			<li class='ja'>{@link org.apache.juneau.uon.annotation.UonConfig#validateEnd()}
	 * 		</ul>
	 * 	<li><b>Methods:</b>
	 * 		<ul>
	 * 			<li class='jm'>{@link org.apache.juneau.uon.UonParserBuilder#validateEnd(boolean)}
	 * 			<li class='jm'>{@link org.apache.juneau.uon.UonParserBuilder#validateEnd()}
	 * 		</ul>
	 * </ul>
	 *
	 * <h5 class='section'>Description:</h5>
	 * <p>
	 * If <jk>true</jk>, after parsing a POJO from the input, verifies that the remaining input in
	 * the stream consists of only comments or whitespace.
	 *
	 * <h5 class='section'>Example:</h5>
	 * <p class='bcode w800'>
	 * 	<jc>// Create a parser using strict mode.</jc>
	 * 	ReaderParser p = UonParser.
	 * 		.<jsm>create</jsm>()
	 * 		.validateEnd()
	 * 		.build();
	 *
	 * 	<jc>// Same, but use property.</jc>
	 * 	ReaderParser p = UonParser.
	 * 		.<jsm>create</jsm>()
	 * 		.set(<jsf>UON_validateEnd</jsf>, <jk>true</jk>)
	 * 		.build();
	 *
	 * 	<jc>// Should fail because input has multiple POJOs.</jc>
	 * 	String in = <js>"(foo=bar)(baz=qux)"</js>;
	 * 	MyBean myBean = p.parse(in, MyBean.<jk>class</jk>);
	 * </p>
	 */
	public static final String UON_validateEnd = PREFIX + ".validateEnd.b";

	//-------------------------------------------------------------------------------------------------------------------
	// Predefined instances
	//-------------------------------------------------------------------------------------------------------------------

	/** Reusable instance of {@link UonParser}, all default settings. */
	public static final UonParser DEFAULT = new UonParser(PropertyStore.DEFAULT);

	/** Reusable instance of {@link UonParser} with decodeChars set to true. */
	public static final UonParser DEFAULT_DECODING = new UonParser.Decoding(PropertyStore.DEFAULT);


	//-------------------------------------------------------------------------------------------------------------------
	// Predefined subclasses
	//-------------------------------------------------------------------------------------------------------------------

	/** Default parser, decoding. */
	public static class Decoding extends UonParser {

		/**
		 * Constructor.
		 *
		 * @param ps The property store containing all the settings for this object.
		 */
		public Decoding(PropertyStore ps) {
			super(ps.builder().set(UON_decoding, true).build());
		}
	}


	//-------------------------------------------------------------------------------------------------------------------
	// Instance
	//-------------------------------------------------------------------------------------------------------------------

	private final boolean
		decoding, validateEnd;
	private final Map<ClassMeta<?>,UonClassMeta> uonClassMetas = new ConcurrentHashMap<>();
	private final Map<BeanPropertyMeta,UonBeanPropertyMeta> uonBeanPropertyMetas = new ConcurrentHashMap<>();

	/**
	 * Constructor.
	 *
	 * @param ps
	 * 	The property store containing all the settings for this object.
	 */
	public UonParser(PropertyStore ps) {
		this(ps, "text/uon");
	}

	/**
	 * Constructor.
	 *
	 * @param ps
	 * 	The property store containing all the settings for this object.
	 * @param consumes
	 * 	The list of media types that this parser consumes (e.g. <js>"application/json"</js>, <js>"*&#8203;/json"</js>).
	 */
	public UonParser(PropertyStore ps, String...consumes) {
		super(ps, consumes);
		this.decoding = getBooleanProperty(UON_decoding, false);
		this.validateEnd = getBooleanProperty(UON_validateEnd, false);
	}

	@Override /* Context */
	public UonParserBuilder builder() {
		return new UonParserBuilder(getPropertyStore());
	}

	/**
	 * Instantiates a new clean-slate {@link UonParserBuilder} object.
	 *
	 * <p>
	 * This is equivalent to simply calling <code><jk>new</jk> UonParserBuilder()</code>.
	 *
	 * <p>
	 * Note that this method creates a builder initialized to all default settings, whereas {@link #builder()} copies
	 * the settings of the object called on.
	 *
	 * @return A new {@link UonParserBuilder} object.
	 */
	public static UonParserBuilder create() {
		return new UonParserBuilder();
	}

	/**
	 * Create a UON parser session for parsing parameter values.
	 *
	 * @return A new parser session.
	 */
	protected final UonParserSession createParameterSession() {
		return new UonParserSession(this, createDefaultSessionArgs(), false);
	}

	//-----------------------------------------------------------------------------------------------------------------
	// Entry point methods
	//-----------------------------------------------------------------------------------------------------------------

	@Override /* Parser */
	public UonParserSession createSession(ParserSessionArgs args) {
		return new UonParserSession(this, args);
	}

	@Override /* HttpPartParser */
	public UonParserSession createSession() {
		return createSession(null);
	}

	@Override /* HttpPartParser */
	public UonParserSession createPartSession(ParserSessionArgs args) {
		return new UonParserSession(this, args);
	}

	@Override /* HttpPartParser */
	public UonParserSession createPartSession() {
		return createPartSession(null);
	}

	@Override /* HttpPartParser */
	public <T> T parse(HttpPartType partType, HttpPartSchema schema, String in, Class<T> toType) throws ParseException, SchemaValidationException {
		return createPartSession().parse(partType, schema, in, toType);
	}

	@Override /* HttpPartParser */
	public <T> T parse(HttpPartType partType, HttpPartSchema schema, String in, Type toType, Type...toTypeArgs) throws ParseException, SchemaValidationException {
		return createPartSession().parse(partType, schema, in, toType, toTypeArgs);
	}

	@Override /* HttpPartParser */
	public <T> T parse(HttpPartSchema schema, String in, Class<T> toType) throws ParseException, SchemaValidationException {
		return createPartSession().parse(null, schema, in, toType);
	}

	@Override /* HttpPartParser */
	public <T> T parse(HttpPartSchema schema, String in, Type toType, Type...toTypeArgs) throws ParseException, SchemaValidationException {
		return createPartSession().parse(null, schema, in, toType, toTypeArgs);
	}

	//-----------------------------------------------------------------------------------------------------------------
	// Extended metadata
	//-----------------------------------------------------------------------------------------------------------------

	@Override /* UonMetaProvider */
	public UonClassMeta getUonClassMeta(ClassMeta<?> cm) {
		UonClassMeta m = uonClassMetas.get(cm);
		if (m == null) {
			m = new UonClassMeta(cm, this);
			uonClassMetas.put(cm, m);
		}
		return m;
	}

	@Override /* UonMetaProvider */
	public UonBeanPropertyMeta getUonBeanPropertyMeta(BeanPropertyMeta bpm) {
		if (bpm == null)
			return UonBeanPropertyMeta.DEFAULT;
		UonBeanPropertyMeta m = uonBeanPropertyMetas.get(bpm);
		if (m == null) {
			m = new UonBeanPropertyMeta(bpm.getDelegateFor(), this);
			uonBeanPropertyMetas.put(bpm, m);
		}
		return m;
	}

	//-----------------------------------------------------------------------------------------------------------------
	// Properties
	//-----------------------------------------------------------------------------------------------------------------

	/**
	 * Configuration property: Decode <js>"%xx"</js> sequences.
	 *
	 * @see #UON_decoding
	 * @return
	 * 	<jk>true</jk> if URI encoded characters should be decoded, <jk>false</jk> if they've already been decoded
	 * 	before being passed to this parser.
	 */
	protected final boolean isDecoding() {
		return decoding;
	}

	/**
	 * Configuration property:  Validate end.
	 *
	 * @see #UON_validateEnd
	 * @return
	 * 	<jk>true</jk> if after parsing a POJO from the input, verifies that the remaining input in
	 * 	the stream consists of only comments or whitespace.
	 */
	protected final boolean isValidateEnd() {
		return validateEnd;
	}

	//-----------------------------------------------------------------------------------------------------------------
	// Other methods
	//-----------------------------------------------------------------------------------------------------------------

	@Override /* Context */
	public ObjectMap toMap() {
		return super.toMap()
			.append("UonParser", new DefaultFilteringObjectMap()
				.append("decoding", decoding)
				.append("validateEnd", validateEnd)
			);
	}
}