/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.juneau.marshall.uon;

import static org.apache.juneau.commons.utils.Shorts.*;
import static org.apache.juneau.commons.utils.SystemUtils.*;

import java.io.*;
import java.lang.reflect.*;
import java.util.*;
import java.util.concurrent.*;

import org.apache.juneau.commons.bean.*;
import org.apache.juneau.commons.collections.*;
import org.apache.juneau.commons.httppart.*;
import org.apache.juneau.marshall.*;
import org.apache.juneau.marshall.httppart.*;
import org.apache.juneau.marshall.parser.*;
import org.apache.juneau.marshall.stream.*;

/**
 * Parses UON (a notation for URL-encoded query parameter values) text into POJO models.
 *
 * <h5 class='topic'>Media types</h5>
 * <p>
 * Handles <c>Content-Type</c> types:  <bc>text/uon</bc>
 *
 * <h5 class='topic'>Description</h5>
 * <p>
 * This parser uses a state machine, which makes it very fast and efficient.
 *
 * <h5 class='figure'>Example input (Map of name/age):</h5>
 * <p class='bcode'>
 *    (name=Alice,age=30)
 * </p>
 *
 * <h5 class='figure'>Complex (nested object + array):</h5>
 * <p class='bcode'>
 *    (name=Alice,age=30,address=(street=123+Main+St,city=Boston,state=MA),tags=@(a,b,c))
 * </p>
 *
 * <h5 class='section'>Notes:</h5><ul>
 *    <li class='note'>This class is thread safe and reusable.
 * </ul>
 *
 * <h5 class='section'>See Also:</h5><ul>
 *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/UonSupport">UON</a>

 * </ul>
 */
@SuppressWarnings({
   "java:S110", // UonParser extends ReaderParser on the shared Parser base-class chain, and UonParser.Decoding subclasses it; the depth comes from that format-family design.
   "java:S1192", // Duplicated literals (argument/property names) read more clearly inline than as constants
   "java:S9149", // Per-format static factories intentionally shadow the parent's.
   "resource" // Closeable resources are owned by the caller's parser session; Eclipse JDT @Owning warning is by design.
})
public class UonParser extends ReaderParser implements HttpPartParser, UonMetaProvider, RecordReadable {

   /**
    * Builder class.
    */
   @SuppressWarnings({
      "java:S119" // 'SELF' (CRTP self-type) is intentional and clearer than a single-letter name.
   })
   public abstract static class Builder<SELF extends Builder<SELF>> extends ReaderParser.Builder<SELF> {

      private static final Cache<HashKey,UonParser> CACHE = Cache.of(HashKey.class, UonParser.class).build();

      private boolean decoding;
      private boolean validateEnd;

      /**
       * Constructor, default settings.
       */
      protected Builder() {
         consumes("text/uon");
         decoding = env("UonParser.decoding", false);
         validateEnd = env("UonParser.validateEnd", false);
      }

      /**
       * Copy constructor.
       *
       * @param copyFrom The builder to copy from.
       *    <br>Cannot be <jk>null</jk>.
       */
      protected Builder(Builder<?> copyFrom) {
         super(reqnn("copyFrom", copyFrom));
         decoding = copyFrom.decoding;
         validateEnd = copyFrom.validateEnd;
      }

      /**
       * Copy constructor.
       *
       * @param copyFrom The bean to copy from.
       *    <br>Cannot be <jk>null</jk>.
       */
      protected Builder(UonParser copyFrom) {
         super(reqnn("copyFrom", copyFrom));
         decoding = copyFrom.decoding;
         validateEnd = copyFrom.validateEnd;
      }

      @Override /* Overridden from Context.Builder<?> */
      public UonParser build() {
         return cache(CACHE).build(UonParser.class);
      }

      @Override /* Overridden from Context.Builder<?> */
      public abstract SELF copy();

      /**
       * Decode <js>"%xx"</js> sequences.
       *
       * <p>
       * When enabled, URI encoded characters will be decoded.  Otherwise it's assumed that they've already been decoded
       * before being passed to this parser.
       *
       * <h5 class='section'>Example:</h5>
       * <p class='bjava'>
       *    <jc>// Create a decoding UON parser.</jc>
       *    ReaderParser <jv>parser</jv> = UonParser.
       *       .<jsm>create</jsm>()
       *       .decoding()
       *       .build();
       *
       *  <jc>// Produces: ["foo bar", "baz quz"].</jc>
       *    String[] <jv>foo</jv> = <jv>parser</jv>.read(<js>"@(foo%20bar,baz%20qux)"</js>, String[].<jk>class</jk>);
       * </p>
       *
       * @return This object.
       */
      public SELF decoding() {
         return decoding(true);
      }

      /**
       * Same as {@link #decoding()} but allows you to explicitly specify the value.
       *
       * @param value The value for this setting.
       * @return This object.
       */
      public SELF decoding(boolean value) {
         decoding = value;
         return self();
      }

      @Override /* Overridden from Context.Builder<?> */
      public HashKey hashKey() {
         // @formatter:off
         return HashKey.of(
            super.hashKey(),
            decoding,
            validateEnd
         );
         // @formatter:on
      }


      /**
       * Validate end.
       *
       * <p>
       * When enabled, 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='bjava'>
       *    <jc>// Create a parser using strict mode.</jc>
       *    ReaderParser <jv>parser</jv> = UonParser.
       *       .<jsm>create</jsm>()
       *       .validateEnd()
       *       .build();
       *
       *    <jc>// Should fail because input has multiple POJOs.</jc>
       *    String <jv>in</jv> = <js>"(foo=bar)(baz=qux)"</js>;
       *    MyBean <jv>myBean</jv> = <jv>parser</jv>.read(<jv>in</jv>, MyBean.<jk>class</jk>);
       * </p>
       *
       * @return This object.
       */
      public SELF validateEnd() {
         return validateEnd(true);
      }

      /**
       * Same as {@link #validateEnd()} but allows you to explicitly specify the value.
       *
       * @param value The value for this setting.
       * @return This object.
       */
      public SELF validateEnd(boolean value) {
         validateEnd = value;
         return self();
      }
   }

   /**
    * Concrete default builder leaf for the non-subclassed {@link UonParser#create()} / {@link UonParser#copy()} path.
    */
   public static final class DefaultBuilder extends Builder<DefaultBuilder> {

      DefaultBuilder() {}

      DefaultBuilder(UonParser copyFrom) {
         super(copyFrom);
      }

      DefaultBuilder(Builder<?> copyFrom) {
         super(copyFrom);
      }

      @Override /* Overridden from Context.Builder<?> */
      public DefaultBuilder copy() {
         return new DefaultBuilder(this);
      }
   }

   /** Default parser, decoding. */
   public static class Decoding extends UonParser {

      /**
       * Constructor.
       *
       * @param builder The builder for this object.
       */
      public Decoding(Builder<?> builder) {
         super(builder.decoding());
      }
   }

   /** Reusable instance of {@link UonParser}, all default settings. */
   public static final UonParser DEFAULT = new UonParser(create());
   /** Reusable instance of {@link UonParser} with decodeChars set to true. */
   public static final UonParser DEFAULT_DECODING = new UonParser.Decoding(create());

   /**
    * Creates a new builder for this object.
    *
    * @return A new builder.
    */
   @SuppressWarnings({
      "java:S1452" // Builder<?> wildcard return intentional; callers chain via fluent API without needing the concrete type
   })
   public static Builder<?> create() {
      return new DefaultBuilder();
   }

   protected final boolean decoding;
   protected final boolean validateEnd;

   private final Map<BeanPropertyMeta,UonBeanPropertyMeta> uonBeanPropertyMetas = new ConcurrentHashMap<>();
   private final Map<ClassMeta<?>,UonClassMeta> uonClassMetas = new ConcurrentHashMap<>();

   /**
    * Constructor.
    *
    * @param builder The builder for this object.
    */
   public UonParser(Builder<?> builder) {
      super(builder);
      decoding = builder.decoding;
      validateEnd = builder.validateEnd;
   }

   @Override /* Overridden from Context */
   public Builder<?> copy() {
      return new DefaultBuilder(this);
   }

   @Override /* Overridden from Context */
   public UonParserSession.Builder<?> createSession() {
      return UonParserSession.create(this);
   }

   @Override
   public <T> ClassMeta<T> getClassMeta(Class<T> c) {
      return getMarshallingContext().getClassMeta(c);
   }

   @Override
   public <T> ClassMeta<T> getClassMeta(Type t, Type...args) {
      return getMarshallingContext().getClassMeta(t, args);
   }

   @Override /* Overridden from HttpPartParser */
   public UonParserSession getPartSession() { return UonParserSession.create(this).build(); }

   @Override /* Overridden from Context */
   public UonParserSession getSession() { return createSession().build(); }

   /**
    * Convenience delegator that opens a whole-value {@link RecordReader} over the input using
    * <b>default session arguments</b> (mirrors {@link #read(Object, Class)}).
    *
    * <p>
    * The real implementation lives on {@link UonParserSession#readRecords(Object)}.  Callers
    * that need request-derived configuration (locale, timezone, schema, swaps) should call
    * {@link #createSession()} and invoke {@link UonParserSession#readRecords(Object)} on the
    * built session instead.
    *
    * @param input The input.
    * @return A new {@link RecordReader} cursor.
    * @throws IOException If a problem occurred opening the underlying input.
    */
   @Override /* RecordReadable */
   public RecordReader readRecords(Object input) throws IOException {
      return getSession().readRecords(input);
   }

   @Override /* RecordReadable */
   public boolean isRecordStreaming() {
      return false;
   }

   @Override /* Overridden from UonMetaProvider */
   public UonBeanPropertyMeta getUonBeanPropertyMeta(BeanPropertyMeta bpm) {
      if (bpm == null)
         return UonBeanPropertyMeta.DEFAULT;
      return uonBeanPropertyMetas.computeIfAbsent(bpm, k -> new UonBeanPropertyMeta(k.getDelegateFor(), this));
   }

   @Override /* Overridden from UonMetaProvider */
   public UonClassMeta getUonClassMeta(ClassMeta<?> cm) {
      return uonClassMetas.computeIfAbsent(cm, k -> new UonClassMeta(k, this));
   }

   /**
    * Converts the specified input to the specified class type.
    *
    * @param <T> The POJO type to transform the input into.
    * @param partType The part type being parsed.
    * @param schema
    *    Schema information about the part.
    *    <br>May be <jk>null</jk>.
    *    <br>Not all part parsers use the schema information.
    * @param in The input being parsed.
    * @param toType The POJO type to transform the input into.
    * @return The parsed value.
    * @throws ParseException Malformed input encountered.
    * @throws SchemaValidationException If the input or resulting HTTP part object fails schema validation.
    */
   public <T> T read(HttpPartType partType, HttpPartSchema schema, String in, Class<T> toType) throws ParseException, SchemaValidationException {
      return getPartSession().read(partType, schema, in, getClassMeta(toType));
   }

   /**
    * Converts the specified input to the specified class type.
    *
    * @param <T> The POJO type to transform the input into.
    * @param partType The part type being parsed.
    * @param schema
    *    Schema information about the part.
    *    <br>May be <jk>null</jk>.
    *    <br>Not all part parsers use the schema information.
    * @param in The input being parsed.
    * @param toType The POJO type to transform the input into.
    * @return The parsed value.
    * @throws ParseException Malformed input encountered.
    * @throws SchemaValidationException If the input or resulting HTTP part object fails schema validation.
    */
   public <T> T read(HttpPartType partType, HttpPartSchema schema, String in, ClassMeta<T> toType) throws ParseException, SchemaValidationException {
      return getPartSession().read(partType, schema, in, toType);
   }

   /**
    * Converts the specified input to the specified class type.
    *
    * @param <T> The POJO type to transform the input into.
    * @param partType The part type being parsed.
    * @param schema
    *    Schema information about the part.
    *    <br>May be <jk>null</jk>.
    *    <br>Not all part parsers use the schema information.
    * @param in The input being parsed.
    * @param toType The POJO type to transform the input into.
    * @param toTypeArgs The generic type arguments of the POJO type to transform the input into.
    * @return The parsed value.
    * @throws ParseException Malformed input encountered.
    * @throws SchemaValidationException If the input or resulting HTTP part object fails schema validation.
    */
   public <T> T read(HttpPartType partType, HttpPartSchema schema, String in, Type toType, Type...toTypeArgs) throws ParseException, SchemaValidationException {
      return getPartSession().read(partType, schema, in, getClassMeta(toType, toTypeArgs));
   }

   /**
    * Decode <js>"%xx"</js> sequences enabled
    *
    * @see Builder#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; }

   /**
    * Validate end enabled.
    *
    * @see Builder#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; }

   @Override /* Overridden from ReaderParser */
   protected FluentMap<String,Object> properties() {
      return super.properties()
         .a("decoding", decoding)
         .a("validateEnd", validateEnd);
   }
}