/*
 * 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.serializer;

import java.io.*;
import java.net.*;
import java.util.*;

import org.apache.juneau.*;
import org.apache.juneau.internal.*;

/**
 * Simple wrapper around a standard {@link Writer} with additional methods.
 *
 * <p>
 * Modeled after the Java ProcessBuilder class so that you can chain commands to reduce the need for string
 * concatenation for performance reasons.
 *
 * <h5 class='section'>Example:</h5>
 * <p class='bjava'>
 *    <jv>writer</jv>.append(<js>"foo"</js>).nl().i(5).append(<js>"bar"</js>);
 * </p>
 *
 * <h5 class='section'>See Also:</h5><ul>
 *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/SerializersAndParsers">Serializers and Parsers</a>
 * </ul>
 */
public class SerializerWriter extends Writer {

   /** The underlying writer. */
   protected final Writer out;

   /** Use-whitespace flag. */
   protected final boolean useWhitespace;

   /** Max indentation levels. */
   protected final int maxIndent;

   /** Trim strings flag. */
   protected final boolean trimStrings;

   /** The quote character being used by this writer. */
   protected final char quoteChar;

   /** The URI resolver of the request. */
   protected final UriResolver uriResolver;

   /**
    * @param out The writer being wrapped.
    * @param useWhitespace
    *    If <jk>true</jk>, calling {@link #cr(int)} will create an indentation and calling {@link #s()} will write a
    *    space character.
    * @param maxIndent The maximum indentation level.
    * @param trimStrings If <jk>true</jk>, strings should be trimmed before they're serialized.
    * @param quoteChar The character to write when {@link #q()} is called.
    * @param uriResolver The URI resolver for resolving URIs to absolute or root-relative form.
    */
   public SerializerWriter(Writer out, boolean useWhitespace, int maxIndent, boolean trimStrings, char quoteChar, UriResolver uriResolver) {
      this.out = out;
      this.useWhitespace = useWhitespace;
      this.maxIndent = maxIndent;
      this.trimStrings = trimStrings;
      this.quoteChar = quoteChar;
      this.uriResolver = uriResolver;
   }

   /**
    * Copy Constructor
    *
    * @param w Writer being copied.
    */
   public SerializerWriter(SerializerWriter w) {
      this.out = w.out;
      this.useWhitespace = w.useWhitespace;
      this.maxIndent = w.maxIndent;
      this.trimStrings = w.trimStrings;
      this.quoteChar = w.quoteChar;
      this.uriResolver = w.uriResolver;
   }

   /**
    * Performs a carriage return.
    *
    * <p>
    * Adds a newline and the specified number of tabs (if the {@code useWhitespace} setting is enabled) to the output.
    *
    * @param depth The indentation.
    * @return This object.
    */
   public SerializerWriter cr(int depth) {
      if (useWhitespace && depth <= maxIndent)
         return nl(depth).i(depth);
      return this;
   }

   /**
    * Performs a carriage return at the end of a line.
    *
    * <p>
    * Adds a newline and the specified number of tabs (if the {@code useWhitespace} setting is enabled) to the output.
    *
    * @param depth The indentation.
    * @return This object.
    */
   public SerializerWriter cre(int depth) {
      if (useWhitespace && depth <= maxIndent-1)
         return nl(depth).i(depth);
      return this;
   }

   /**
    * Writes an indent (if the {@code useWhitespace} setting is enabled), followed by text, followed by a newline
    * (if the {@code useWhitespace} setting is enabled).
    *
    * @param indent The number of tabs to indent.
    * @param value The text to write.
    * @return This object.
    */
   public SerializerWriter appendln(int indent, String value) {
      return append(indent, true, value);
   }

   /**
    * Writes the specified text followed by a newline (if the {@code useWhitespace} setting is enabled).
    *
    * @param value The text to write.
    * @return This object.
    */
   public SerializerWriter appendln(String value) {
      return append(0, true, value);
   }

   /**
    * Writes an indent (if the {@code useWhitespace} setting is enabled), followed by text.
    *
    * @param indent The number of tabs to indent.
    * @param value The text to write.
    * @return This object.
    */
   public SerializerWriter append(int indent, String value) {
      return append(indent, false, value);
   }

   /**
    * Writes an indent (if the {@code useWhitespace} setting is enabled), followed by text.
    *
    * @param indent The number of tabs to indent.
    * @param value The character to write.
    * @return This object.
    */
   public SerializerWriter append(int indent, char value) {
      return i(indent).w(value);
   }

   /**
    * Writes an indent (if the {@code useWhitespace} setting is enabled), followed by text, optionally followed by a
    * newline (if the {@code useWhitespace} setting is enabled).
    *
    * @param indent The number of tabs to indent.
    * @param newline If <jk>true</jk>, then a newline is written.
    * @param value The text to write.
    * @throws IOException If a problem occurred trying to write to the writer.
    * @return This object.
    */
   private SerializerWriter append(int indent, boolean newline, String value) {

      if (value == null)
         return this;

      // If text contains newlines, we break it up into lines and indent them separately.
      if (value.indexOf('\n') != -1 && useWhitespace && indent <= maxIndent) {
         for (StringTokenizer st = new StringTokenizer(value, "\n"); st.hasMoreTokens();)
            i(indent).w(st.nextToken()).w("\n");
      } else {
         i(indent).w(value);
      }

      if (newline)
         nl(indent);

      return this;
   }

   /**
    * Appends the specified object as a URI.
    *
    * <p>
    * Object is converted to a <c>String</c> using <c>toString()</c>, so this will work on {@link URL} or
    * {@link URI} objects, or any other type that returns a URI via it's <c>toString()</c> method.
    *
    * <p>
    * The URI is resolved based on the {@link Serializer.Builder#uriRelativity(UriRelativity)} and
    * {@link Serializer.Builder#uriResolution(UriResolution)} settings and the {@link UriContext} that's part of the
    * session.
    *
    * @param value The URI to serialize.
    * @return This object.
    */
   public SerializerWriter appendUri(Object value) {
      uriResolver.append(this, value);
      return this;
   }

   /**
    * Appends the specified characters to this writer.
    *
    * @param value The characters to append to this writer.
    * @return This object.
    */
   public SerializerWriter append(char[] value) {
      for (char c : value)
         w(c);
      return this;
   }

   /**
    * Adds a whitespace character to the output if the {@code useWhitespace} setting is enabled.
    *
    * @return This object.
    */
   public SerializerWriter s() {
      if (useWhitespace)
         w(' ');
      return this;
   }

   /**
    * Adds the quote character specified by the {@code quoteChar} setting to the output.
    *
    * @return This object.
    */
   public SerializerWriter q() {
      w(quoteChar);
      return this;
   }

   /**
    * Writes an indent to the writer if the {@code useWhitespace} setting is enabled.
    *
    * @param indent The number of tabs to indent.
    * @return This object.
    */
   public SerializerWriter i(int indent) {
      if (useWhitespace && indent <= maxIndent)
         for (int i = 0; i < indent; i++)
            w('\t');
      return this;
   }

   /**
    * Writes an end-of-line indent to the writer if the {@code useWhitespace} setting is enabled.
    *
    * @param indent The number of tabs to indent.
    * @return This object.
    */
   public SerializerWriter ie(int indent) {
      if (useWhitespace && indent <= maxIndent-1)
         for (int i = 0; i < indent; i++)
            w('\t');
      return this;
   }

   /**
    * Writes a newline to the writer if the {@code useWhitespace} setting is enabled.
    *
    * @param indent The current indentation level.
    * @return This object.
    */
   public SerializerWriter nl(int indent) {
      if (useWhitespace && indent <= maxIndent)
         w('\n');
      return this;
   }

   /**
    * Writes a space if the boolean expression is <jk>true</jk> and {@code useWhitespace} is false.
    *
    * <p>
    * Intended for cases in XML where text should be separated by either a space or newline.
    * This ensures the text is separated by a space if whitespace is disabled.
    *
    * @param flag The boolean flag.
    * @return This object.
    */
   public SerializerWriter sIf(boolean flag) {
      if (flag && ! useWhitespace)
         w(' ');
      return this;
   }

   /**
    * Writes a newline to the writer if the {@code useWhitespace} setting is enabled and the boolean flag is true.
    *
    * @param flag The boolean flag.
    * @param indent The current indentation level.
    * @return This object.
    */
   public SerializerWriter nlIf(boolean flag, int indent) {
      if (flag && useWhitespace && indent <= maxIndent)
         w('\n');
      return this;
   }

   /**
    * Writes the specified text to the writer if it isn't <jk>null</jk>.
    *
    * @param value The text to write.
    * @return This object.
    */
   public SerializerWriter append(Object value) {
      w(value == null ? null : value.toString());
      return this;
   }

   /**
    * Writes the specified text to the writer if it isn't <jk>null</jk>.
    *
    * @param value The text to write.
    * @return This object.
    */
   public SerializerWriter append(String value) {
      if (value != null)
         w(value);
      return this;
   }

   /**
    * Writes the specified text to the writer if b is true.
    *
    * @param flag Boolean flag.
    * @param value The text to write.
    * @return This object.
    */
   public SerializerWriter appendIf(boolean flag, String value) {
      if (flag)
         w(value);
      return this;
   }

   /**
    * Writes the specified text to the writer if b is true.
    *
    * @param flag Boolean flag.
    * @param value The text to write.
    * @return This object.
    */
   public SerializerWriter appendIf(boolean flag, char value) {
      if (flag)
         w(value);
      return this;
   }

   /**
    * Writes the specified character to the writer.
    *
    * @param value The character to write.
    * @return This object.
    */
   public SerializerWriter w(char value) {
      try {
         out.write(value);
      } catch (IOException e) {
         throw new SerializeException(e);
      }
      return this;
   }

   /**
    * Writes the specified string to the writer.
    *
    * @param value The string to write.
    * @return This object.
    */
   public SerializerWriter w(String value) {
      try {
         out.write(value);
      } catch (IOException e) {
         throw new SerializeException(e);
      }
      return this;
   }

   //-----------------------------------------------------------------------------------------------------------------
   // Overridden methods
   //-----------------------------------------------------------------------------------------------------------------

   @Override /* Writer */
   public SerializerWriter append(char c) {
      try {
         out.write(c);
      } catch (IOException e) {
         throw new SerializeException(e);
      }
      return this;
   }

   @Override /* Writer */
   public void write(char[] cbuf, int off, int len) {
      try {
         out.write(cbuf, off, len);
      } catch (IOException e) {
         throw new SerializeException(e);
      }
   }

   @Override /* Writer */
   public void flush() throws IOException {
      out.flush();
   }

   @Override /* Writer */
   public void close() throws IOException {
      out.close();
   }
}