/*
 * 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.solr.bench.generators;

import static org.apache.solr.bench.generators.SourceDSL.checkArguments;
import static org.apache.solr.bench.generators.SourceDSL.integers;

import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.Random;
import java.util.Scanner;
import java.util.SplittableRandom;
import org.apache.solr.bench.BaseBenchState;
import org.apache.solr.bench.SolrGenerate;
import org.apache.solr.bench.SolrRandomnessSource;
import org.quicktheories.core.Gen;
import org.quicktheories.core.RandomnessSource;
import org.quicktheories.impl.SplittableRandomSource;

/** The type Strings dsl. */
public class StringsDSL {

  private static final int BASIC_LATIN_LAST_CODEPOINT = 0x007E;
  private static final int BASIC_LATIN_FIRST_CODEPOINT = 0x0020;
  private static final int ASCII_LAST_CODEPOINT = 0x007F;
  private static final int LARGEST_DEFINED_BMP_CODEPOINT = 65533;

  private static final List<String> words;

  private static final int WORD_SIZE;

  static {
    // english word list via https://github.com/dwyl/english-words

    words = new ArrayList<>(1000);
    InputStream inputStream = StringsDSL.class.getClassLoader().getResourceAsStream("words.txt");
    try (Scanner scanner =
        new Scanner(Objects.requireNonNull(inputStream), StandardCharsets.UTF_8.name())) {
      while (scanner.hasNextLine()) {
        words.add(scanner.nextLine());
      }
    }
    Collections.shuffle(words, new Random(BaseBenchState.getRandomSeed()));
    WORD_SIZE = words.size();
  }

  /**
   * Word list word list generator builder.
   *
   * @return the word list generator builder
   */
  public WordListGeneratorBuilder wordList() {
    return new WordListGeneratorBuilder(
        new SolrGen<>(new WordListStringSolrGen(), String.class).describedAs("WordList Word"));
  }

  /**
   * Generates integers as Strings, and shrinks towards "0".
   *
   * @return a Source of type String
   */
  public SolrGen<String> numeric() {
    return new SolrGen<>(numericBetween(Integer.MIN_VALUE, Integer.MAX_VALUE), String.class);
  }

  /**
   * Generates integers within the interval as Strings.
   *
   * @param startInclusive - lower inclusive bound of integer domain
   * @param endInclusive - upper inclusive bound of integer domain
   * @return a Source of type String
   */
  public SolrGen<String> numericBetween(int startInclusive, int endInclusive) {
    checkArguments(
        startInclusive <= endInclusive,
        "There are no Integer values to be generated between startInclusive (%s) and endInclusive (%s)",
        startInclusive,
        endInclusive);
    return new SolrGen<>(Strings.boundedNumericStrings(startInclusive, endInclusive), String.class);
  }

  /**
   * Constructs a StringGeneratorBuilder which will build Strings composed of all defined code
   * points
   *
   * @return a StringGeneratorBuilder
   */
  public StringGeneratorBuilder allPossible() {
    return betweenCodePoints(Character.MIN_CODE_POINT, Character.MAX_CODE_POINT);
  }

  /**
   * Realistic unicode realistic unicode generator builder.
   *
   * @param minLength the min length
   * @param maxLength the max length
   * @return the realistic unicode generator builder
   */
  public RealisticUnicodeGeneratorBuilder realisticUnicode(int minLength, int maxLength) {
    return new RealisticUnicodeGeneratorBuilder(
        new SolrGen<>() {
          @Override
          public String generate(SolrRandomnessSource in) {

            int block =
                integers()
                    .between(0, blockStarts.length - 1)
                    .describedAs("Realistic Unicode BLock Index")
                    .generate(in);

            return Strings.ofBoundedLengthStrings(
                    blockStarts[block], blockEnds[block], minLength, maxLength)
                .describedAs("Realistic Unicode")
                .generate(in);
          }
        });
  }

  /**
   * Constructs a StringGeneratorBuilder which will build Strings composed of all defined code
   * points in the Basic Multilingual Plane
   *
   * @return a StringGeneratorBuilder
   */
  public StringGeneratorBuilder basicMultilingualPlaneAlphabet() {
    return betweenCodePoints(Character.MIN_CODE_POINT, LARGEST_DEFINED_BMP_CODEPOINT);
  }

  /**
   * Constructs a StringGeneratorBuilder which will build Strings composed of Unicode Basic Latin
   * Alphabet
   *
   * @return a StringGeneratorBuilder
   */
  public StringGeneratorBuilder basicLatinAlphabet() {
    return betweenCodePoints(BASIC_LATIN_FIRST_CODEPOINT, BASIC_LATIN_LAST_CODEPOINT);
  }

  /**
   * Alpha string generator builder.
   *
   * @return the string generator builder
   */
  public StringGeneratorBuilder alpha() {
    return betweenCodePoints('a', 'z' + 1);
  }

  /**
   * Alpha numeric string generator builder.
   *
   * @return the string generator builder
   */
  public StringGeneratorBuilder alphaNumeric() {
    return betweenCodePoints(' ', 'z' + 1);
  }

  /**
   * Constructs a StringGeneratorBuilder which will build Strings composed of Unicode Ascii Alphabet
   *
   * @return a StringGeneratorBuilder
   */
  public StringGeneratorBuilder ascii() {
    return betweenCodePoints(Character.MIN_CODE_POINT, ASCII_LAST_CODEPOINT);
  }

  /**
   * Strings with characters between two (inclusive) code points
   *
   * @param minInclusive minimum code point
   * @param maxInclusive max code point
   * @return Builder for strings
   */
  public StringGeneratorBuilder betweenCodePoints(int minInclusive, int maxInclusive) {
    return new StringGeneratorBuilder(minInclusive, maxInclusive);
  }

  /** The type Word list generator builder. */
  public static class WordListGeneratorBuilder {
    private final SolrGen<String> strings;

    /**
     * Instantiates a new Word list generator builder.
     *
     * @param strings the strings
     */
    WordListGeneratorBuilder(SolrGen<String> strings) {
      this.strings = strings;
    }

    /**
     * Of one solr gen.
     *
     * @return the solr gen
     */
    public SolrGen<String> ofOne() {
      return strings;
    }

    /**
     * Multi solr gen.
     *
     * @param count the count
     * @return the solr gen
     */
    public SolrGen<String> multi(int count) {
      return multiStringGen(strings, count);
    }

    /**
     * With distribution word list generator builder.
     *
     * @param distribution the distribution
     * @return the word list generator builder
     */
    public WordListGeneratorBuilder withDistribution(Distribution distribution) {
      this.strings.withDistribution(distribution);
      return this;
    }
  }

  /** The type Realistic unicode generator builder. */
  public static class RealisticUnicodeGeneratorBuilder {
    private final SolrGen<String> strings;

    /**
     * Instantiates a new Realistic unicode generator builder.
     *
     * @param strings the strings
     */
    RealisticUnicodeGeneratorBuilder(SolrGen<String> strings) {
      this.strings = strings;
    }

    /**
     * Of one solr gen.
     *
     * @return the solr gen
     */
    public SolrGen<String> ofOne() {
      return strings;
    }

    /**
     * Multi solr gen.
     *
     * @param count the count
     * @return the solr gen
     */
    public SolrGen<String> multi(int count) {
      return multiStringGen(strings, count);
    }
  }

  /** The type String generator builder. */
  public static class StringGeneratorBuilder {

    private final int minCodePoint;
    private final int maxCodePoint;
    private Integer cardinalityStart;
    private Gen<Integer> maxCardinality;
    private int multi;

    private StringGeneratorBuilder(int minCodePoint, int maxCodePoint) {
      this.minCodePoint = minCodePoint;
      this.maxCodePoint = maxCodePoint;
    }

    /**
     * Generates Strings of a fixed number of code points.
     *
     * @param codePoints - the fixed number of code points for the String
     * @return a a Source of type String
     */
    public SolrGen<String> ofFixedNumberOfCodePoints(int codePoints) {
      checkArguments(
          codePoints >= 0,
          "The number of codepoints cannot be negative; %s is not an accepted argument",
          codePoints);
      return new SolrGen<>(
          Strings.withCodePoints(minCodePoint, maxCodePoint, SolrGenerate.constant(codePoints)),
          String.class);
    }

    /**
     * Generates Strings of a fixed length.
     *
     * @param fixedLength - the fixed length for the Strings
     * @return a Source of type String
     */
    public SolrGen<String> ofLength(int fixedLength) {
      return ofLengthBetween(fixedLength, fixedLength);
    }

    /**
     * Max cardinality string generator builder.
     *
     * @param max the max
     * @return the string generator builder
     */
    public StringGeneratorBuilder maxCardinality(int max) {
      maxCardinality = SolrGenerate.constant(max);
      return this;
    }

    /**
     * Max cardinality string generator builder.
     *
     * @param max the max
     * @return the string generator builder
     */
    public StringGeneratorBuilder maxCardinality(Gen<Integer> max) {
      maxCardinality = max;
      return this;
    }

    /**
     * Multi string generator builder.
     *
     * @param count the count
     * @return the string generator builder
     */
    public StringGeneratorBuilder multi(int count) {
      this.multi = count;
      return this;
    }

    /**
     * Generates Strings of length bounded between minLength and maxLength inclusively.
     *
     * @param minLength - minimum inclusive length of String
     * @param maxLength - maximum inclusive length of String
     * @return a Source of type String
     */
    public SolrGen<String> ofLengthBetween(int minLength, int maxLength) {
      checkArguments(
          minLength <= maxLength,
          "The minLength (%s) is longer than the maxLength(%s)",
          minLength,
          maxLength);
      checkArguments(
          minLength >= 0,
          "The length of a String cannot be negative; %s is not an accepted argument",
          minLength);
      SolrGen<String> strings =
          Strings.ofBoundedLengthStrings(minCodePoint, maxCodePoint, minLength, maxLength);

      if (maxCardinality != null) {
        SolrGen<String> gen =
            new SolrGen<>(
                new SolrGen<>() {
                  @Override
                  public String generate(SolrRandomnessSource in) {
                    Integer maxCard = maxCardinality.generate(in);

                    if (cardinalityStart == null) {
                      cardinalityStart =
                          SolrGenerate.range(0, Integer.MAX_VALUE - maxCard - 1).generate(in);
                    }

                    long seed =
                        SolrGenerate.range(cardinalityStart, cardinalityStart + maxCard - 1)
                            .generate(in);
                    return strings.generate(
                        (RandomnessSource) new SplittableRandomSource(new SplittableRandom(seed)));
                  }

                  @Override
                  public String generate(RandomnessSource in) {
                    return generate((SolrRandomnessSource) in);
                  }
                },
                String.class);
        if (multi > 1) {
          return multiStringGen(gen, multi);
        }
        return new SolrGen<>(gen, String.class);
      } else {
        if (multi > 1) {
          return multiStringGen(strings, multi);
        }
        return new SolrGen<>(strings, String.class);
      }
    }
  }

  private static SolrGen<String> multiStringGen(SolrGen<String> strings, int multi) {
    return new SolrGen<>(MultiString.class) {

      {
        describedAs("MultiString");
      }

      @Override
      public String generate(SolrRandomnessSource in) {
        StringBuilder sb = new StringBuilder(64);
        for (int i = 0; i < multi; i++) {
          sb.append(strings.generate(in));
          if (i < multi - 1) {
            sb.append(' ');
          }
        }
        return sb.toString();
      }
    };
  }

  private static class WordListStringSolrGen extends SolrGen<String> {
    /** Instantiates a new Word list string solr gen. */
    public WordListStringSolrGen() {
      super(String.class);
    }

    @Override
    public String generate(RandomnessSource in) {
      return words.get(
          integers()
              .between(0, WORD_SIZE - 1)
              .describedAs("WordList Index")
              .withDistribution(this.getDistribution())
              .generate(in));
    }
  }

  private static final int[] blockStarts = {
    0x0000, 0x0080, 0x0100, 0x0180, 0x0250, 0x02B0, 0x0300, 0x0370, 0x0400, 0x0500, 0x0530, 0x0590,
    0x0600, 0x0700, 0x0750, 0x0780, 0x07C0, 0x0800, 0x0900, 0x0980, 0x0A00, 0x0A80, 0x0B00, 0x0B80,
    0x0C00, 0x0C80, 0x0D00, 0x0D80, 0x0E00, 0x0E80, 0x0F00, 0x1000, 0x10A0, 0x1100, 0x1200, 0x1380,
    0x13A0, 0x1400, 0x1680, 0x16A0, 0x1700, 0x1720, 0x1740, 0x1760, 0x1780, 0x1800, 0x18B0, 0x1900,
    0x1950, 0x1980, 0x19E0, 0x1A00, 0x1A20, 0x1B00, 0x1B80, 0x1C00, 0x1C50, 0x1CD0, 0x1D00, 0x1D80,
    0x1DC0, 0x1E00, 0x1F00, 0x2000, 0x2070, 0x20A0, 0x20D0, 0x2100, 0x2150, 0x2190, 0x2200, 0x2300,
    0x2400, 0x2440, 0x2460, 0x2500, 0x2580, 0x25A0, 0x2600, 0x2700, 0x27C0, 0x27F0, 0x2800, 0x2900,
    0x2980, 0x2A00, 0x2B00, 0x2C00, 0x2C60, 0x2C80, 0x2D00, 0x2D30, 0x2D80, 0x2DE0, 0x2E00, 0x2E80,
    0x2F00, 0x2FF0, 0x3000, 0x3040, 0x30A0, 0x3100, 0x3130, 0x3190, 0x31A0, 0x31C0, 0x31F0, 0x3200,
    0x3300, 0x3400, 0x4DC0, 0x4E00, 0xA000, 0xA490, 0xA4D0, 0xA500, 0xA640, 0xA6A0, 0xA700, 0xA720,
    0xA800, 0xA830, 0xA840, 0xA880, 0xA8E0, 0xA900, 0xA930, 0xA960, 0xA980, 0xAA00, 0xAA60, 0xAA80,
    0xABC0, 0xAC00, 0xD7B0, 0xE000, 0xF900, 0xFB00, 0xFB50, 0xFE00, 0xFE10, 0xFE20, 0xFE30, 0xFE50,
    0xFE70, 0xFF00, 0xFFF0, 0x10000, 0x10080, 0x10100, 0x10140, 0x10190, 0x101D0, 0x10280, 0x102A0,
    0x10300, 0x10330, 0x10380, 0x103A0, 0x10400, 0x10450, 0x10480, 0x10800, 0x10840, 0x10900,
    0x10920, 0x10A00, 0x10A60, 0x10B00, 0x10B40, 0x10B60, 0x10C00, 0x10E60, 0x11080, 0x12000,
    0x12400, 0x13000, 0x1D000, 0x1D100, 0x1D200, 0x1D300, 0x1D360, 0x1D400, 0x1F000, 0x1F030,
    0x1F100, 0x1F200, 0x20000, 0x2A700, 0x2F800, 0xE0000, 0xE0100, 0xF0000, 0x100000
  };

  private static final int[] blockEnds = {
    0x007F, 0x00FF, 0x017F, 0x024F, 0x02AF, 0x02FF, 0x036F, 0x03FF, 0x04FF, 0x052F, 0x058F, 0x05FF,
    0x06FF, 0x074F, 0x077F, 0x07BF, 0x07FF, 0x083F, 0x097F, 0x09FF, 0x0A7F, 0x0AFF, 0x0B7F, 0x0BFF,
    0x0C7F, 0x0CFF, 0x0D7F, 0x0DFF, 0x0E7F, 0x0EFF, 0x0FFF, 0x109F, 0x10FF, 0x11FF, 0x137F, 0x139F,
    0x13FF, 0x167F, 0x169F, 0x16FF, 0x171F, 0x173F, 0x175F, 0x177F, 0x17FF, 0x18AF, 0x18FF, 0x194F,
    0x197F, 0x19DF, 0x19FF, 0x1A1F, 0x1AAF, 0x1B7F, 0x1BBF, 0x1C4F, 0x1C7F, 0x1CFF, 0x1D7F, 0x1DBF,
    0x1DFF, 0x1EFF, 0x1FFF, 0x206F, 0x209F, 0x20CF, 0x20FF, 0x214F, 0x218F, 0x21FF, 0x22FF, 0x23FF,
    0x243F, 0x245F, 0x24FF, 0x257F, 0x259F, 0x25FF, 0x26FF, 0x27BF, 0x27EF, 0x27FF, 0x28FF, 0x297F,
    0x29FF, 0x2AFF, 0x2BFF, 0x2C5F, 0x2C7F, 0x2CFF, 0x2D2F, 0x2D7F, 0x2DDF, 0x2DFF, 0x2E7F, 0x2EFF,
    0x2FDF, 0x2FFF, 0x303F, 0x309F, 0x30FF, 0x312F, 0x318F, 0x319F, 0x31BF, 0x31EF, 0x31FF, 0x32FF,
    0x33FF, 0x4DBF, 0x4DFF, 0x9FFF, 0xA48F, 0xA4CF, 0xA4FF, 0xA63F, 0xA69F, 0xA6FF, 0xA71F, 0xA7FF,
    0xA82F, 0xA83F, 0xA87F, 0xA8DF, 0xA8FF, 0xA92F, 0xA95F, 0xA97F, 0xA9DF, 0xAA5F, 0xAA7F, 0xAADF,
    0xABFF, 0xD7AF, 0xD7FF, 0xF8FF, 0xFAFF, 0xFB4F, 0xFDFF, 0xFE0F, 0xFE1F, 0xFE2F, 0xFE4F, 0xFE6F,
    0xFEFF, 0xFFEF, 0xFFFF, 0x1007F, 0x100FF, 0x1013F, 0x1018F, 0x101CF, 0x101FF, 0x1029F, 0x102DF,
    0x1032F, 0x1034F, 0x1039F, 0x103DF, 0x1044F, 0x1047F, 0x104AF, 0x1083F, 0x1085F, 0x1091F,
    0x1093F, 0x10A5F, 0x10A7F, 0x10B3F, 0x10B5F, 0x10B7F, 0x10C4F, 0x10E7F, 0x110CF, 0x123FF,
    0x1247F, 0x1342F, 0x1D0FF, 0x1D1FF, 0x1D24F, 0x1D35F, 0x1D37F, 0x1D7FF, 0x1F02F, 0x1F09F,
    0x1F1FF, 0x1F2FF, 0x2A6DF, 0x2B73F, 0x2FA1F, 0xE007F, 0xE01EF, 0xFFFFF, 0x10FFFF
  };
}
