package org.jcodec.common;

import java.nio.ByteBuffer;
import org.jcodec.common.io.NIOUtils;

public abstract class RunLength {
  protected IntArrayList counts = IntArrayList.createIntArrayList();
  
  public int estimateSize() {
    int[] counts = getCounts();
    int recCount = 0;
    for (int i = 0; i < counts.length; i++, recCount++) {
      int count = counts[i];
      while (count >= 256) {
        recCount++;
        count -= 256;
      } 
    } 
    return recCount * recSize() + 4;
  }
  
  protected abstract int recSize();
  
  protected abstract void finish();
  
  public int[] getCounts() {
    finish();
    return this.counts.toArray();
  }
  
  public static class Integer extends RunLength {
    private static final int MIN_VALUE = -2147483648;
    
    private int lastValue;
    
    private int count = 0;
    
    private IntArrayList values;
    
    public Integer() {
      this.lastValue = Integer.MIN_VALUE;
      this.values = IntArrayList.createIntArrayList();
    }
    
    public void add(int value) {
      if (this.lastValue == Integer.MIN_VALUE || this.lastValue != value) {
        if (this.lastValue != Integer.MIN_VALUE) {
          this.values.add(this.lastValue);
          this.counts.add(this.count);
          this.count = 0;
        } 
        this.lastValue = value;
      } 
      this.count++;
    }
    
    public int[] getValues() {
      finish();
      return this.values.toArray();
    }
    
    protected void finish() {
      if (this.lastValue != Integer.MIN_VALUE) {
        this.values.add(this.lastValue);
        this.counts.add(this.count);
        this.lastValue = Integer.MIN_VALUE;
        this.count = 0;
      } 
    }
    
    public void serialize(ByteBuffer bb) {
      ByteBuffer dup = bb.duplicate();
      int[] counts = getCounts();
      int[] values = getValues();
      NIOUtils.skip(bb, 4);
      int recCount = 0;
      for (int i = 0; i < counts.length; i++, recCount++) {
        int count = counts[i];
        while (count >= 256) {
          bb.put((byte)-1);
          bb.putInt(values[i]);
          recCount++;
          count -= 256;
        } 
        bb.put((byte)(count - 1));
        bb.putInt(values[i]);
      } 
      dup.putInt(recCount);
    }
    
    public static Integer parse(ByteBuffer bb) {
      Integer rl = new Integer();
      int recCount = bb.getInt();
      for (int i = 0; i < recCount; i++) {
        int count = (bb.get() & 0xFF) + 1;
        int value = bb.getInt();
        rl.counts.add(count);
        rl.values.add(value);
      } 
      return rl;
    }
    
    protected int recSize() {
      return 5;
    }
    
    public int[] flattern() {
      int[] counts = getCounts();
      int total = 0;
      for (int i = 0; i < counts.length; i++)
        total += counts[i]; 
      int[] values = getValues();
      int[] result = new int[total];
      for (int j = 0, ind = 0; j < counts.length; j++) {
        for (int k = 0; k < counts[j]; k++, ind++)
          result[ind] = values[j]; 
      } 
      return result;
    }
  }
  
  public static class Long extends RunLength {
    private static final long MIN_VALUE = -9223372036854775808L;
    
    private long lastValue;
    
    private int count = 0;
    
    private LongArrayList values;
    
    public Long() {
      this.lastValue = Long.MIN_VALUE;
      this.values = LongArrayList.createLongArrayList();
    }
    
    public void add(long value) {
      if (this.lastValue == Long.MIN_VALUE || this.lastValue != value) {
        if (this.lastValue != Long.MIN_VALUE) {
          this.values.add(this.lastValue);
          this.counts.add(this.count);
          this.count = 0;
        } 
        this.lastValue = value;
      } 
      this.count++;
    }
    
    public int[] getCounts() {
      finish();
      return this.counts.toArray();
    }
    
    public long[] getValues() {
      finish();
      return this.values.toArray();
    }
    
    protected void finish() {
      if (this.lastValue != Long.MIN_VALUE) {
        this.values.add(this.lastValue);
        this.counts.add(this.count);
        this.lastValue = Long.MIN_VALUE;
        this.count = 0;
      } 
    }
    
    public void serialize(ByteBuffer bb) {
      ByteBuffer dup = bb.duplicate();
      int[] counts = getCounts();
      long[] values = getValues();
      NIOUtils.skip(bb, 4);
      int recCount = 0;
      for (int i = 0; i < counts.length; i++, recCount++) {
        int count = counts[i];
        while (count >= 256) {
          bb.put((byte)-1);
          bb.putLong(values[i]);
          recCount++;
          count -= 256;
        } 
        bb.put((byte)(count - 1));
        bb.putLong(values[i]);
      } 
      dup.putInt(recCount);
    }
    
    public static Long parse(ByteBuffer bb) {
      Long rl = new Long();
      int recCount = bb.getInt();
      for (int i = 0; i < recCount; i++) {
        int count = (bb.get() & 0xFF) + 1;
        long value = bb.getLong();
        rl.counts.add(count);
        rl.values.add(value);
      } 
      return rl;
    }
    
    protected int recSize() {
      return 9;
    }
    
    public long[] flattern() {
      int[] counts = getCounts();
      int total = 0;
      for (int i = 0; i < counts.length; i++)
        total += counts[i]; 
      long[] values = getValues();
      long[] result = new long[total];
      for (int j = 0, ind = 0; j < counts.length; j++) {
        for (int k = 0; k < counts[j]; k++, ind++)
          result[ind] = values[j]; 
      } 
      return result;
    }
  }
}