using System;
using System.Collections.Generic;
namespace osu.Game.Rulesets.Taiko.Difficulty.Preprocessing.Colour
{
///
/// Encodes a list of s, grouped together by back and forth repetition of the same
/// . Also stores the repetition interval between this and the previous .
///
public class CoupledColourEncoding
{
///
/// Maximum amount of s to look back to find a repetition.
///
private const int max_repetition_interval = 16;
///
/// The s that are grouped together within this .
///
public List Payload = new List();
///
/// The previous . This is used to determine the repetition interval.
///
public CoupledColourEncoding? Previous = null;
///
/// How many between the current and previous identical .
/// If no repetition is found this will have a value of + 1.
///
public int RepetitionInterval { get; private set; } = max_repetition_interval + 1;
///
/// Returns true if other is considered a repetition of this encoding. This is true if other's first two payload
/// identical mono lengths.
///
public bool isRepetitionOf(CoupledColourEncoding other)
{
if (this.Payload.Count != other.Payload.Count) return false;
for (int i = 0; i < Math.Min(this.Payload.Count, 2); i++)
{
if (!this.Payload[i].hasIdenticalMonoLength(other.Payload[i])) return false;
}
return true;
}
///
/// Finds the closest previous that has the identical .
/// Interval is defined as the amount of chunks between the current and repeated encoding.
///
public void FindRepetitionInterval()
{
if (Previous?.Previous == null)
{
RepetitionInterval = max_repetition_interval + 1;
return;
}
CoupledColourEncoding? other = Previous.Previous;
int interval = 2;
while (interval < max_repetition_interval)
{
if (this.isRepetitionOf(other))
{
RepetitionInterval = Math.Min(interval, max_repetition_interval);
return;
}
other = other.Previous;
if (other == null) break;
++interval;
}
RepetitionInterval = max_repetition_interval + 1;
}
}
}