package net.minecraft.client.multiplayer.chat;

import com.mojang.serialization.Codec;
import com.mojang.serialization.DataResult;
import java.util.ArrayList;
import java.util.List;
import org.jspecify.annotations.Nullable;

public class ChatLog {
	private final LoggedChatEvent[] buffer;
	private int nextId;

	public static Codec<ChatLog> codec(final int capacity) {
		return Codec.list(LoggedChatEvent.CODEC)
			.comapFlatMap(
				loggedChatEvents -> {
					int parsedSize = loggedChatEvents.size();
					return parsedSize > capacity
						? DataResult.error(() -> "Expected: a buffer of size less than or equal to " + capacity + " but: " + parsedSize + " is greater than " + capacity)
						: DataResult.success(new ChatLog(capacity, loggedChatEvents));
				},
				ChatLog::loggedChatEvents
			);
	}

	public ChatLog(final int capacity) {
		this.buffer = new LoggedChatEvent[capacity];
	}

	private ChatLog(final int capacity, final List<LoggedChatEvent> buffer) {
		this.buffer = (LoggedChatEvent[])buffer.toArray(LoggedChatEvent[]::new);
		this.nextId = buffer.size();
	}

	private List<LoggedChatEvent> loggedChatEvents() {
		List<LoggedChatEvent> loggedChatEvents = new ArrayList(this.size());

		for (int i = this.start(); i <= this.end(); i++) {
			loggedChatEvents.add(this.lookup(i));
		}

		return loggedChatEvents;
	}

	public void push(final LoggedChatEvent event) {
		this.buffer[this.index(this.nextId++)] = event;
	}

	@Nullable
	public LoggedChatEvent lookup(final int id) {
		return id >= this.start() && id <= this.end() ? this.buffer[this.index(id)] : null;
	}

	private int index(final int id) {
		return id % this.buffer.length;
	}

	public int start() {
		return Math.max(this.nextId - this.buffer.length, 0);
	}

	public int end() {
		return this.nextId - 1;
	}

	private int size() {
		return this.end() - this.start() + 1;
	}
}