package net.minecraft.util.valueproviders;

import com.mojang.serialization.Codec;
import com.mojang.serialization.DataResult;
import com.mojang.serialization.MapCodec;
import com.mojang.serialization.codecs.RecordCodecBuilder;
import net.minecraft.util.Mth;
import net.minecraft.util.RandomSource;

public record TrapezoidInt(int minInclusive, int maxInclusive, int plateau) implements IntProvider {
	public static final MapCodec<TrapezoidInt> MAP_CODEC = RecordCodecBuilder.<TrapezoidInt>mapCodec(
			i -> i.group(
					Codec.INT.fieldOf("min").forGetter(TrapezoidInt::minInclusive),
					Codec.INT.fieldOf("max").forGetter(TrapezoidInt::maxInclusive),
					Codec.INT.fieldOf("plateau").forGetter(TrapezoidInt::plateau)
				)
				.apply(i, TrapezoidInt::new)
		)
		.validate(
			c -> {
				if (c.maxInclusive < c.minInclusive) {
					return DataResult.error(() -> "Max must be larger than min: [" + c.minInclusive + ", " + c.maxInclusive + "]");
				} else {
					return c.plateau > c.maxInclusive - c.minInclusive
						? DataResult.error(() -> "Plateau can at most be the full span: [" + c.minInclusive + ", " + c.maxInclusive + "]")
						: DataResult.success(c);
				}
			}
		);

	public static TrapezoidInt of(final int min, final int max, final int plateau) {
		return new TrapezoidInt(min, max, plateau);
	}

	public static IntProvider triangle(final int range) {
		return of(-range, range, 0);
	}

	@Override
	public int sample(final RandomSource random) {
		if (this.plateau == 0 && this.maxInclusive == -this.minInclusive) {
			return random.nextInt(this.maxInclusive + 1) - random.nextInt(this.maxInclusive + 1);
		} else {
			int range = this.maxInclusive - this.minInclusive;
			if (this.plateau == range) {
				return Mth.randomBetweenInclusive(random, this.minInclusive, this.maxInclusive);
			} else {
				int plateauStart = (range - this.plateau) / 2;
				int plateauEnd = range - plateauStart;
				return this.minInclusive + Mth.randomBetweenInclusive(random, 0, plateauEnd) + Mth.randomBetweenInclusive(random, 0, plateauStart);
			}
		}
	}

	@Override
	public MapCodec<TrapezoidInt> codec() {
		return MAP_CODEC;
	}

	public String toString() {
		return "trapezoid(" + this.plateau + ") in [" + this.minInclusive + "-" + this.maxInclusive + "]";
	}
}