package net.minecraft.util.profiling.metrics;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import it.unimi.dsi.fastutil.ints.Int2DoubleMap;
import it.unimi.dsi.fastutil.ints.Int2DoubleOpenHashMap;
import java.util.Locale;
import java.util.function.Consumer;
import java.util.function.DoubleSupplier;
import java.util.function.ToDoubleFunction;
import javax.annotation.Nullable;

public class MetricSampler {
    private final String name;
    private final MetricCategory category;
    private final DoubleSupplier sampler;
    private final ByteBuf ticks;
    private final ByteBuf values;
    private volatile boolean isRunning;
    @Nullable
    private final Runnable beforeTick;
    @Nullable
    final MetricSampler.ThresholdTest thresholdTest;
    private double currentValue;

    protected MetricSampler(
        String p_145996_, MetricCategory p_145997_, DoubleSupplier p_145998_, @Nullable Runnable p_145999_, @Nullable MetricSampler.ThresholdTest p_146000_
    ) {
        this.name = p_145996_;
        this.category = p_145997_;
        this.beforeTick = p_145999_;
        this.sampler = p_145998_;
        this.thresholdTest = p_146000_;
        this.values = ByteBufAllocator.DEFAULT.buffer();
        this.ticks = ByteBufAllocator.DEFAULT.buffer();
        this.isRunning = true;
    }

    public static MetricSampler create(String p_146010_, MetricCategory p_146011_, DoubleSupplier p_146012_) {
        return new MetricSampler(p_146010_, p_146011_, p_146012_, null, null);
    }

    public static <T> MetricSampler create(String p_146005_, MetricCategory p_146006_, T p_146007_, ToDoubleFunction<T> p_146008_) {
        return builder(p_146005_, p_146006_, p_146008_, p_146007_).build();
    }

    public static <T> MetricSampler.MetricSamplerBuilder<T> builder(String p_146014_, MetricCategory p_146015_, ToDoubleFunction<T> p_146016_, T p_146017_) {
        return new MetricSampler.MetricSamplerBuilder<>(p_146014_, p_146015_, p_146016_, p_146017_);
    }

    public void onStartTick() {
        if (!this.isRunning) {
            throw new IllegalStateException("Not running");
        } else {
            if (this.beforeTick != null) {
                this.beforeTick.run();
            }
        }
    }

    public void onEndTick(int p_146003_) {
        this.verifyRunning();
        this.currentValue = this.sampler.getAsDouble();
        this.values.writeDouble(this.currentValue);
        this.ticks.writeInt(p_146003_);
    }

    public void onFinished() {
        this.verifyRunning();
        this.values.release();
        this.ticks.release();
        this.isRunning = false;
    }

    private void verifyRunning() {
        if (!this.isRunning) {
            throw new IllegalStateException(String.format(Locale.ROOT, "Sampler for metric %s not started!", this.name));
        }
    }

    DoubleSupplier getSampler() {
        return this.sampler;
    }

    public String getName() {
        return this.name;
    }

    public MetricCategory getCategory() {
        return this.category;
    }

    public MetricSampler.SamplerResult result() {
        Int2DoubleMap int2doublemap = new Int2DoubleOpenHashMap();
        int i = Integer.MIN_VALUE;
        int j = Integer.MIN_VALUE;

        while (this.values.isReadable(8)) {
            int k = this.ticks.readInt();
            if (i == Integer.MIN_VALUE) {
                i = k;
            }

            int2doublemap.put(k, this.values.readDouble());
            j = k;
        }

        return new MetricSampler.SamplerResult(i, j, int2doublemap);
    }

    public boolean triggersThreshold() {
        return this.thresholdTest != null && this.thresholdTest.test(this.currentValue);
    }

    @Override
    public boolean equals(Object p_146023_) {
        if (this == p_146023_) {
            return true;
        } else if (p_146023_ != null && this.getClass() == p_146023_.getClass()) {
            MetricSampler metricsampler = (MetricSampler)p_146023_;
            return this.name.equals(metricsampler.name) && this.category.equals(metricsampler.category);
        } else {
            return false;
        }
    }

    @Override
    public int hashCode() {
        return this.name.hashCode();
    }

    public static class MetricSamplerBuilder<T> {
        private final String name;
        private final MetricCategory category;
        private final DoubleSupplier sampler;
        private final T context;
        @Nullable
        private Runnable beforeTick;
        @Nullable
        private MetricSampler.ThresholdTest thresholdTest;

        public MetricSamplerBuilder(String p_146035_, MetricCategory p_146036_, ToDoubleFunction<T> p_146037_, T p_146038_) {
            this.name = p_146035_;
            this.category = p_146036_;
            this.sampler = () -> p_146037_.applyAsDouble(p_146038_);
            this.context = p_146038_;
        }

        public MetricSampler.MetricSamplerBuilder<T> withBeforeTick(Consumer<T> p_146043_) {
            this.beforeTick = () -> p_146043_.accept(this.context);
            return this;
        }

        public MetricSampler.MetricSamplerBuilder<T> withThresholdAlert(MetricSampler.ThresholdTest p_146041_) {
            this.thresholdTest = p_146041_;
            return this;
        }

        public MetricSampler build() {
            return new MetricSampler(this.name, this.category, this.sampler, this.beforeTick, this.thresholdTest);
        }
    }

    public static class SamplerResult {
        private final Int2DoubleMap recording;
        private final int firstTick;
        private final int lastTick;

        public SamplerResult(int p_146053_, int p_146054_, Int2DoubleMap p_146055_) {
            this.firstTick = p_146053_;
            this.lastTick = p_146054_;
            this.recording = p_146055_;
        }

        public double valueAtTick(int p_146058_) {
            return this.recording.get(p_146058_);
        }

        public int getFirstTick() {
            return this.firstTick;
        }

        public int getLastTick() {
            return this.lastTick;
        }
    }

    public interface ThresholdTest {
        boolean test(double p_146060_);
    }

    public static class ValueIncreasedByPercentage implements MetricSampler.ThresholdTest {
        private final float percentageIncreaseThreshold;
        private double previousValue = Double.MIN_VALUE;

        public ValueIncreasedByPercentage(float p_146064_) {
            this.percentageIncreaseThreshold = p_146064_;
        }

        @Override
        public boolean test(double p_146066_) {
            boolean flag;
            if (this.previousValue != Double.MIN_VALUE && !(p_146066_ <= this.previousValue)) {
                flag = (p_146066_ - this.previousValue) / this.previousValue >= this.percentageIncreaseThreshold;
            } else {
                flag = false;
            }

            this.previousValue = p_146066_;
            return flag;
        }
    }
}