/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the "Elastic License
 * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
 * Public License v 1"; you may not use this file except in compliance with, at
 * your election, the "Elastic License 2.0", the "GNU Affero General Public
 * License v3.0 only", or the "Server Side Public License, v 1".
 */

package org.elasticsearch.health;

import org.elasticsearch.cluster.coordination.CoordinationDiagnosticsService;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.io.stream.Writeable;

import java.io.IOException;
import java.util.Comparator;
import java.util.Locale;
import java.util.stream.Stream;

public enum HealthStatus implements Writeable {
    GREEN((byte) 0),
    UNKNOWN((byte) 1),
    YELLOW((byte) 2),
    RED((byte) 3);

    private final byte value;

    HealthStatus(byte value) {
        this.value = value;
    }

    public static HealthStatus read(StreamInput in) throws IOException {
        byte value = in.readByte();
        return switch (value) {
            case 0 -> GREEN;
            case 1 -> UNKNOWN;
            case 2 -> YELLOW;
            case 3 -> RED;
            default -> throw new IllegalArgumentException("unknown value for health status [" + value + "]");
        };
    }

    @Override
    public void writeTo(StreamOutput out) throws IOException {
        out.writeByte(value);
    }

    public byte value() {
        return value;
    }

    /**
     * @return true if the HealthStatus is YELLOW or RED.
     */
    public boolean indicatesHealthProblem() {
        return value > UNKNOWN.value();
    }

    public static HealthStatus merge(Stream<HealthStatus> statuses) {
        return statuses.max(Comparator.comparing(HealthStatus::value))
            .orElseThrow(() -> new IllegalArgumentException("Cannot merge empty health status stream."));
    }

    public String xContentValue() {
        return name().toLowerCase(Locale.ROOT);
    }

    public static HealthStatus fromCoordinationDiagnosticsStatus(
        CoordinationDiagnosticsService.CoordinationDiagnosticsStatus coordinationDiagnosticsStatus
    ) {
        return switch (coordinationDiagnosticsStatus) {
            case GREEN -> HealthStatus.GREEN;
            case YELLOW -> HealthStatus.YELLOW;
            case RED -> HealthStatus.RED;
            case UNKNOWN -> HealthStatus.UNKNOWN;
        };
    }
}