com.qwlabs.tree.Location Maven / Gradle / Ivy

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package com.qwlabs.tree;

import com.google.common.collect.Lists;
import jakarta.validation.constraints.NotNull;
import lombok.Getter;

import java.util.List;
import java.util.Objects;
import java.util.Optional;
import java.util.function.Function;
import java.util.stream.Collectors;

@Getter
public class Location {
    private static final RootLocation ROOT = new RootLocation<>();
    @NotNull
    private final List path;

    public Location(List path) {
        this.path = path;
    }

    @NotNull
    public Optional> parent() {
        return isRoot() ? Optional.empty() :
                Optional.of(Location.of(path.subList(0, path.size() - 1)));
    }

    public boolean isRoot() {
        return path.isEmpty();
    }

    public  Location map(Function mapper) {
        return Location.of(mapPath(mapper));
    }

    public  List mapPath(Function mapper) {
        return path.stream().map(mapper)
                .collect(Collectors.toList());
    }

    public Location child(N node) {
        List childPath = Lists.newArrayList(path);
        childPath.add(node);
        return Location.of(childPath);
    }

    public Optional tail() {
        return isRoot() ? Optional.empty() : Optional.of(path.get(path.size() - 1));
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        Location location = (Location) o;
        return Objects.equals(path, location.path);
    }

    @Override
    public int hashCode() {
        return Objects.hash(path);
    }

    public static  Location root() {
        return (Location) ROOT;
    }

    public static  Location of(List path) {
        return new Location<>(path);
    }

    public static  Location of(N... path) {
        return of(List.of(path));
    }

    public static class RootLocation> extends Location {
        public RootLocation() {
            super(List.of());
        }
    }
}