net.hamnaberg.json.patch.JsonPatch Maven / Gradle / Ivy

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package net.hamnaberg.json.patch;


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

import net.hamnaberg.json.Json;
import net.hamnaberg.json.pointer.JsonPointer;

public final class JsonPatch implements Function {

    public static JsonPatch fromArray(Json.JArray array) {
        List operations = array.mapToList(j -> Operation.fromJson(j.asJsonObjectOrEmpty()));
        return new JsonPatch(operations);
    }

    private final List operations;

    public JsonPatch() {
        this(List.of());
    }

    private JsonPatch(List operations) {
        this.operations = operations;
    }

    public JsonPatch add(String path, Json.JValue value) {
        return add(JsonPointer.compile(path), value);
    }

    public JsonPatch add(JsonPointer path, Json.JValue value) {
        return op(Operation.Op.Add, Optional.empty(), path, Optional.of(value));
    }

    public JsonPatch remove(String path) {
        return remove(JsonPointer.compile(path));
    }

    public JsonPatch remove(JsonPointer path) {
        return op(Operation.Op.Remove, Optional.empty(), path, Optional.empty());
    }

    public JsonPatch replace(String path, Json.JValue value) {
        return replace(JsonPointer.compile(path), value);
    }

    public JsonPatch replace(JsonPointer path, Json.JValue value) {
        return op(Operation.Op.Replace, Optional.empty(), path, Optional.of(value));
    }

    public JsonPatch test(String path, Json.JValue value) {
        return test(JsonPointer.compile(path), value);
    }

    public JsonPatch test(JsonPointer path, Json.JValue value) {
        return op(Operation.Op.Test, Optional.empty(), path, Optional.of(value));
    }

    public JsonPatch copy(String from, String path) {
        return copy(JsonPointer.compile(from), JsonPointer.compile(path));
    }

    public JsonPatch copy(JsonPointer from, JsonPointer path) {
        return op(Operation.Op.Copy, Optional.of(from), path, Optional.empty());
    }

    public JsonPatch move(String from, String path) {
        return move(JsonPointer.compile(from), JsonPointer.compile(path));
    }

    public JsonPatch move(JsonPointer from, JsonPointer path) {
        return op(Operation.Op.Move, Optional.of(from), path, Optional.empty());
    }

    private JsonPatch op(Operation.Op op, Optional from, JsonPointer path, Optional value) {
        List ops = Stream.concat(this.operations.stream(), Stream.of(new Operation(op, from, path, value))).collect(Collectors.toUnmodifiableList());
        return new JsonPatch(ops);
    }

    public Json.JValue apply(final Json.JValue json) {
        Json.JValue modified = json;
        for (Operation op : operations) {
            switch (op.op) {
                case Add:
                    modified = op.path.add(modified, op.value.orElseThrow(() -> new IllegalStateException("Missing value")));
                    break;
                case Remove:
                    modified = op.path.remove(modified);
                    break;
                case Replace:
                    modified = op.path.replace(modified, op.value.orElseThrow(() -> new IllegalStateException("Missing value")));
                    break;
                case Move:
                    modified = op.path.move(json, op.from.orElseThrow(() -> new IllegalStateException("Missing from")));
                    break;
                case Copy:
                    modified = op.path.copy(json, op.from.orElseThrow(() -> new IllegalStateException("Missing from")));
                    break;
                case Test:
                    modified = op.path.test(json, op.value.orElseThrow(() -> new IllegalStateException("Missing value"))) ? modified : modified;
                    break;
            }
        }
        return modified;
    }

    public Json.JArray toJson() {
        return Json.jArray(this.operations.stream().map(Operation::toJson).collect(Collectors.toUnmodifiableList()));
    }
}