XFEServerManager

package com.xfestudio.xfeservermanager.core.trigger;

import java.util.List;
import java.util.Locale;
import java.util.Objects;
import java.util.UUID;

/** A transport-safe, strongly typed expression tree. */
public record TriggerExpression(
        UUID nodeId,
        Kind kind,
        String valueType,
        Object literal,
        String name,
        List<TriggerExpression> arguments) {

    public TriggerExpression {
        nodeId = nodeId == null ? UUID.randomUUID() : nodeId;
        Objects.requireNonNull(kind, "kind");
        valueType = valueType == null || valueType.isBlank()
                ? "any" : valueType.strip().toLowerCase(Locale.ROOT);
        if (!valueType.equals("any")) valueType = TriggerValueTypes.normalizeVariableType(valueType);
        name = name == null ? "" : name.strip();
        arguments = List.copyOf(arguments == null ? List.of() : arguments);
        if (arguments.stream().anyMatch(Objects::isNull)) {
            throw new IllegalArgumentException("expression argument must not be null");
        }
        if (kind.requiresName() && name.isBlank()) {
            throw new IllegalArgumentException(kind.name().toLowerCase(Locale.ROOT) + " expression requires a name");
        }
    }

    public static TriggerExpression literal(String type, Object value) {
        return new TriggerExpression(UUID.randomUUID(), Kind.LITERAL, type, value, "", List.of());
    }

    public static TriggerExpression reference(String type, String name) {
        return new TriggerExpression(UUID.randomUUID(), Kind.REFERENCE, type, null, name, List.of());
    }

    public enum Kind {
        LITERAL,
        REFERENCE,
        UNARY,
        BINARY,
        FUNCTION,
        INDEX,
        COALESCE,
        CONVERT;

        boolean requiresName() {
            return this == REFERENCE || this == UNARY || this == BINARY
                    || this == FUNCTION || this == CONVERT;
        }
    }
}