LibJF/libjf-config-core-v1/src/main/java/io/gitlab/jfronny/libjf/config/api/v1/type/Type.java

package io.gitlab.jfronny.libjf.config.api.v1.type;

import org.jetbrains.annotations.Nullable;

/**
 * An internal representation of types for the purpose of identifying field types
 */
public sealed interface Type {
    static Type ofClass(java.lang.reflect.Type klazz) {
        if (klazz == int.class || klazz == Integer.class) return TInt.INSTANCE;
        else if (klazz == long.class || klazz == Long.class) return TLong.INSTANCE;
        else if (klazz == float.class || klazz == Float.class) return TFloat.INSTANCE;
        else if (klazz == double.class || klazz == Double.class) return TDouble.INSTANCE;
        else if (klazz == String.class) return TString.INSTANCE;
        else if (klazz == boolean.class || klazz == Boolean.class) return TBool.INSTANCE;
        else if (klazz instanceof Class<?> k && k.isEnum()) return new TEnum<>(k);
        else return new TUnknown<>(klazz);
    }

    default boolean isInt() {
        return false;
    }
    default boolean isLong() {
        return false;
    }
    default boolean isFloat() {
        return false;
    }
    default boolean isDouble() {
        return false;
    }
    default boolean isString() {
        return false;
    }
    default boolean isBool() {
        return false;
    }
    default boolean isEnum() {
        return false;
    }

    @Nullable java.lang.reflect.Type asClass();

    String getName();

    final class TInt implements Type {
        public static TInt INSTANCE = new TInt();
        private TInt() {}
        @Override
        public boolean isInt() {
            return true;
        }

        @Override
        public Class<Integer> asClass() {
            return Integer.class;
        }

        @Override
        public String getName() {
            return "Integer";
        }
    }

    final class TLong implements Type {
        public static TLong INSTANCE = new TLong();
        private TLong() {}
        @Override
        public boolean isLong() {
            return true;
        }

        @Override
        public Class<Long> asClass() {
            return Long.class;
        }

        @Override
        public String getName() {
            return "Long";
        }
    }

    final class TFloat implements Type {
        public static TFloat INSTANCE = new TFloat();
        private TFloat() {}
        @Override
        public boolean isFloat() {
            return true;
        }

        @Override
        public Class<Float> asClass() {
            return Float.class;
        }

        @Override
        public String getName() {
            return "Float";
        }
    }

    final class TDouble implements Type {
        public static TDouble INSTANCE = new TDouble();
        private TDouble() {}
        @Override
        public boolean isDouble() {
            return true;
        }

        @Override
        public Class<Double> asClass() {
            return Double.class;
        }

        @Override
        public String getName() {
            return "Double";
        }
    }

    final class TString implements Type {
        public static TString INSTANCE = new TString();
        private TString() {}
        @Override
        public boolean isString() {
            return true;
        }

        @Override
        public Class<String> asClass() {
            return String.class;
        }

        @Override
        public String getName() {
            return "String";
        }
    }

    final class TBool implements Type {
        public static TBool INSTANCE = new TBool();
        private TBool() {}
        @Override
        public boolean isBool() {
            return true;
        }

        @Override
        public Class<Boolean> asClass() {
            return Boolean.class;
        }

        @Override
        public String getName() {
            return "Boolean";
        }
    }

    final record TEnum<T>(@Nullable Class<T> klazz, String name, T[] options) implements Type {
        public TEnum(Class<T> klazz) {
            this(klazz, klazz.getSimpleName(), klazz.getEnumConstants());
        }

        public static TEnum<String> create(String name, String[] options) {
            return new TEnum<>(null, name, options);
        }

        @Override
        public boolean isEnum() {
            return true;
        }

        @Override
        public Class<T> asClass() {
            return klazz;
        }

        @Override
        public String getName() {
            return name;
        }

        public T optionForString(String string) {
            for (T option : options) {
                if (option.toString().equals(string)) return option;
            }
            return null;
        }
    }

    final record TUnknown<T>(java.lang.reflect.Type klazz) implements Type {
        @Override
        public @Nullable java.lang.reflect.Type asClass() {
            return klazz;
        }

        @Override
        public String getName() {
            return klazz instanceof Class<?> k ? k.getSimpleName() : klazz.getTypeName();
        }
    }
}