package io.gitlab.jfronny.libjf.unsafe;

import net.fabricmc.loader.api.FabricLoader;
import net.fabricmc.loader.api.ModContainer;
import net.fabricmc.loader.impl.ModContainerImpl;
import net.fabricmc.loader.impl.metadata.EntrypointMetadata;

import java.lang.reflect.InvocationTargetException;
import java.util.*;
import java.util.function.Consumer;

public class DynamicEntry {
    /**
     * Execute an entrypoint.
     *
     * @param name           the name of the entrypoint to execute.
     * @param entrypointType the entrypoint type.
     * @param onExecute      entrypoint execution callback with an instance of the entrypoint type.
     * @param <T>            the entrypoint type.
     */
    public static <T> void execute(final String name, final Class<T> entrypointType, final Consumer<ConsumableEntrypoint<T>> onExecute) {
        final List<ConsumableEntrypoint<T>> targets = new ArrayList<>();
        for (final EntrypointContainer entrypoint : getEntrypointTargets(name)) {
            try {
                targets.add(new ConsumableEntrypoint<>(
                        entrypointType.cast(Class.forName(entrypoint.entrypoint).getConstructor().newInstance()),
                        entrypoint.mod
                ));
            } catch (final ClassNotFoundException exception) {
                throw new IllegalArgumentException(String.format("class %s specified in the %s entrypoint of mod %s does not exist", entrypoint.entrypoint, name, entrypoint.mod), exception);
            } catch (final IllegalAccessException | InstantiationException | NoSuchMethodException exception) {
                throw new IllegalStateException(String.format("class %s specified in the %s entrypoint of mod %s cannot be instantiated", entrypoint.entrypoint, name, entrypoint.mod), exception);
            } catch (final InvocationTargetException exception) {
                throw new RuntimeException(String.format("an error was encountered during the instantiation of the %s entrypoint class %s", name, entrypoint.entrypoint), exception);
            }
        }

        for (ConsumableEntrypoint<T> target : targets) {
            onExecute.accept(target);
        }
    }

    private static Collection<EntrypointContainer> getEntrypointTargets(final String entrypoint) {
        final List<EntrypointContainer> entrypoints = new LinkedList<>();
        for (final ModContainer mod : FabricLoader.getInstance().getAllMods()) {
            final List<EntrypointMetadata> modEntrypoints = ((ModContainerImpl)mod).getMetadata().getEntrypoints(entrypoint);

            if (modEntrypoints != null) {
                for (final EntrypointMetadata metadata : modEntrypoints) {
                    entrypoints.add(new EntrypointContainer(metadata.getValue(), mod.getMetadata().getId()));
                }
            }
        }

        return entrypoints;
    }

    record EntrypointContainer(String entrypoint, String mod) {
    }

    public record ConsumableEntrypoint<T>(T instance, String modId) {
    }
}