package net.minecraft.gametest.framework;

import com.mojang.brigadier.context.CommandContext;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;
import java.util.function.Supplier;
import java.util.function.UnaryOperator;
import java.util.stream.Stream;
import net.minecraft.commands.CommandSourceStack;
import net.minecraft.core.BlockPos;
import net.minecraft.core.Holder;

public class TestFinder implements TestInstanceFinder, TestPosFinder {
	private static final TestInstanceFinder NO_FUNCTIONS = Stream::empty;
	private static final TestPosFinder NO_STRUCTURES = Stream::empty;
	private final TestInstanceFinder testInstanceFinder;
	private final TestPosFinder testPosFinder;
	private final CommandSourceStack source;

	@Override
	public Stream<BlockPos> findTestPos() {
		return this.testPosFinder.findTestPos();
	}

	public static TestFinder.Builder builder() {
		return new TestFinder.Builder();
	}

	private TestFinder(final CommandSourceStack source, final TestInstanceFinder testInstanceFinder, final TestPosFinder testPosFinder) {
		this.source = source;
		this.testInstanceFinder = testInstanceFinder;
		this.testPosFinder = testPosFinder;
	}

	public CommandSourceStack source() {
		return this.source;
	}

	@Override
	public Stream<Holder.Reference<GameTestInstance>> findTests() {
		return this.testInstanceFinder.findTests();
	}

	public static class Builder {
		private final UnaryOperator<Supplier<Stream<Holder.Reference<GameTestInstance>>>> testFinderWrapper;
		private final UnaryOperator<Supplier<Stream<BlockPos>>> structureBlockPosFinderWrapper;

		public Builder() {
			this.testFinderWrapper = f -> f;
			this.structureBlockPosFinderWrapper = f -> f;
		}

		private Builder(
			final UnaryOperator<Supplier<Stream<Holder.Reference<GameTestInstance>>>> testFinderWrapper,
			final UnaryOperator<Supplier<Stream<BlockPos>>> structureBlockPosFinderWrapper
		) {
			this.testFinderWrapper = testFinderWrapper;
			this.structureBlockPosFinderWrapper = structureBlockPosFinderWrapper;
		}

		public TestFinder.Builder createMultipleCopies(final int amount) {
			return new TestFinder.Builder(createCopies(amount), createCopies(amount));
		}

		private static <Q> UnaryOperator<Supplier<Stream<Q>>> createCopies(final int amount) {
			return source -> {
				List<Q> copyList = new LinkedList();
				List<Q> sourceList = ((Stream)source.get()).toList();

				for (int i = 0; i < amount; i++) {
					copyList.addAll(sourceList);
				}

				return copyList::stream;
			};
		}

		private TestFinder build(final CommandSourceStack source, final TestInstanceFinder testInstanceFinder, final TestPosFinder testPosFinder) {
			return new TestFinder(
				source,
				((Supplier)this.testFinderWrapper.apply(testInstanceFinder::findTests))::get,
				((Supplier)this.structureBlockPosFinderWrapper.apply(testPosFinder::findTestPos))::get
			);
		}

		public TestFinder radius(final CommandContext<CommandSourceStack> sourceStack, final int radius) {
			CommandSourceStack source = sourceStack.getSource();
			BlockPos pos = BlockPos.containing(source.getPosition());
			return this.build(source, TestFinder.NO_FUNCTIONS, () -> StructureUtils.findTestBlocks(pos, radius, source.getLevel()));
		}

		public TestFinder nearest(final CommandContext<CommandSourceStack> sourceStack) {
			CommandSourceStack source = sourceStack.getSource();
			BlockPos pos = BlockPos.containing(source.getPosition());
			return this.build(source, TestFinder.NO_FUNCTIONS, () -> StructureUtils.findNearestTest(pos, 15, source.getLevel()).stream());
		}

		public TestFinder allNearby(final CommandContext<CommandSourceStack> sourceStack) {
			CommandSourceStack source = sourceStack.getSource();
			BlockPos pos = BlockPos.containing(source.getPosition());
			return this.build(source, TestFinder.NO_FUNCTIONS, () -> StructureUtils.findTestBlocks(pos, 250, source.getLevel()));
		}

		public TestFinder lookedAt(final CommandContext<CommandSourceStack> sourceStack) {
			CommandSourceStack source = sourceStack.getSource();
			return this.build(
				source,
				TestFinder.NO_FUNCTIONS,
				() -> StructureUtils.lookedAtTestPos(BlockPos.containing(source.getPosition()), source.getPlayer().getCamera(), source.getLevel())
			);
		}

		public TestFinder failedTests(final CommandContext<CommandSourceStack> sourceStack, final boolean onlyRequiredTests) {
			return this.build(
				sourceStack.getSource(),
				() -> FailedTestTracker.getLastFailedTests().filter(test -> !onlyRequiredTests || ((GameTestInstance)test.value()).required()),
				TestFinder.NO_STRUCTURES
			);
		}

		public TestFinder byResourceSelection(final CommandContext<CommandSourceStack> sourceStack, final Collection<Holder.Reference<GameTestInstance>> holders) {
			return this.build(sourceStack.getSource(), holders::stream, TestFinder.NO_STRUCTURES);
		}

		public TestFinder failedTests(final CommandContext<CommandSourceStack> sourceStack) {
			return this.failedTests(sourceStack, false);
		}
	}
}