#include <doctest/doctest.h>
#include "Components/Configs/WorldConfig.hpp"
#include "Core/WorldInstance.h"
#include "Components/Chute.hpp"

TEST_SUITE("Chute") {
	TEST_CASE("chute transports item from source to destination") {
		WorldConfig config{};
		uint16_t stoneID = config.RegisterItem("Stone");

		WorldInstance world{ config };

		// source inventory with items, destination empty
		auto source = world.GetEcsWorld().entity();
		Inventory_Helper(source, config, 100);
		source.ensure<Inventory>().AddItems(stoneID, 3);

		auto dest = world.GetEcsWorld().entity();
		Inventory_Helper(dest, config, 100);

		// vertical drop: (0,10) -> (0,0), should be fast
		std::vector<Vector2> path = { {0, 10}, {0, 0} };
		auto chuteEntity = world.GetEcsWorld().entity();
		Chute_Helper(chuteEntity, path,
			source.get<Inventory>(),
			dest.get<Inventory>());

		// get the transit time
		auto chute = chuteEntity.get<Chute>();
		uint16_t transitTicks = chute.Data.GetMetaData()->TicksToReachEnd;
		CHECK(transitTicks > 0);

		// tick once to pull items from source into chute
		world.ProcessFrame();

		auto srcInv = source.get<Inventory>();
		CHECK(srcInv.GetItemsAmount(stoneID) == 0);

		// tick until items arrive
		for (uint16_t i = 1; i < transitTicks; ++i)
			world.ProcessFrame();

		auto destInv = dest.get<Inventory>();
		CHECK(destInv.GetItemsAmount(stoneID) == 0);

		world.ProcessFrame();

		destInv = dest.get<Inventory>();
		CHECK(destInv.GetItemsAmount(stoneID) == 3);
	}

	TEST_CASE("chute respects transit time for longer paths") {
		WorldConfig config{};
		uint16_t ironID = config.RegisterItem("Iron");

		WorldInstance world{ config };

		auto source = world.GetEcsWorld().entity();
		Inventory_Helper(source, config, 100);
		source.ensure<Inventory>().AddItems(ironID, 1);

		auto dest = world.GetEcsWorld().entity();
		Inventory_Helper(dest, config, 100);

		// multi-link path with gradual descent
		std::vector<Vector2> path = { {0, 10}, {1, 9}, {2, 8}, {3, 7}, {4, 6}, {5, 5} };
		auto chuteEntity = world.GetEcsWorld().entity();
		Chute_Helper(chuteEntity, path,
			source.get<Inventory>(),
			dest.get<Inventory>());

		auto chute = chuteEntity.get<Chute>();
		uint16_t transitTicks = chute.Data.GetMetaData()->TicksToReachEnd;
		CHECK(transitTicks > 1);

		// pull items into chute
		world.ProcessFrame();

		// tick one less than transit time — item should not have arrived
		for (uint16_t i = 1; i < transitTicks; ++i)
			world.ProcessFrame();

		auto destInv = dest.get<Inventory>();
		CHECK(destInv.GetItemsAmount(ironID) == 0);

		// one more tick — item arrives
		world.ProcessFrame();

		destInv = dest.get<Inventory>();
		CHECK(destInv.GetItemsAmount(ironID) == 1);
	}

	TEST_CASE("chute overflows to world inventory when destination is full") {
		WorldConfig config{};
		uint16_t stoneID = config.RegisterItem("Stone");

		WorldInstance world{ config };

		auto source = world.GetEcsWorld().entity();
		Inventory_Helper(source, config, 100);
		source.ensure<Inventory>().AddItems(stoneID, 3);

		// destination can only hold 1
		auto dest = world.GetEcsWorld().entity();
		Inventory_Helper(dest, config, 1);

		std::vector<Vector2> path = { {0, 10}, {0, 0} };
		auto chuteEntity = world.GetEcsWorld().entity();
		Chute_Helper(chuteEntity, path,
			source.get<Inventory>(),
			dest.get<Inventory>());

		auto chute = chuteEntity.get<Chute>();
		uint16_t transitTicks = chute.Data.GetMetaData()->TicksToReachEnd;

		// tick enough for all items to arrive
		for (uint16_t i = 0; i <= transitTicks; ++i)
			world.ProcessFrame();

		auto destInv = dest.get<Inventory>();
		CHECK(destInv.GetItemsAmount(stoneID) == 1);

		auto& worldInv = world.GetEcsWorld().ensure<WorldInventory>();
		CHECK(worldInv.GetItemsAmount(stoneID) == 2);
	}

	TEST_CASE("horizontal chute uses minimum speed") {
		WorldConfig config{};
		uint16_t woodID = config.RegisterItem("Wood");

		WorldInstance world{ config };

		auto source = world.GetEcsWorld().entity();
		Inventory_Helper(source, config, 100);
		source.ensure<Inventory>().AddItems(woodID, 1);

		auto dest = world.GetEcsWorld().entity();
		Inventory_Helper(dest, config, 100);

		// flat path: dy=0 throughout, should use MinSpeed
		ChuteConfig chuteConfig{ .Gravity = 1.0f, .MinSpeed = 0.5f };
		std::vector<Vector2> path = { {0, 0}, {5, 0} };
		auto chuteEntity = world.GetEcsWorld().entity();
		Chute_Helper(chuteEntity, path,
			source.get<Inventory>(),
			dest.get<Inventory>(),
			chuteConfig);

		auto chute = chuteEntity.get<Chute>();
		uint16_t transitTicks = chute.Data.GetMetaData()->TicksToReachEnd;

		// distance=5, speed=0.5 -> 10 ticks
		CHECK(transitTicks == 10);

		// tick enough for item to arrive
		for (uint16_t i = 0; i <= transitTicks; ++i)
			world.ProcessFrame();

		auto destInv = dest.get<Inventory>();
		CHECK(destInv.GetItemsAmount(woodID) == 1);
	}
}