/*
 * SpellTargetsEvaluatorTest.cpp, part of VCMI engine
 *
 * Authors: listed in file AUTHORS in main folder
 *
 * License: GNU General Public License v2.0 or later
 * Full text of license available in license.txt file, in main folder
 *
 */
#include "StdInc.h"

#include "../mock/BattleFake.h"
#include "../mock/mock_battle_Unit.h"
#include "../mock/mock_spells_Mechanics.h"
#include "AI/BattleAI/SpellTargetsEvaluator.h"
#include "lib/CStack.h"
#include "lib/battle/CBattleInfoCallback.h"

namespace test
{
using namespace ::testing;
using namespace spells;
using namespace battle;
using PossiblePositions = std::vector<BattleHex>;

class CBattleInfoCallbackMock : public CBattleInfoCallback
{
public:
	MOCK_CONST_METHOD1(battleGetAllUnits, battle::Units(bool));
	MOCK_CONST_METHOD0(getBattle, IBattleInfo *());
	MOCK_CONST_METHOD0(getPlayerID, std::optional<PlayerColor>());
#if SCRIPTING_ENABLED
	MOCK_CONST_METHOD0(getContextPool, scripting::Pool *());
#endif
};

class CStackMock : public CStack
{
public:
	MOCK_CONST_METHOD0(unitSide, BattleSide());
};

class SpellTargetEvaluatorTest : public ::testing::Test
{
public:
	MechanicsMock mechMock;
	CBattleInfoCallbackMock battleMock;
	battle::Units allUnits;
	TStacks allStacks;
	BattleSide casterSide = BattleSide::ATTACKER;
	BattleSide enemySide = BattleSide::DEFENDER;

	void SetUp() override
	{
		mechMock.casterSide = casterSide;
		ON_CALL(mechMock, battle()).WillByDefault(Return(&battleMock));
		ON_CALL(mechMock, canBeCastAt(_, _)).WillByDefault(Return(true));
	}

	void TearDown() override
	{
		for(const auto * unit : allUnits)
			delete unit;
		allUnits.clear();
		for(const auto * stack : allStacks)
			delete stack;
		allStacks.clear();
	}

	void spellTargetTypes(std::vector<AimType> targetTypes)
	{
		ON_CALL(mechMock, getTargetTypes()).WillByDefault(Return(std::move(targetTypes)));
	}

	CStackMock * addStack(BattleHex position, BattleSide battleSide, bool isSuspectible = true)
	{
		auto * stack = new CStackMock();
		ON_CALL(*stack, unitSide()).WillByDefault(Return(battleSide));
		allStacks.push_back(stack);
		auto * unit = new UnitMock();
		ON_CALL(*unit, getPosition()).WillByDefault(Return(position));
		allUnits.push_back(unit);

		if(!isSuspectible)
			ON_CALL(mechMock, canBeCastAt(Contains(Field(&Destination::hexValue, position)), _)).WillByDefault(Return(false));
		return stack;
	}

	void setAffectedStacksForCast(BattleHex position, std::vector<const CStack *> stacks)
	{
		ON_CALL(mechMock, getAffectedStacks(Contains(Field(&Destination::hexValue, position)))).WillByDefault(Return(stacks));
	}

	void confirmResults(std::vector<PossiblePositions> allRequiredCasts)
	{
		std::vector<Target> result = SpellTargetEvaluator::getViableTargets(&mechMock);
		basicCheck(result);
		ASSERT_EQ(result.size(), allRequiredCasts.size());

		std::vector<BattleHex> targetedHexes;
		targetedHexes.reserve(result.size());
		for(Target target : result)
			targetedHexes.push_back(target.front().hexValue);

		for(const PossiblePositions & requiredCast : allRequiredCasts)
			EXPECT_TRUE(containCommonValue(requiredCast, targetedHexes));
	}

	void basicCheck(std::vector<Target> & result)
	{
		for(const Target & target : result)
			EXPECT_EQ(target.size(), 1); //multi-destination spells are not handled by targetEvaluator
	}

	template<typename T>
	bool containCommonValue(const std::vector<T> & v1, const std::vector<T> & v2)
	{
		for(T val1 : v1)
		{
			for(T val2 : v2)
			{
				if(val1 == val2)
					return true;
			}
		}
		return false;
	}
};

TEST_F(SpellTargetEvaluatorTest, ReturnsEmptyIfMultiDestinationSpell)
{
	spellTargetTypes({AimType::CREATURE, AimType::LOCATION});
	std::vector<Target> result = SpellTargetEvaluator::getViableTargets(&mechMock);
	EXPECT_TRUE(result.empty());
}

TEST_F(SpellTargetEvaluatorTest, ReturnSingleEmptyDestinationIfTargetIsNone)
{
	spellTargetTypes({AimType::NO_TARGET});
	std::vector<Target> result = SpellTargetEvaluator::getViableTargets(&mechMock);
	EXPECT_EQ(result.size(), 1);
	EXPECT_TRUE(result.front().empty());
}

TEST_F(SpellTargetEvaluatorTest, ReturnsSuspectibleCreaturePositionsIfSpellTargetsCreatures)
{
	spellTargetTypes({AimType::CREATURE});

	addStack(BattleHex(1), casterSide);
	addStack(BattleHex(2), enemySide, false);
	addStack(BattleHex(3), casterSide);
	ON_CALL(battleMock, battleGetAllUnits(Eq(false))).WillByDefault(Return(allUnits));

	confirmResults({{BattleHex(1)}, {BattleHex(3)}});
}

TEST_F(SpellTargetEvaluatorTest, ReturnsSuspectibleCreaturePositionsAndSingleRandomSurroundingHexForEachStackIfNeutralLocationSpell)
{
	spellTargetTypes({AimType::LOCATION});
	ON_CALL(mechMock, isNeutralSpell()).WillByDefault(Return(true));

	addStack(BattleHex(72), casterSide);
	addStack(BattleHex(159), enemySide, false);
	addStack(BattleHex(23), casterSide);
	ON_CALL(battleMock, battleGetAllUnits(Eq(false))).WillByDefault(Return(allUnits));

	confirmResults(
		{{BattleHex(72)},
		 BattleHex(72).getAllNeighbouringTiles().toVector(),
		 BattleHex(159).getAllNeighbouringTiles().toVector(),
		 {BattleHex(23)},
		 BattleHex(23).getAllNeighbouringTiles().toVector()}
	);
}

TEST_F(SpellTargetEvaluatorTest, ReturnsOneCaseOfEachOptimalCastIfNegativeLocationSpell)
{
	spellTargetTypes({AimType::LOCATION});
	ON_CALL(mechMock, isNegativeSpell()).WillByDefault(Return(true));

	auto * enemyStack1 = addStack(BattleHex(90), enemySide);
	auto * enemyStack2 = addStack(BattleHex(106), enemySide);
	auto * enemyStack3 = addStack(BattleHex(1), enemySide);
	auto * enemyStack4 = addStack(BattleHex(37), enemySide);
	auto * enemyStack5 = addStack(BattleHex(41), enemySide);

	auto * alliedStack1 = addStack(BattleHex(107), casterSide);
	auto * alliedStack2 = addStack(BattleHex(19), casterSide);

	//optimal
	setAffectedStacksForCast(BattleHex(71), {enemyStack1, enemyStack2});
	setAffectedStacksForCast(BattleHex(88), {enemyStack1, enemyStack2});
	//suboptimal
	setAffectedStacksForCast(BattleHex(55), {enemyStack1});
	setAffectedStacksForCast(BattleHex(89), {enemyStack1, enemyStack2, alliedStack1});

	//optimal
	setAffectedStacksForCast(BattleHex(18), {enemyStack3, alliedStack2});
	setAffectedStacksForCast(BattleHex(2), {enemyStack3, alliedStack2});
	//suboptimal
	setAffectedStacksForCast(BattleHex(53), {alliedStack2});

	//optimal
	setAffectedStacksForCast(BattleHex(39), {enemyStack4, enemyStack5});
	//suboptimal
	setAffectedStacksForCast(BattleHex(21), {enemyStack4});
	setAffectedStacksForCast(BattleHex(25), {enemyStack5});

	confirmResults({
		{BattleHex(71), BattleHex(88)},
        {BattleHex(2), BattleHex(18)},
        {BattleHex(39)}
	});
}

}