/*
	Mechanics of Sliding Puzzle Game
	"Just let me go home... please!!!" - javidx9

	License (OLC-3)
	~~~~~~~~~~~~~~~

	Copyright 2018-2020 OneLoneCoder.com

	Redistribution and use in source and binary forms, with or without
	modification, are permitted provided that the following conditions
	are met:

	1. Redistributions or derivations of source code must retain the above
	copyright notice, this list of conditions and the following disclaimer.

	2. Redistributions or derivative works in binary form must reproduce
	the above copyright notice. This list of conditions and the following
	disclaimer must be reproduced in the documentation and/or other
	materials provided with the distribution.

	3. Neither the name of the copyright holder nor the names of its
	contributors may be used to endorse or promote products derived
	from this software without specific prior written permission.

	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

	Relevant Video: https://www.youtube.com/watch?v=l7YEaa2otVE

	Links
	~~~~~
	YouTube:	https://www.youtube.com/javidx9
				https://www.youtube.com/javidx9extra
	Discord:	https://discord.gg/WhwHUMV
	Twitter:	https://www.twitter.com/javidx9
	Twitch:		https://www.twitch.tv/javidx9
	GitHub:		https://www.github.com/onelonecoder
	Patreon:	https://www.patreon.com/javidx9
	Homepage:	https://www.onelonecoder.com

	Community Blog: https://community.onelonecoder.com

	Author
	~~~~~~
	David Barr, aka javidx9, ŠOneLoneCoder 2018, 2019, 2020
*/

#define OLC_PGE_APPLICATION
#include "olcPixelGameEngine.h"


constexpr int NORTH = 0;
constexpr int EAST = 1;
constexpr int SOUTH = 2;
constexpr int WEST = 3;


class BlockPuzzle : public olc::PixelGameEngine
{
public:
	BlockPuzzle()
	{
		sAppName = "BlockPuzzle";
	}

	std::string sLevel =
		"################"
		"#..............#"
		"#...+....+.....#"
		"#........+..|..#"
		"#........+..|..#"
		"#....P......|..#"
		"#..5....---....#"
		"#..............#"
		"#..+++....#..@.#"
		"#.........#..@.#"
		"#..-.........@.#"
		"#.....+....|...#"
		"#........+.....#"
		"#..............#"
		"################";

	olc::vf2d vLevelSize = { 16, 15 };
	olc::vf2d vBlockSize = { 16, 16 };

	std::vector<olc::vi2d> vGoals;

	olc::Renderable gfxTiles;

	struct block
	{
		block()
		{

		}

		virtual void DrawSelf(olc::PixelGameEngine* pge, const olc::vi2d& pos, const olc::vi2d& size, const olc::Renderable& skin)
		{

		}

		virtual bool Push(const int from)
		{
			return true;
		}

		virtual void Move()
		{

		}

	};

	struct block_solid : public block
	{		
		void DrawSelf(olc::PixelGameEngine* pge, const olc::vi2d& pos, const olc::vi2d& size, const olc::Renderable& skin) override
		{
			//pge->FillRect(pos * size, size, olc::BLUE);
			pge->DrawPartialSprite(pos * size, skin.Sprite(), olc::vi2d(0, 0) * size, size);

		}

		bool Push(const int from) override
		{
			return false;
		}

	};


	struct block_player : public block
	{
		void DrawSelf(olc::PixelGameEngine* pge, const olc::vi2d& pos, const olc::vi2d& size, const olc::Renderable& skin) override
		{
			pge->FillRect(pos * size, size, olc::WHITE);
		}

		bool Push(const int from) override
		{
			return true;
		}
	};


	struct block_simple : public block
	{
		void DrawSelf(olc::PixelGameEngine* pge, const olc::vi2d& pos, const olc::vi2d& size, const olc::Renderable& skin) override
		{
			//pge->FillRect(pos * size, size, olc::RED);
			pge->DrawPartialSprite(pos * size, skin.Sprite(), olc::vi2d(1, 0) * size, size);
		}

		bool Push(const int from) override
		{
			return true;
		}
	};


	struct block_horizontal : public block
	{
		void DrawSelf(olc::PixelGameEngine* pge, const olc::vi2d& pos, const olc::vi2d& size, const olc::Renderable& skin) override
		{
			//pge->FillRect(pos * size, size, olc::GREEN);
			pge->DrawPartialSprite(pos * size, skin.Sprite(), olc::vi2d(3, 0) * size, size);
		}

		bool Push(const int from) override
		{
			return from == EAST || from == WEST;
		}
	};

	struct block_vertical : public block
	{
		void DrawSelf(olc::PixelGameEngine* pge, const olc::vi2d& pos, const olc::vi2d& size, const olc::Renderable& skin) override
		{
			//pge->FillRect(pos * size, size, olc::YELLOW);
			pge->DrawPartialSprite(pos * size, skin.Sprite(), olc::vi2d(2, 0) * size, size);
		}

		bool Push(const int from) override
		{
			return from == NORTH || from == SOUTH;
		}
	};

	struct block_countdown : public block
	{
		block_countdown(int m)
		{
			nMoves = m;
		}

		void DrawSelf(olc::PixelGameEngine* pge, const olc::vi2d& pos, const olc::vi2d& size, const olc::Renderable& skin) override
		{
			//pge->FillRect(pos * size, size, olc::CYAN);
			pge->DrawPartialSprite(pos * size, skin.Sprite(), olc::vi2d(4, 0) * size, size);
			pge->DrawString(pos * size + olc::vi2d(4, 4), std::to_string(nMoves), olc::BLACK);
		}

		bool Push(const int from) override
		{
			return nMoves > 0;
		}

		void Move() override
		{
			nMoves--;
		}

		int nMoves = 0;
	};


	olc::vi2d vPlayer;
	std::vector<std::unique_ptr<block>> vLevel;


public:
	void LoadLevel(int n)
	{
		vLevel.clear();
		vGoals.clear();


		for (int y = 0; y < vLevelSize.y; y++)
		{
			for (int x = 0; x < vLevelSize.x; x++)
			{
				switch (sLevel[y * vLevelSize.x + x])
				{
				case '#':
					vLevel.emplace_back(std::make_unique<block_solid>());
					break;

				case 'P':
					vLevel.emplace_back(std::make_unique<block_player>());
					vPlayer = { x, y };
					break;

				case '+':
					vLevel.emplace_back(std::make_unique<block_simple>());
					break;

				case '-':
					vLevel.emplace_back(std::make_unique<block_horizontal>());
					break;

				case '|':
					vLevel.emplace_back(std::make_unique<block_vertical>());
					break;

				case '5':
					vLevel.emplace_back(std::make_unique<block_countdown>(5));
					break;

				case '@':
					vGoals.push_back({ x, y });
					vLevel.emplace_back(nullptr);
					break;
			

				default:
					vLevel.emplace_back(nullptr);
				}
			}
		}
	}

	bool OnUserCreate() override
	{
		gfxTiles.Load("./gfx/blocks.png");
		LoadLevel(0);
		return true;
	}

	bool OnUserUpdate(float fElapsedTime) override
	{

		bool bPushing = false;
		int dirPush = 0;

		if (GetKey(olc::Key::W).bPressed)
		{
			dirPush = NORTH;
			bPushing = true;
		}

		if (GetKey(olc::Key::S).bPressed)
		{
			dirPush = SOUTH;
			bPushing = true;
		}

		if (GetKey(olc::Key::A).bPressed)
		{
			dirPush = WEST;
			bPushing = true;
		}

		if (GetKey(olc::Key::D).bPressed)
		{
			dirPush = EAST;
			bPushing = true;
		}

		if (GetKey(olc::Key::R).bPressed)
		{
			LoadLevel(0);
		}

		auto id = [&](olc::vi2d& pos) { return pos.y * vLevelSize.x + pos.x; };

		if (bPushing)
		{
			olc::vi2d vBlock = vPlayer;

			bool bAllowPush = false;
			bool bTest = true;

			while (bTest)
			{
				if (vLevel[id(vBlock)] != nullptr)
				{
					if (vLevel[id(vBlock)]->Push((dirPush + 2) % 4))
					{
						// Block allows push
						switch (dirPush)
						{
						case NORTH: vBlock.y--; break;
						case SOUTH: vBlock.y++; break;
						case EAST: vBlock.x++; break;
						case WEST: vBlock.x--; break;
						}
					}
					else
						bTest = false;
				}
				else
				{
					bAllowPush = true;
					bTest = false;
				}
			}

			if (bAllowPush)
			{
				while (vBlock != vPlayer)
				{
					olc::vi2d vSource = vBlock;
					switch (dirPush)
					{
					case NORTH: vSource.y++; break;
					case SOUTH: vSource.y--; break;
					case EAST: vSource.x--; break;
					case WEST: vSource.x++; break;
					}


					if (vLevel[id(vSource)] != nullptr) vLevel[id(vSource)]->Move();
					std::swap(vLevel[id(vSource)], vLevel[id(vBlock)]);

					vBlock = vSource;
				}

				switch (dirPush)
				{
				case NORTH: vPlayer.y--; break;
				case SOUTH: vPlayer.y++; break;
				case EAST: vPlayer.x++; break;
				case WEST: vPlayer.x--; break;
				}

			}

		}


		int nGoals = 0;
		for (auto& g : vGoals)
			if (vLevel[id(g)]) nGoals++;


		Clear(olc::BLACK);


		for (auto& g : vGoals)
			FillCircle(g * vBlockSize + vBlockSize / 2, vBlockSize.x / 2 - 2, olc::YELLOW);


		olc::vi2d vTilePos = { 0,0 };
		for (vTilePos.y = 0; vTilePos.y < vLevelSize.y; vTilePos.y++)
		{
			for (vTilePos.x = 0; vTilePos.x < vLevelSize.x; vTilePos.x++)
			{

				auto& b = vLevel[id(vTilePos)];


				if (b)
				{
					b->DrawSelf(this, vTilePos, vBlockSize, gfxTiles);
				}
			}
		}

		DrawString(4, 4, "Goals: " + std::to_string(nGoals) + " / " + std::to_string(vGoals.size()), olc::WHITE);


		return true;
	}
};

int main()
{
	BlockPuzzle demo;
	if (demo.Construct(256, 240, 4, 4))
		demo.Start();
	return 0;
}