/**
 * @file dun_render.hpp
 *
 * Interface of functionality for rendering the level tiles.
 */
#pragma once

#include <cstdint>

#include <SDL_endian.h>

#include "engine.h"

// #define DUN_RENDER_STATS
#ifdef DUN_RENDER_STATS
#include <unordered_map>
#endif

namespace devilution {

/**
 * Level tile type.
 *
 * The tile type determines data encoding and the shape.
 *
 * Each tile type has its own encoding but they all encode data in the order
 * of bottom-to-top (bottom row first).
 */
enum class TileType : uint8_t {
	/**
	 * 🮆 A 32x32 square. Stored as an array of pixels.
	 */
	Square,

	/**
	 * 🮆 A 32x32 square with transparency. RLE encoded.
	 *
	 * Each run starts with an int8_t value.
	 * If positive, it is followed by this many pixels.
	 * If negative, it indicates `-value` fully transparent pixels, which are omitted.
	 *
	 * Runs do not cross row boundaries.
	 */
	TransparentSquare,

	/**
	 *🭮 Left-pointing 32x31 triangle. Encoded as 31 varying-width rows with 2 padding bytes before every even row.
	 *
	 * The smallest rows (bottom and top) are 2px wide, the largest row is 16px wide (middle row).
	 *
	 * Encoding:
	 * for i in [0, 30]:
	 * - 2 unused bytes if i is even
	 * - row (only the pixels within the triangle)
	 */
	LeftTriangle,

	/**
	 * 🭬Right-pointing 32x31 triangle.  Encoded as 31 varying-width rows with 2 padding bytes after every even row.
	 *
	 * The smallest rows (bottom and top) are 2px wide, the largest row is 16px wide (middle row).
	 *
	 * Encoding:
	 * for i in [0, 30]:
	 * - row (only the pixels within the triangle)
	 * - 2 unused bytes if i is even
	 */
	RightTriangle,

	/**
	 * 🭓 Left-pointing 32x32 trapezoid: a 32x16 rectangle and the 16x16 bottom part of `LeftTriangle`.
	 *
	 * Begins with triangle part, which uses the `LeftTriangle` encoding,
	 * and is followed by a flat array of pixels for the top rectangle part.
	 */
	LeftTrapezoid,

	/**
	 * 🭞 Right-pointing 32x32 trapezoid: 32x16 rectangle and the 16x16 bottom part of `RightTriangle`.
	 *
	 * Begins with the triangle part, which uses the `RightTriangle` encoding,
	 * and is followed by a flat array of pixels for the top rectangle part.
	 */
	RightTrapezoid,
};

/**
 * @brief Specifies the mask to use for rendering.
 */
enum class MaskType : uint8_t {
	/** @brief The entire tile is opaque. */
	Solid,

	/** @brief The entire tile is blended with transparency. */
	Transparent,

	/**
	 * @brief Upper-right triangle is blended with transparency.
	 *
	 * Can only be used with `TileType::LeftTrapezoid` and
	 * `TileType::TransparentSquare`.
	 *
	 * The lower 16 rows are opaque.
	 * The upper 16 rows are arranged like this (🮆 = opaque, 🮐 = blended):
	 *
	 * 🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 */
	Right,

	/**
	 * @brief Upper-left triangle is blended with transparency.
	 *
	 * Can only be used with `TileType::RightTrapezoid` and
	 * `TileType::TransparentSquare`.
	 *
	 * The lower 16 rows are opaque.
	 * The upper 16 rows are arranged like this (🮆 = opaque, 🮐 = blended):
	 *
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 */
	Left,

	/**
	 * @brief Only the upper-left triangle is rendered.
	 *
	 * Can only be used with `TileType::TransparentSquare`.
	 *
	 * The lower 16 rows are skipped.
	 * The upper 16 rows are arranged like this (🮆 = opaque, 🮐 = not rendered):
	 *
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆🮆🮆
	 * 🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮆🮆
	 */
	RightFoliage,

	/**
	 * @brief Only the upper right triangle is rendered.
	 *
	 * Can only be used with `TileType::TransparentSquare`.
	 *
	 * The lower 16 rows are skipped.
	 * The upper 16 rows are arranged like this (🮆 = opaque, 🮐 = not rendered):
	 *
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 * 🮆🮆🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐🮐
	 */
	LeftFoliage,
};

/**
 * Specifies the current MIN block of the level CEL file, as used during rendering of the level tiles.
 */
class LevelCelBlock {
public:
	explicit LevelCelBlock(uint16_t data)
	    : data_(data)
	{
	}

	[[nodiscard]] bool hasValue() const
	{
		return data_ != 0;
	}

	[[nodiscard]] TileType type() const
	{
		return static_cast<TileType>((data_ & 0x7000) >> 12);
	}

	[[nodiscard]] uint16_t frame() const
	{
		return data_ & 0xFFF;
	}

private:
	uint16_t data_;
};

#ifdef DUN_RENDER_STATS
struct DunRenderType {
	TileType tileType;
	MaskType maskType;
	bool operator==(const DunRenderType &other) const
	{
		return tileType == other.tileType && maskType == other.maskType;
	}
};
struct DunRenderTypeHash {
	size_t operator()(DunRenderType t) const noexcept
	{
		return std::hash<uint32_t> {}((1 < static_cast<uint8_t>(t.tileType)) | static_cast<uint8_t>(t.maskType));
	}
};
extern std::unordered_map<DunRenderType, size_t, DunRenderTypeHash> DunRenderStats;

string_view TileTypeToString(TileType tileType);

string_view MaskTypeToString(MaskType maskType);
#endif

/**
 * @brief Blit current world CEL to the given buffer
 * @param out Target buffer
 * @param position Target buffer coordinates
 * @param levelCelBlock The MIN block of the level CEL file.
 * @param maskType The mask to use,
 * @param lightTableIndex The light level to use for rendering (index into LightTables / 256).
 */
void RenderTile(const Surface &out, Point position,
    LevelCelBlock levelCelBlock, MaskType maskType, uint8_t lightTableIndex);

/**
 * @brief Render a black 64x31 tile ◆
 * @param out Target buffer
 * @param sx Target buffer coordinate (left corner of the tile)
 * @param sy Target buffer coordinate (bottom corner of the tile)
 */
void world_draw_black_tile(const Surface &out, int sx, int sy);

} // namespace devilution