#pragma once

#include "../rsx_utils.h"
#include "TextureUtils.h"

namespace rsx
{
	using texture_channel_remap_t = std::pair<std::array<u8, 4>, std::array<u8, 4>>;

	// Defines pixel operation to be performed on a surface before it is ready for use
	enum surface_transform : u32
	{
		identity = 0,                // Nothing
		argb_to_bgra = 1,            // Swap ARGB to BGRA (endian swap)
		coordinate_transform = 2     // Incoming source coordinates may generated based on the format of the secondary (dest) surface. Recalculate them before use.
	};

	template<typename image_resource_type>
	struct copy_region_descriptor_base
	{
		image_resource_type src;
		flags32_t xform;
		u8  level;
		u16 src_x;
		u16 src_y;
		u16 dst_x;
		u16 dst_y;
		u16 dst_z;
		u16 src_w;
		u16 src_h;
		u16 dst_w;
		u16 dst_h;
	};

	// Deferred texture processing commands
	enum class deferred_request_command : u32
	{
		nop = 0,                  // Nothing
		copy_image_static,        // Copy image and cache the results
		copy_image_dynamic,       // Copy image but do not cache the results
		cubemap_gather,           // Provided list of sections generates a cubemap
		cubemap_unwrap,           // One large texture provided to be partitioned into a cubemap
		atlas_gather,             // Provided list of sections generates a texture atlas
		_3d_gather,               // Provided list of sections generates a 3D array
		_3d_unwrap,               // One large texture provided to be partitioned into a 3D array
		mipmap_gather             // Provided list of sections to be reassembled as mipmap levels of the same texture
	};

	struct image_section_attributes_t
	{
		u32 address;
		u32 gcm_format;
		u16 width;
		u16 height;
		u16 depth;
		u16 pitch;
		u16 slice_h;
		u8  bpp;
	};

	struct blit_op_result
	{
		bool succeeded = false;
		u32 real_dst_address = 0;
		u32 real_dst_size = 0;

		blit_op_result(bool success) : succeeded(success)
		{}

		inline address_range to_address_range() const
		{
			return address_range::start_length(real_dst_address, real_dst_size);
		}
	};

	struct texture_cache_search_options
	{
		u8 lookup_mask = 0xff;
		bool is_compressed_format = false;
		bool skip_texture_barriers = false;
		bool skip_texture_merge = false;
		bool prefer_surface_cache = false;
	};

	namespace texture_cache_helpers
	{
		static inline bool is_gcm_depth_format(u32 format)
		{
			switch (format)
			{
			case CELL_GCM_TEXTURE_DEPTH16:
			case CELL_GCM_TEXTURE_DEPTH16_FLOAT:
			case CELL_GCM_TEXTURE_DEPTH24_D8:
			case CELL_GCM_TEXTURE_DEPTH24_D8_FLOAT:
				return true;
			default:
				return false;
			}
		}

		static inline u32 get_compatible_depth_format(u32 gcm_format)
		{
			switch (gcm_format)
			{
			case CELL_GCM_TEXTURE_DEPTH24_D8:
			case CELL_GCM_TEXTURE_DEPTH24_D8_FLOAT:
			case CELL_GCM_TEXTURE_A8R8G8B8:
				return CELL_GCM_TEXTURE_DEPTH24_D8;
			case CELL_GCM_TEXTURE_DEPTH16:
			case CELL_GCM_TEXTURE_DEPTH16_FLOAT:
			case CELL_GCM_TEXTURE_X16:
				//case CELL_GCM_TEXTURE_A4R4G4B4:
				//case CELL_GCM_TEXTURE_G8B8:
				//case CELL_GCM_TEXTURE_A1R5G5B5:
				//case CELL_GCM_TEXTURE_R5G5B5A1:
				//case CELL_GCM_TEXTURE_R5G6B5:
				//case CELL_GCM_TEXTURE_R6G5B5:
				return CELL_GCM_TEXTURE_DEPTH16;
			}

			LOG_ERROR(RSX, "Unsupported depth conversion (0x%X)", gcm_format);
			return gcm_format;
		}

		static inline u32 get_sized_blit_format(bool _32_bit, bool depth_format)
		{
			if (LIKELY(_32_bit))
			{
				return (!depth_format) ? CELL_GCM_TEXTURE_A8R8G8B8 : CELL_GCM_TEXTURE_DEPTH24_D8;
			}
			else
			{
				return (!depth_format) ? CELL_GCM_TEXTURE_R5G6B5 : CELL_GCM_TEXTURE_DEPTH16;
			}
		}

		static inline bool is_compressed_gcm_format(u32 format)
		{
			switch (format)
			{
			default:
				return false;
			case CELL_GCM_TEXTURE_COMPRESSED_DXT1:
			case CELL_GCM_TEXTURE_COMPRESSED_DXT23:
			case CELL_GCM_TEXTURE_COMPRESSED_DXT45:
			case CELL_GCM_TEXTURE_COMPRESSED_B8R8_G8R8:
			case CELL_GCM_TEXTURE_COMPRESSED_R8B8_R8G8:
			case CELL_GCM_TEXTURE_COMPRESSED_HILO8:
			case CELL_GCM_TEXTURE_COMPRESSED_HILO_S8:
				return true;
			}
		}

		static inline format_type get_format_class(u32 gcm_format)
		{
			switch (gcm_format)
			{
			default:
				return format_type::color;
			case CELL_GCM_TEXTURE_DEPTH16:
			case CELL_GCM_TEXTURE_DEPTH24_D8:
				return format_type::depth_uint;
			case CELL_GCM_TEXTURE_DEPTH16_FLOAT:
			case CELL_GCM_TEXTURE_DEPTH24_D8_FLOAT:
				return format_type::depth_float;
			}
		}

		template<typename section_storage_type, typename copy_region_type, typename surface_store_list_type>
		void gather_texture_slices(
			std::vector<copy_region_type>& out,
			const surface_store_list_type& fbos,
			const std::vector<section_storage_type*>& local,
			const image_section_attributes_t& attr,
			u16 count, bool is_depth)
		{
			// Need to preserve sorting order
			struct sort_helper
			{
				u64 tag;   // Timestamp
				u32 list;  // List source, 0 = fbo, 1 = local
				u32 index; // Index in list
			};

			std::vector<sort_helper> sort_list;

			if (!fbos.empty() && !local.empty())
			{
				// Generate sorting tree if both resources are available and overlapping
				sort_list.reserve(fbos.size() + local.size());

				for (u32 index = 0; index < fbos.size(); ++index)
				{
					sort_list.push_back({ fbos[index].surface->last_use_tag, 0, index });
				}

				for (u32 index = 0; index < local.size(); ++index)
				{
					if (local[index]->get_context() != rsx::texture_upload_context::blit_engine_dst)
						continue;

					sort_list.push_back({ local[index]->last_write_tag, 1, index });
				}

				std::sort(sort_list.begin(), sort_list.end(), [](const auto& a, const auto& b)
				{
					return (a.tag < b.tag);
				});
			}

			auto add_rtt_resource = [&](auto& section, u16 slice)
			{
				if (section.is_depth != is_depth)
				{
					// TODO
					return;
				}

				const u32 slice_begin = (slice * attr.slice_h);
				const u32 slice_end = (slice_begin + attr.height);

				const u32 section_end = section.dst_area.y + section.dst_area.height;
				if (section.dst_area.y >= slice_end || section_end <= slice_begin)
				{
					// Belongs to a different slice
					return;
				}

				// How much of this slice to read?
				int rebased = int(section.dst_area.y) - slice_begin;
				const auto src_x = section.src_area.x;
				const auto dst_x = section.dst_area.x;
				auto src_y = section.src_area.y;
				auto dst_y = section.dst_area.y;

				if (rebased < 0)
				{
					const u16 delta = u16(-rebased);
					src_y += delta;
					dst_y += delta;
				}

				verify(HERE), dst_y >= slice_begin;
				dst_y = (dst_y - slice_begin);

				const auto h = std::min(section_end, slice_end) - section.dst_area.y;
				const auto src_width = rsx::apply_resolution_scale(section.src_area.width, true);
				const auto src_height = rsx::apply_resolution_scale(h, true);
				const auto dst_width = rsx::apply_resolution_scale(section.dst_area.width, true);
				const auto dst_height = src_height;

				out.push_back
				({
					section.surface->get_surface(rsx::surface_access::read),
					surface_transform::identity,
					0,
					rsx::apply_resolution_scale(src_x, true),
					rsx::apply_resolution_scale(src_y, true),
					rsx::apply_resolution_scale(dst_x, true),
					rsx::apply_resolution_scale(dst_y, true),
					slice,
					src_width, src_height,
					dst_width, dst_height
					});
			};

			auto add_local_resource = [&](auto& section, u32 address, u16 slice, bool scaling = true)
			{
				if (section->is_depth_texture() != is_depth)
				{
					// TODO
					return;
				}

				// Intersect this resource with the original one
				const auto section_bpp = get_format_block_size_in_bytes(section->get_gcm_format());
				const auto normalized_width = (section->get_width() * section_bpp) / attr.bpp;

				const auto clipped = rsx::intersect_region(
					section->get_section_base(), normalized_width, section->get_height(), section_bpp, /* parent region (extractee) */
					address, attr.width, attr.slice_h, attr.bpp, /* child region (extracted) */
					attr.pitch);

				// Rect intersection test
				// TODO: Make the intersection code cleaner with proper 2D regions
				if (std::get<0>(clipped).x >= section->get_width())
				{
					// Overlap lies outside the image area!
					return;
				}

				const u32 slice_begin = slice * attr.slice_h;
				const u32 slice_end = slice_begin + attr.height;

				const auto dst_y = std::get<1>(clipped).y;
				const auto dst_h = std::get<2>(clipped).height;

				const auto section_end = dst_y + dst_h;
				if (dst_y >= slice_end || section_end <= slice_begin)
				{
					// Belongs to a different slice
					return;
				}

				const u16 dst_w = static_cast<u16>(std::get<2>(clipped).width);
				const u16 src_w = static_cast<u16>(dst_w * attr.bpp) / section_bpp;
				const u16 height = static_cast<u16>(std::get<2>(clipped).height);

				if (scaling)
				{
					// Since output is upscaled, also upscale on dst
					out.push_back
					({
						section->get_raw_texture(),
						surface_transform::identity,
						0,
						static_cast<u16>(std::get<0>(clipped).x),
						static_cast<u16>(std::get<0>(clipped).y),
						rsx::apply_resolution_scale(static_cast<u16>(std::get<1>(clipped).x), true),
						rsx::apply_resolution_scale(static_cast<u16>(std::get<1>(clipped).y), true),
						slice,
						src_w,
						height,
						rsx::apply_resolution_scale(dst_w, true),
						rsx::apply_resolution_scale(height, true),
						});
				}
				else
				{
					out.push_back
					({
						section->get_raw_texture(),
						surface_transform::identity,
						0,
						static_cast<u16>(std::get<0>(clipped).x),
						static_cast<u16>(std::get<0>(clipped).y),
						static_cast<u16>(std::get<1>(clipped).x),
						static_cast<u16>(std::get<1>(clipped).y),
						0,
						src_w,
						height,
						dst_w,
						height,
						});
				}
			};

			u32 current_address = attr.address;
			u16 current_src_offset = 0;
			u16 current_dst_offset = 0;
			u32 slice_size = (attr.pitch * attr.slice_h);

			out.reserve(count);
			u16 found_slices = 0;

			for (u16 slice = 0; slice < count; ++slice)
			{
				auto num_surface = out.size();

				if (LIKELY(local.empty()))
				{
					for (auto& section : fbos)
					{
						add_rtt_resource(section, slice);
					}
				}
				else if (fbos.empty())
				{
					for (auto& section : local)
					{
						add_local_resource(section, current_address, slice, false);
					}
				}
				else
				{
					for (const auto& e : sort_list)
					{
						if (e.list == 0)
						{
							add_rtt_resource(fbos[e.index], slice);
						}
						else
						{
							add_local_resource(local[e.index], current_address, slice);
						}
					}
				}

				current_address += slice_size;
				if (out.size() != num_surface)
				{
					found_slices++;
				}
			}

			if (found_slices < count)
			{
				if (found_slices > 0)
				{
					//TODO: Gather remaining sides from the texture cache or upload from cpu (too slow?)
					LOG_ERROR(RSX, "Could not gather all required slices for cubemap/3d generation");
				}
				else
				{
					LOG_WARNING(RSX, "Could not gather textures into an atlas; using CPU fallback...");
				}
			}
		}

		template<typename render_target_type>
		bool check_framebuffer_resource(
			render_target_type texptr,
			const image_section_attributes_t& attr,
			texture_dimension_extended extended_dimension)
		{
			if (!rsx::pitch_compatible(texptr, attr.pitch, attr.height))
			{
				return false;
			}

			const auto surface_width = texptr->get_surface_width(rsx::surface_metrics::samples);
			const auto surface_height = texptr->get_surface_height(rsx::surface_metrics::samples);

			switch (extended_dimension)
			{
			case rsx::texture_dimension_extended::texture_dimension_1d:
				return (surface_width >= attr.width);
			case rsx::texture_dimension_extended::texture_dimension_2d:
				return (surface_width >= attr.width && surface_height >= attr.height);
			case rsx::texture_dimension_extended::texture_dimension_3d:
				return (surface_width >= attr.width && surface_height >= (attr.slice_h * attr.depth));
			case rsx::texture_dimension_extended::texture_dimension_cubemap:
				return (surface_width == attr.height && surface_width >= attr.width && surface_height >= (attr.slice_h * 6));
			}

			return false;
		}

		template <typename sampled_image_descriptor, typename commandbuffer_type, typename render_target_type>
		sampled_image_descriptor process_framebuffer_resource_fast(commandbuffer_type& cmd,
			render_target_type texptr,
			const image_section_attributes_t& attr,
			const size2f& scale,
			texture_dimension_extended extended_dimension,
			u32 encoded_remap, const texture_channel_remap_t& decoded_remap,
			bool surface_is_rop_target,
			bool force_convert)
		{
			texptr->read_barrier(cmd);

			const auto surface_width = texptr->get_surface_width(rsx::surface_metrics::samples);
			const auto surface_height = texptr->get_surface_height(rsx::surface_metrics::samples);

			bool is_depth = texptr->is_depth_surface();
			auto attr2 = attr;

			if (const bool gcm_format_is_depth = is_gcm_depth_format(attr2.gcm_format);
				gcm_format_is_depth != is_depth)
			{
				if (force_convert)
				{
					is_depth = gcm_format_is_depth;
				}
				else
				{
					attr2.gcm_format = get_compatible_depth_format(attr2.gcm_format);
				}

				// Always make sure the conflict is resolved!
				verify(HERE), is_gcm_depth_format(attr2.gcm_format) == is_depth;
			}

			if (LIKELY(extended_dimension == rsx::texture_dimension_extended::texture_dimension_2d ||
				extended_dimension == rsx::texture_dimension_extended::texture_dimension_1d))
			{
				if (extended_dimension == rsx::texture_dimension_extended::texture_dimension_1d)
				{
					verify(HERE), attr.height == 1;
				}

				if ((surface_is_rop_target && g_cfg.video.strict_rendering_mode) ||
					attr2.width < surface_width ||
					attr2.height < surface_height ||
					force_convert)
				{
					const auto scaled_w = rsx::apply_resolution_scale(attr2.width, true);
					const auto scaled_h = rsx::apply_resolution_scale(attr2.height, true);

					const auto format_class = (force_convert) ? get_format_class(attr2.gcm_format) : texptr->get_format_type();
					const auto command = surface_is_rop_target ? deferred_request_command::copy_image_dynamic : deferred_request_command::copy_image_static;

					attr2.width = scaled_w;
					attr2.height = scaled_h;

					return { texptr->get_surface(rsx::surface_access::read), command, attr2, {},
							texture_upload_context::framebuffer_storage, format_class, scale,
							extended_dimension, decoded_remap };
				}

				return{ texptr->get_view(encoded_remap, decoded_remap), texture_upload_context::framebuffer_storage,
						texptr->get_format_type(), scale, rsx::texture_dimension_extended::texture_dimension_2d, surface_is_rop_target };
			}

			const auto scaled_w = rsx::apply_resolution_scale(attr2.width, true);
			const auto scaled_h = rsx::apply_resolution_scale(attr2.height, true);

			if (extended_dimension == rsx::texture_dimension_extended::texture_dimension_3d)
			{
				return{ texptr->get_surface(rsx::surface_access::read), deferred_request_command::_3d_unwrap,
						attr2, {},
						texture_upload_context::framebuffer_storage, texptr->get_format_type(), scale,
						rsx::texture_dimension_extended::texture_dimension_3d, decoded_remap };
			}

			verify(HERE), extended_dimension == rsx::texture_dimension_extended::texture_dimension_cubemap;

			attr2.width = scaled_w;
			attr2.height = scaled_h;

			return{ texptr->get_surface(rsx::surface_access::read), deferred_request_command::cubemap_unwrap,
					attr2, {},
					texture_upload_context::framebuffer_storage, texptr->get_format_type(), scale,
					rsx::texture_dimension_extended::texture_dimension_cubemap, decoded_remap };
		}

		template <typename sampled_image_descriptor, typename surface_store_list_type, typename section_storage_type>
		sampled_image_descriptor merge_cache_resources(
			const surface_store_list_type& fbos, const std::vector<section_storage_type*>& local,
			const image_section_attributes_t& attr,
			const size2f& scale,
			texture_dimension_extended extended_dimension,
			u32 encoded_remap, const texture_channel_remap_t& decoded_remap,
			int select_hint = -1)
		{
			verify(HERE), (select_hint & 0x1) == select_hint;

			bool is_depth;
			auto attr2 = attr;

			if (is_depth = (select_hint == 0) ? fbos.back().is_depth : local.back()->is_depth_texture();
				is_depth)
			{
				if (const auto suggested_format = get_compatible_depth_format(attr.gcm_format);
					!is_gcm_depth_format(suggested_format))
				{
					// Failed!
					is_depth = false;
				}
				else
				{
					attr2.gcm_format = suggested_format;
				}
			}

			// If this method was called, there is no easy solution, likely means atlas gather is needed
			auto scaled_w = rsx::apply_resolution_scale(attr2.width, true);
			auto scaled_h = rsx::apply_resolution_scale(attr2.height, true);
			const auto format_class = get_format_class(attr2.gcm_format);

			if (extended_dimension == rsx::texture_dimension_extended::texture_dimension_cubemap)
			{
				attr2.width = scaled_w;
				attr2.height = scaled_h;
				attr2.depth = 1;

				sampled_image_descriptor desc = { nullptr, deferred_request_command::cubemap_gather,
						attr2, {},
						texture_upload_context::framebuffer_storage, format_class, scale,
						rsx::texture_dimension_extended::texture_dimension_cubemap, decoded_remap };

				gather_texture_slices(desc.external_subresource_desc.sections_to_copy, fbos, local, attr, 6, is_depth);
				return desc;
			}
			else if (extended_dimension == rsx::texture_dimension_extended::texture_dimension_3d && attr.depth > 1)
			{
				attr2.width = scaled_w;
				attr2.height = scaled_h;

				sampled_image_descriptor desc = { nullptr, deferred_request_command::_3d_gather,
					attr2, {},
					texture_upload_context::framebuffer_storage, format_class, scale,
					rsx::texture_dimension_extended::texture_dimension_3d, decoded_remap };

				gather_texture_slices(desc.external_subresource_desc.sections_to_copy, fbos, local, attr, attr.depth, is_depth);
				return desc;
			}

			if (extended_dimension == rsx::texture_dimension_extended::texture_dimension_1d)
			{
				verify(HERE), attr.height == 1;
			}

			if (!fbos.empty())
			{
				attr2.width = scaled_w;
				attr2.height = scaled_h;
			}

			sampled_image_descriptor result = { nullptr, deferred_request_command::atlas_gather,
					attr2, {}, texture_upload_context::framebuffer_storage, format_class,
					scale, rsx::texture_dimension_extended::texture_dimension_2d, decoded_remap };

			gather_texture_slices(result.external_subresource_desc.sections_to_copy, fbos, local, attr, 1, is_depth);
			result.simplify();
			return result;
		}

		template<typename sampled_image_descriptor, typename copy_region_descriptor_type>
		bool append_mipmap_level(
			std::vector<copy_region_descriptor_type>& sections,   // Destination list
			const sampled_image_descriptor& level,                // Descriptor for the image level being checked
			const image_section_attributes_t& attr,               // Attributes of image level
			u8 mipmap_level,                                      // Level index
			bool apply_upscaling,                                 // Whether to upscale the results or not
			const image_section_attributes_t& level0_attr)        // Attributes of the first mipmap level
		{
			if (level.image_handle)
			{
				copy_region_descriptor_type mip{};
				mip.src = level.image_handle->image();
				mip.xform = surface_transform::coordinate_transform;
				mip.level = mipmap_level;
				mip.dst_w = attr.width;
				mip.dst_h = attr.height;

				if (level.upload_context == rsx::texture_upload_context::framebuffer_storage)
				{
					mip.src_w = rsx::apply_resolution_scale(attr.width, true);
					mip.src_h = rsx::apply_resolution_scale(attr.height, true);
				}
				else
				{
					mip.src_w = attr.width;
					mip.src_h = attr.height;
				}

				sections.push_back(mip);
			}
			else
			{

				switch (level.external_subresource_desc.op)
				{
				case deferred_request_command::copy_image_dynamic:
				case deferred_request_command::copy_image_static:
				{
					copy_region_descriptor_type mip{};
					mip.src = level.external_subresource_desc.external_handle;
					mip.xform = surface_transform::coordinate_transform;
					mip.level = mipmap_level;
					mip.src_w = level.external_subresource_desc.width;
					mip.src_h = level.external_subresource_desc.height;
					mip.dst_w = attr.width;
					mip.dst_h = attr.height;
					sections.push_back(mip);
					break;
				}
				default:
				{
					// TODO
					return false;
				}
				}
			}

			// Check for upscaling if requested
			if (apply_upscaling)
			{
				auto& mip = sections.back();
				mip.dst_w = rsx::apply_resolution_scale(mip.dst_w, true, level0_attr.width);
				mip.dst_h = rsx::apply_resolution_scale(mip.dst_h, true, level0_attr.height);
			}

			return true;
		}
	};
}
