#ifndef __JABYENGINE_GPU_INTERNAL_HPP__
#define __JABYENGINE_GPU_INTERNAL_HPP__
#include <PSX/GPU/gpu.hpp>
#include <PSX/System/IOPorts/dma_io.hpp>
#include <PSX/System/IOPorts/gpu_io.hpp>

namespace JabyEngine {
    namespace GPU {
        namespace internal {
            struct Display {
                typedef ::JabyEngine::GPU::Display PublicDisplay;

                static constexpr auto Width  = PublicDisplay::Width;
                static constexpr auto Height = PublicDisplay::Height;
                
                #ifdef JABYENGINE_PAL
                    static constexpr auto     DisplayMode = GPU_IO::DisplayMode_t::PAL();
                    static constexpr uint16_t ScanlinesV  = 288;
                #else
                    static constexpr auto     DisplayMode = GPU_IO::DisplayMode_t::NTSC();
                    static constexpr uint16_t ScanlinesV  = 240;
                #endif //JABYENGINE_PAL

                static uint32_t exchange_buffer_and_display();
            };

            void wait_vsync(uint8_t syncs);

            static void wait_ready_for_CMD() {
                while(!GPU_IO::GPUSTAT.is_set(GPU_IO::GPUSTAT_t::GP0ReadyForCMD));
            }

            static void set_draw_area(uint16_t x, uint16_t y) {
                const auto top_left     = GPU_IO::Command::DrawAreaTopLeft(x, y);
                const auto bottom_right = GPU_IO::Command::DrawAreaBottomRight((x + Display::Width - 1), (y + Display::Height - 1));

                wait_ready_for_CMD();
                GPU_IO::GP0 = top_left;
                wait_ready_for_CMD();
                GPU_IO::GP0 = bottom_right;
            }

            static void copy_vram_to_vram(const AreaU16& dst, const PositionU16& src) {
                wait_ready_for_CMD();
                GPU_IO::GP0 = GPU_IO::Command::VRAM2VRAM_Blitting();
                GPU_IO::GP0 = GPU_IO::Command::TopLeftPosition(src.x, src.y);
                GPU_IO::GP0 = GPU_IO::Command::TopLeftPosition(dst.position.x, dst.position.y);
                GPU_IO::GP0 = GPU_IO::Command::WidthHeight(dst.size.width, dst.size.height);
            }

            static void quick_fill_fast(const Color24& color, const AreaU16& area) {
                wait_ready_for_CMD();
                GPU_IO::GP0 = GPU_IO::Command::QuickFill(color);
                GPU_IO::GP0 = GPU_IO::Command::TopLeftPosition(area.position.x, area.position.y);
                GPU_IO::GP0 = GPU_IO::Command::WidthHeight(area.size.width, area.size.height);
            }

            static void set_draw_offset(int16_t x, int16_t y) {
                wait_ready_for_CMD();
                GPU_IO::GP0 = GPU_IO::Command::SetDrawOffset(x, y);
            }

            static void reset_cmd_buffer() {
                GPU_IO::GP1 = GPU_IO::Command::ResetCMDBufer();
            }

            namespace DMA {
                static void wait() {
                    ::JabyEngine::DMA_IO::GPU.wait();
                }

                static void end() {
                    reset_cmd_buffer();
                }

                namespace Receive {
                    static void prepare() {
                        GPU_IO::GP1 = GPU_IO::Command::DMADirection(GPU_IO::DMADirection::CPU2GPU);
                        reset_cmd_buffer();
                    }

                    static void set_src(uintptr_t adr) {
                        DMA_IO::GPU.set_adr(adr);
                    }

                    static void set_dst(const PositionU16& position, const SizeU16& size) {
                        wait_ready_for_CMD();
                        GPU_IO::GP0 = GPU_IO::Command::CPU2VRAM_Blitting();
                        GPU_IO::GP0 = GPU_IO::Command::TopLeftPosition(position.x, position.y);
                        GPU_IO::GP0 = GPU_IO::Command::WidthHeight(size.width, size.height);
                    }

                    static void start(uint16_t blockCount, uint16_t wordsPerBlock = 0x10) {
                        typedef DMA_IO::BCR_t::SyncMode1 SyncMode1;

                        DMA_IO::GPU.block_ctrl   = DMA_IO::BCR_t::from(SyncMode1::BlockSize.with(wordsPerBlock), SyncMode1::BlockAmount.with(blockCount));
                        DMA_IO::GPU.channel_ctrl = DMA_IO::CHCHR_t::StartGPUReceive();
                    }
                }
            }
        }
    }
}

#endif //!__JABYENGINE_GPU_INTERNAL_HPP__