// SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#include "common/algorithm.h"
#include "common/assert.h"
#include "common/logging/log.h"
#include "common/microprofile.h"
#include "common/settings.h"
#include "core/core.h"
#include "video_core/engines/maxwell_3d.h"
#include "video_core/engines/maxwell_dma.h"
#include "video_core/memory_manager.h"
#include "video_core/renderer_base.h"
#include "video_core/textures/decoders.h"

MICROPROFILE_DECLARE(GPU_DMAEngine);
MICROPROFILE_DEFINE(GPU_DMAEngine, "GPU", "DMA Engine", MP_RGB(224, 224, 128));

namespace Tegra::Engines {

using namespace Texture;

MaxwellDMA::MaxwellDMA(Core::System& system_, MemoryManager& memory_manager_)
    : system{system_}, memory_manager{memory_manager_} {}

MaxwellDMA::~MaxwellDMA() = default;

void MaxwellDMA::BindRasterizer(VideoCore::RasterizerInterface* rasterizer_) {
    rasterizer = rasterizer_;
}

void MaxwellDMA::CallMethod(u32 method, u32 method_argument, bool is_last_call) {
    ASSERT_MSG(method < NUM_REGS, "Invalid MaxwellDMA register");

    regs.reg_array[method] = method_argument;

    if (method == offsetof(Regs, launch_dma) / sizeof(u32)) {
        Launch();
    }
}

void MaxwellDMA::CallMultiMethod(u32 method, const u32* base_start, u32 amount,
                                 u32 methods_pending) {
    for (size_t i = 0; i < amount; ++i) {
        CallMethod(method, base_start[i], methods_pending - static_cast<u32>(i) <= 1);
    }
}

void MaxwellDMA::Launch() {
    MICROPROFILE_SCOPE(GPU_DMAEngine);
    LOG_TRACE(Render_OpenGL, "DMA copy 0x{:x} -> 0x{:x}", static_cast<GPUVAddr>(regs.offset_in),
              static_cast<GPUVAddr>(regs.offset_out));

    // TODO(Subv): Perform more research and implement all features of this engine.
    const LaunchDMA& launch = regs.launch_dma;
    ASSERT(launch.interrupt_type == LaunchDMA::InterruptType::NONE);
    ASSERT(launch.data_transfer_type == LaunchDMA::DataTransferType::NON_PIPELINED);

    const bool is_src_pitch = launch.src_memory_layout == LaunchDMA::MemoryLayout::PITCH;
    const bool is_dst_pitch = launch.dst_memory_layout == LaunchDMA::MemoryLayout::PITCH;

    if (!is_src_pitch && !is_dst_pitch) {
        // If both the source and the destination are in block layout, assert.
        UNIMPLEMENTED_MSG("Tiled->Tiled DMA transfers are not yet implemented");
        return;
    }

    if (is_src_pitch && is_dst_pitch) {
        CopyPitchToPitch();
    } else {
        ASSERT(launch.multi_line_enable == 1);

        if (!is_src_pitch && is_dst_pitch) {
            CopyBlockLinearToPitch();
        } else {
            CopyPitchToBlockLinear();
        }
    }
    ReleaseSemaphore();
}

void MaxwellDMA::CopyPitchToPitch() {
    // When `multi_line_enable` bit is enabled we copy a 2D image of dimensions
    // (line_length_in, line_count).
    // Otherwise the copy is performed as if we were copying a 1D buffer of length line_length_in.
    const bool remap_enabled = regs.launch_dma.remap_enable != 0;
    if (regs.launch_dma.multi_line_enable) {
        UNIMPLEMENTED_IF(remap_enabled);

        // Perform a line-by-line copy.
        // We're going to take a subrect of size (line_length_in, line_count) from the source
        // rectangle. There is no need to manually flush/invalidate the regions because CopyBlock
        // does that for us.
        for (u32 line = 0; line < regs.line_count; ++line) {
            const GPUVAddr source_line = regs.offset_in + static_cast<size_t>(line) * regs.pitch_in;
            const GPUVAddr dest_line = regs.offset_out + static_cast<size_t>(line) * regs.pitch_out;
            memory_manager.CopyBlock(dest_line, source_line, regs.line_length_in);
        }
        return;
    }
    // TODO: allow multisized components.
    auto& accelerate = rasterizer->AccessAccelerateDMA();
    const bool is_const_a_dst = regs.remap_const.dst_x == RemapConst::Swizzle::CONST_A;
    const bool is_buffer_clear = remap_enabled && is_const_a_dst;
    if (is_buffer_clear) {
        ASSERT(regs.remap_const.component_size_minus_one == 3);
        accelerate.BufferClear(regs.offset_out, regs.line_length_in, regs.remap_consta_value);
        std::vector<u32> tmp_buffer(regs.line_length_in, regs.remap_consta_value);
        memory_manager.WriteBlockUnsafe(regs.offset_out, reinterpret_cast<u8*>(tmp_buffer.data()),
                                        regs.line_length_in * sizeof(u32));
        return;
    }
    UNIMPLEMENTED_IF(remap_enabled);
    if (!accelerate.BufferCopy(regs.offset_in, regs.offset_out, regs.line_length_in)) {
        std::vector<u8> tmp_buffer(regs.line_length_in);
        memory_manager.ReadBlockUnsafe(regs.offset_in, tmp_buffer.data(), regs.line_length_in);
        memory_manager.WriteBlock(regs.offset_out, tmp_buffer.data(), regs.line_length_in);
    }
}

void MaxwellDMA::CopyBlockLinearToPitch() {
    UNIMPLEMENTED_IF(regs.src_params.block_size.width != 0);
    UNIMPLEMENTED_IF(regs.src_params.layer != 0);

    const bool is_remapping = regs.launch_dma.remap_enable != 0;

    // Optimized path for micro copies.
    const size_t dst_size = static_cast<size_t>(regs.pitch_out) * regs.line_count;
    if (!is_remapping && dst_size < GOB_SIZE && regs.pitch_out <= GOB_SIZE_X &&
        regs.src_params.height > GOB_SIZE_Y) {
        FastCopyBlockLinearToPitch();
        return;
    }

    // Deswizzle the input and copy it over.
    UNIMPLEMENTED_IF(regs.launch_dma.remap_enable != 0);
    const Parameters& src_params = regs.src_params;

    const u32 num_remap_components = regs.remap_const.num_dst_components_minus_one + 1;
    const u32 remap_components_size = regs.remap_const.component_size_minus_one + 1;

    const u32 base_bpp = !is_remapping ? 1U : num_remap_components * remap_components_size;

    u32 width = src_params.width;
    u32 x_elements = regs.line_length_in;
    u32 x_offset = src_params.origin.x;
    u32 bpp_shift = 0U;
    if (!is_remapping) {
        bpp_shift = Common::FoldRight(
            4U, [](u32 x, u32 y) { return std::min(x, static_cast<u32>(std::countr_zero(y))); },
            width, x_elements, x_offset, static_cast<u32>(regs.offset_in));
        width >>= bpp_shift;
        x_elements >>= bpp_shift;
        x_offset >>= bpp_shift;
    }

    const u32 bytes_per_pixel = base_bpp << bpp_shift;
    const u32 height = src_params.height;
    const u32 depth = src_params.depth;
    const u32 block_height = src_params.block_size.height;
    const u32 block_depth = src_params.block_size.depth;
    const size_t src_size =
        CalculateSize(true, bytes_per_pixel, width, height, depth, block_height, block_depth);

    if (read_buffer.size() < src_size) {
        read_buffer.resize(src_size);
    }
    if (write_buffer.size() < dst_size) {
        write_buffer.resize(dst_size);
    }

    memory_manager.ReadBlock(regs.offset_in, read_buffer.data(), src_size);
    memory_manager.ReadBlock(regs.offset_out, write_buffer.data(), dst_size);

    UnswizzleSubrect(write_buffer, read_buffer, bytes_per_pixel, width, height, depth, x_offset,
                     src_params.origin.y, x_elements, regs.line_count, block_height, block_depth,
                     regs.pitch_out);

    memory_manager.WriteBlock(regs.offset_out, write_buffer.data(), dst_size);
}

void MaxwellDMA::CopyPitchToBlockLinear() {
    UNIMPLEMENTED_IF_MSG(regs.dst_params.block_size.width != 0, "Block width is not one");
    UNIMPLEMENTED_IF(regs.dst_params.layer != 0);
    UNIMPLEMENTED_IF(regs.launch_dma.remap_enable != 0);

    const bool is_remapping = regs.launch_dma.remap_enable != 0;
    const u32 num_remap_components = regs.remap_const.num_dst_components_minus_one + 1;
    const u32 remap_components_size = regs.remap_const.component_size_minus_one + 1;

    const auto& dst_params = regs.dst_params;

    const u32 base_bpp = !is_remapping ? 1U : num_remap_components * remap_components_size;

    u32 width = dst_params.width;
    u32 x_elements = regs.line_length_in;
    u32 x_offset = dst_params.origin.x;
    u32 bpp_shift = 0U;
    if (!is_remapping) {
        bpp_shift = Common::FoldRight(
            4U, [](u32 x, u32 y) { return std::min(x, static_cast<u32>(std::countr_zero(y))); },
            width, x_elements, x_offset, static_cast<u32>(regs.offset_out));
        width >>= bpp_shift;
        x_elements >>= bpp_shift;
        x_offset >>= bpp_shift;
    }

    const u32 bytes_per_pixel = base_bpp << bpp_shift;
    const u32 height = dst_params.height;
    const u32 depth = dst_params.depth;
    const u32 block_height = dst_params.block_size.height;
    const u32 block_depth = dst_params.block_size.depth;
    const size_t dst_size =
        CalculateSize(true, bytes_per_pixel, width, height, depth, block_height, block_depth);
    const size_t src_size = static_cast<size_t>(regs.pitch_in) * regs.line_count;

    if (read_buffer.size() < src_size) {
        read_buffer.resize(src_size);
    }
    if (write_buffer.size() < dst_size) {
        write_buffer.resize(dst_size);
    }

    memory_manager.ReadBlock(regs.offset_in, read_buffer.data(), src_size);
    if (Settings::IsGPULevelExtreme()) {
        memory_manager.ReadBlock(regs.offset_out, write_buffer.data(), dst_size);
    } else {
        memory_manager.ReadBlockUnsafe(regs.offset_out, write_buffer.data(), dst_size);
    }

    // If the input is linear and the output is tiled, swizzle the input and copy it over.
    SwizzleSubrect(write_buffer, read_buffer, bytes_per_pixel, width, height, depth, x_offset,
                   dst_params.origin.y, x_elements, regs.line_count, block_height, block_depth,
                   regs.pitch_in);

    memory_manager.WriteBlock(regs.offset_out, write_buffer.data(), dst_size);
}

void MaxwellDMA::FastCopyBlockLinearToPitch() {
    const u32 bytes_per_pixel = 1U;
    const size_t src_size = GOB_SIZE;
    const size_t dst_size = static_cast<size_t>(regs.pitch_out) * regs.line_count;
    u32 pos_x = regs.src_params.origin.x;
    u32 pos_y = regs.src_params.origin.y;
    const u64 offset = GetGOBOffset(regs.src_params.width, regs.src_params.height, pos_x, pos_y,
                                    regs.src_params.block_size.height, bytes_per_pixel);
    const u32 x_in_gob = 64 / bytes_per_pixel;
    pos_x = pos_x % x_in_gob;
    pos_y = pos_y % 8;

    if (read_buffer.size() < src_size) {
        read_buffer.resize(src_size);
    }
    if (write_buffer.size() < dst_size) {
        write_buffer.resize(dst_size);
    }

    if (Settings::IsGPULevelExtreme()) {
        memory_manager.ReadBlock(regs.offset_in + offset, read_buffer.data(), src_size);
        memory_manager.ReadBlock(regs.offset_out, write_buffer.data(), dst_size);
    } else {
        memory_manager.ReadBlockUnsafe(regs.offset_in + offset, read_buffer.data(), src_size);
        memory_manager.ReadBlockUnsafe(regs.offset_out, write_buffer.data(), dst_size);
    }

    UnswizzleSubrect(write_buffer, read_buffer, bytes_per_pixel, regs.src_params.width,
                     regs.src_params.height, 1, pos_x, pos_y, regs.line_length_in, regs.line_count,
                     regs.src_params.block_size.height, regs.src_params.block_size.depth,
                     regs.pitch_out);

    memory_manager.WriteBlock(regs.offset_out, write_buffer.data(), dst_size);
}

void MaxwellDMA::ReleaseSemaphore() {
    const auto type = regs.launch_dma.semaphore_type;
    const GPUVAddr address = regs.semaphore.address;
    switch (type) {
    case LaunchDMA::SemaphoreType::NONE:
        break;
    case LaunchDMA::SemaphoreType::RELEASE_ONE_WORD_SEMAPHORE:
        memory_manager.Write<u32>(address, regs.semaphore.payload);
        break;
    case LaunchDMA::SemaphoreType::RELEASE_FOUR_WORD_SEMAPHORE:
        memory_manager.Write<u64>(address, static_cast<u64>(regs.semaphore.payload));
        memory_manager.Write<u64>(address + 8, system.GPU().GetTicks());
        break;
    default:
        ASSERT_MSG(false, "Unknown semaphore type: {}", static_cast<u32>(type.Value()));
    }
}

} // namespace Tegra::Engines
