// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2
// Refer to the license.txt file included.

#include <algorithm>
#include <condition_variable>
#include <cstdint>
#include <cstring>
#include <fstream>
#include <map>
#include <mutex>
#include <stdexcept>
#include <string>

#ifdef HAVE_PNG
#include <png.h>
#include <setjmp.h>
#endif

#include <nihstro/bit_field.h>
#include <nihstro/float24.h>
#include <nihstro/shader_binary.h>
#include "common/assert.h"
#include "common/bit_field.h"
#include "common/color.h"
#include "common/common_types.h"
#include "common/file_util.h"
#include "common/logging/log.h"
#include "common/math_util.h"
#include "common/vector_math.h"
#include "video_core/debug_utils/debug_utils.h"
#include "video_core/pica_state.h"
#include "video_core/pica_types.h"
#include "video_core/rasterizer_interface.h"
#include "video_core/regs_rasterizer.h"
#include "video_core/regs_shader.h"
#include "video_core/regs_texturing.h"
#include "video_core/renderer_base.h"
#include "video_core/shader/shader.h"
#include "video_core/texture/texture_decode.h"
#include "video_core/utils.h"
#include "video_core/video_core.h"

using nihstro::DVLBHeader;
using nihstro::DVLEHeader;
using nihstro::DVLPHeader;

namespace Pica {

void DebugContext::DoOnEvent(Event event, void* data) {
    {
        std::unique_lock<std::mutex> lock(breakpoint_mutex);

        // Commit the rasterizer's caches so framebuffers, render targets, etc. will show on debug
        // widgets
        VideoCore::g_renderer->Rasterizer()->FlushAll();

        // TODO: Should stop the CPU thread here once we multithread emulation.

        active_breakpoint = event;
        at_breakpoint = true;

        // Tell all observers that we hit a breakpoint
        for (auto& breakpoint_observer : breakpoint_observers) {
            breakpoint_observer->OnPicaBreakPointHit(event, data);
        }

        // Wait until another thread tells us to Resume()
        resume_from_breakpoint.wait(lock, [&] { return !at_breakpoint; });
    }
}

void DebugContext::Resume() {
    {
        std::lock_guard<std::mutex> lock(breakpoint_mutex);

        // Tell all observers that we are about to resume
        for (auto& breakpoint_observer : breakpoint_observers) {
            breakpoint_observer->OnPicaResume();
        }

        // Resume the waiting thread (i.e. OnEvent())
        at_breakpoint = false;
    }

    resume_from_breakpoint.notify_one();
}

std::shared_ptr<DebugContext> g_debug_context; // TODO: Get rid of this global

namespace DebugUtils {

void DumpShader(const std::string& filename, const ShaderRegs& config,
                const Shader::ShaderSetup& setup,
                const RasterizerRegs::VSOutputAttributes* output_attributes) {
    struct StuffToWrite {
        const u8* pointer;
        u32 size;
    };
    std::vector<StuffToWrite> writing_queue;
    u32 write_offset = 0;

    auto QueueForWriting = [&writing_queue, &write_offset](const u8* pointer, u32 size) {
        writing_queue.push_back({pointer, size});
        u32 old_write_offset = write_offset;
        write_offset += size;
        return old_write_offset;
    };

    // First off, try to translate Pica state (one enum for output attribute type and component)
    // into shbin format (separate type and component mask).
    union OutputRegisterInfo {
        enum Type : u64 {
            POSITION = 0,
            QUATERNION = 1,
            COLOR = 2,
            TEXCOORD0 = 3,
            TEXCOORD1 = 5,
            TEXCOORD2 = 6,

            VIEW = 8,
        };

        BitField<0, 64, u64> hex;

        BitField<0, 16, Type> type;
        BitField<16, 16, u64> id;
        BitField<32, 4, u64> component_mask;
    };

    // This is put into a try-catch block to make sure we notice unknown configurations.
    std::vector<OutputRegisterInfo> output_info_table;
    for (unsigned i = 0; i < 7; ++i) {
        using OutputAttributes = Pica::RasterizerRegs::VSOutputAttributes;

        // TODO: It's still unclear how the attribute components map to the register!
        //       Once we know that, this code probably will not make much sense anymore.
        std::map<OutputAttributes::Semantic, std::pair<OutputRegisterInfo::Type, u32>> map = {
            {OutputAttributes::POSITION_X, {OutputRegisterInfo::POSITION, 1}},
            {OutputAttributes::POSITION_Y, {OutputRegisterInfo::POSITION, 2}},
            {OutputAttributes::POSITION_Z, {OutputRegisterInfo::POSITION, 4}},
            {OutputAttributes::POSITION_W, {OutputRegisterInfo::POSITION, 8}},
            {OutputAttributes::QUATERNION_X, {OutputRegisterInfo::QUATERNION, 1}},
            {OutputAttributes::QUATERNION_Y, {OutputRegisterInfo::QUATERNION, 2}},
            {OutputAttributes::QUATERNION_Z, {OutputRegisterInfo::QUATERNION, 4}},
            {OutputAttributes::QUATERNION_W, {OutputRegisterInfo::QUATERNION, 8}},
            {OutputAttributes::COLOR_R, {OutputRegisterInfo::COLOR, 1}},
            {OutputAttributes::COLOR_G, {OutputRegisterInfo::COLOR, 2}},
            {OutputAttributes::COLOR_B, {OutputRegisterInfo::COLOR, 4}},
            {OutputAttributes::COLOR_A, {OutputRegisterInfo::COLOR, 8}},
            {OutputAttributes::TEXCOORD0_U, {OutputRegisterInfo::TEXCOORD0, 1}},
            {OutputAttributes::TEXCOORD0_V, {OutputRegisterInfo::TEXCOORD0, 2}},
            {OutputAttributes::TEXCOORD1_U, {OutputRegisterInfo::TEXCOORD1, 1}},
            {OutputAttributes::TEXCOORD1_V, {OutputRegisterInfo::TEXCOORD1, 2}},
            {OutputAttributes::TEXCOORD2_U, {OutputRegisterInfo::TEXCOORD2, 1}},
            {OutputAttributes::TEXCOORD2_V, {OutputRegisterInfo::TEXCOORD2, 2}},
            {OutputAttributes::VIEW_X, {OutputRegisterInfo::VIEW, 1}},
            {OutputAttributes::VIEW_Y, {OutputRegisterInfo::VIEW, 2}},
            {OutputAttributes::VIEW_Z, {OutputRegisterInfo::VIEW, 4}},
        };

        for (const auto& semantic : std::vector<OutputAttributes::Semantic>{
                 output_attributes[i].map_x, output_attributes[i].map_y, output_attributes[i].map_z,
                 output_attributes[i].map_w}) {
            if (semantic == OutputAttributes::INVALID)
                continue;

            try {
                OutputRegisterInfo::Type type = map.at(semantic).first;
                u32 component_mask = map.at(semantic).second;

                auto it = std::find_if(output_info_table.begin(), output_info_table.end(),
                                       [&i, &type](const OutputRegisterInfo& info) {
                                           return info.id == i && info.type == type;
                                       });

                if (it == output_info_table.end()) {
                    output_info_table.emplace_back();
                    output_info_table.back().type.Assign(type);
                    output_info_table.back().component_mask.Assign(component_mask);
                    output_info_table.back().id.Assign(i);
                } else {
                    it->component_mask.Assign(it->component_mask | component_mask);
                }
            } catch (const std::out_of_range&) {
                DEBUG_ASSERT_MSG(false, "Unknown output attribute mapping");
                LOG_ERROR(HW_GPU, "Unknown output attribute mapping: %03x, %03x, %03x, %03x",
                          (int)output_attributes[i].map_x.Value(),
                          (int)output_attributes[i].map_y.Value(),
                          (int)output_attributes[i].map_z.Value(),
                          (int)output_attributes[i].map_w.Value());
            }
        }
    }

    struct {
        DVLBHeader header;
        u32 dvle_offset;
    } dvlb{{DVLBHeader::MAGIC_WORD, 1}}; // 1 DVLE

    DVLPHeader dvlp{DVLPHeader::MAGIC_WORD};
    DVLEHeader dvle{DVLEHeader::MAGIC_WORD};

    QueueForWriting(reinterpret_cast<const u8*>(&dvlb), sizeof(dvlb));
    u32 dvlp_offset = QueueForWriting(reinterpret_cast<const u8*>(&dvlp), sizeof(dvlp));
    dvlb.dvle_offset = QueueForWriting(reinterpret_cast<const u8*>(&dvle), sizeof(dvle));

    // TODO: Reduce the amount of binary code written to relevant portions
    dvlp.binary_offset = write_offset - dvlp_offset;
    dvlp.binary_size_words = static_cast<uint32_t>(setup.program_code.size());
    QueueForWriting(reinterpret_cast<const u8*>(setup.program_code.data()),
                    static_cast<u32>(setup.program_code.size()) * sizeof(u32));

    dvlp.swizzle_info_offset = write_offset - dvlp_offset;
    dvlp.swizzle_info_num_entries = static_cast<uint32_t>(setup.swizzle_data.size());
    u32 dummy = 0;
    for (unsigned int i = 0; i < setup.swizzle_data.size(); ++i) {
        QueueForWriting(reinterpret_cast<const u8*>(&setup.swizzle_data[i]),
                        sizeof(setup.swizzle_data[i]));
        QueueForWriting(reinterpret_cast<const u8*>(&dummy), sizeof(dummy));
    }

    dvle.main_offset_words = config.main_offset;
    dvle.output_register_table_offset = write_offset - dvlb.dvle_offset;
    dvle.output_register_table_size = static_cast<u32>(output_info_table.size());
    QueueForWriting(reinterpret_cast<const u8*>(output_info_table.data()),
                    static_cast<u32>(output_info_table.size() * sizeof(OutputRegisterInfo)));

    // TODO: Create a label table for "main"

    std::vector<nihstro::ConstantInfo> constant_table;
    for (unsigned i = 0; i < setup.uniforms.b.size(); ++i) {
        nihstro::ConstantInfo constant;
        memset(&constant, 0, sizeof(constant));
        constant.type = nihstro::ConstantInfo::Bool;
        constant.regid = i;
        constant.b = setup.uniforms.b[i];
        constant_table.emplace_back(constant);
    }
    for (unsigned i = 0; i < setup.uniforms.i.size(); ++i) {
        nihstro::ConstantInfo constant;
        memset(&constant, 0, sizeof(constant));
        constant.type = nihstro::ConstantInfo::Int;
        constant.regid = i;
        constant.i.x = setup.uniforms.i[i].x;
        constant.i.y = setup.uniforms.i[i].y;
        constant.i.z = setup.uniforms.i[i].z;
        constant.i.w = setup.uniforms.i[i].w;
        constant_table.emplace_back(constant);
    }
    for (unsigned i = 0; i < sizeof(setup.uniforms.f) / sizeof(setup.uniforms.f[0]); ++i) {
        nihstro::ConstantInfo constant;
        memset(&constant, 0, sizeof(constant));
        constant.type = nihstro::ConstantInfo::Float;
        constant.regid = i;
        constant.f.x = nihstro::to_float24(setup.uniforms.f[i].x.ToFloat32());
        constant.f.y = nihstro::to_float24(setup.uniforms.f[i].y.ToFloat32());
        constant.f.z = nihstro::to_float24(setup.uniforms.f[i].z.ToFloat32());
        constant.f.w = nihstro::to_float24(setup.uniforms.f[i].w.ToFloat32());

        // Store constant if it's different from zero..
        if (setup.uniforms.f[i].x.ToFloat32() != 0.0 || setup.uniforms.f[i].y.ToFloat32() != 0.0 ||
            setup.uniforms.f[i].z.ToFloat32() != 0.0 || setup.uniforms.f[i].w.ToFloat32() != 0.0)
            constant_table.emplace_back(constant);
    }
    dvle.constant_table_offset = write_offset - dvlb.dvle_offset;
    dvle.constant_table_size = static_cast<uint32_t>(constant_table.size());
    for (const auto& constant : constant_table) {
        QueueForWriting(reinterpret_cast<const u8*>(&constant), sizeof(constant));
    }

    // Write data to file
    std::ofstream file(filename, std::ios_base::out | std::ios_base::binary);

    for (const auto& chunk : writing_queue) {
        file.write(reinterpret_cast<const char*>(chunk.pointer), chunk.size);
    }
}

static std::unique_ptr<PicaTrace> pica_trace;
static std::mutex pica_trace_mutex;
bool g_is_pica_tracing = false;

void StartPicaTracing() {
    if (g_is_pica_tracing) {
        LOG_WARNING(HW_GPU, "StartPicaTracing called even though tracing already running!");
        return;
    }

    std::lock_guard<std::mutex> lock(pica_trace_mutex);
    pica_trace = std::make_unique<PicaTrace>();

    g_is_pica_tracing = true;
}

void OnPicaRegWrite(PicaTrace::Write write) {
    std::lock_guard<std::mutex> lock(pica_trace_mutex);

    if (!g_is_pica_tracing)
        return;

    pica_trace->writes.push_back(write);
}

std::unique_ptr<PicaTrace> FinishPicaTracing() {
    if (!g_is_pica_tracing) {
        LOG_WARNING(HW_GPU, "FinishPicaTracing called even though tracing isn't running!");
        return {};
    }

    // signalize that no further tracing should be performed
    g_is_pica_tracing = false;

    // Wait until running tracing is finished
    std::lock_guard<std::mutex> lock(pica_trace_mutex);
    std::unique_ptr<PicaTrace> ret(std::move(pica_trace));

    return ret;
}

#ifdef HAVE_PNG
// Adapter functions to libpng to write/flush to File::IOFile instances.
static void WriteIOFile(png_structp png_ptr, png_bytep data, png_size_t length) {
    auto* fp = static_cast<FileUtil::IOFile*>(png_get_io_ptr(png_ptr));
    if (!fp->WriteBytes(data, length))
        png_error(png_ptr, "Failed to write to output PNG file.");
}

static void FlushIOFile(png_structp png_ptr) {
    auto* fp = static_cast<FileUtil::IOFile*>(png_get_io_ptr(png_ptr));
    if (!fp->Flush())
        png_error(png_ptr, "Failed to flush to output PNG file.");
}
#endif

void DumpTexture(const TexturingRegs::TextureConfig& texture_config, u8* data) {
#ifndef HAVE_PNG
    return;
#else
    if (!data)
        return;

    // Write data to file
    static int dump_index = 0;
    std::string filename =
        std::string("texture_dump") + std::to_string(++dump_index) + std::string(".png");
    u32 row_stride = texture_config.width * 3;

    u8* buf;

    char title[] = "Citra texture dump";
    char title_key[] = "Title";
    png_structp png_ptr = nullptr;
    png_infop info_ptr = nullptr;

    // Open file for writing (binary mode)
    FileUtil::IOFile fp(filename, "wb");

    // Initialize write structure
    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
    if (png_ptr == nullptr) {
        LOG_ERROR(Debug_GPU, "Could not allocate write struct");
        goto finalise;
    }

    // Initialize info structure
    info_ptr = png_create_info_struct(png_ptr);
    if (info_ptr == nullptr) {
        LOG_ERROR(Debug_GPU, "Could not allocate info struct");
        goto finalise;
    }

    // Setup Exception handling
    if (setjmp(png_jmpbuf(png_ptr))) {
        LOG_ERROR(Debug_GPU, "Error during png creation");
        goto finalise;
    }

    png_set_write_fn(png_ptr, static_cast<void*>(&fp), WriteIOFile, FlushIOFile);

    // Write header (8 bit color depth)
    png_set_IHDR(png_ptr, info_ptr, texture_config.width, texture_config.height, 8,
                 PNG_COLOR_TYPE_RGB /*_ALPHA*/, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
                 PNG_FILTER_TYPE_BASE);

    png_text title_text;
    title_text.compression = PNG_TEXT_COMPRESSION_NONE;
    title_text.key = title_key;
    title_text.text = title;
    png_set_text(png_ptr, info_ptr, &title_text, 1);

    png_write_info(png_ptr, info_ptr);

    buf = new u8[row_stride * texture_config.height];
    for (unsigned y = 0; y < texture_config.height; ++y) {
        for (unsigned x = 0; x < texture_config.width; ++x) {
            Pica::Texture::TextureInfo info;
            info.width = texture_config.width;
            info.height = texture_config.height;
            info.stride = row_stride;
            info.format = g_state.regs.texturing.texture0_format;
            Math::Vec4<u8> texture_color = Pica::Texture::LookupTexture(data, x, y, info);
            buf[3 * x + y * row_stride] = texture_color.r();
            buf[3 * x + y * row_stride + 1] = texture_color.g();
            buf[3 * x + y * row_stride + 2] = texture_color.b();
        }
    }

    // Write image data
    for (unsigned y = 0; y < texture_config.height; ++y) {
        u8* row_ptr = (u8*)buf + y * row_stride;
        png_write_row(png_ptr, row_ptr);
    }

    delete[] buf;

    // End write
    png_write_end(png_ptr, nullptr);

finalise:
    if (info_ptr != nullptr)
        png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
    if (png_ptr != nullptr)
        png_destroy_write_struct(&png_ptr, (png_infopp) nullptr);
#endif
}

static std::string ReplacePattern(const std::string& input, const std::string& pattern,
                                  const std::string& replacement) {
    size_t start = input.find(pattern);
    if (start == std::string::npos)
        return input;

    std::string ret = input;
    ret.replace(start, pattern.length(), replacement);
    return ret;
}

static std::string GetTevStageConfigSourceString(
    const TexturingRegs::TevStageConfig::Source& source) {

    using Source = TexturingRegs::TevStageConfig::Source;
    static const std::map<Source, std::string> source_map = {
        {Source::PrimaryColor, "PrimaryColor"},
        {Source::PrimaryFragmentColor, "PrimaryFragmentColor"},
        {Source::SecondaryFragmentColor, "SecondaryFragmentColor"},
        {Source::Texture0, "Texture0"},
        {Source::Texture1, "Texture1"},
        {Source::Texture2, "Texture2"},
        {Source::Texture3, "Texture3"},
        {Source::PreviousBuffer, "PreviousBuffer"},
        {Source::Constant, "Constant"},
        {Source::Previous, "Previous"},
    };

    const auto src_it = source_map.find(source);
    if (src_it == source_map.end())
        return "Unknown";

    return src_it->second;
}

static std::string GetTevStageConfigColorSourceString(
    const TexturingRegs::TevStageConfig::Source& source,
    const TexturingRegs::TevStageConfig::ColorModifier modifier) {

    using ColorModifier = TexturingRegs::TevStageConfig::ColorModifier;
    static const std::map<ColorModifier, std::string> color_modifier_map = {
        {ColorModifier::SourceColor, "%source.rgb"},
        {ColorModifier::OneMinusSourceColor, "(1.0 - %source.rgb)"},
        {ColorModifier::SourceAlpha, "%source.aaa"},
        {ColorModifier::OneMinusSourceAlpha, "(1.0 - %source.aaa)"},
        {ColorModifier::SourceRed, "%source.rrr"},
        {ColorModifier::OneMinusSourceRed, "(1.0 - %source.rrr)"},
        {ColorModifier::SourceGreen, "%source.ggg"},
        {ColorModifier::OneMinusSourceGreen, "(1.0 - %source.ggg)"},
        {ColorModifier::SourceBlue, "%source.bbb"},
        {ColorModifier::OneMinusSourceBlue, "(1.0 - %source.bbb)"},
    };

    auto src_str = GetTevStageConfigSourceString(source);
    auto modifier_it = color_modifier_map.find(modifier);
    std::string modifier_str = "%source.????";
    if (modifier_it != color_modifier_map.end())
        modifier_str = modifier_it->second;

    return ReplacePattern(modifier_str, "%source", src_str);
}

static std::string GetTevStageConfigAlphaSourceString(
    const TexturingRegs::TevStageConfig::Source& source,
    const TexturingRegs::TevStageConfig::AlphaModifier modifier) {

    using AlphaModifier = TexturingRegs::TevStageConfig::AlphaModifier;
    static const std::map<AlphaModifier, std::string> alpha_modifier_map = {
        {AlphaModifier::SourceAlpha, "%source.a"},
        {AlphaModifier::OneMinusSourceAlpha, "(1.0 - %source.a)"},
        {AlphaModifier::SourceRed, "%source.r"},
        {AlphaModifier::OneMinusSourceRed, "(1.0 - %source.r)"},
        {AlphaModifier::SourceGreen, "%source.g"},
        {AlphaModifier::OneMinusSourceGreen, "(1.0 - %source.g)"},
        {AlphaModifier::SourceBlue, "%source.b"},
        {AlphaModifier::OneMinusSourceBlue, "(1.0 - %source.b)"},
    };

    auto src_str = GetTevStageConfigSourceString(source);
    auto modifier_it = alpha_modifier_map.find(modifier);
    std::string modifier_str = "%source.????";
    if (modifier_it != alpha_modifier_map.end())
        modifier_str = modifier_it->second;

    return ReplacePattern(modifier_str, "%source", src_str);
}

static std::string GetTevStageConfigOperationString(
    const TexturingRegs::TevStageConfig::Operation& operation) {

    using Operation = TexturingRegs::TevStageConfig::Operation;
    static const std::map<Operation, std::string> combiner_map = {
        {Operation::Replace, "%source1"},
        {Operation::Modulate, "(%source1 * %source2)"},
        {Operation::Add, "(%source1 + %source2)"},
        {Operation::AddSigned, "(%source1 + %source2) - 0.5"},
        {Operation::Lerp, "lerp(%source1, %source2, %source3)"},
        {Operation::Subtract, "(%source1 - %source2)"},
        {Operation::Dot3_RGB, "dot(%source1, %source2)"},
        {Operation::MultiplyThenAdd, "((%source1 * %source2) + %source3)"},
        {Operation::AddThenMultiply, "((%source1 + %source2) * %source3)"},
    };

    const auto op_it = combiner_map.find(operation);
    if (op_it == combiner_map.end())
        return "Unknown op (%source1, %source2, %source3)";

    return op_it->second;
}

std::string GetTevStageConfigColorCombinerString(const TexturingRegs::TevStageConfig& tev_stage) {
    auto op_str = GetTevStageConfigOperationString(tev_stage.color_op);
    op_str = ReplacePattern(
        op_str, "%source1",
        GetTevStageConfigColorSourceString(tev_stage.color_source1, tev_stage.color_modifier1));
    op_str = ReplacePattern(
        op_str, "%source2",
        GetTevStageConfigColorSourceString(tev_stage.color_source2, tev_stage.color_modifier2));
    return ReplacePattern(
        op_str, "%source3",
        GetTevStageConfigColorSourceString(tev_stage.color_source3, tev_stage.color_modifier3));
}

std::string GetTevStageConfigAlphaCombinerString(const TexturingRegs::TevStageConfig& tev_stage) {
    auto op_str = GetTevStageConfigOperationString(tev_stage.alpha_op);
    op_str = ReplacePattern(
        op_str, "%source1",
        GetTevStageConfigAlphaSourceString(tev_stage.alpha_source1, tev_stage.alpha_modifier1));
    op_str = ReplacePattern(
        op_str, "%source2",
        GetTevStageConfigAlphaSourceString(tev_stage.alpha_source2, tev_stage.alpha_modifier2));
    return ReplacePattern(
        op_str, "%source3",
        GetTevStageConfigAlphaSourceString(tev_stage.alpha_source3, tev_stage.alpha_modifier3));
}

void DumpTevStageConfig(const std::array<TexturingRegs::TevStageConfig, 6>& stages) {
    std::string stage_info = "Tev setup:\n";
    for (size_t index = 0; index < stages.size(); ++index) {
        const auto& tev_stage = stages[index];
        stage_info += "Stage " + std::to_string(index) + ": " +
                      GetTevStageConfigColorCombinerString(tev_stage) + "   " +
                      GetTevStageConfigAlphaCombinerString(tev_stage) + "\n";
    }
    LOG_TRACE(HW_GPU, "%s", stage_info.c_str());
}

} // namespace

} // namespace