// Copyright 2019 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.

#pragma once

#include <algorithm>
#include <memory>
#include "common/assert.h"
#include "common/common_types.h"
#include "video_core/engines/maxwell_3d.h"
#include "video_core/shader/const_buffer_locker.h"

namespace VideoCommon::Shader {

using Tegra::Engines::SamplerDescriptor;

ConstBufferLocker::ConstBufferLocker(Tegra::Engines::ShaderType shader_stage)
    : stage{shader_stage} {}

ConstBufferLocker::ConstBufferLocker(Tegra::Engines::ShaderType shader_stage,
                                     Tegra::Engines::ConstBufferEngineInterface& engine)
    : stage{shader_stage}, engine{&engine} {}

std::optional<u32> ConstBufferLocker::ObtainKey(u32 buffer, u32 offset) {
    const std::pair<u32, u32> key = {buffer, offset};
    const auto iter = keys.find(key);
    if (iter != keys.end()) {
        return iter->second;
    }
    if (!engine) {
        return {};
    }
    const u32 value = engine->AccessConstBuffer32(stage, buffer, offset);
    keys.emplace(key, value);
    return value;
}

std::optional<SamplerDescriptor> ConstBufferLocker::ObtainBoundSampler(u32 offset) {
    const u32 key = offset;
    const auto iter = bound_samplers.find(key);
    if (iter != bound_samplers.end()) {
        return iter->second;
    }
    if (!engine) {
        return {};
    }
    const SamplerDescriptor value = engine->AccessBoundSampler(stage, offset);
    bound_samplers.emplace(key, value);
    return value;
}

std::optional<Tegra::Engines::SamplerDescriptor> ConstBufferLocker::ObtainBindlessSampler(
    u32 buffer, u32 offset) {
    const std::pair key = {buffer, offset};
    const auto iter = bindless_samplers.find(key);
    if (iter != bindless_samplers.end()) {
        return iter->second;
    }
    if (!engine) {
        return {};
    }
    const SamplerDescriptor value = engine->AccessBindlessSampler(stage, buffer, offset);
    bindless_samplers.emplace(key, value);
    return value;
}

void ConstBufferLocker::InsertKey(u32 buffer, u32 offset, u32 value) {
    keys.insert_or_assign({buffer, offset}, value);
}

void ConstBufferLocker::InsertBoundSampler(u32 offset, SamplerDescriptor sampler) {
    bound_samplers.insert_or_assign(offset, sampler);
}

void ConstBufferLocker::InsertBindlessSampler(u32 buffer, u32 offset, SamplerDescriptor sampler) {
    bindless_samplers.insert_or_assign({buffer, offset}, sampler);
}

bool ConstBufferLocker::IsConsistent() const {
    if (!engine) {
        return false;
    }
    return std::all_of(keys.begin(), keys.end(),
                       [](const auto& key) {
                           const auto [value, other_value] = key.first;
                           return value == other_value;
                       }) &&
           std::all_of(bound_samplers.begin(), bound_samplers.end(),
                       [this](const auto& sampler) {
                           const auto [key, value] = sampler;
                           const auto other_value = engine->AccessBoundSampler(stage, key);
                           return value == other_value;
                       }) &&
           std::all_of(
               bindless_samplers.begin(), bindless_samplers.end(), [this](const auto& sampler) {
                   const auto [cbuf, offset] = sampler.first;
                   const auto value = sampler.second;
                   const auto other_value = engine->AccessBindlessSampler(stage, cbuf, offset);
                   return value == other_value;
               });
}

} // namespace VideoCommon::Shader