/* Copyright (c) 2015-2021 The Khronos Group Inc.
 * Copyright (c) 2015-2021 Valve Corporation
 * Copyright (c) 2015-2021 LunarG, Inc.
 * Copyright (C) 2015-2021 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Author: Chris Forbes <chrisf@ijw.co.nz>
 *
 * The Shader Validation file is in charge of taking the Shader Module data and validating it
 */
#ifndef VULKAN_SHADER_VALIDATION_H
#define VULKAN_SHADER_VALIDATION_H

#include <cstdlib>

#include "vulkan/vulkan.h"
#include <generated/spirv_tools_commit_id.h>
#include "shader_module.h"

struct DeviceFeatures;
struct DeviceExtensions;

struct shader_stage_attributes {
    char const *const name;
    bool arrayed_input;
    bool arrayed_output;
    VkShaderStageFlags stage;
};

class ValidationCache {
    // hashes of shaders that have passed validation before, and can be skipped.
    // we don't store negative results, as we would have to also store what was
    // wrong with them; also, we expect they will get fixed, so we're less
    // likely to see them again.
    layer_data::unordered_set<uint32_t> good_shader_hashes;
    ValidationCache() {}

  public:
    static VkValidationCacheEXT Create(VkValidationCacheCreateInfoEXT const *pCreateInfo) {
        auto cache = new ValidationCache();
        cache->Load(pCreateInfo);
        return VkValidationCacheEXT(cache);
    }

    void Load(VkValidationCacheCreateInfoEXT const *pCreateInfo) {
        const auto headerSize = 2 * sizeof(uint32_t) + VK_UUID_SIZE;
        auto size = headerSize;
        if (!pCreateInfo->pInitialData || pCreateInfo->initialDataSize < size) return;

        uint32_t const *data = (uint32_t const *)pCreateInfo->pInitialData;
        if (data[0] != size) return;
        if (data[1] != VK_VALIDATION_CACHE_HEADER_VERSION_ONE_EXT) return;
        uint8_t expected_uuid[VK_UUID_SIZE];
        Sha1ToVkUuid(SPIRV_TOOLS_COMMIT_ID, expected_uuid);
        if (memcmp(&data[2], expected_uuid, VK_UUID_SIZE) != 0) return;  // different version

        data = (uint32_t const *)(reinterpret_cast<uint8_t const *>(data) + headerSize);

        for (; size < pCreateInfo->initialDataSize; data++, size += sizeof(uint32_t)) {
            good_shader_hashes.insert(*data);
        }
    }

    void Write(size_t *pDataSize, void *pData) {
        const auto headerSize = 2 * sizeof(uint32_t) + VK_UUID_SIZE;  // 4 bytes for header size + 4 bytes for version number + UUID
        if (!pData) {
            *pDataSize = headerSize + good_shader_hashes.size() * sizeof(uint32_t);
            return;
        }

        if (*pDataSize < headerSize) {
            *pDataSize = 0;
            return;  // Too small for even the header!
        }

        uint32_t *out = (uint32_t *)pData;
        size_t actualSize = headerSize;

        // Write the header
        *out++ = headerSize;
        *out++ = VK_VALIDATION_CACHE_HEADER_VERSION_ONE_EXT;
        Sha1ToVkUuid(SPIRV_TOOLS_COMMIT_ID, reinterpret_cast<uint8_t *>(out));
        out = (uint32_t *)(reinterpret_cast<uint8_t *>(out) + VK_UUID_SIZE);

        for (auto it = good_shader_hashes.begin(); it != good_shader_hashes.end() && actualSize < *pDataSize;
             it++, out++, actualSize += sizeof(uint32_t)) {
            *out = *it;
        }

        *pDataSize = actualSize;
    }

    void Merge(ValidationCache const *other) {
        good_shader_hashes.reserve(good_shader_hashes.size() + other->good_shader_hashes.size());
        for (auto h : other->good_shader_hashes) good_shader_hashes.insert(h);
    }

    static uint32_t MakeShaderHash(VkShaderModuleCreateInfo const *smci);

    bool Contains(uint32_t hash) { return good_shader_hashes.count(hash) != 0; }

    void Insert(uint32_t hash) { good_shader_hashes.insert(hash); }

  private:
    void Sha1ToVkUuid(const char *sha1_str, uint8_t *uuid) {
        // Convert sha1_str from a hex string to binary. We only need VK_UUID_SIZE bytes of
        // output, so pad with zeroes if the input string is shorter than that, and truncate
        // if it's longer.
#if defined(__GNUC__) && (__GNUC__ > 8)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wstringop-truncation"
#endif
        char padded_sha1_str[2 * VK_UUID_SIZE + 1] = {};  // 2 hex digits == 1 byte
        std::strncpy(padded_sha1_str, sha1_str, 2 * VK_UUID_SIZE);
#if defined(__GNUC__) && (__GNUC__ > 8)
#pragma GCC diagnostic pop
#endif
        for (uint32_t i = 0; i < VK_UUID_SIZE; ++i) {
            const char byte_str[] = {padded_sha1_str[2 * i + 0], padded_sha1_str[2 * i + 1], '\0'};
            uuid[i] = static_cast<uint8_t>(std::strtoul(byte_str, nullptr, 16));
        }
    }
};

spv_target_env PickSpirvEnv(uint32_t api_version, bool spirv_1_4);

void AdjustValidatorOptions(const DeviceExtensions &device_extensions, const DeviceFeatures &enabled_features,
                            spvtools::ValidatorOptions &options);

#endif  // VULKAN_SHADER_VALIDATION_H