// Copyright 2019 The Dawn & Tint Authors
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its
//    contributors may be used to endorse or promote products derived from
//    this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/439062058): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif

#include <limits>
#include <memory>

#include "dawn/common/Assert.h"
#include "dawn/common/StringViewUtils.h"
#include "dawn/wire/BufferConsumer_impl.h"
#include "dawn/wire/WireCmd_autogen.h"
#include "dawn/wire/WireResult.h"
#include "dawn/wire/server/Server.h"

namespace dawn::wire::server {

WireResult Server::PreHandleDeviceCreateErrorBuffer(const DeviceCreateErrorBufferCmd& cmd) {
    // mappedAtCreation isn't implemented in CreateErrorBuffer.
    // The client blocks this, so we can treat it as a fatal wire error (for fuzzers).
    if (cmd.descriptor->mappedAtCreation) {
        return WireResult::FatalError;
    }

    return WireResult::Success;
}

WireResult Server::PreHandleBufferUnmap(const BufferUnmapCmd& cmd) {
    Known<WGPUBuffer> buffer;
    WIRE_TRY(Get(cmd.selfId, &buffer));

    if (buffer->mappedAtCreation && !(buffer->usage & WGPUBufferUsage_MapWrite)) {
        // This indicates the writeHandle is for mappedAtCreation only. Destroy on unmap
        // writeHandle could have possibly been deleted if buffer is already destroyed so we
        // don't assert it's non-null
        buffer->writeHandle = nullptr;
    }

    buffer->mapWriteState = BufferMapWriteState::Unmapped;

    return WireResult::Success;
}

WireResult Server::PreHandleBufferDestroy(const BufferDestroyCmd& cmd) {
    // Destroying a buffer does an implicit unmapping.
    Known<WGPUBuffer> buffer;
    WIRE_TRY(Get(cmd.selfId, &buffer));

    // The buffer was destroyed. Clear the Read/WriteHandle.
    buffer->readHandle = nullptr;
    buffer->writeHandle = nullptr;
    buffer->mapWriteState = BufferMapWriteState::Unmapped;

    return WireResult::Success;
}

WireResult Server::DoBufferMapAsync(Known<WGPUBuffer> buffer,
                                    ObjectHandle eventManager,
                                    WGPUFuture future,
                                    WGPUMapMode mode,
                                    uint64_t offset64,
                                    uint64_t size64) {
    // These requests are just forwarded to the buffer, with userdata containing what the
    // client will require in the return command.
    std::unique_ptr<MapUserdata> userdata = MakeUserdata<MapUserdata>();
    userdata->buffer = buffer.AsHandle();
    userdata->eventManager = eventManager;
    userdata->bufferObj = buffer->handle;
    userdata->future = future;
    userdata->mode = mode;

    // Make sure that the deserialized offset and size are no larger than
    // std::numeric_limits<size_t>::max() so that they are CPU-addressable, and size is not
    // WGPU_WHOLE_MAP_SIZE, which is by definition std::numeric_limits<size_t>::max(). Since
    // client does the default size computation, we should always have a valid actual size here
    // in server. All other invalid actual size can be caught by dawn native side validation.
    if (offset64 > std::numeric_limits<size_t>::max()) {
        static constexpr WGPUStringView kOffsetOutOfRange = {"Buffer offset was out of range.", 31};
        OnBufferMapAsyncCallback(userdata.get(), WGPUMapAsyncStatus_Error, kOffsetOutOfRange);
        return WireResult::Success;
    }
    if (size64 >= WGPU_WHOLE_MAP_SIZE) {
        static constexpr WGPUStringView kSizeOutOfRange = {"Buffer size was out of range.", 29};
        OnBufferMapAsyncCallback(userdata.get(), WGPUMapAsyncStatus_Error, kSizeOutOfRange);
        return WireResult::Success;
    }

    size_t offset = static_cast<size_t>(offset64);
    size_t size = static_cast<size_t>(size64);

    userdata->offset = offset;
    userdata->size = size;

    mProcs.bufferMapAsync(
        buffer->handle, mode, offset, size,
        MakeCallbackInfo<WGPUBufferMapCallbackInfo, &Server::OnBufferMapAsyncCallback>(
            userdata.release()));

    return WireResult::Success;
}

WireResult Server::DoDeviceCreateBuffer(Known<WGPUDevice> device,
                                        const WGPUBufferDescriptor* descriptor,
                                        ObjectHandle bufferHandle,
                                        uint64_t readHandleCreateInfoLength,
                                        const uint8_t* readHandleCreateInfo,
                                        uint64_t writeHandleCreateInfoLength,
                                        const uint8_t* writeHandleCreateInfo) {
    // Create and register the buffer object.
    Reserved<WGPUBuffer> buffer;
    WIRE_TRY(Allocate(&buffer, bufferHandle));
    buffer->handle = mProcs.deviceCreateBuffer(device->handle, descriptor);
    buffer->usage = descriptor->usage;
    buffer->mappedAtCreation = (descriptor->mappedAtCreation != 0u);

    // isReadMode and isWriteMode could be true at the same time if usage contains
    // WGPUBufferUsage_MapRead and buffer is mappedAtCreation
    bool isReadMode = (descriptor->usage & WGPUBufferUsage_MapRead) != 0u;
    bool isWriteMode = ((descriptor->usage & WGPUBufferUsage_MapWrite) != 0u) ||
                       (descriptor->mappedAtCreation != 0u);

    // This is the size of data deserialized from the command stream to create the read/write
    // handle, which must be CPU-addressable.
    if (readHandleCreateInfoLength > std::numeric_limits<size_t>::max() ||
        writeHandleCreateInfoLength > std::numeric_limits<size_t>::max() ||
        readHandleCreateInfoLength >
            std::numeric_limits<size_t>::max() - writeHandleCreateInfoLength) {
        return WireResult::FatalError;
    }

    if (isWriteMode) {
        if (buffer->handle == nullptr) {
            DAWN_ASSERT(descriptor->mappedAtCreation);
            // A null buffer indicates that mapping-at-creation failed inside createBuffer.
            // - Unmark the buffer as allocated so we will skip freeing it.
            buffer->state = AllocationState::Reserved;
            // - Remember the buffer is an error so we will skip subsequent mapping operations.
            buffer->mapWriteState = BufferMapWriteState::MapError;
            return WireResult::Success;
        }

        MemoryTransferService::WriteHandle* writeHandle = nullptr;
        // Deserialize metadata produced from the client to create a companion server handle.
        if (!mMemoryTransferService->DeserializeWriteHandle(
                writeHandleCreateInfo, static_cast<size_t>(writeHandleCreateInfoLength),
                &writeHandle)) {
            return WireResult::FatalError;
        }
        DAWN_ASSERT(writeHandle != nullptr);
        buffer->writeHandle.reset(writeHandle);
        writeHandle->SetDataLength(descriptor->size);

        if (descriptor->mappedAtCreation) {
            void* mapping = mProcs.bufferGetMappedRange(buffer->handle, 0, descriptor->size);
            if (mapping == nullptr) {
                DAWN_ASSERT(descriptor->size % 4 != 0);
                // GetMappedRange can still fail if the buffer's size isn't aligned.
                // - Remember the buffer is an error so we will skip subsequent mapping operations.
                buffer->mapWriteState = BufferMapWriteState::MapError;
                return WireResult::Success;
            }
            DAWN_ASSERT(mapping != nullptr);
            writeHandle->SetTarget(mapping);

            buffer->mapWriteState = BufferMapWriteState::Mapped;
        }
    }

    if (isReadMode) {
        MemoryTransferService::ReadHandle* readHandle = nullptr;
        // Deserialize metadata produced from the client to create a companion server handle.
        if (!mMemoryTransferService->DeserializeReadHandle(
                readHandleCreateInfo, static_cast<size_t>(readHandleCreateInfoLength),
                &readHandle)) {
            return WireResult::FatalError;
        }
        DAWN_ASSERT(readHandle != nullptr);

        buffer->readHandle.reset(readHandle);
    }

    return WireResult::Success;
}

WireResult Server::DoBufferUpdateMappedData(Known<WGPUBuffer> buffer,
                                            uint64_t writeDataUpdateInfoLength,
                                            const uint8_t* writeDataUpdateInfo,
                                            uint64_t offset,
                                            uint64_t size) {
    if (writeDataUpdateInfoLength > std::numeric_limits<size_t>::max() ||
        offset > std::numeric_limits<size_t>::max() || size > std::numeric_limits<size_t>::max()) {
        return WireResult::FatalError;
    }

    switch (buffer->mapWriteState) {
        case BufferMapWriteState::Unmapped:
            return WireResult::FatalError;
        case BufferMapWriteState::MapError:
            // The buffer is mapped but there was an error allocating mapped data.
            // Do not perform the memcpy.
            return WireResult::Success;
        case BufferMapWriteState::Mapped:
            break;
    }
    if (!buffer->writeHandle) {
        // This check is performed after the check for the MapError state. It is permissible
        // to Unmap and attempt to update mapped data of an error buffer.
        return WireResult::FatalError;
    }

    // Deserialize the flush info and flush updated data from the handle into the target
    // of the handle. The target is set via WriteHandle::SetTarget.
    if (!buffer->writeHandle->DeserializeDataUpdate(
            writeDataUpdateInfo, static_cast<size_t>(writeDataUpdateInfoLength),
            static_cast<size_t>(offset), static_cast<size_t>(size))) {
        return WireResult::FatalError;
    }
    return WireResult::Success;
}

void Server::OnBufferMapAsyncCallback(MapUserdata* data,
                                      WGPUMapAsyncStatus status,
                                      WGPUStringView message) {
    // Skip sending the callback if the buffer has already been destroyed.
    Known<WGPUBuffer> buffer;
    if (Get(data->buffer.id, &buffer) != WireResult::Success ||
        buffer->generation != data->buffer.generation) {
        return;
    }

    bool isRead = (data->mode & WGPUMapMode_Read) != 0u;
    bool isSuccess = status == WGPUMapAsyncStatus_Success;

    ReturnBufferMapAsyncCallbackCmd cmd = {};
    cmd.eventManager = data->eventManager;
    cmd.future = data->future;
    cmd.status = status;
    cmd.message = message;
    // Set the pointer length, but the pointed-to data itself won't be serialized as usual (due
    // to skip_serialize). Instead, the custom CommandExtension below fills that memory.
    cmd.readDataUpdateInfoLength = 0;
    cmd.readDataUpdateInfo = nullptr;  // Skipped by skip_serialize.

    const void* readData = nullptr;
    size_t readDataUpdateInfoLength = 0;
    if (isSuccess) {
        if (isRead) {
            // Get the serialization size of the message to initialize ReadHandle data.
            readData = mProcs.bufferGetConstMappedRange(data->bufferObj, data->offset, data->size);
            readDataUpdateInfoLength =
                buffer->readHandle->SizeOfSerializeDataUpdate(data->offset, data->size);
            cmd.readDataUpdateInfoLength = readDataUpdateInfoLength;
        } else {
            DAWN_ASSERT(data->mode & WGPUMapMode_Write);
            // The in-flight map request returned successfully.
            buffer->mapWriteState = BufferMapWriteState::Mapped;
            // Set the target of the WriteHandle to the mapped buffer data.
            // writeHandle Target always refers to the buffer base address.
            // but we call getMappedRange exactly with the range of data that is potentially
            // modified (i.e. we don't want getMappedRange(0, wholeBufferSize) if only a
            // subset of the buffer is actually mapped) in case the implementation does some
            // range tracking.
            buffer->writeHandle->SetTarget(static_cast<uint8_t*>(mProcs.bufferGetMappedRange(
                                               data->bufferObj, data->offset, data->size)) -
                                           data->offset);
        }
    }

    SerializeCommand(cmd,
                     // Extensions to replace fields skipped by skip_serialize.
                     CommandExtension{readDataUpdateInfoLength, [&](char* readHandleBuffer) {
                                          if (isSuccess && isRead) {
                                              // The in-flight map request returned
                                              // successfully.
                                              buffer->readHandle->SerializeDataUpdate(
                                                  readData, data->offset, data->size,
                                                  readHandleBuffer);
                                          }
                                      }});
}

}  // namespace dawn::wire::server