/*
 * Copyright 2022 The Android Open Source Project
 *
 * 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.
 */

#include "DrmClient.h"

#include <cros_gralloc_handle.h>

using ::gfxstream::guest::AutoReadLock;
using ::gfxstream::guest::AutoWriteLock;
using ::gfxstream::guest::ReadWriteLock;

namespace aidl::android::hardware::graphics::composer3::impl {

DrmClient::~DrmClient() {
    if (mFd > 0) {
        drmDropMaster(mFd.get());
    }
}

::android::base::unique_fd DrmClient::OpenVirtioGpuDrmFd() {
    for (int i = 0; i < 10; i++) {
        const std::string path = "/dev/dri/card" + std::to_string(i);
        DEBUG_LOG("%s: trying to open DRM device at %s", __FUNCTION__, path.c_str());

        ::android::base::unique_fd fd(open(path.c_str(), O_RDWR | O_CLOEXEC));

        if (fd < 0) {
            ALOGE("%s: failed to open drm device %s: %s", __FUNCTION__, path.c_str(),
                  strerror(errno));
            continue;
        }

        auto version = drmGetVersion(fd.get());
        const std::string name = version->name;
        drmFreeVersion(version);

        DEBUG_LOG("%s: The DRM device at %s is \"%s\"", __FUNCTION__, path.c_str(), name.c_str());
        if (name.find("virtio") != std::string::npos) {
            return fd;
        }
    }

    ALOGE(
        "Failed to find virtio-gpu DRM node. Ranchu HWComposer "
        "is only expected to be used with \"virtio_gpu\"");

    return ::android::base::unique_fd(-1);
}

HWC3::Error DrmClient::init() {
    DEBUG_LOG("%s", __FUNCTION__);

    mFd = OpenVirtioGpuDrmFd();
    if (mFd < 0) {
        ALOGE("%s: failed to open drm device: %s", __FUNCTION__, strerror(errno));
        return HWC3::Error::NoResources;
    }

    int ret = drmSetClientCap(mFd.get(), DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);
    if (ret) {
        ALOGE("%s: failed to set cap universal plane %s\n", __FUNCTION__, strerror(errno));
        return HWC3::Error::NoResources;
    }

    ret = drmSetClientCap(mFd.get(), DRM_CLIENT_CAP_ATOMIC, 1);
    if (ret) {
        ALOGE("%s: failed to set cap atomic %s\n", __FUNCTION__, strerror(errno));
        return HWC3::Error::NoResources;
    }

    drmSetMaster(mFd.get());

    if (!drmIsMaster(mFd.get())) {
        ALOGE("%s: failed to get master drm device", __FUNCTION__);
        return HWC3::Error::NoResources;
    }

    {
        AutoWriteLock lock(mDisplaysMutex);
        bool success = loadDrmDisplays();
        if (success) {
            DEBUG_LOG("%s: Successfully initialized DRM backend", __FUNCTION__);
        } else {
            ALOGE("%s: Failed to initialize DRM backend", __FUNCTION__);
            return HWC3::Error::NoResources;
        }
    }

    mDrmEventListener = DrmEventListener::create(mFd, [this]() { handleHotplug(); });
    if (!mDrmEventListener) {
        ALOGE("%s: Failed to initialize DRM event listener", __FUNCTION__);
    } else {
        DEBUG_LOG("%s: Successfully initialized DRM event listener", __FUNCTION__);
    }

    DEBUG_LOG("%s: Successfully initialized.", __FUNCTION__);
    return HWC3::Error::None;
}

HWC3::Error DrmClient::getDisplayConfigs(std::vector<DisplayConfig>* configs) const {
    DEBUG_LOG("%s", __FUNCTION__);

    AutoReadLock lock(mDisplaysMutex);

    configs->clear();

    for (const auto& display : mDisplays) {
        if (!display->isConnected()) {
            continue;
        }

        configs->emplace_back(DisplayConfig{
            .id = display->getId(),
            .width = display->getWidth(),
            .height = display->getHeight(),
            .dpiX = display->getDpiX(),
            .dpiY = display->getDpiY(),
            .refreshRateHz = display->getRefreshRateUint(),
        });
    }

    return HWC3::Error::None;
}

HWC3::Error DrmClient::registerOnHotplugCallback(const HotplugCallback& cb) {
    mHotplugCallback = cb;
    return HWC3::Error::None;
}

HWC3::Error DrmClient::unregisterOnHotplugCallback() {
    mHotplugCallback.reset();
    return HWC3::Error::None;
}

bool DrmClient::loadDrmDisplays() {
    DEBUG_LOG("%s", __FUNCTION__);

    std::vector<std::unique_ptr<DrmCrtc>> crtcs;
    std::vector<std::unique_ptr<DrmConnector>> connectors;
    std::vector<std::unique_ptr<DrmPlane>> planes;

    drmModePlaneResPtr drmPlaneResources = drmModeGetPlaneResources(mFd.get());
    for (uint32_t i = 0; i < drmPlaneResources->count_planes; ++i) {
        const uint32_t planeId = drmPlaneResources->planes[i];

        auto crtc = DrmPlane::create(mFd, planeId);
        if (!crtc) {
            ALOGE("%s: Failed to create DRM CRTC.", __FUNCTION__);
            return false;
        }

        planes.emplace_back(std::move(crtc));
    }
    drmModeFreePlaneResources(drmPlaneResources);

    drmModeRes* drmResources = drmModeGetResources(mFd.get());
    for (uint32_t crtcIndex = 0; crtcIndex < drmResources->count_crtcs; crtcIndex++) {
        const uint32_t crtcId = drmResources->crtcs[crtcIndex];

        auto crtc = DrmCrtc::create(mFd, crtcId, crtcIndex);
        if (!crtc) {
            ALOGE("%s: Failed to create DRM CRTC.", __FUNCTION__);
            return false;
        }

        crtcs.emplace_back(std::move(crtc));
    }

    for (uint32_t i = 0; i < drmResources->count_connectors; ++i) {
        const uint32_t connectorId = drmResources->connectors[i];

        auto connector = DrmConnector::create(mFd, connectorId);
        if (!connector) {
            ALOGE("%s: Failed to create DRM CRTC.", __FUNCTION__);
            return false;
        }

        connectors.emplace_back(std::move(connector));
    }

    drmModeFreeResources(drmResources);

    if (crtcs.size() != connectors.size()) {
        ALOGE("%s: Failed assumption mCrtcs.size():%zu equals mConnectors.size():%zu", __FUNCTION__,
              crtcs.size(), connectors.size());
        return false;
    }

    for (uint32_t i = 0; i < crtcs.size(); i++) {
        std::unique_ptr<DrmCrtc> crtc = std::move(crtcs[i]);
        std::unique_ptr<DrmConnector> connector = std::move(connectors[i]);

        auto planeIt =
            std::find_if(planes.begin(), planes.end(), [&](const std::unique_ptr<DrmPlane>& plane) {
                if (!plane->isOverlay() && !plane->isPrimary()) {
                    return false;
                }
                return plane->isCompatibleWith(*crtc);
            });
        if (planeIt == planes.end()) {
            ALOGE("%s: Failed to find plane for display:%" PRIu32, __FUNCTION__, i);
            return false;
        }

        std::unique_ptr<DrmPlane> plane = std::move(*planeIt);
        planes.erase(planeIt);

        auto display =
            DrmDisplay::create(i, std::move(connector), std::move(crtc), std::move(plane), mFd);
        if (!display) {
            return false;
        }
        mDisplays.push_back(std::move(display));
    }

    return true;
}

std::tuple<HWC3::Error, std::shared_ptr<DrmBuffer>> DrmClient::create(
    const native_handle_t* handle) {
    cros_gralloc_handle* crosHandle = (cros_gralloc_handle*)handle;
    if (crosHandle == nullptr) {
        ALOGE("%s: invalid cros_gralloc_handle", __FUNCTION__);
        return std::make_tuple(HWC3::Error::NoResources, nullptr);
    }

    DrmPrimeBufferHandle primeHandle = 0;
    int ret = drmPrimeFDToHandle(mFd.get(), crosHandle->fds[0], &primeHandle);
    if (ret) {
        ALOGE("%s: drmPrimeFDToHandle failed: %s (errno %d)", __FUNCTION__, strerror(errno), errno);
        return std::make_tuple(HWC3::Error::NoResources, nullptr);
    }

    auto buffer = std::shared_ptr<DrmBuffer>(new DrmBuffer(*this));
    buffer->mWidth = crosHandle->width;
    buffer->mHeight = crosHandle->height;
    buffer->mDrmFormat = crosHandle->format;
    buffer->mPlaneFds[0] = crosHandle->fds[0];
    buffer->mPlaneHandles[0] = primeHandle;
    buffer->mPlanePitches[0] = crosHandle->strides[0];
    buffer->mPlaneOffsets[0] = crosHandle->offsets[0];

    uint32_t framebuffer = 0;
    ret = drmModeAddFB2(mFd.get(), buffer->mWidth, buffer->mHeight, buffer->mDrmFormat,
                        buffer->mPlaneHandles, buffer->mPlanePitches, buffer->mPlaneOffsets,
                        &framebuffer, 0);
    if (ret) {
        ALOGE("%s: drmModeAddFB2 failed: %s (errno %d)", __FUNCTION__, strerror(errno), errno);
        return std::make_tuple(HWC3::Error::NoResources, nullptr);
    }
    DEBUG_LOG("%s: created framebuffer:%" PRIu32, __FUNCTION__, framebuffer);
    buffer->mDrmFramebuffer = framebuffer;

    return std::make_tuple(HWC3::Error::None, std::shared_ptr<DrmBuffer>(buffer));
}

HWC3::Error DrmClient::destroyDrmFramebuffer(DrmBuffer* buffer) {
    if (buffer->mDrmFramebuffer) {
        uint32_t framebuffer = *buffer->mDrmFramebuffer;
        if (drmModeRmFB(mFd.get(), framebuffer)) {
            ALOGE("%s: drmModeRmFB failed: %s (errno %d)", __FUNCTION__, strerror(errno), errno);
            return HWC3::Error::NoResources;
        }
        DEBUG_LOG("%s: destroyed framebuffer:%" PRIu32, __FUNCTION__, framebuffer);
        buffer->mDrmFramebuffer.reset();
    }
    if (buffer->mPlaneHandles[0]) {
        struct drm_gem_close gem_close = {};
        gem_close.handle = buffer->mPlaneHandles[0];
        if (drmIoctl(mFd.get(), DRM_IOCTL_GEM_CLOSE, &gem_close)) {
            ALOGE("%s: DRM_IOCTL_GEM_CLOSE failed: %s (errno %d)", __FUNCTION__, strerror(errno),
                  errno);
            return HWC3::Error::NoResources;
        }
    }

    return HWC3::Error::None;
}

bool DrmClient::handleHotplug() {
    DEBUG_LOG("%s", __FUNCTION__);

    struct HotplugToReport {
        uint32_t id;
        uint32_t width;
        uint32_t height;
        uint32_t dpiX;
        uint32_t dpiY;
        uint32_t rr;
        bool connected;
    };

    std::vector<HotplugToReport> hotplugs;

    {
        AutoWriteLock lock(mDisplaysMutex);

        for (auto& display : mDisplays) {
            auto change = display->checkAndHandleHotplug(mFd);
            if (change == DrmHotplugChange::kNoChange) {
                continue;
            }

            hotplugs.push_back(HotplugToReport{
                .id = display->getId(),
                .width = display->getWidth(),
                .height = display->getHeight(),
                .dpiX = display->getDpiX(),
                .dpiY = display->getDpiY(),
                .rr = display->getRefreshRateUint(),
                .connected = change == DrmHotplugChange::kConnected,
            });
        }
    }

    for (const auto& hotplug : hotplugs) {
        if (mHotplugCallback) {
            (*mHotplugCallback)(hotplug.connected,  //
                                hotplug.id,         //
                                hotplug.width,      //
                                hotplug.height,     //
                                hotplug.dpiX,       //
                                hotplug.dpiY,       //
                                hotplug.rr);
        }
    }

    return true;
}

std::tuple<HWC3::Error, ::android::base::unique_fd> DrmClient::flushToDisplay(
    uint32_t displayId, const std::shared_ptr<DrmBuffer>& buffer,
    ::android::base::borrowed_fd inSyncFd) {
    ATRACE_CALL();

    if (!buffer->mDrmFramebuffer) {
        ALOGE("%s: failed, no framebuffer created.", __FUNCTION__);
        return std::make_tuple(HWC3::Error::NoResources, ::android::base::unique_fd());
    }

    AutoReadLock lock(mDisplaysMutex);
    return mDisplays[displayId]->flush(mFd, inSyncFd, buffer);
}

std::optional<std::vector<uint8_t>> DrmClient::getEdid(uint32_t displayId) {
    AutoReadLock lock(mDisplaysMutex);

    if (displayId >= mDisplays.size()) {
        DEBUG_LOG("%s: invalid display:%" PRIu32, __FUNCTION__, displayId);
        return std::nullopt;
    }

    return mDisplays[displayId]->getEdid();
}

}  // namespace aidl::android::hardware::graphics::composer3::impl