/* SPDX-License-Identifier: MIT */

#include "drm++/syncobject.hpp"
#include "drm++/helper.hpp"
#include "drm++/ioctl.hpp"

#include <cstddef>
#include <optional>
#include <span>
#include <stdexcept>
#include <vector>

#include <drm.h>
#include <unistd.h>

using namespace drm;
using namespace drm::syncobj;

/* Base sync object class */

SyncObjectBase::SyncObjectBase(int fd, bool signaled) : m_fd(fd) {
    drm_syncobj_create args{
        .flags = signaled ? DRM_SYNCOBJ_CREATE_SIGNALED : 0U
    };
    ioctl::perform(this->m_fd, DRM_IOCTL_SYNCOBJ_CREATE, args);

    this->m_handle = args.handle;
}

SyncObjectBase::SyncObjectBase(int fd, int syncobj_fd, bool close) : m_fd(fd) {
    try {
        drm_syncobj_handle args{
            .fd = syncobj_fd
        };
        ioctl::perform(this->m_fd, DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE, args);

        this->m_handle = args.handle;
    } catch (...) {
        if (close) {
            ::close(syncobj_fd);
        }

        throw;
    }

    if (close) {
        ::close(syncobj_fd);
    }
}

int SyncObjectBase::exportFd() const {
    drm_syncobj_handle args{
        .handle = this->m_handle,
    };
    ioctl::perform(this->m_fd, DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, args);

    return args.fd;
}

void SyncObjectBase::destruct() noexcept {
    if (this->m_fd < 0) {
        return;
    }

    drm_syncobj_destroy args{
        .handle = this->m_handle
    };
    try {
        ioctl::perform(this->m_fd, DRM_IOCTL_SYNCOBJ_DESTROY, args);
    } catch(...) {
        (void) 0; // not much we can do about the leak
    }

    this->m_fd = -1;
}

/* Importing/exporting sync fiels */

namespace {
    void importSyncFile(int fd, u32 syncobj, int syncfile_fd, u64 point, bool close) {
        try {
            drm_syncobj_handle args{
                .handle = syncobj,
                .flags = DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE
                    | (point != 0 ? DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_TIMELINE : 0U),
                .fd = syncfile_fd,
                .point = point
            };
            ioctl::perform(fd, DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE, args);
        } catch (...) {
            if (close) {
                ::close(syncfile_fd);
            }

            throw;
        }

        if (close) {
            ::close(syncfile_fd);
        }
    }
    int exportSyncFile(int fd, u32 syncobj, u64 point) {
        drm_syncobj_handle args{
            .handle = syncobj,
            .flags = DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE
                | (point != 0 ? DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_TIMELINE : 0U),
            .point = point
        };
        ioctl::perform(fd, DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, args);

        return args.fd;
    }
}

void SyncObject::importSyncFile(int syncfile_fd, bool close) const {
    ::importSyncFile(this->m_fd, this->m_handle, syncfile_fd, 0, close);
}
int SyncObject::exportSyncFile() const {
    return ::exportSyncFile(this->m_fd, this->m_handle, 0);
}
void TimelineSyncObject::importSyncFile(int syncfile_fd, u64 point, bool close) const {
    ::importSyncFile(this->m_fd, this->m_handle, syncfile_fd, point, close);
}
int TimelineSyncObject::exportSyncFile(u64 point) const {
    return ::exportSyncFile(this->m_fd, this->m_handle, point);
}

/* Transfer operations */

namespace {
    void transfer(int fd, u32 src, u32 dst, u64 srcPoint, u64 dstPoint) {
        drm_syncobj_transfer args{
            .src_handle = src,
            .dst_handle = dst,
            .src_point = srcPoint,
            .dst_point = dstPoint
        };
        ioctl::perform(fd, DRM_IOCTL_SYNCOBJ_TRANSFER, args);
    }
}

void SyncObject::transfer(const SyncObject& dest) const {
    ::transfer(this->m_fd, this->m_handle, dest.m_handle, 0, 0);
}
void SyncObject::transfer(const TimelineSyncObject& dest, u64 destPoint) const {
    ::transfer(this->m_fd, this->m_handle, dest.m_handle, 0, destPoint);
}
void TimelineSyncObject::transfer(const TimelineSyncObject& dest,
        u64 srcPoint, u64 destPoint) const {
    ::transfer(this->m_fd, this->m_handle, dest.m_handle, srcPoint, destPoint);
}
void TimelineSyncObject::transfer(const SyncObject& dest, u64 srcPoint) const {
    ::transfer(this->m_fd, this->m_handle, dest.m_handle, srcPoint, 0);
}

/* Registering eventfds */

namespace {
    void registerEventFd(int fd, u32 syncobj, int eventfd_fd, u64 point, bool waitAvailable) {
        drm_syncobj_eventfd args{
            .handle = syncobj,
            .flags = waitAvailable ? DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE : 0U,
            .point = point,
            .fd = eventfd_fd
        };
        ioctl::perform(fd, DRM_IOCTL_SYNCOBJ_EVENTFD, args);
    }
}

void SyncObject::registerEventFd(int eventfd_fd, bool waitAvailable) const {
    ::registerEventFd(this->m_fd, this->m_handle, eventfd_fd, 0, waitAvailable);
}
void TimelineSyncObject::registerEventFd(int eventfd_fd, u64 point, bool waitAvailable) const {
    ::registerEventFd(this->m_fd, this->m_handle, eventfd_fd, point, waitAvailable);
}

/* Binary signal & reset operations */

namespace {
    template<unsigned long OP>
    void signal(int fd, std::span<const u32> syncobjs) {
        drm_syncobj_array args{
            .handles = reinterpret_cast<u64>(syncobjs.data()),
            .count_handles = static_cast<u32>(syncobjs.size())
        };
        ioctl::perform(fd, OP, args);
    }
    template<unsigned long OP>
    void signalBulk(const std::vector<ref<const SyncObject>>& syncobjs) {
        if (syncobjs.empty()) {
            return;
        }

        std::vector<u32> handles(syncobjs.size());
        for (size_t i = 0; i < syncobjs.size(); ++i) {
            handles.at(i) = syncobjs.at(i).get().handle();
        }

        ::signal<OP>(syncobjs.front().get().fd(), handles);
    }
}

void SyncObject::signal() const {
    ::signal<DRM_IOCTL_SYNCOBJ_SIGNAL>(this->m_fd, std::span(&this->m_handle, 1));
}
void SyncObject::reset() const {
    ::signal<DRM_IOCTL_SYNCOBJ_RESET>(this->m_fd, std::span(&this->m_handle, 1));
}
void syncobj::signal(const std::vector<ref<const SyncObject>>& objs) {
    ::signalBulk<DRM_IOCTL_SYNCOBJ_SIGNAL>(objs);
}
void syncobj::reset(const std::vector<ref<const SyncObject>>& objs) {
    ::signalBulk<DRM_IOCTL_SYNCOBJ_RESET>(objs);
}

/* Timeline signal & query operations */

namespace {
    template<unsigned long OP>
    void signal(int fd, std::span<const u32> syncobjs, std::span<u64> points, bool lastSubmitted) {
        drm_syncobj_timeline_array args{
            .handles = reinterpret_cast<u64>(syncobjs.data()),
            .points = reinterpret_cast<u64>(points.data()),
            .count_handles = static_cast<u32>(syncobjs.size()),
            .flags = lastSubmitted ? DRM_SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED : 0U
        };
        ioctl::perform(fd, OP, args);
    }
    template<unsigned long OP>
    void signalBulk(const std::vector<ref<const TimelineSyncObject>>& syncobjs,
            std::span<u64> points, bool lastSubmitted) {
        if (syncobjs.empty()) {
            return;
        }

        if (syncobjs.size() != points.size()) {
            throw std::invalid_argument("syncobjs and points must have the same size");
        }

        std::vector<u32> handles(syncobjs.size());
        for (size_t i = 0; i < syncobjs.size(); ++i) {
            handles.at(i) = syncobjs.at(i).get().handle();
        }

        ::signal<OP>(syncobjs.front().get().fd(), handles, points, lastSubmitted);
    }
}

void TimelineSyncObject::signal(u64 point) const {
    ::signal<DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL>(this->m_fd,
        std::span(&this->m_handle, 1), std::span(&point, 1), false);
}
u64 TimelineSyncObject::query(bool lastSubmitted) const {
    u64 point{};
    ::signal<DRM_IOCTL_SYNCOBJ_QUERY>(this->m_fd,
        std::span(&this->m_handle, 1), std::span(&point, 1), lastSubmitted);
    return point;
}
void syncobj::signal(
    const std::vector<ref<const TimelineSyncObject>>& objs,
    std::vector<u64> points
) {
    ::signalBulk<DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL>(objs, points, false);
}
std::vector<u64> syncobj::query(
    const std::vector<ref<const TimelineSyncObject>>& objs,
    bool lastSubmitted
) {
    std::vector<u64> points(objs.size());
    ::signalBulk<DRM_IOCTL_SYNCOBJ_QUERY>(objs, points, lastSubmitted);
    return points;
}

/* Wait operations */

void SyncObject::wait(
    s64 timeout,
    WaitMode waitMode,
    std::optional<u64> deadlineHint
) const {
    drm_syncobj_wait args{
        .handles = reinterpret_cast<u64>(&this->m_handle),
        .timeout_nsec = timeout,
        .count_handles = 1,
        .flags = (waitMode == WaitMode::WaitEmpty ? DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT : 0U) |
            (waitMode == WaitMode::WaitAvailable ? DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE : 0U) |
            (deadlineHint.has_value() ? DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE : 0U),
        .deadline_nsec = deadlineHint.value_or(0)
    };
    ioctl::perform(this->m_fd, DRM_IOCTL_SYNCOBJ_WAIT, args);
}

const SyncObject& syncobj::wait(
    const std::vector<ref<const SyncObject>>& objs,
    s64 timeout,
    bool waitAll,
    WaitMode waitMode,
    std::optional<u64> deadlineHint
) {
    if (objs.empty()) {
        throw std::invalid_argument("must wait on at least one object");
    }

    std::vector<u32> handles(objs.size());
    for (size_t i = 0; i < objs.size(); ++i) {
        handles.at(i) = objs.at(i).get().handle();
    }

    drm_syncobj_wait args{
        .handles = reinterpret_cast<u64>(handles.data()),
        .timeout_nsec = timeout,
        .count_handles = static_cast<u32>(handles.size()),
        .flags = (waitAll ? 0U : DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL) |
            (waitMode == WaitMode::WaitEmpty ? DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT : 0U) |
            (waitMode == WaitMode::WaitAvailable ? DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE : 0U) |
            (deadlineHint.has_value() ? DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE : 0U),
        .deadline_nsec = deadlineHint.value_or(0)
    };
    ioctl::perform(objs.front().get().fd(), DRM_IOCTL_SYNCOBJ_WAIT, args);

    return objs.at(args.first_signaled).get();
}

void TimelineSyncObject::wait(
    s64 timeout,
    u64 point,
    bool waitAvailable,
    std::optional<u64> deadlineHint
) const {
    drm_syncobj_timeline_wait args{
        .handles = reinterpret_cast<u64>(&this->m_handle),
        .points = reinterpret_cast<u64>(&point),
        .timeout_nsec = timeout,
        .count_handles = 1,
        .flags = (waitAvailable ? DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE : 0U) |
            (deadlineHint.has_value() ? DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE : 0U),
        .deadline_nsec = deadlineHint.value_or(0)
    };
    ioctl::perform(this->m_fd, DRM_IOCTL_SYNCOBJ_WAIT, args);
}

void syncobj::wait(
    const std::vector<ref<const TimelineSyncObject>>& objs,
    const std::vector<u64>& points,
    s64 timeout,
    bool waitAll,
    bool waitAvailable,
    std::optional<u64> deadlineHint
) {
    if (objs.empty()) {
        return;
    }

    std::vector<u32> handles(objs.size());
    for (size_t i = 0; i < objs.size(); ++i) {
        handles.at(i) = objs.at(i).get().handle();
    }

    drm_syncobj_timeline_wait args{
        .handles = reinterpret_cast<u64>(handles.data()),
        .points = reinterpret_cast<u64>(points.data()),
        .timeout_nsec = timeout,
        .count_handles = static_cast<u32>(handles.size()),
        .flags = (waitAll ? 0U : DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL) |
            (waitAvailable ? DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE : 0U) |
            (deadlineHint.has_value() ? DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE : 0U),
        .deadline_nsec = deadlineHint.value_or(0)
    };
    ioctl::perform(objs.front().get().fd(), DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT, args);
}