/* SPDX-License-Identifier: MIT */

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

#include <stdexcept>
#include <string>

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

using namespace drm;

Device::Device(int fd) : m_fd(fd) {
    if (this->m_fd < 0) {
        throw std::invalid_argument("invalid file descriptor");
    }

    drm_version args{
        .version_major = 0,
    };
    ioctl::perform(this->m_fd, DRM_IOCTL_VERSION, args);

    this->m_version = {
        args.version_major,
        args.version_minor,
        args.version_patchlevel
    };
    this->m_name.resize(args.name_len);
    this->m_date.resize(args.date_len);
    this->m_description.resize(args.desc_len);

    args = {
        .name_len = this->m_name.size(),
        .name = this->m_name.data(),
        .date_len = this->m_date.size(),
        .date = this->m_date.data(),
        .desc_len = this->m_description.size(),
        .desc = this->m_description.data()
    };
    ioctl::perform(this->m_fd, DRM_IOCTL_VERSION, args);
}

void Device::setClientName(const std::string& name) const {
    drm_set_client_name name_args{
        .name_len = name.size(),
        .name = reinterpret_cast<u64>(name.data())
    };
    ioctl::perform(this->m_fd, DRM_IOCTL_SET_CLIENT_NAME, name_args);
}

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

    ::close(this->m_fd);
    this->m_fd = -1;
}

/* Authentication */

void Device::acquireMaster() const {
    ioctl::perform(this->m_fd, DRM_IOCTL_SET_MASTER);
}

void Device::releaseMaster() const {
    ioctl::perform(this->m_fd, DRM_IOCTL_DROP_MASTER);
}

u32 Device::magic() const {
    drm_auth auth_args{
        .magic = 0
    };
    ioctl::perform(this->m_fd, DRM_IOCTL_GET_MAGIC, auth_args);
    return auth_args.magic;
}

void Device::authenticate(u32 magic) const {
    drm_auth args{
        .magic = magic
    };
    ioctl::perform(this->m_fd, DRM_IOCTL_AUTH_MAGIC, args);
}

/* Device information */

std::string Device::unique() const {
    drm_set_version version_args{
        .drm_di_major = 1,
        .drm_di_minor = 4, // See kernel drm_ioctl.c for why this is here
        .drm_dd_major = -1,
        .drm_dd_minor = -1
    };
    ioctl::perform(this->m_fd, DRM_IOCTL_SET_VERSION, version_args);

    drm_unique unique_args{
        .unique_len = 0,
    };
    ioctl::perform(this->m_fd, DRM_IOCTL_GET_UNIQUE, unique_args);

    std::string unique(unique_args.unique_len, '\0');

    unique_args = {
        .unique_len = unique.size(),
        .unique = unique.data()
    };
    ioctl::perform(this->m_fd, DRM_IOCTL_GET_UNIQUE, unique_args);

    return unique;
}