/*
  Copyright 2018-2022, Barcelona Supercomputing Center (BSC), Spain
  Copyright 2015-2022, Johannes Gutenberg Universitaet Mainz, Germany

  This software was partially supported by the
  EC H2020 funded project NEXTGenIO (Project ID: 671951, www.nextgenio.eu).

  This software was partially supported by the
  ADA-FS project under the SPPEXA project funded by the DFG.

  This file is part of GekkoFS.

  GekkoFS is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  GekkoFS is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with GekkoFS.  If not, see <https://www.gnu.org/licenses/>.

  SPDX-License-Identifier: GPL-3.0-or-later
*/

/* C++ includes */
#include <CLI11/CLI11.hpp>
#include <nlohmann/json.hpp>
#include <memory>
#include <fmt/format.h>
#include <commands.hpp>
#include <reflection.hpp>
#include <serialize.hpp>
#include <binary_buffer.hpp>

/* C includes */
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

using json = nlohmann::json;

struct syscall_coverage_options {
    bool verbose{};
    std::string pathname;


    REFL_DECL_STRUCT(syscall_coverage_options, REFL_DECL_MEMBER(bool, verbose),
                     REFL_DECL_MEMBER(std::string, pathname));
};

struct syscall_coverage_output {
    int retval;
    int errnum;

    REFL_DECL_STRUCT(syscall_coverage_output, REFL_DECL_MEMBER(int, retval),
                     REFL_DECL_MEMBER(int, errnum));
};

void
to_json(json& record, const syscall_coverage_output& out) {
    record = serialize(out);
}

void output (const std::string syscall, const int ret, const syscall_coverage_options& opts) {
    if(opts.verbose) {
            fmt::print(
                    "syscall_coverage[{}](pathname=\"{}\") = {}, errno: {} [{}]\n",
                    syscall, opts.pathname, ret, errno, ::strerror(errno));
        }

    json out = syscall_coverage_output{ret, errno};
    fmt::print("{}\n", out.dump(2));
}
void
syscall_coverage_exec(const syscall_coverage_options& opts) {

    int fd = ::open(opts.pathname.c_str(), O_RDWR);

    if(fd == -1) {
        output ("open", fd, opts);
        return;
    }

    // Internal

    auto rv = ::faccessat(AT_FDCWD, opts.pathname.c_str(), F_OK, 0);

    if(rv < 0) {
        output ("faccessat", rv, opts);

        return;
    }

    // External

    rv = ::faccessat(AT_FDCWD, "/tmp", F_OK, 0);

    if(rv < 0) {
        output ("faccessat, external", rv, opts);

        return;
    }

    // lstat

    struct stat st;
    rv = ::lstat(opts.pathname.c_str(), &st);

    if (rv < 0) {
        output ("lstat", rv, opts);

        return;
    }


   

    rv = ::fchmod(fd, 0777);
    if (errno != ENOTSUP) {
        output ("fchmod", rv, opts);
        return;
    }

    rv = ::fchmodat(AT_FDCWD, opts.pathname.c_str(), 0777, 0);
    if (errno != ENOTSUP) {
        output ("fchmodat", rv, opts);
        return;
    }

    rv = ::dup3(fd, 0, 0);
    if (errno != ENOTSUP) {
        output ("dup3", rv, opts);
        return;
    }

    // fcntl
    rv = ::fcntl(fd, F_GETFD);
    if (rv < 0) {
        output ("fcntl, F_GETFD", rv, opts);
        return;
    }

    rv = ::fcntl(fd, F_GETFL);
    if (rv < 0 || rv != O_RDWR) {
        output ("fcntl, F_GETFL", rv, opts);
        return;
    }


    rv = ::fcntl(fd, F_SETFD, 0);
    if (rv < 0) {
        output ("fcntl, F_SETFD", rv, opts);
        return;
    }

    rv = ::fcntl(fd, F_SETFL, 0);
    if (errno != ENOTSUP) {
        output ("fcntl, F_SETFL", rv, opts);
        return;
    }


    rv = 0;
    errno = 0;
    json out = syscall_coverage_output{(int) rv, errno};
    fmt::print("{}\n", out.dump(2));
    return;
}

void
syscall_coverage_init(CLI::App& app) {

    // Create the option and subcommand objects
    auto opts = std::make_shared<syscall_coverage_options>();
    auto* cmd = app.add_subcommand(
            "syscall_coverage",
            "Execute severals syscalls");

    // Add options to cmd, binding them to opts
    cmd->add_flag("-v,--verbose", opts->verbose,
                  "Produce human writeable output");

    cmd->add_option("pathname", opts->pathname, "File name")
            ->required()
            ->type_name("");

    cmd->callback([opts]() { syscall_coverage_exec(*opts); });
}