// Take a look at the license at the top of the repository in the LICENSE file.

#![doc = include_str!("../README.md")]
#![allow(unknown_lints)]
#![deny(missing_docs)]
#![deny(rustdoc::broken_intra_doc_links)]
#![allow(clippy::upper_case_acronyms)]
#![allow(clippy::non_send_fields_in_send_ty)]
#![allow(renamed_and_removed_lints)]
#![allow(unknown_lints)]

#[macro_use]
mod macros;

cfg_if::cfg_if! {
    if #[cfg(feature = "unknown-ci")] {
        // This is used in CI to check that the build for unknown targets is compiling fine.
        mod unknown;
        use unknown as sys;

        #[cfg(test)]
        pub(crate) const MIN_USERS: usize = 0;
    } else if #[cfg(any(target_os = "macos", target_os = "ios"))] {
        mod apple;
        use apple as sys;
        extern crate core_foundation_sys;

        #[cfg(test)]
        pub(crate) const MIN_USERS: usize = 1;
    } else if #[cfg(windows)] {
        mod windows;
        use windows as sys;
        extern crate winapi;
        extern crate ntapi;

        #[cfg(test)]
        pub(crate) const MIN_USERS: usize = 1;
    } else if #[cfg(any(target_os = "linux", target_os = "android"))] {
        mod linux;
        use linux as sys;
        pub(crate) mod users;

        #[cfg(test)]
        pub(crate) const MIN_USERS: usize = 1;
    } else if #[cfg(target_os = "freebsd")] {
        mod freebsd;
        use freebsd as sys;
        pub(crate) mod users;

        #[cfg(test)]
        pub(crate) const MIN_USERS: usize = 1;
    } else {
        mod unknown;
        use unknown as sys;

        #[cfg(test)]
        pub(crate) const MIN_USERS: usize = 0;
    }
}

pub use common::{
    get_current_pid, CpuRefreshKind, DiskType, DiskUsage, Gid, LoadAvg, NetworksIter, Pid, PidExt,
    ProcessRefreshKind, ProcessStatus, RefreshKind, Signal, Uid, User,
};
pub use sys::{Component, Cpu, Disk, NetworkData, Networks, Process, System};
pub use traits::{
    ComponentExt, CpuExt, DiskExt, NetworkExt, NetworksExt, ProcessExt, SystemExt, UserExt,
};

#[cfg(feature = "c-interface")]
pub use c_interface::*;

#[cfg(feature = "c-interface")]
mod c_interface;
mod common;
mod debug;
mod system;
mod traits;
mod utils;

/// This function is only used on linux targets, on the other platforms it does nothing and returns
/// `false`.
///
/// On linux, to improve performance, we keep a `/proc` file open for each process we index with
/// a maximum number of files open equivalent to half of the system limit.
///
/// The problem is that some users might need all the available file descriptors so we need to
/// allow them to change this limit.
///
/// Note that if you set a limit bigger than the system limit, the system limit will be set.
///
/// Returns `true` if the new value has been set.
///
/// ```no_run
/// use sysinfo::{System, SystemExt, set_open_files_limit};
///
/// // We call the function before any call to the processes update.
/// if !set_open_files_limit(10) {
///     // It'll always return false on non-linux targets.
///     eprintln!("failed to update the open files limit...");
/// }
/// let s = System::new_all();
/// ```
pub fn set_open_files_limit(mut _new_limit: isize) -> bool {
    cfg_if::cfg_if! {
        if #[cfg(all(not(feature = "unknown-ci"), any(target_os = "linux", target_os = "android")))]
        {
            if _new_limit < 0 {
                _new_limit = 0;
            }
            let max = sys::system::get_max_nb_fds();
            if _new_limit > max {
                _new_limit = max;
            }
            unsafe {
                if let Ok(ref mut x) = sys::system::REMAINING_FILES.lock() {
                    // If files are already open, to be sure that the number won't be bigger when those
                    // files are closed, we subtract the current number of opened files to the new
                    // limit.
                    let diff = max.saturating_sub(**x);
                    **x = _new_limit.saturating_sub(diff);
                    true
                } else {
                    false
                }
            }
        } else {
            false
        }
    }
}

// FIXME: Can be removed once negative trait bounds are supported.
#[cfg(doctest)]
mod doctest {
    /// Check that `Process` doesn't implement `Clone`.
    ///
    /// First we check that the "basic" code works:
    ///
    /// ```no_run
    /// use sysinfo::{Process, System, SystemExt};
    ///
    /// let mut s = System::new_all();
    /// let p: &Process = s.processes().values().next().unwrap();
    /// ```
    ///
    /// And now we check if it fails when we try to clone it:
    ///
    /// ```compile_fail
    /// use sysinfo::{Process, System, SystemExt};
    ///
    /// let mut s = System::new_all();
    /// let p: &Process = s.processes().values().next().unwrap();
    /// let p = (*p).clone();
    /// ```
    mod process_clone {}

    /// Check that `System` doesn't implement `Clone`.
    ///
    /// First we check that the "basic" code works:
    ///
    /// ```no_run
    /// use sysinfo::{Process, System, SystemExt};
    ///
    /// let s = System::new();
    /// ```
    ///
    /// And now we check if it fails when we try to clone it:
    ///
    /// ```compile_fail
    /// use sysinfo::{Process, System, SystemExt};
    ///
    /// let s = System::new();
    /// let s = s.clone();
    /// ```
    mod system_clone {}
}

#[cfg(test)]
mod test {
    use crate::*;

    #[cfg(feature = "unknown-ci")]
    #[test]
    fn check_unknown_ci_feature() {
        assert!(!System::IS_SUPPORTED);
    }

    #[test]
    fn check_process_memory_usage() {
        let mut s = System::new();
        s.refresh_all();

        if System::IS_SUPPORTED {
            // No process should have 0 as memory usage.
            #[cfg(not(feature = "apple-sandbox"))]
            assert!(!s.processes().iter().all(|(_, proc_)| proc_.memory() == 0));
        } else {
            // There should be no process, but if there is one, its memory usage should be 0.
            assert!(s.processes().iter().all(|(_, proc_)| proc_.memory() == 0));
        }
    }

    #[test]
    fn check_memory_usage() {
        let mut s = System::new();

        assert_eq!(s.total_memory(), 0);
        assert_eq!(s.free_memory(), 0);
        assert_eq!(s.available_memory(), 0);
        assert_eq!(s.used_memory(), 0);
        assert_eq!(s.total_swap(), 0);
        assert_eq!(s.free_swap(), 0);
        assert_eq!(s.used_swap(), 0);

        s.refresh_memory();
        if System::IS_SUPPORTED {
            assert!(s.total_memory() > 0);
            assert!(s.used_memory() > 0);
            if s.total_swap() > 0 {
                // I think it's pretty safe to assume that there is still some swap left...
                assert!(s.free_swap() > 0);
            }
        } else {
            assert_eq!(s.total_memory(), 0);
            assert_eq!(s.used_memory(), 0);
            assert_eq!(s.total_swap(), 0);
            assert_eq!(s.free_swap(), 0);
        }
    }

    #[cfg(target_os = "linux")]
    #[test]
    fn check_processes_cpu_usage() {
        if !System::IS_SUPPORTED {
            return;
        }
        let mut s = System::new();

        s.refresh_processes();
        // All CPU usage will start at zero until the second refresh
        assert!(s
            .processes()
            .iter()
            .all(|(_, proc_)| proc_.cpu_usage() == 0.0));

        // Wait a bit to update CPU usage values
        std::thread::sleep(std::time::Duration::from_millis(100));
        s.refresh_processes();
        assert!(s
            .processes()
            .iter()
            .all(|(_, proc_)| proc_.cpu_usage() >= 0.0
                && proc_.cpu_usage() <= (s.cpus().len() as f32) * 100.0));
        assert!(s
            .processes()
            .iter()
            .any(|(_, proc_)| proc_.cpu_usage() > 0.0));
    }

    #[test]
    fn check_cpu_usage() {
        if !System::IS_SUPPORTED {
            return;
        }
        let mut s = System::new();
        for _ in 0..10 {
            s.refresh_cpu();
            // Wait a bit to update CPU usage values
            std::thread::sleep(std::time::Duration::from_millis(100));
            if s.cpus().iter().any(|c| c.cpu_usage() > 0.0) {
                // All good!
                return;
            }
        }
        panic!("CPU usage is always zero...");
    }

    #[test]
    fn check_users() {
        let mut s = System::new();
        assert!(s.users().is_empty());
        s.refresh_users_list();
        assert!(s.users().len() >= MIN_USERS);

        let mut s = System::new();
        assert!(s.users().is_empty());
        s.refresh_all();
        assert!(s.users().is_empty());

        let s = System::new_all();
        assert!(s.users().len() >= MIN_USERS);
    }

    #[test]
    fn check_uid_gid() {
        let mut s = System::new();
        assert!(s.users().is_empty());
        s.refresh_users_list();
        let users = s.users();
        assert!(users.len() >= MIN_USERS);

        if System::IS_SUPPORTED {
            #[cfg(not(target_os = "windows"))]
            {
                let user = users
                    .iter()
                    .find(|u| u.name() == "root")
                    .expect("no root user");
                assert_eq!(**user.id(), 0);
                assert_eq!(*user.group_id(), 0);
                if let Some(user) = users.iter().find(|u| *u.group_id() > 0) {
                    assert!(**user.id() > 0);
                    assert!(*user.group_id() > 0);
                }
                assert!(users.iter().filter(|u| **u.id() > 0).count() > 0);
            }

            // And now check that our `get_user_by_id` method works.
            s.refresh_processes();
            assert!(s
                .processes()
                .iter()
                .filter_map(|(_, p)| p.user_id())
                .any(|uid| s.get_user_by_id(uid).is_some()));
        }
    }

    #[test]
    fn check_system_info() {
        // We don't want to test on unsupported systems.
        if System::IS_SUPPORTED {
            let s = System::new();
            assert!(!s.name().expect("Failed to get system name").is_empty());

            assert!(!s
                .kernel_version()
                .expect("Failed to get kernel version")
                .is_empty());

            assert!(!s.os_version().expect("Failed to get os version").is_empty());

            assert!(!s
                .long_os_version()
                .expect("Failed to get long OS version")
                .is_empty());
        }
    }

    #[test]
    fn check_host_name() {
        // We don't want to test on unsupported systems.
        if System::IS_SUPPORTED {
            let s = System::new();
            assert!(s.host_name().is_some());
        }
    }

    #[test]
    fn check_refresh_process_return_value() {
        // We don't want to test on unsupported systems.
        if System::IS_SUPPORTED {
            let _pid = get_current_pid().expect("Failed to get current PID");

            #[cfg(not(feature = "apple-sandbox"))]
            {
                let mut s = System::new();
                // First check what happens in case the process isn't already in our process list.
                assert!(s.refresh_process(_pid));
                // Then check that it still returns true if the process is already in our process list.
                assert!(s.refresh_process(_pid));
            }
        }
    }

    #[test]
    fn ensure_is_supported_is_set_correctly() {
        if MIN_USERS > 0 {
            assert!(System::IS_SUPPORTED);
        } else {
            assert!(!System::IS_SUPPORTED);
        }
    }

    #[test]
    fn check_cpus_number() {
        let mut s = System::new();

        // This information isn't retrieved by default.
        assert!(s.cpus().is_empty());
        if System::IS_SUPPORTED {
            // The physical cores count is recomputed every time the function is called, so the
            // information must be relevant even with nothing initialized.
            let physical_cores_count = s
                .physical_core_count()
                .expect("failed to get number of physical cores");

            s.refresh_cpu();
            // The cpus shouldn't be empty anymore.
            assert!(!s.cpus().is_empty());

            // In case we are running inside a VM, it's possible to not have a physical core, only
            // logical ones, which is why we don't test `physical_cores_count > 0`.
            let physical_cores_count2 = s
                .physical_core_count()
                .expect("failed to get number of physical cores");
            assert!(physical_cores_count2 <= s.cpus().len());
            assert_eq!(physical_cores_count, physical_cores_count2);
        } else {
            assert_eq!(s.physical_core_count(), None);
        }
        assert!(s.physical_core_count().unwrap_or(0) <= s.cpus().len());
    }

    #[test]
    fn check_nb_supported_signals() {
        if System::IS_SUPPORTED {
            assert!(
                !System::SUPPORTED_SIGNALS.is_empty(),
                "SUPPORTED_SIGNALS shoudn't be empty on supported systems!"
            );
        } else {
            assert!(
                System::SUPPORTED_SIGNALS.is_empty(),
                "SUPPORTED_SIGNALS should be empty on not support systems!"
            );
        }
    }

    // Ensure that the CPUs frequency isn't retrieved until we ask for it.
    #[test]
    #[cfg(not(target_os = "freebsd"))] // In a VM, it'll fail.
    fn check_cpu_frequency() {
        if !System::IS_SUPPORTED {
            return;
        }
        let mut s = System::new();
        s.refresh_processes();
        for proc_ in s.cpus() {
            assert_eq!(proc_.frequency(), 0);
        }
        s.refresh_cpu();
        for proc_ in s.cpus() {
            assert_ne!(proc_.frequency(), 0);
        }
    }

    // In case `Process::updated` is misused, `System::refresh_processes` might remove them
    // so this test ensures that it doesn't happen.
    #[test]
    fn check_refresh_process_update() {
        if !System::IS_SUPPORTED {
            return;
        }
        let mut s = System::new_all();
        let total = s.processes().len() as isize;
        s.refresh_processes();
        let new_total = s.processes().len() as isize;
        // There should be almost no difference in the processes count.
        assert!(
            (new_total - total).abs() < 5,
            "{} < 5",
            (new_total - total).abs()
        );
    }
}