//! All the constants.
//!
//! These constants are tested on a per-platform basis by `libpam-sys-test`'s
//! `test_constants.rs`.

use libpam_sys_impls::cfg_pam_impl;

/// Macro to make defining a bunch of constants way easier.
macro_rules! define {
    ($(#[$attr:meta])* $($name:ident = $value:expr);+$(;)?) => {
        define!(
            @meta { $(#[$attr])* }
            $(pub const $name: i32 = $value;)+
        );
    };
    (@meta $m:tt $($i:item)+) => { define!(@expand $($m $i)+); };
    (@expand $({ $(#[$m:meta])* } $i:item)+) => {$($(#[$m])* $i)+};
}

/// Macro to make defining C-style enums way easier.
macro_rules! c_enum {
    ($(#[$attr:meta])* $($name:ident $(= $value:expr)?,)*) => {
        c_enum!(
            (0)
            $(#[$attr])*
            $($name $(= $value)?,)*
        );
    };
    (($n:expr) $(#[$attr:meta])* $name:ident, $($rest:ident $(= $rv:expr)?,)*) => {
        $(#[$attr])* pub const $name: i32 = $n;
        c_enum!(($n + 1) $(#[$attr])* $($rest $(= $rv)?,)*);
    };
    (($n:expr) $(#[$attr:meta])* $name:ident = $value:expr, $($rest:ident $(= $rv:expr)?,)*) => {
        $(#[$attr])* pub const $name: i32 = $value;
        c_enum!(($value + 1) $(#[$attr])* $($rest $(= $rv)?,)*);
    };
    (($n:expr) $(#[$attr:meta])*) => {};
}

// There are a few truly universal constants.
// They are defined here directly.
pub const PAM_SUCCESS: i32 = 0;

c_enum!(
    /// An item type.
    PAM_SERVICE = 1,
    PAM_USER,
    PAM_TTY,
    PAM_RHOST,
    PAM_CONV,
    PAM_AUTHTOK,
    PAM_OLDAUTHTOK,
    PAM_RUSER,
);

c_enum!(
    /// A message style.
    PAM_PROMPT_ECHO_OFF = 1,
    PAM_PROMPT_ECHO_ON,
    PAM_ERROR_MSG,
    PAM_TEXT_INFO,
);

define!(
    /// Maximum size of PAM conversation elements (suggested).
    PAM_MAX_NUM_MSG = 32;
    PAM_MAX_MSG_SIZE = 512;
    PAM_MAX_RESP_SIZE = 512;
);

#[cfg_pam_impl("LinuxPam")]
pub use linux_pam::*;
#[cfg_pam_impl("LinuxPam")]
mod linux_pam {
    c_enum!(
        /// An error code.
        PAM_OPEN_ERR = 1,
        PAM_SYMBOL_ERR,
        PAM_SERVICE_ERR,
        PAM_SYSTEM_ERR,
        PAM_BUF_ERR,
        PAM_PERM_DENIED,
        PAM_AUTH_ERR,
        PAM_CRED_INSUFFICIENT,
        PAM_AUTHINFO_UNAVAIL,
        PAM_USER_UNKNOWN,
        PAM_MAXTRIES,
        PAM_NEW_AUTHTOK_REQD,
        PAM_ACCT_EXPIRED,
        PAM_SESSION_ERR,
        PAM_CRED_UNAVAIL,
        PAM_CRED_EXPIRED,
        PAM_CRED_ERR,
        PAM_NO_MODULE_DATA,
        PAM_CONV_ERR,
        PAM_AUTHTOK_ERR,
        PAM_AUTHTOK_RECOVERY_ERR,
        PAM_AUTHTOK_LOCK_BUSY,
        PAM_AUTHTOK_DISABLE_AGING,
        PAM_TRY_AGAIN,
        PAM_IGNORE,
        PAM_ABORT,
        PAM_AUTHTOK_EXPIRED,
        PAM_MODULE_UNKNOWN,
        PAM_BAD_ITEM,
        PAM_CONV_AGAIN,
        PAM_INCOMPLETE,
        _PAM_RETURN_VALUES,
    );
    /// An error code.
    pub const PAM_AUTHTOK_RECOVER_ERR: i32 = 21;

    define!(
        /// A flag value.
        PAM_SILENT = 0x8000;
        PAM_DISALLOW_NULL_AUTHTOK = 0x0001;
        PAM_ESTABLISH_CRED = 0x0002;
        PAM_DELETE_CRED = 0x0004;
        PAM_REINITIALIZE_CRED = 0x0008;
        PAM_REFRESH_CRED = 0x0010;

        PAM_CHANGE_EXPIRED_AUTHTOK = 0x0020;

        PAM_PRELIM_CHECK = 0x4000;
        PAM_UPDATE_AUTHTOK = 0x2000;
        PAM_DATA_REPLACE = 0x20000000;
    );

    c_enum!(
        PAM_USER_PROMPT = 9,
        PAM_FAIL_DELAY,
        PAM_XDISPLAY,
        PAM_XAUTHDATA,
        PAM_AUTHTOK_TYPE,
    );

    /// To suppress messages in the item cleanup function.
    pub const PAM_DATA_SILENT: i32 = 0x40000000;

    // Message styles
    define!(
        /// A message style.
        PAM_RADIO_TYPE = 5;
        PAM_BINARY_PROMPT = 7;
    );
}

#[cfg_pam_impl(any("OpenPam", "OpenPamMinimal", "Sun"))]
pub use openpam_sun::*;
#[cfg_pam_impl(any("OpenPam", "OpenPamMinimal", "Sun"))]
mod openpam_sun {
    c_enum!(
        /// An error code.
        PAM_OPEN_ERR = 1,
        PAM_SYMBOL_ERR,
        PAM_SERVICE_ERR,
        PAM_SYSTEM_ERR,
        PAM_BUF_ERR,
        PAM_CONV_ERR,
        PAM_PERM_DENIED,
        PAM_MAXTRIES,
        PAM_AUTH_ERR,
        PAM_NEW_AUTHTOK_REQD,
        PAM_CRED_INSUFFICIENT,
        PAM_AUTHINFO_UNAVAIL,
        PAM_USER_UNKNOWN,
        PAM_CRED_UNAVAIL,
        PAM_CRED_EXPIRED,
        PAM_CRED_ERR,
        PAM_ACCT_EXPIRED,
        PAM_AUTHTOK_EXPIRED,
        PAM_SESSION_ERR,
        PAM_AUTHTOK_ERR,
        PAM_AUTHTOK_RECOVERY_ERR,
        PAM_AUTHTOK_LOCK_BUSY,
        PAM_AUTHTOK_DISABLE_AGING,
        PAM_NO_MODULE_DATA,
        PAM_IGNORE,
        PAM_ABORT,
        PAM_TRY_AGAIN,
    );

    define!(
        /// An item type.
        PAM_USER_PROMPT = 9;
        PAM_REPOSITORY = 10;
    );

    /// A general flag for PAM operations.
    pub const PAM_SILENT: i32 = 0x80000000u32 as i32;

    /// The password must be non-null.
    pub const PAM_DISALLOW_NULL_AUTHTOK: i32 = 0b1;

    define!(
        /// A flag for `pam_setcred`.
        PAM_ESTABLISH_CRED = 0b0001;
        PAM_DELETE_CRED = 0b0010;
        PAM_REINITIALIZE_CRED = 0b0100;
        PAM_REFRESH_CRED = 0b1000;
    );

    define!(
        /// A flag for `pam_chauthtok`.
        PAM_PRELIM_CHECK = 0b0001;
        PAM_UPDATE_AUTHTOK = 0b0010;
        PAM_CHANGE_EXPIRED_AUTHTOK = 0b0100;
    );
}

#[cfg_pam_impl("OpenPam")]
pub use openpam::*;
#[cfg_pam_impl("OpenPam")]
mod openpam {
    c_enum!(
        /// An error code.
        PAM_MODULE_UNKNOWN = 28,
        PAM_DOMAIN_UNKNOWN,
        PAM_BAD_HANDLE,
        PAM_BAD_ITEM,
        PAM_BAD_FEATURE,
        PAM_BAD_CONSTANT,
    );
    /// The total number of PAM error codes.
    pub const PAM_NUM_ERRORS: i32 = 34;

    c_enum!(
        /// An item type.
        PAM_AUTHTOK_PROMPT = 11,
        PAM_OLDAUTHTOK_PROMPT,
        PAM_HOST,
    );
    /// The total number of PAM items.
    pub const PAM_NUM_ITEMS: i32 = 14;

    c_enum!(
        /// An optional OpenPAM feature.
        OPENPAM_RESTRICT_SERVICE_NAME,
        OPENPAM_VERIFY_POLICY_FILE,
        OPENPAM_RESTRICT_MODULE_NAME,
        OPENPAM_VERIFY_MODULE_FILE,
        OPENPAM_FALLBACK_TO_OTHER,
    );
    /// The number of optional OpenPAM features.
    pub const OPENPAM_NUM_FEATURES: i32 = 5;

    c_enum!(
        /// Log level.
        PAM_LOG_LIBDEBUG = -1,
        PAM_LOG_DEBUG,
        PAM_LOG_VERBOSE,
        PAM_LOG_NOTICE,
        PAM_LOG_ERROR,
    );
}

/// Constants exclusive to Illumos.
#[cfg_pam_impl("Sun")]
pub use sun::*;
#[cfg_pam_impl("Sun")]
mod sun {
    /// The total number of PAM error codes.
    pub const PAM_TOTAL_ERRNUM: i32 = 28;

    define!(
        /// An item type.
        PAM_RESOURCE = 11;
        PAM_AUSER = 12;
    );

    /// A flag for `pam_chauthtok`.
    pub const PAM_NO_AUTHTOK_CHECK: i32 = 0b1000;
}