/* Copyright (c) 2024, Google Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

//! Helpers to ensure that some temporary objects are always freed.

use crate::initialized_struct;

/// A scoped `EC_KEY`.
pub struct EvpPkey(*mut bssl_sys::EVP_PKEY);

impl EvpPkey {
    pub fn new() -> Self {
        let ptr = unsafe { bssl_sys::EVP_PKEY_new() };
        // `ptr` is only NULL if we're out of memory, which this crate
        // doesn't handle.
        assert!(!ptr.is_null());
        EvpPkey(ptr)
    }

    pub fn from_ptr(ptr: *mut bssl_sys::EVP_PKEY) -> Self {
        EvpPkey(ptr)
    }

    pub fn as_ffi_ptr(&mut self) -> *mut bssl_sys::EVP_PKEY {
        self.0
    }
}

impl Drop for EvpPkey {
    fn drop(&mut self) {
        unsafe { bssl_sys::EVP_PKEY_free(self.0) }
    }
}

/// A scoped `EC_KEY`.
pub struct EcKey(*mut bssl_sys::EC_KEY);

impl EcKey {
    pub fn new() -> Self {
        let ptr = unsafe { bssl_sys::EC_KEY_new() };
        // `ptr` is only NULL if we're out of memory, which this crate
        // doesn't handle.
        assert!(!ptr.is_null());
        EcKey(ptr)
    }

    pub fn as_ffi_ptr(&mut self) -> *mut bssl_sys::EC_KEY {
        self.0
    }
}

impl Drop for EcKey {
    fn drop(&mut self) {
        unsafe { bssl_sys::EC_KEY_free(self.0) }
    }
}

/// A scoped `EVP_HPKE_CTX`.
pub struct EvpHpkeCtx(*mut bssl_sys::EVP_HPKE_CTX);

impl EvpHpkeCtx {
    pub fn new() -> Self {
        let ptr = unsafe { bssl_sys::EVP_HPKE_CTX_new() };
        // `ptr` is only NULL if we're out of memory, which this crate
        // doesn't handle.
        assert!(!ptr.is_null());
        EvpHpkeCtx(ptr)
    }

    pub fn as_ffi_ptr(&self) -> *const bssl_sys::EVP_HPKE_CTX {
        self.0
    }

    pub fn as_mut_ffi_ptr(&mut self) -> *mut bssl_sys::EVP_HPKE_CTX {
        self.0
    }
}

impl Drop for EvpHpkeCtx {
    fn drop(&mut self) {
        unsafe { bssl_sys::EVP_HPKE_CTX_free(self.0) }
    }
}

/// A scoped `EVP_HPKE_KEY`.
pub struct EvpHpkeKey(bssl_sys::EVP_HPKE_KEY);

impl EvpHpkeKey {
    pub fn new() -> Self {
        EvpHpkeKey(unsafe { initialized_struct(|ptr| bssl_sys::EVP_HPKE_KEY_zero(ptr)) })
    }

    pub fn as_ffi_ptr(&self) -> *const bssl_sys::EVP_HPKE_KEY {
        &self.0
    }

    pub fn as_mut_ffi_ptr(&mut self) -> *mut bssl_sys::EVP_HPKE_KEY {
        &mut self.0
    }
}

impl Drop for EvpHpkeKey {
    fn drop(&mut self) {
        // unsafe: the only way to create a `EvpHpkeKey` is via `new` and that
        // ensures that this structure is initialized.
        unsafe { bssl_sys::EVP_HPKE_KEY_cleanup(&mut self.0) }
    }
}

/// A scoped `BIGNUM`.
pub struct Bignum(bssl_sys::BIGNUM);

impl Bignum {
    pub fn from_u64(value: u64) -> Self {
        let mut ret = Bignum(unsafe { initialized_struct(|ptr| bssl_sys::BN_init(ptr)) });
        assert_eq!(1, unsafe { bssl_sys::BN_set_u64(&mut ret.0, value) });
        ret
    }

    pub unsafe fn as_ffi_ptr(&self) -> *const bssl_sys::BIGNUM {
        &self.0
    }
}

impl Drop for Bignum {
    fn drop(&mut self) {
        unsafe { bssl_sys::BN_free(&mut self.0) }
    }
}