// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

use std::{ffi::CString, path::Path, ptr};

use either::Either;
use libc::{c_char, c_int, c_void};

use libcryptsetup_rs_sys::crypt_device;

use crate::{
    activate::CryptActivationHandle,
    backup::CryptBackupHandle,
    context::CryptContextHandle,
    err::LibcryptErr,
    format::CryptFormatHandle,
    key::CryptVolumeKeyHandle,
    keyfile::CryptKeyfileHandle,
    keyslot::CryptKeyslotHandle,
    luks2::{
        flags::CryptLuks2FlagsHandle, reencrypt::CryptLuks2ReencryptHandle,
        token::CryptLuks2TokenHandle,
    },
    runtime::CryptRuntimeHandle,
    settings::CryptSettingsHandle,
    status::CryptDeviceStatusHandle,
    wipe::CryptWipeHandle,
};

type ConfirmCallback = unsafe extern "C" fn(msg: *const c_char, usrptr: *mut c_void) -> c_int;

/// Initialization handle for devices
pub struct CryptInit;

impl CryptInit {
    /// Initialize by device path
    pub fn init(device_path: &Path) -> Result<CryptDevice, LibcryptErr> {
        let mut cdevice: *mut crypt_device = ptr::null_mut();
        let device_path_cstring = path_to_cstring!(device_path)?;
        errno!(mutex!(libcryptsetup_rs_sys::crypt_init(
            &mut cdevice as *mut *mut crypt_device,
            device_path_cstring.as_ptr(),
        )))?;
        Ok(CryptDevice { ptr: cdevice })
    }

    /// Initialize by device path or a header path and a data device path
    pub fn init_with_data_device(
        device_paths: Either<&Path, (&Path, &Path)>,
    ) -> Result<CryptDevice, LibcryptErr> {
        let mut cdevice: *mut crypt_device = ptr::null_mut();
        let (device_path_cstring, data_device_option) = match device_paths {
            Either::Left(device) => (path_to_cstring!(device)?, None),
            Either::Right((header_device, data_device)) => (
                path_to_cstring!(header_device)?,
                Some(path_to_cstring!(data_device)?),
            ),
        };

        errno!(mutex!(libcryptsetup_rs_sys::crypt_init_data_device(
            &mut cdevice as *mut *mut crypt_device,
            device_path_cstring.as_ptr(),
            match data_device_option {
                Some(ref d) => d.as_ptr(),
                None => ptr::null(),
            },
        )))?;
        Ok(CryptDevice { ptr: cdevice })
    }

    /// Initialize by name and header device path
    pub fn init_by_name_and_header(
        name: &str,
        header_device_path: Option<&Path>,
    ) -> Result<CryptDevice, LibcryptErr> {
        let mut cdevice: *mut crypt_device = ptr::null_mut();
        let name_cstring = to_cstring!(name)?;

        let mut header_device_path_cstring = CString::default();
        if let Some(path) = header_device_path {
            header_device_path_cstring = path_to_cstring!(path)?;
        }

        errno!(mutex!(libcryptsetup_rs_sys::crypt_init_by_name_and_header(
            &mut cdevice as *mut *mut crypt_device,
            name_cstring.as_ptr(),
            if header_device_path.is_some() {
                header_device_path_cstring.as_ptr()
            } else {
                ptr::null()
            },
        )))?;
        Ok(CryptDevice { ptr: cdevice })
    }
}

/// Data type that is a handle for a crypt device
pub struct CryptDevice {
    ptr: *mut crypt_device,
}

impl CryptDevice {
    /// Reconstruct a `CryptDevice` object from a pointer
    pub fn from_ptr(ptr: *mut crypt_device) -> Self {
        CryptDevice { ptr }
    }

    /// Get a settings option handle
    pub fn settings_handle(&mut self) -> CryptSettingsHandle<'_> {
        CryptSettingsHandle::new(self)
    }

    /// Get a format option handle
    pub fn format_handle(&mut self) -> CryptFormatHandle<'_> {
        CryptFormatHandle::new(self)
    }

    /// Get a context option handle
    pub fn context_handle(&mut self) -> CryptContextHandle<'_> {
        CryptContextHandle::new(self)
    }

    /// Get a keyslot option handle
    pub fn keyslot_handle(&mut self) -> CryptKeyslotHandle<'_> {
        CryptKeyslotHandle::new(self)
    }

    /// Get a runtime attribute option handle
    pub fn runtime_handle<'a>(&'a mut self, name: &'a str) -> CryptRuntimeHandle<'a> {
        CryptRuntimeHandle::new(self, name)
    }

    /// Get LUKS2 flags option handle
    pub fn luks2_flag_handle<T>(&mut self) -> CryptLuks2FlagsHandle<'_, T> {
        CryptLuks2FlagsHandle::new(self)
    }

    /// Get activation option handle
    pub fn activate_handle(&mut self) -> CryptActivationHandle<'_> {
        CryptActivationHandle::new(self)
    }

    /// Get volume key option handle
    pub fn volume_key_handle(&mut self) -> CryptVolumeKeyHandle<'_> {
        CryptVolumeKeyHandle::new(self)
    }

    /// Get crypt device status option handle
    pub fn status_handle(&mut self) -> CryptDeviceStatusHandle<'_> {
        CryptDeviceStatusHandle::new(self)
    }

    /// Get crypt device backup option handle
    pub fn backup_handle(&mut self) -> CryptBackupHandle<'_> {
        CryptBackupHandle::new(self)
    }

    /// Get crypt device keyfile option handle
    pub fn keyfile_handle(&mut self) -> CryptKeyfileHandle<'_> {
        CryptKeyfileHandle::new(self)
    }

    /// Get crypt device wipe option handle
    pub fn wipe_handle(&mut self) -> CryptWipeHandle<'_> {
        CryptWipeHandle::new(self)
    }

    /// Get crypt device LUKS2 token option handle
    pub fn token_handle(&mut self) -> CryptLuks2TokenHandle<'_> {
        CryptLuks2TokenHandle::new(self)
    }

    /// Get crypt device reencryption option handle
    pub fn reencrypt_handle(&mut self) -> CryptLuks2ReencryptHandle<'_> {
        CryptLuks2ReencryptHandle::new(self)
    }

    /// Set the callback that prompts the user to confirm an action
    pub fn set_confirm_callback<T>(
        &mut self,
        confirm: Option<ConfirmCallback>,
        usrdata: Option<&mut T>,
    ) {
        mutex!(libcryptsetup_rs_sys::crypt_set_confirm_callback(
            self.ptr,
            confirm,
            match usrdata {
                Some(ud) => ud as *mut _ as *mut c_void,
                None => ptr::null_mut(),
            },
        ))
    }

    /// Set the device path for a data device
    pub fn set_data_device(&mut self, device_path: &Path) -> Result<(), LibcryptErr> {
        let device_path_cstring = path_to_cstring!(device_path)?;
        errno!(mutex!(libcryptsetup_rs_sys::crypt_set_data_device(
            self.ptr,
            device_path_cstring.as_ptr()
        )))
    }

    /// Set the offset in 4096-byte sectors for the data section on a device
    pub fn set_data_offset(&mut self, offset: u64) -> Result<(), LibcryptErr> {
        errno!(mutex!(libcryptsetup_rs_sys::crypt_set_data_offset(
            self.ptr,
            offset * 8
        )))
    }

    pub(crate) fn as_ptr(&mut self) -> *mut crypt_device {
        self.ptr
    }
}

impl Drop for CryptDevice {
    fn drop(&mut self) {
        mutex!(libcryptsetup_rs_sys::crypt_free(self.ptr))
    }
}