//! Common types, traits, and functions needed across user/group/document apis
//! If it can be defined in API specific file, it should go there to keep this file's
//! size to a minimum.

use crate::internal::{
    group_api::GroupId,
    rest::{Authorization, IronCoreRequest, SignatureUrlString},
    user_api::UserId,
};
use base64::engine::Engine;
use base64::prelude::BASE64_STANDARD;
use futures::Future;
use lazy_static::lazy_static;
use log::error;
use protobuf::{self, Error as ProtobufError};
use quick_error::quick_error;
use recrypt::api::{
    CryptoOps, Ed25519, Hashable, KeyGenOps, Plaintext, PrivateKey as RecryptPrivateKey,
    PublicKey as RecryptPublicKey, RandomBytes, Recrypt, RecryptErr, Sha256,
    SigningKeypair as RecryptSigningKeypair,
};
use regex::Regex;
use reqwest::Method;
use serde::{Deserialize, Deserializer, Serialize, Serializer};
use std::{
    convert::{TryFrom, TryInto},
    fmt::{Error, Formatter},
    result::Result,
    sync::{Mutex, MutexGuard},
};
use time::OffsetDateTime;

pub mod document_api;
pub mod group_api;
mod rest;
pub mod user_api;

lazy_static! {
    pub static ref URL_STRING: String = match std::env::var("IRONCORE_ENV") {
        Ok(url) => match url.to_lowercase().as_ref() {
            "stage" => "https://api-staging.ironcorelabs.com/api/1/",
            "prod" => "https://api.ironcorelabs.com/api/1/",
            url_choice => url_choice,
        }
        .to_string(),
        _ => "https://api.ironcorelabs.com/api/1/".to_string(),
    };
    pub static ref OUR_REQUEST: IronCoreRequest = IronCoreRequest::new(URL_STRING.as_str());
}

#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
pub enum RequestErrorCode {
    UserVerify,
    UserCreate,
    UserUpdate,
    UserDeviceAdd,
    UserDeviceDelete,
    UserDeviceList,
    UserKeyList,
    UserKeyUpdate,
    UserGetCurrent,
    GroupCreate,
    GroupDelete,
    GroupList,
    GroupGet,
    GroupAddMember,
    GroupUpdate,
    GroupMemberRemove,
    GroupAdminRemove,
    GroupKeyUpdate,
    DocumentList,
    DocumentGet,
    DocumentCreate,
    DocumentUpdate,
    DocumentGrantAccess,
    DocumentRevokeAccess,
    EdekTransform,
    PolicyGet,
}

/// Public SDK operations
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
pub enum SdkOperation {
    InitializeSdk,
    InitializeSdkCheckRotation,
    RotateAll,
    DocumentList,
    DocumentGetMetadata,
    DocumentEncrypt,
    DocumentUpdateBytes,
    DocumentDecrypt,
    DocumentUpdateName,
    DocumentGrantAccess,
    DocumentRevokeAccess,
    DocumentEncryptUnmanaged,
    DocumentDecryptUnmanaged,
    UserCreate,
    UserListDevices,
    GenerateNewDevice,
    UserDeleteDevice,
    UserVerify,
    UserGetPublicKey,
    UserRotatePrivateKey,
    UserChangePassword,
    GroupList,
    GroupCreate,
    GroupGetMetadata,
    GroupDelete,
    GroupUpdateName,
    GroupAddMembers,
    GroupRemoveMembers,
    GroupAddAdmins,
    GroupRemoveAdmins,
    GroupRotatePrivateKey,
}

impl std::fmt::Display for SdkOperation {
    fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
        write!(f, "'{self:?}'")
    }
}

quick_error! {
    /// Errors generated by IronOxide SDK operations
    #[derive(Debug)]
    #[non_exhaustive]
    pub enum IronOxideErr {
        ValidationError(field_name: String, err: String) {
            display("'{}' failed validation with the error '{}'", field_name, err)
        }
        DocumentHeaderParseFailure(message: String) {
            display("{}", message)
        }
        WrongSizeError(actual_size: Option<usize>, expected_size: Option<usize>) {
        }
        KeyGenerationError {
            display("Key generation failed")
        }
        AesError(err: ring::error::Unspecified) {
            source(err)
        }
        AesEncryptedDocSizeError{
            display("Provided document is not long enough to be an encrypted document.")
        }
        InvalidRecryptEncryptedValue(msg: String) {
            display("Got an unexpected Recrypt EncryptedValue: '{}'", msg)
        }
        RecryptError(msg: String) {
            display("Recrypt operation failed with error '{}'", msg)
        }
        UserDoesNotExist(msg: String) {
            display("Operation failed with error '{}'", msg)
        }
        UserOrGroupDoesNotExist(user_or_group: document_api::UserOrGroup) {
            display("User or group {} does not exist.", user_or_group)
        }
        InitializeError(cause: String) {
            display("SDK initialization failed. Underlying cause '{}'", cause)
        }
        RequestError { message: String, code: RequestErrorCode, http_status: Option<u16> } {
            display("Request failed with HTTP status code '{:?}' message '{}' and code '{:?}'", http_status, message, code)
        }
        ///This is used if the response from the server was an error. In that case we know that the format of the errors will be `ServerError`.
        RequestServerErrors {errors: Vec<rest::ServerError>, code: RequestErrorCode, http_status: Option<u16> } {
            display("Request failed with HTTP status code '{:?}' errors list is '{:?}' and code '{:?}'", http_status, errors, code)
        }
        MissingTransformBlocks {
            display("Expected at least one TransformBlock in transformed value but received none.")
        }
        ///The operation failed because the accessing user was not a group admin, but must be for the operation to work.
        NotGroupAdmin(id: GroupId) {
            display("You are not an administrator of group '{}'", id.id())
        }
        /// No policy exists for the segment
        PolicyDoesNotExist {
            display("No policy is defined. Please visit https://admin.ironcorelabs.com/policy to set a policy")
        }
        /// Protobuf encode/decode error
        ProtobufSerdeError(err: ProtobufError) {
            source(err)
        }
        /// Protobuf decode succeeded, but the result is not valid
        ProtobufValidationError(msg: String) {
            display("Protobuf validation failed with '{}'", msg)
        }
        UnmanagedDecryptionError(edek_doc_id: String, edek_segment_id: i32,
                                 edoc_doc_id: String, edoc_segment_id: i32) {
            display("Edeks and EncryptedDocument do not match. \
            Edeks are for DocumentId({}) and SegmentId({}) and\
            Encrypted Document is DocumentId({}) and SegmentId({})",
            edek_doc_id, edek_segment_id, edoc_doc_id, edoc_segment_id)
        }
        UserPrivateKeyRotationError(msg: String) {
            display("User private key rotation failed with '{}'", msg)
        }
        GroupPrivateKeyRotationError(msg: String) {
            display("Group private key rotation failed with '{}'", msg)
        }
        OperationTimedOut{operation: SdkOperation, duration: std::time::Duration} {
            display("Operation {} timed out after {}ms", operation, duration.as_millis())
        }
        JoinError(msg: String) {
            display("{}", msg)
        }
    }
}

/// A way to turn IronSdkErr into Strings for the Java binding
impl From<IronOxideErr> for String {
    fn from(err: IronOxideErr) -> Self {
        err.to_string()
    }
}

impl From<RecryptErr> for IronOxideErr {
    fn from(recrypt_err: RecryptErr) -> Self {
        match recrypt_err {
            RecryptErr::InputWrongSize(_, expected_size) => {
                IronOxideErr::WrongSizeError(None, Some(expected_size))
            }
            RecryptErr::InvalidPublicKey(_) => IronOxideErr::KeyGenerationError,
            //Fallback for all other error types that Recrypt can have that we don't have specific mappings for
            other_recrypt_err => IronOxideErr::RecryptError(other_recrypt_err.to_string()),
        }
    }
}

impl From<ProtobufError> for IronOxideErr {
    fn from(e: ProtobufError) -> Self {
        IronOxideErr::ProtobufSerdeError(e)
    }
}

impl From<recrypt::nonemptyvec::NonEmptyVecError> for IronOxideErr {
    fn from(_: recrypt::nonemptyvec::NonEmptyVecError) -> Self {
        IronOxideErr::MissingTransformBlocks
    }
}

impl From<tokio::task::JoinError> for IronOxideErr {
    fn from(e: tokio::task::JoinError) -> Self {
        IronOxideErr::JoinError(e.to_string())
    }
}

const NAME_AND_ID_MAX_LEN: usize = 100;

/// Validate that the provided id is valid for our user/document/group IDs. Validates that the
/// ID has a length and that it matches our restricted set of characters. Also takes the readable
/// type of ID for usage within any resulting error messages.
pub fn validate_id(id: &str, id_type: &str) -> Result<String, IronOxideErr> {
    let id_regex = Regex::new("^[a-zA-Z0-9_.$#|@/:;=+'-]+$").expect("regex is valid");
    let trimmed_id = id.trim();
    if trimmed_id.is_empty() || trimmed_id.len() > NAME_AND_ID_MAX_LEN {
        Err(IronOxideErr::ValidationError(
            id_type.to_string(),
            format!("'{trimmed_id}' must have length between 1 and 100"),
        ))
    } else if !id_regex.is_match(trimmed_id) {
        Err(IronOxideErr::ValidationError(
            id_type.to_string(),
            format!("'{trimmed_id}' contains invalid characters"),
        ))
    } else {
        Ok(trimmed_id.to_string())
    }
}

/// Validate that the provided document/group name is valid. Ensures that the length of
/// the name is between 1-100 characters. Also takes the readable type of the name for
/// usage within any resulting error messages.
pub fn validate_name(name: &str, name_type: &str) -> Result<String, IronOxideErr> {
    let trimmed_name = name.trim();
    if trimmed_name.trim().is_empty() || trimmed_name.len() > NAME_AND_ID_MAX_LEN {
        Err(IronOxideErr::ValidationError(
            name_type.to_string(),
            format!("'{trimmed_name}' must have length between 1 and 100"),
        ))
    } else {
        Ok(trimmed_name.trim().to_string())
    }
}

pub mod auth_v2 {
    use time::OffsetDateTime;

    use super::*;

    /// API Auth version 2.
    /// Fully constructing a valid auth v2 header is a two step process.
    /// Step 1 is done on construction via `new`
    /// Step 2 is done via `finish_with` as a request is being sent out and the bytes of the body are available.
    pub struct AuthV2Builder<'a> {
        pub(in crate::internal::auth_v2) req_auth: &'a RequestAuth,
        pub(in crate::internal::auth_v2) timestamp: OffsetDateTime,
    }

    impl<'a> AuthV2Builder<'a> {
        pub fn new(req_auth: &'a RequestAuth, timestamp: OffsetDateTime) -> AuthV2Builder {
            AuthV2Builder {
                req_auth,
                timestamp,
            }
        }

        /// Always returns Authorization::Version2
        /// # Arguments
        /// `sig_url`       URL path to be signed over
        /// `method`        Method of request (POST, GET, PUT, etc)
        /// `body_bytes`    Reference to the bytes of the body (or none)
        ///
        /// # Returns
        /// Authorization::Version2 that contains all the information necessary to make an
        /// IronCore authenticated request to the webservice.
        pub fn finish_with(
            &self,
            sig_url: SignatureUrlString,
            method: Method,
            body_bytes: Option<&'a [u8]>,
        ) -> Authorization<'a> {
            self.req_auth
                .create_signature_v2(self.timestamp, sig_url, method, body_bytes)
        }
    }
}

///Structure that contains all the info needed to make a signed API request from a device.
#[derive(Clone, Debug, Eq, Hash, PartialEq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct RequestAuth {
    ///The user's given id, which uniquely identifies them inside the segment.
    account_id: UserId,
    ///The segment_id for the above user.
    segment_id: usize,
    ///The signing key which was generated for the device. “expanded private key” (both pub/priv)
    signing_private_key: DeviceSigningKeyPair,
    #[serde(skip_serializing, skip_deserializing)]
    pub(crate) request: IronCoreRequest,
}
impl RequestAuth {
    pub fn create_signature_v2<'a>(
        &'a self,
        current_time: OffsetDateTime,
        sig_url: SignatureUrlString,
        method: Method,
        body: Option<&'a [u8]>,
    ) -> Authorization<'a> {
        Authorization::create_signatures_v2(
            current_time,
            self.segment_id,
            &self.account_id,
            method,
            sig_url,
            body,
            &self.signing_private_key,
        )
    }

    pub fn account_id(&self) -> &UserId {
        &self.account_id
    }

    pub fn segment_id(&self) -> usize {
        self.segment_id
    }

    pub fn signing_private_key(&self) -> &DeviceSigningKeyPair {
        &self.signing_private_key
    }
}

/// Signing and encryption key pairs and metadata for a device.
///
/// Required to initialize the SDK with a set of device keys (see [ironoxide::initialize](../fn.initialize.html)).
///
/// Can be generated by calling [generate_new_device](../user/trait.UserOps.html#tymethod.generate_new_device) and
/// passing the result to `DeviceContext::from`.
#[derive(Clone, Debug, Eq, Hash, PartialEq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct DeviceContext {
    #[serde(flatten)]
    auth: RequestAuth,
    /// The private key which was generated for a particular device for the user. Not the user's master private key.
    device_private_key: PrivateKey,
}
impl DeviceContext {
    /// Constructs a `DeviceContext` from its components.
    ///
    /// To instead generate a new `DeviceContext` for the user, call [generate_new_device](../user/trait.UserOps.html#tymethod.generate_new_device)
    /// and pass the result to `DeviceContext::from`.
    pub fn new(
        account_id: UserId,
        segment_id: usize,
        device_private_key: PrivateKey,
        signing_private_key: DeviceSigningKeyPair,
    ) -> DeviceContext {
        DeviceContext {
            auth: RequestAuth {
                account_id,
                segment_id,
                signing_private_key,
                request: IronCoreRequest::new(OUR_REQUEST.base_url()),
            },
            device_private_key,
        }
    }

    pub(crate) fn auth(&self) -> &RequestAuth {
        &self.auth
    }
    /// ID of the device's owner
    pub fn account_id(&self) -> &UserId {
        &self.auth.account_id
    }
    /// ID of the segment
    pub fn segment_id(&self) -> usize {
        self.auth.segment_id
    }
    /// Private signing key of the device
    pub fn signing_private_key(&self) -> &DeviceSigningKeyPair {
        &self.auth.signing_private_key
    }
    /// Private encryption key of the device
    pub fn device_private_key(&self) -> &PrivateKey {
        &self.device_private_key
    }
}

/// Newtype wrapper around Recrypt TransformKey type
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct TransformKey(recrypt::api::TransformKey);
impl From<recrypt::api::TransformKey> for TransformKey {
    fn from(tk: recrypt::api::TransformKey) -> Self {
        TransformKey(tk)
    }
}
impl Hashable for TransformKey {
    fn to_bytes(&self) -> Vec<u8> {
        self.0.to_bytes()
    }
}

/// Newtype wrapper around Recrypt SchnorrSignature type
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct SchnorrSignature(recrypt::api::SchnorrSignature);
impl From<recrypt::api::SchnorrSignature> for SchnorrSignature {
    fn from(s: recrypt::api::SchnorrSignature) -> Self {
        SchnorrSignature(s)
    }
}
impl From<SchnorrSignature> for Vec<u8> {
    fn from(sig: SchnorrSignature) -> Self {
        sig.0.bytes().to_vec()
    }
}

/// Asymmetric public encryption key.
#[derive(Clone, Debug, Eq, Hash, PartialEq)]
pub struct PublicKey(RecryptPublicKey);
impl PublicKey {
    fn to_bytes_x_y(&self) -> (Vec<u8>, Vec<u8>) {
        let (x, y) = self.0.bytes_x_y();
        (x.to_vec(), y.to_vec())
    }
    pub fn new_from_slice(bytes: (&[u8], &[u8])) -> Result<Self, IronOxideErr> {
        let re_pub = RecryptPublicKey::new_from_slice(bytes)?;
        Ok(PublicKey(re_pub))
    }
    /// Bytes of the public key
    pub fn as_bytes(&self) -> Vec<u8> {
        let (mut x, mut y) = self.to_bytes_x_y();
        x.append(&mut y);
        x
    }
}
impl From<RecryptPublicKey> for PublicKey {
    fn from(recrypt_pub: RecryptPublicKey) -> Self {
        PublicKey(recrypt_pub)
    }
}
impl From<PublicKey> for RecryptPublicKey {
    fn from(public_key: PublicKey) -> Self {
        public_key.0
    }
}
impl From<&PublicKey> for RecryptPublicKey {
    fn from(public_key: &PublicKey) -> Self {
        public_key.0
    }
}
impl From<PublicKey> for crate::proto::transform::PublicKey {
    fn from(pubk: PublicKey) -> Self {
        crate::proto::transform::PublicKey {
            x: pubk.to_bytes_x_y().0.into(),
            y: pubk.to_bytes_x_y().1.into(),
            ..Default::default()
        }
    }
}
impl TryFrom<&[u8]> for PublicKey {
    type Error = IronOxideErr;
    fn try_from(key_bytes: &[u8]) -> Result<PublicKey, IronOxideErr> {
        if key_bytes.len() == RecryptPublicKey::ENCODED_SIZE_BYTES {
            PublicKey::new_from_slice(key_bytes.split_at(RecryptPublicKey::ENCODED_SIZE_BYTES / 2))
        } else {
            Err(IronOxideErr::WrongSizeError(
                Some(RecryptPublicKey::ENCODED_SIZE_BYTES),
                Some(key_bytes.len()),
            ))
        }
    }
}

/// Asymmetric private encryption key.
#[derive(Clone, Debug, Eq, Hash, PartialEq)]
pub struct PrivateKey(RecryptPrivateKey);
impl PrivateKey {
    const BYTES_SIZE: usize = RecryptPrivateKey::ENCODED_SIZE_BYTES;
    /// Bytes of the private key
    pub fn as_bytes(&self) -> &[u8; PrivateKey::BYTES_SIZE] {
        self.0.bytes()
    }
    fn recrypt_key(&self) -> &RecryptPrivateKey {
        &self.0
    }
    /// Augment this private key with another, producing a new PrivateKey
    fn augment<F: FnOnce(String) -> IronOxideErr>(
        &self,
        augmenting_key: &AugmentationFactor,
        error_fn: F,
    ) -> Result<PrivateKey, IronOxideErr> {
        let zero: RecryptPrivateKey = RecryptPrivateKey::new([0u8; 32]);
        if RecryptPrivateKey::from(augmenting_key.clone()) == zero {
            Err(error_fn("Augmenting key cannot be zero".into()))
        } else if RecryptPrivateKey::from(augmenting_key.clone()) == self.0 {
            Err(error_fn(
                "PrivateKey augmentation failed with a zero value".into(),
            ))
        } else {
            // this subtraction needs to be the additive inverse of what the service is doing
            let augmented_key = self.0.augment_minus(&augmenting_key.clone().into());
            Ok(augmented_key.into())
        }
    }
    /// A convenience function to pass a user rotation error to `augment()`
    fn augment_user(
        &self,
        augmenting_key: &AugmentationFactor,
    ) -> Result<PrivateKey, IronOxideErr> {
        self.augment(augmenting_key, IronOxideErr::UserPrivateKeyRotationError)
    }
    /// A convenience function to pass a user rotation error to `augment()`
    fn augment_group(
        &self,
        augmenting_key: &AugmentationFactor,
    ) -> Result<PrivateKey, IronOxideErr> {
        self.augment(augmenting_key, IronOxideErr::GroupPrivateKeyRotationError)
    }
}
impl From<RecryptPrivateKey> for PrivateKey {
    fn from(recrypt_priv: RecryptPrivateKey) -> Self {
        PrivateKey(recrypt_priv)
    }
}
impl From<PrivateKey> for RecryptPrivateKey {
    fn from(priv_key: PrivateKey) -> Self {
        priv_key.0
    }
}
impl From<[u8; 32]> for PrivateKey {
    fn from(bytes: [u8; 32]) -> Self {
        PrivateKey(RecryptPrivateKey::new(bytes))
    }
}
impl TryFrom<&[u8]> for PrivateKey {
    type Error = IronOxideErr;
    fn try_from(key_bytes: &[u8]) -> Result<PrivateKey, IronOxideErr> {
        RecryptPrivateKey::new_from_slice(key_bytes)
            .map(PrivateKey)
            .map_err(|e| e.into())
    }
}
impl Serialize for PrivateKey {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: Serializer,
    {
        serializer.serialize_str(&BASE64_STANDARD.encode(self.0.bytes()))
    }
}
impl<'de> Deserialize<'de> for PrivateKey {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        use serde::de::Error;
        let s = String::deserialize(deserializer)?;
        let keys_bytes = BASE64_STANDARD
            .decode(s)
            .map_err(|e| Error::custom(e.to_string()))?;
        PrivateKey::try_from(&keys_bytes[..]).map_err(|e| Error::custom(e.to_string()))
    }
}

/// Private key used to augment another PrivateKey
#[derive(Clone, Debug)]
pub(crate) struct AugmentationFactor(PrivateKey);
impl AugmentationFactor {
    /// Use recrypt to generate a new AugmentationFactor
    pub fn generate_new<R: KeyGenOps>(recrypt: &R) -> AugmentationFactor {
        AugmentationFactor(recrypt.random_private_key().into())
    }

    pub fn as_bytes(&self) -> &[u8; 32] {
        self.0.as_bytes()
    }
}
impl From<AugmentationFactor> for RecryptPrivateKey {
    fn from(aug: AugmentationFactor) -> Self {
        (aug.0).0
    }
}

/// Key pair used to sign all requests to the IronCore API endpoints.
#[derive(Clone, Debug, Eq, Hash, PartialEq)]
pub struct DeviceSigningKeyPair(RecryptSigningKeypair);
impl DeviceSigningKeyPair {
    pub fn sign(&self, payload: &[u8]) -> [u8; 64] {
        self.0.sign(&payload).into()
    }
    /// Bytes of the signing key pair
    pub fn as_bytes(&self) -> &[u8; 64] {
        self.0.bytes()
    }
    pub fn public_key(&self) -> [u8; 32] {
        self.0.public_key().into()
    }
}
impl From<&DeviceSigningKeyPair> for RecryptSigningKeypair {
    fn from(dsk: &DeviceSigningKeyPair) -> RecryptSigningKeypair {
        dsk.0.clone()
    }
}
impl From<RecryptSigningKeypair> for DeviceSigningKeyPair {
    fn from(rsk: RecryptSigningKeypair) -> DeviceSigningKeyPair {
        DeviceSigningKeyPair(rsk)
    }
}
impl TryFrom<&[u8]> for DeviceSigningKeyPair {
    type Error = IronOxideErr;
    fn try_from(signing_key_bytes: &[u8]) -> Result<DeviceSigningKeyPair, Self::Error> {
        RecryptSigningKeypair::from_byte_slice(signing_key_bytes)
            .map(DeviceSigningKeyPair)
            .map_err(|e| {
                IronOxideErr::ValidationError("DeviceSigningKeyPair".to_string(), e.to_string())
            })
    }
}
impl Serialize for DeviceSigningKeyPair {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: Serializer,
    {
        let base64 = BASE64_STANDARD.encode(self.0.bytes());
        serializer.serialize_str(&base64)
    }
}
impl<'de> Deserialize<'de> for DeviceSigningKeyPair {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        use serde::de::Error;
        let s = String::deserialize(deserializer)?;
        let keys_bytes = BASE64_STANDARD
            .decode(s)
            .map_err(|e| Error::custom(e.to_string()))?;
        DeviceSigningKeyPair::try_from(&keys_bytes[..]).map_err(|e| Error::custom(e.to_string()))
    }
}

/// Newtype wrapper around a string which represents the users master private key escrow password
#[derive(Debug, PartialEq, Eq)]
pub struct Password(String);
impl TryFrom<&str> for Password {
    type Error = IronOxideErr;
    fn try_from(maybe_password: &str) -> Result<Self, Self::Error> {
        if !maybe_password.trim().is_empty() {
            Ok(Password(maybe_password.to_string()))
        } else {
            Err(IronOxideErr::ValidationError(
                "maybe_password".to_string(),
                "length must be > 0".to_string(),
            ))
        }
    }
}

#[derive(Clone, Debug, Eq, Hash, PartialEq)]
pub struct WithKey<T> {
    pub(crate) id: T,
    pub(crate) public_key: PublicKey,
}
impl<T> WithKey<T> {
    pub fn new(id: T, public_key: PublicKey) -> WithKey<T> {
        WithKey { id, public_key }
    }
}

/// Acquire mutex in a blocking fashion. If the Mutex is or becomes poisoned, write out an error
/// message and panic.
///
/// The lock is released when the returned MutexGuard falls out of scope.
///
/// # Usage:
/// single statement (mut)
/// `let result = take_lock(&t).deref_mut().call_method_on_t();`
///
/// multi-statement (mut)
/// ```ignore
/// let t = T {};
/// let result = {
///     let g = &mut *take_lock(&t);
///     g.call_method_on_t()
/// }; // lock released here
/// ```
///
pub(crate) fn take_lock<T>(m: &Mutex<T>) -> MutexGuard<T> {
    m.lock().unwrap_or_else(|e| {
        let error = format!("Error when acquiring lock: {e}");
        error!("{}", error);
        panic!("{}", error);
    })
}

/// Attempts to augment an existing private key with a newly generated augmentation factor.
/// There is a very small chance that an augmentation factor could not be compatible with
/// the given PrivateKey, so we retry once internally before giving the caller an error.
fn augment_private_key_with_retry<R: KeyGenOps>(
    recrypt: &R,
    priv_key: &PrivateKey,
) -> Result<(PrivateKey, AugmentationFactor), IronOxideErr> {
    let aug_private_key = || {
        let aug_factor = AugmentationFactor::generate_new(recrypt);
        priv_key.augment_user(&aug_factor).map(|p| (p, aug_factor))
    };
    // retry generation of augmentation factor one time. If this fails twice there's something wrong.
    aug_private_key().or_else(|_| aug_private_key())
}

/// Subtracts a generated private key from the provided PrivateKey, returning
/// the result and the plaintext associated with the generated key.
/// There is a very small chance that the generated private key could not be compatible with
/// the given PrivateKey, so we retry once internally before giving the caller an error.
fn gen_plaintext_and_aug_with_retry<R: CryptoOps>(
    recrypt: &R,
    priv_key: &PrivateKey,
) -> Result<(Plaintext, AugmentationFactor), IronOxideErr> {
    let aug_private_key = || -> Result<(Plaintext, AugmentationFactor), IronOxideErr> {
        let new_plaintext = recrypt.gen_plaintext();
        let new_group_private_key = recrypt.derive_private_key(&new_plaintext);
        let new_key_aug = AugmentationFactor(new_group_private_key.into());
        let aug_factor = priv_key.augment_group(&new_key_aug)?;
        Ok((new_plaintext, AugmentationFactor(aug_factor)))
    };
    // retry generation of private key one time. If this fails twice there's something wrong.
    aug_private_key().or_else(|_| aug_private_key())
}

/// Runs a future with a timeout or just runs the future, depending on if a timeout is specified.
///
/// If a timeout limit is reached, the result will be an IronOxideErr::OperationTimedOut.
/// If no timeout is specified, or if the operation finishes before the timeout, the
/// result is the result of the sdk operation.
pub async fn add_optional_timeout<F: Future>(
    f: F,
    timeout: Option<std::time::Duration>,
    op: SdkOperation,
) -> Result<F::Output, IronOxideErr> {
    use futures::future::TryFutureExt;
    let result = match timeout {
        Some(d) => {
            tokio::time::timeout(d, f)
                .map_err(|_| IronOxideErr::OperationTimedOut {
                    operation: op,
                    duration: d,
                })
                .await?
        }

        // no timeout, just run the Future and return
        None => f.await,
    };

    Ok(result)
}

#[cfg(test)]
pub(crate) mod tests {
    use super::*;
    use double::*;
    use galvanic_assert::{matchers::*, *};
    use std::fmt::Debug;
    use tokio::time::Duration;
    use vec1::vec1;

    /// String contains matcher to assert that the provided substring exists in the provided value
    pub fn contains<'a>(expected: &'a str) -> Box<dyn Matcher<String> + 'a> {
        Box::new(move |actual: &String| {
            let builder = MatchResultBuilder::for_("contains");
            if actual.contains(expected) {
                builder.matched()
            } else {
                let expected_string: String = expected.to_string();
                builder.failed_comparison(actual, &expected_string)
            }
        })
    }

    /// Length matcher to assert that the provided iterable value has the expected size
    pub fn length<'a, I, T>(expected: &'a usize) -> Box<dyn Matcher<I> + 'a>
    where
        T: 'a,
        &'a I: Debug + Sized + IntoIterator<Item = &'a T> + 'a,
    {
        Box::new(move |actual: &'a I| {
            let actual_list: Vec<_> = actual.into_iter().collect();
            let builder = MatchResultBuilder::for_("contains");
            if &actual_list.len() == expected {
                builder.matched()
            } else {
                builder.failed_because(&format!(
                    "Expected '{:?}' to have length of {} but found length of {}",
                    actual,
                    expected,
                    actual_list.len()
                ))
            }
        })
    }

    #[test]
    fn serde_devicecontext_roundtrip() -> Result<(), IronOxideErr> {
        let priv_key: recrypt::api::PrivateKey = recrypt::api::PrivateKey::new_from_slice(
            BASE64_STANDARD
                .decode("bzb0Rlg0u7gx9wDuk1ppRI77OH/0ferXleenJ3Ag6Jg=")
                .unwrap()
                .as_slice(),
        )?;
        let dev_keys = recrypt::api::SigningKeypair::from_byte_slice(&[
            1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
            1, 1, 1, 138, 136, 227, 221, 116, 9, 241, 149, 253, 82, 219, 45, 60, 186, 93, 114, 202,
            103, 9, 191, 29, 148, 18, 27, 243, 116, 136, 1, 180, 15, 111, 92,
        ])
        .unwrap();
        let context = DeviceContext::new(
            "account_id".try_into()?,
            22,
            priv_key.into(),
            DeviceSigningKeyPair::from(dev_keys),
        );
        let json = serde_json::to_string(&context).unwrap();
        let expect_json = r#"{"accountId":"account_id","segmentId":22,"signingPrivateKey":"AQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQGKiOPddAnxlf1S2y08ul1yymcJvx2UEhvzdIgBtA9vXA==","devicePrivateKey":"bzb0Rlg0u7gx9wDuk1ppRI77OH/0ferXleenJ3Ag6Jg="}"#;

        assert_eq!(json, expect_json);

        let de: DeviceContext = serde_json::from_str(&json).unwrap();

        assert_eq!(context.account_id(), de.account_id());
        assert_eq!(
            context.auth.signing_private_key.as_bytes().to_vec(),
            de.auth.signing_private_key.as_bytes().to_vec()
        );
        assert_eq!(
            context.device_private_key.as_bytes().to_vec(),
            de.device_private_key.as_bytes().to_vec()
        );
        Ok(())
    }

    #[test]
    fn validate_id_success() {
        let valid_id = "abcABC012_.$#|@/:;=+'-";
        let id = validate_id(valid_id, "id_type");
        assert_that!(&id, is_variant!(Ok));
        assert_that!(&id.unwrap(), eq(valid_id.to_string()))
    }

    #[test]
    fn valid_id_whitespace() {
        let valid_id = " abc212     ";
        let id = validate_id(valid_id, "id_type");
        assert_that!(&id, is_variant!(Ok));
        assert_that!(&id.unwrap(), eq("abc212".to_string()))
    }

    #[test]
    fn validate_id_failure() {
        let invalid_id = "with spaces";
        let id_type = "id_type";
        let id = validate_id(invalid_id, id_type);
        assert_that!(&id, is_variant!(Err));
        let validation_error = id.unwrap_err();
        assert_that!(
            &validation_error,
            is_variant!(IronOxideErr::ValidationError)
        );
        assert_that!(&format!("{}", validation_error), contains(id_type));
        assert_that!(&format!("{}", validation_error), contains(invalid_id));
    }

    #[test]
    fn validate_id_all_whitespace() {
        let invalid_id = "     ";
        let id_type = "id_type";
        let id = validate_id(invalid_id, id_type);
        assert_that!(&id, is_variant!(Err));
        let validation_error = id.unwrap_err();
        assert_that!(
            &validation_error,
            is_variant!(IronOxideErr::ValidationError)
        );
        assert_that!(&format!("{}", validation_error), contains(id_type));
    }

    #[test]
    fn validate_name_success() {
        let valid_name = "name with any char _.$#|@/:;=+'-";
        let id = validate_name(valid_name, "name_type");
        assert_that!(&id, is_variant!(Ok));
        assert_that!(&id.unwrap(), eq(valid_name.to_string()))
    }

    #[test]
    fn validate_name_surrounding_whitespace() {
        let valid_name = "   a good name    ";
        let id = validate_name(valid_name, "name_type");
        assert_that!(&id, is_variant!(Ok));
        assert_that!(&id.unwrap(), eq("a good name".to_string()))
    }

    #[test]
    fn validate_name_failure() {
        let name_type = "name_type";
        let invalid_name = "too many chars 012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789";
        let name = validate_name(invalid_name, name_type);
        assert_that!(&name, is_variant!(Err));
        let validation_error = name.unwrap_err();
        assert_that!(
            &validation_error,
            is_variant!(IronOxideErr::ValidationError)
        );
        assert_that!(&format!("{}", validation_error), contains(invalid_name));
        assert_that!(&format!("{}", validation_error), contains(name_type));
    }

    #[test]
    fn validate_name_all_whitespace() {
        let invalid_name = "        ";
        let name_type = "name_type";

        let name = validate_name(invalid_name, name_type);
        assert_that!(&name, is_variant!(Err));
        let validation_error = name.unwrap_err();
        assert_that!(
            &validation_error,
            is_variant!(IronOxideErr::ValidationError)
        );
        assert_that!(&format!("{}", validation_error), contains(name_type));
    }

    #[test]
    fn passphrase_validation() {
        let result = Password::try_from("");
        assert!(result.is_err())
    }

    #[test]
    fn encode_proto_public_key() -> Result<(), IronOxideErr> {
        let recr = recrypt::api::Recrypt::new();
        let (_, re_pubk) = recr.generate_key_pair()?;
        let pubk: PublicKey = re_pubk.into();

        let proto_pubk: crate::proto::transform::PublicKey = pubk.clone().into();
        assert_eq!(
            (&pubk.to_bytes_x_y().0, &pubk.to_bytes_x_y().1),
            (&proto_pubk.x.to_vec(), &proto_pubk.y.to_vec())
        );
        Ok(())
    }

    #[test]
    fn public_key_try_from_slice() -> Result<(), IronOxideErr> {
        let recr = recrypt::api::Recrypt::new();
        let (_, re_pubk) = recr.generate_key_pair()?;
        let pubk: PublicKey = re_pubk.into();
        let pubk2: PublicKey = pubk.as_bytes().as_slice().try_into()?;
        assert_eq!(pubk, pubk2);
        Ok(())
    }

    #[test]
    fn public_key_try_from_slice_invalid() {
        let bytes = [1u8; 8];
        let maybe_public_key: Result<PublicKey, IronOxideErr> = bytes[..].try_into();
        assert!(maybe_public_key.is_err())
    }

    pub fn gen_priv_key() -> PrivateKey {
        let recr = recrypt::api::Recrypt::new();
        let (re_privk, _) = recr.generate_key_pair().unwrap();
        re_privk.into()
    }

    #[test]
    fn private_key_augment_with_self_is_none() {
        let privk = gen_priv_key();

        let result = privk.augment_user(&AugmentationFactor(privk.clone()));
        assert_that!(&result, is_variant!(Err));
        assert_that!(
            &result.unwrap_err(),
            is_variant!(IronOxideErr::UserPrivateKeyRotationError)
        )
    }

    #[test]
    fn private_key_augmentation_is_augment_minus() {
        let p1 = gen_priv_key();
        let p2 = gen_priv_key();

        let p3 = p1.0.augment_minus(&p2.0);

        let aug_p = p1.augment_user(&AugmentationFactor(p2)).unwrap();
        assert_eq!(aug_p.0, p3)
    }

    #[test]
    fn private_key_augmentation_aug_key_of_zero_is_err() {
        let priv_key_orig = gen_priv_key();
        let zero_aug_factor = AugmentationFactor(PrivateKey(RecryptPrivateKey::new([0u8; 32])));
        let new_priv_key = priv_key_orig.augment_user(&zero_aug_factor);
        assert_that!(&new_priv_key, is_variant!(Err));
        assert_that!(
            &new_priv_key.unwrap_err(),
            is_variant!(IronOxideErr::UserPrivateKeyRotationError)
        )
    }

    mock_trait!(
        MockKeyGenOps,
        random_private_key() -> recrypt::api::PrivateKey
    );
    impl KeyGenOps for MockKeyGenOps {
        fn compute_public_key(
            &self,
            _private_key: &RecryptPrivateKey,
        ) -> Result<RecryptPublicKey, RecryptErr> {
            unimplemented!()
        }

        mock_method!(random_private_key(&self) -> RecryptPrivateKey);

        fn generate_key_pair(&self) -> Result<(RecryptPrivateKey, RecryptPublicKey), RecryptErr> {
            unimplemented!()
        }

        fn generate_transform_key(
            &self,
            _from_private_key: &RecryptPrivateKey,
            _to_public_key: &RecryptPublicKey,
            _signing_keypair: &recrypt::api::SigningKeypair,
        ) -> Result<recrypt::api::TransformKey, RecryptErr> {
            unimplemented!()
        }
    }
    mock_trait!(MockCryptoOps,
        gen_plaintext() -> recrypt::api::Plaintext
    );
    impl CryptoOps for MockCryptoOps {
        fn derive_symmetric_key(
            &self,
            _: &recrypt::api::Plaintext,
        ) -> recrypt::api::DerivedSymmetricKey {
            unimplemented!()
        }
        mock_method!(gen_plaintext(&self) -> recrypt::api::Plaintext);
        fn transform(
            &self,
            _: recrypt::api::EncryptedValue,
            _: recrypt::api::TransformKey,
            _: &recrypt::api::SigningKeypair,
        ) -> std::result::Result<recrypt::api::EncryptedValue, RecryptErr> {
            unimplemented!()
        }
        fn decrypt(
            &self,
            _: recrypt::api::EncryptedValue,
            _: &recrypt::api::PrivateKey,
        ) -> std::result::Result<recrypt::api::Plaintext, RecryptErr> {
            unimplemented!()
        }
        fn encrypt(
            &self,
            _: &recrypt::api::Plaintext,
            _: &recrypt::api::PublicKey,
            _: &recrypt::api::SigningKeypair,
        ) -> std::result::Result<recrypt::api::EncryptedValue, RecryptErr> {
            unimplemented!()
        }
        fn derive_private_key(&self, pt: &recrypt::api::Plaintext) -> recrypt::api::PrivateKey {
            let recrypt = recrypt::api::Recrypt::new();
            recrypt.derive_private_key(pt)
        }
    }
    #[test]
    fn augment_private_key_with_retry_retries_once() {
        let recrypt_mock = MockKeyGenOps::default();
        let good_re_private_key = RecryptPrivateKey::new([42u8; 32]); // good private key
        recrypt_mock.random_private_key.return_values(vec![
            RecryptPrivateKey::new([0u8; 32]), // bad private key, 0s
            good_re_private_key.clone(),       // good private key. Used for aug factor
        ]);

        let curr_priv_key = PrivateKey::from([100u8; 32]);
        let expected_priv_key_bytes: [u8; 32] = [
            58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58, 58,
            58, 58, 58, 58, 58, 58, 58, 58, 58, 58,
        ];

        let result = augment_private_key_with_retry(&recrypt_mock, &curr_priv_key).unwrap();
        assert_eq!(
            (result.0).0,
            RecryptPrivateKey::new(expected_priv_key_bytes)
        );
        assert_eq!(((result.1).0).0, good_re_private_key)
    }
    #[test]
    fn augment_private_key_with_retry_retries_only_once() {
        let recrypt_mock = MockKeyGenOps::default();
        recrypt_mock.random_private_key.return_values(vec![
            RecryptPrivateKey::new([0u8; 32]),   // bad private key, 0s
            RecryptPrivateKey::new([100u8; 32]), // bad private key, matches current
            RecryptPrivateKey::new([42u8; 32]),  // good private key, never returned
        ]);

        let curr_priv_key = PrivateKey::from([100u8; 32]);

        let result = augment_private_key_with_retry(&recrypt_mock, &curr_priv_key);
        assert_that!(
            &result.unwrap_err(),
            is_variant!(IronOxideErr::UserPrivateKeyRotationError)
        );
    }
    #[test]
    fn gen_plaintext_and_diff_with_retry_retries_once() {
        let recrypt_mock = MockCryptoOps::default();
        // creating a real recrypt to make a valid plaintext
        let recrypt = recrypt::api::Recrypt::new();
        let bad_plaintext = recrypt.gen_plaintext();
        let bad_private_key = recrypt.derive_private_key(&bad_plaintext);
        let good_plaintext = recrypt.gen_plaintext();
        recrypt_mock
            .gen_plaintext
            .return_values(vec![bad_plaintext, good_plaintext.clone()]);

        // since this will generate bad_plaintext, which bad_private_key is derived from,
        // the augmentation will result in zero, causing the function to retry.
        let result =
            gen_plaintext_and_aug_with_retry(&recrypt_mock, &bad_private_key.into()).unwrap();
        assert_eq!(result.0, good_plaintext);
    }

    #[test]
    fn gen_plaintext_and_diff_with_retry_retries_only_once() {
        let recrypt_mock = MockCryptoOps::default();
        // creating a real recrypt to make a valid plaintext
        let recrypt = recrypt::api::Recrypt::new();
        let bad_plaintext = recrypt.gen_plaintext();
        let bad_private_key = recrypt.derive_private_key(&bad_plaintext);
        let good_plaintext = recrypt.gen_plaintext();
        // Ideally this would also check that it retries/fails when the generated private key is zero,
        // but I don't know the plaintext to return to force that to happen.
        // Mocking `derive_private_key()` doesn't appear to be possible without Eq and Hash on Plaintext.
        recrypt_mock.gen_plaintext.return_values(vec![
            bad_plaintext.clone(),
            bad_plaintext,
            good_plaintext,
        ]);

        // since this will generate bad_plaintext, which bad_private_key is derived from,
        // the augmentation will result in zero, causing the function to retry.
        let result = gen_plaintext_and_aug_with_retry(&recrypt_mock, &bad_private_key.into());
        assert_that!(
            &result.unwrap_err(),
            is_variant!(IronOxideErr::GroupPrivateKeyRotationError)
        );
    }

    #[test]
    fn init_and_rotation_user_and_groups() -> Result<(), IronOxideErr> {
        use crate::{
            check_groups_and_collect_rotation,
            internal::{
                group_api::tests::create_group_meta_result, user_api::tests::create_user_result,
            },
            InitAndRotationCheck, IronOxide,
        };
        let recrypt = recrypt::api::Recrypt::new();
        let (_, pub_key) = recrypt.generate_key_pair()?;
        let time = OffsetDateTime::now_utc();
        let create_gmr = |id: GroupId, needs_rotation: Option<bool>| {
            create_group_meta_result(
                id,
                None,
                pub_key.into(),
                true,
                true,
                time,
                time,
                needs_rotation,
            )
        };
        let de_json = r#"{"deviceId":314,"accountId":"account_id","segmentId":22,"signingPrivateKey":"AQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQGKiOPddAnxlf1S2y08ul1yymcJvx2UEhvzdIgBtA9vXA==","devicePrivateKey":"bzb0Rlg0u7gx9wDuk1ppRI77OH/0ferXleenJ3Ag6Jg="}"#;
        let de: DeviceContext = serde_json::from_str(de_json).unwrap();
        let user_id = UserId::try_from("account_id")?;
        let user = create_user_result(user_id.clone(), 22, pub_key.into(), true);
        let io = IronOxide::create(&user, &de, &Default::default());

        let good_group_id = GroupId::try_from("group")?;
        let gmr_vec = vec![
            create_gmr(good_group_id.clone(), Some(true)),
            create_gmr(GroupId::try_from("notthisone")?, Some(false)),
            create_gmr(GroupId::try_from("northisone")?, None),
        ];
        let init = check_groups_and_collect_rotation(&gmr_vec, true, user_id.clone(), io);
        let rotation = match init {
            InitAndRotationCheck::NoRotationNeeded(_) => panic!("user and group need rotation"),
            InitAndRotationCheck::RotationNeeded(_, rotation) => rotation,
        };
        assert_eq!(
            rotation.group_rotation_needed(),
            Some(&vec1![good_group_id])
        );
        assert_eq!(rotation.user_rotation_needed(), Some(&user_id));
        Ok(())
    }

    #[tokio::test]
    async fn run_maybe_timed_sdk_op_no_timeout() -> Result<(), IronOxideErr> {
        async fn get_42() -> u8 {
            tokio::time::sleep(Duration::from_millis(100)).await;
            42
        }
        let forty_two = get_42();
        let result =
            add_optional_timeout(forty_two, None, SdkOperation::DocumentRevokeAccess).await?;
        assert_eq!(result, 42);

        let forty_two = get_42();
        let result = add_optional_timeout(
            forty_two,
            Some(Duration::from_secs(1)),
            SdkOperation::DocumentRevokeAccess,
        )
        .await?;
        assert_eq!(result, 42);

        async fn get_err() -> Result<(), IronOxideErr> {
            tokio::time::sleep(Duration::from_millis(100)).await;
            Err(IronOxideErr::MissingTransformBlocks)
        }

        let err_f = get_err();
        let result = add_optional_timeout(err_f, None, SdkOperation::DocumentRevokeAccess).await?;
        assert!(result.is_err());
        assert_that!(
            &result.unwrap_err(),
            is_variant!(IronOxideErr::MissingTransformBlocks)
        );

        let err_f = get_err();
        let result = add_optional_timeout(
            err_f,
            Some(Duration::from_secs(1)),
            SdkOperation::DocumentRevokeAccess,
        )
        .await?;
        assert!(result.is_err());
        assert_that!(
            &result.unwrap_err(),
            is_variant!(IronOxideErr::MissingTransformBlocks)
        );

        Ok(())
    }

    #[tokio::test]
    async fn run_maybe_timed_sdk_op_with_timeout() -> Result<(), IronOxideErr> {
        async fn get_42() -> u8 {
            // allow other futures to run, like the timer
            // without this the future will run to completion, regardless of the timer
            tokio::time::sleep(Duration::from_millis(100)).await;
            42
        }

        let forty_two = get_42();
        let result = add_optional_timeout(
            forty_two,
            Some(Duration::from_nanos(1)),
            SdkOperation::DocumentRevokeAccess,
        )
        .await;
        assert!(result.is_err());
        assert_that!(
            &result.unwrap_err(),
            is_variant!(IronOxideErr::OperationTimedOut)
        );

        async fn get_err() -> Result<u8, IronOxideErr> {
            tokio::time::sleep(Duration::from_millis(100)).await;
            Err(IronOxideErr::MissingTransformBlocks)
        }

        let err_f = get_err();
        let result = add_optional_timeout(
            err_f,
            Some(Duration::from_millis(1)),
            SdkOperation::DocumentRevokeAccess,
        )
        .await;
        assert!(result.is_err());
        assert_that!(
            &result.unwrap_err(),
            is_variant!(IronOxideErr::OperationTimedOut)
        );
        Ok(())
    }
}