//! # MLS group errors
//!
//! This module contains errors that originate at lower levels and are partially re-exported in errors thrown by functions of the `MlsGroup` API.

use thiserror::Error;

pub use super::mls_group::errors::*;
use super::public_group::errors::{CreationFromExternalError, PublicGroupBuildError};
use crate::{
    ciphersuite::signable::SignatureError,
    error::LibraryError,
    extensions::errors::{ExtensionError, InvalidExtensionError},
    framing::errors::{MessageDecryptionError, SenderError},
    key_packages::errors::KeyPackageVerifyError,
    key_packages::errors::{KeyPackageExtensionSupportError, KeyPackageNewError},
    messages::{group_info::GroupInfoError, GroupSecretsError},
    schedule::errors::PskError,
    treesync::errors::*,
};

/// Welcome error
#[derive(Error, Debug, PartialEq, Clone)]
pub enum WelcomeError<KeyStoreError> {
    /// See [`GroupSecretsError`] for more details.
    #[error(transparent)]
    GroupSecrets(#[from] GroupSecretsError),
    /// Private part of `init_key` not found in key store.
    #[error("Private part of `init_key` not found in key store.")]
    PrivateInitKeyNotFound,
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
    /// Ciphersuites in Welcome and key package bundle don't match.
    #[error("Ciphersuites in Welcome and key package bundle don't match.")]
    CiphersuiteMismatch,
    /// See [`GroupInfoError`] for more details.
    #[error(transparent)]
    GroupInfo(#[from] GroupInfoError),
    /// No joiner secret found in the Welcome message.
    #[error("No joiner secret found in the Welcome message.")]
    JoinerSecretNotFound,
    /// No ratchet tree available to build initial tree after receiving a Welcome message.
    #[error("No ratchet tree available to build initial tree after receiving a Welcome message.")]
    MissingRatchetTree,
    /// The computed confirmation tag does not match the expected one.
    #[error("The computed confirmation tag does not match the expected one.")]
    ConfirmationTagMismatch,
    /// The signature on the GroupInfo is not valid.
    #[error("The signature on the GroupInfo is not valid.")]
    InvalidGroupInfoSignature,
    /// We don't support the version of the group we are trying to join.
    #[error("We don't support the version of the group we are trying to join.")]
    UnsupportedMlsVersion,
    /// We don't support all capabilities of the group.
    #[error("We don't support all capabilities of the group.")]
    UnsupportedCapability,
    /// Sender not found in tree.
    #[error("Sender not found in tree.")]
    UnknownSender,
    /// Malformed Welcome message.
    #[error("Malformed Welcome message.")]
    MalformedWelcomeMessage,
    /// Could not decrypt the Welcome message.
    #[error("Could not decrypt the Welcome message.")]
    UnableToDecrypt,
    /// Unsupported extensions found in the KeyPackage of another member.
    #[error("Unsupported extensions found in the KeyPackage of another member.")]
    UnsupportedExtensions,
    /// See [`PskError`] for more details.
    #[error(transparent)]
    Psk(#[from] PskError),
    /// No matching encryption key was found in the key store.
    #[error("No matching encryption key was found in the key store.")]
    NoMatchingEncryptionKey,
    /// No matching key package was found in the key store.
    #[error("No matching key package was found in the key store.")]
    NoMatchingKeyPackage,
    /// Error accessing the key store.
    #[error("Error accessing the key store.")]
    KeyStoreError(KeyStoreError),
    /// This error indicates the public tree is invalid. See [`PublicTreeError`] for more details.
    #[error(transparent)]
    PublicTreeError(#[from] PublicTreeError),
    /// This error indicates the public tree is invalid. See
    /// [`CreationFromExternalError`] for more details.
    #[error(transparent)]
    PublicGroupError(#[from] CreationFromExternalError),
    /// This error indicates the leaf node is invalid. See [`LeafNodeValidationError`] for more details.
    #[error(transparent)]
    LeafNodeValidation(#[from] LeafNodeValidationError),
}

/// External Commit error
#[derive(Error, Debug, PartialEq, Clone)]
pub enum ExternalCommitError {
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
    /// No ratchet tree available to build initial tree.
    #[error("No ratchet tree available to build initial tree.")]
    MissingRatchetTree,
    /// No external_pub extension available to join group by external commit.
    #[error("No external_pub extension available to join group by external commit.")]
    MissingExternalPub,
    /// We don't support the ciphersuite of the group we are trying to join.
    #[error("We don't support the ciphersuite of the group we are trying to join.")]
    UnsupportedCiphersuite,
    /// Sender not found in tree.
    #[error("Sender not found in tree.")]
    UnknownSender,
    /// The signature over the given group info is invalid.
    #[error("The signature over the given group info is invalid.")]
    InvalidGroupInfoSignature,
    /// Error creating external commit.
    #[error("Error creating external commit.")]
    CommitError,
    /// This error indicates the public tree is invalid. See
    /// [`CreationFromExternalError`] for more details.
    #[error(transparent)]
    PublicGroupError(#[from] CreationFromExternalError),
    /// Credential is missing from external commit.
    #[error("Credential is missing from external commit.")]
    MissingCredential,
}

/// Stage Commit error
#[derive(Error, Debug, PartialEq, Clone)]
pub enum StageCommitError {
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
    /// The epoch of the group context and PublicMessage didn't match.
    #[error("The epoch of the group context and PublicMessage didn't match.")]
    EpochMismatch,
    /// The Commit was created by this client.
    #[error("The Commit was created by this client.")]
    OwnCommit,
    /// stage_commit was called with an PublicMessage that is not a Commit.
    #[error("stage_commit was called with an PublicMessage that is not a Commit.")]
    WrongPlaintextContentType,
    /// Unable to verify the leaf node signature.
    #[error("Unable to verify the leaf node signature.")]
    PathLeafNodeVerificationFailure,
    /// Unable to determine commit path.
    #[error("Unable to determine commit path.")]
    RequiredPathNotFound,
    /// The confirmation Tag is missing.
    #[error("The confirmation Tag is missing.")]
    ConfirmationTagMissing,
    /// The confirmation tag is invalid.
    #[error("The confirmation tag is invalid.")]
    ConfirmationTagMismatch,
    /// The committer can't remove themselves.
    #[error("The committer can't remove themselves.")]
    AttemptedSelfRemoval,
    /// The proposal queue is missing a proposal for the commit.
    #[error("The proposal queue is missing a proposal for the commit.")]
    MissingProposal,
    /// Missing own key to apply proposal.
    #[error("Missing own key to apply proposal.")]
    OwnKeyNotFound,
    /// External Committer used the wrong index.
    #[error("External Committer used the wrong index.")]
    InconsistentSenderIndex,
    /// The sender is of type external, which is not valid.
    #[error("The sender is of type external, which is not valid.")]
    SenderTypeExternal,
    /// The sender is of type `NewMemberProposal`, which is not valid.
    #[error("The sender is of type NewMemberProposal, which is not valid.")]
    SenderTypeNewMemberProposal,
    /// Too many new members: the tree is full.
    #[error("Too many new members: the tree is full.")]
    TooManyNewMembers,
    /// See [`ProposalValidationError`] for more details.
    #[error(transparent)]
    ProposalValidationError(#[from] ProposalValidationError),
    /// See [`PskError`] for more details.
    #[error(transparent)]
    PskError(#[from] PskError),
    /// See [`ExternalCommitValidationError`] for more details.
    #[error(transparent)]
    ExternalCommitValidation(#[from] ExternalCommitValidationError),
    /// See [`ApplyUpdatePathError`] for more details.
    #[error(transparent)]
    UpdatePathError(#[from] ApplyUpdatePathError),
    /// Missing decryption key.
    #[error("Missing decryption key.")]
    MissingDecryptionKey,
    /// See [`UpdatePathError`] for more details.
    #[error(transparent)]
    VerifiedUpdatePathError(#[from] UpdatePathError),
}

/// Create commit error
#[derive(Error, Debug, PartialEq, Clone)]
pub enum CreateCommitError<KeyStoreError> {
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
    /// Missing own key to apply proposal.
    #[error("Missing own key to apply proposal.")]
    OwnKeyNotFound,
    /// The Commit tried to remove self from the group. This is not possible.
    #[error("The Commit tried to remove self from the group. This is not possible.")]
    CannotRemoveSelf,
    /// The proposal queue is missing a proposal for the commit.
    #[error("The proposal queue is missing a proposal for the commit.")]
    MissingProposal,
    /// A proposal has the wrong sender type.
    #[error("A proposal has the wrong sender type.")]
    WrongProposalSenderType,
    /// See [`PskError`] for more details.
    #[error(transparent)]
    PskError(#[from] PskError),
    /// See [`ProposalValidationError`] for more details.
    #[error(transparent)]
    ProposalValidationError(#[from] ProposalValidationError),
    /// Error interacting with the key store.
    #[error("Error interacting with the key store.")]
    KeyStoreError(KeyStoreError),
    /// See [`KeyPackageNewError`] for more details.
    #[error(transparent)]
    KeyPackageGenerationError(#[from] KeyPackageNewError<KeyStoreError>),
    /// See [`SignatureError`] for more details.
    #[error(transparent)]
    SignatureError(#[from] SignatureError),
    /// Credential is missing from external commit.
    #[error("Credential is missing from external commit.")]
    MissingCredential,
    /// This error indicates the public tree is invalid. See [`PublicTreeError`] for more details.
    #[error(transparent)]
    PublicTreeError(#[from] PublicTreeError),
    /// See [`InvalidExtensionError`] for more details.
    #[error(transparent)]
    InvalidExtensionError(#[from] InvalidExtensionError),
}

/// Validation error
#[derive(Error, Debug, PartialEq, Clone)]
pub enum ValidationError {
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
    /// Message group ID differs from the group's group ID.
    #[error("Message group ID differs from the group's group ID.")]
    WrongGroupId,
    /// Message epoch differs from the group's epoch.
    #[error("Message epoch differs from the group's epoch.")]
    WrongEpoch,
    /// The PublicMessage is not a Commit despite the sender begin of type [NewMemberCommit](crate::prelude::Sender::NewMemberCommit).
    #[error("The PublicMessage is not a Commit despite the sender begin of type NewMemberCommit.")]
    NotACommit,
    /// The PublicMessage is not an External Add Proposal despite the sender begin of type [NewMemberProposal](crate::prelude::Sender::NewMemberProposal).
    #[error("The PublicMessage is not an external Add proposal despite the sender begin of type NewMemberProposal.")]
    NotAnExternalAddProposal,
    /// The Commit doesn't have a path despite the sender being of type NewMemberCommit.
    #[error("The Commit doesn't have a path despite the sender being of type NewMemberCommit.")]
    NoPath,
    /// The PublicMessage contains an application message but was not encrypted.
    #[error("The PublicMessage contains an application message but was not encrypted.")]
    UnencryptedApplicationMessage,
    /// Sender is not part of the group.
    #[error("Sender is not part of the group.")]
    UnknownMember,
    /// Membership tag is missing.
    #[error("Membership tag is missing.")]
    MissingMembershipTag,
    /// Membership tag is invalid.
    #[error("Membership tag is invalid.")]
    InvalidMembershipTag,
    /// The confirmation tag is missing.
    #[error("The confirmation tag is missing.")]
    MissingConfirmationTag,
    /// Wrong wire format.
    #[error("Wrong wire format.")]
    WrongWireFormat,
    /// Verifying the signature failed.
    #[error("Verifying the signature failed.")]
    InvalidSignature,
    /// An application message was sent from an external sender.
    #[error("An application message was sent from an external sender.")]
    NonMemberApplicationMessage,
    /// Could not decrypt the message
    #[error(transparent)]
    UnableToDecrypt(#[from] MessageDecryptionError),
    /// The message is from an epoch too far in the past.
    #[error("The message is from an epoch too far in the past.")]
    NoPastEpochData,
    /// The provided external sender is not authorized to send external proposals
    #[error("The provided external sender is not authorized to send external proposals")]
    UnauthorizedExternalSender,
    /// The group doesn't contain external senders extension.
    #[error("The group doesn't contain external senders extension")]
    NoExternalSendersExtension,
    /// The KeyPackage could not be validated.
    #[error(transparent)]
    KeyPackageVerifyError(#[from] KeyPackageVerifyError),
    /// The UpdatePath could not be validated.
    #[error(transparent)]
    UpdatePathError(#[from] UpdatePathError),
    /// Invalid LeafNode signature.
    #[error("Invalid LeafNode signature.")]
    InvalidLeafNodeSignature,
    /// Invalid LeafNode source type
    #[error("Invalid LeafNode source type")]
    InvalidLeafNodeSourceType,
    /// Invalid sender type.
    #[error("Invalid sender type")]
    InvalidSenderType,
    /// The Commit includes update proposals from the committer.
    #[error("The Commit includes update proposals from the committer.")]
    CommitterIncludedOwnUpdate,
    /// The ciphersuite in the KeyPackage of the Add proposal does not match the group context.
    #[error(
        "The ciphersuite in the KeyPackage of the Add proposal does not match the group context."
    )]
    InvalidAddProposalCiphersuite,
}

/// Proposal validation error
#[derive(Error, Debug, PartialEq, Clone)]
pub enum ProposalValidationError {
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
    /// The sender could not be matched to a member of the group.
    #[error("The sender could not be matched to a member of the group.")]
    UnknownMember,
    /// Duplicate signature key in proposals and group.
    #[error("Duplicate signature key in proposals and group.")]
    DuplicateSignatureKey,
    /// Duplicate encryption key in proposals and group.
    #[error("Duplicate encryption key in proposals and group.")]
    DuplicateEncryptionKey,
    /// Duplicate init key in proposals.
    #[error("Duplicate init key in proposals.")]
    DuplicateInitKey,
    /// The HPKE init and encryption keys are the same.
    #[error("The HPKE init and encryption keys are the same.")]
    InitEncryptionKeyCollision,
    /// Duplicate remove proposals for the same member.
    #[error("Duplicate remove proposals for the same member.")]
    DuplicateMemberRemoval,
    /// The remove proposal referenced a non-existing member.
    #[error("The remove proposal referenced a non-existing member.")]
    UnknownMemberRemoval,
    /// Found an update from a non-member.
    #[error("Found an update from a non-member.")]
    UpdateFromNonMember,
    /// The Commit includes update proposals from the committer.
    #[error("The Commit includes update proposals from the committer.")]
    CommitterIncludedOwnUpdate,
    /// The capabilities of the add proposal are insufficient for this group.
    #[error("The capabilities of the add proposal are insufficient for this group.")]
    InsufficientCapabilities,
    /// The add proposal's ciphersuite or protocol version do not match the ones in the group context.
    #[error(
        "The add proposal's ciphersuite or protocol version do not match the ones in the group context."
    )]
    InvalidAddProposalCiphersuiteOrVersion,
    /// See [`PskError`] for more details.
    #[error(transparent)]
    Psk(#[from] PskError),
}

/// External Commit validaton error
#[derive(Error, Debug, PartialEq, Clone)]
pub enum ExternalCommitValidationError {
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
    /// No ExternalInit proposal found.
    #[error("No ExternalInit proposal found.")]
    NoExternalInitProposals,
    /// Multiple ExternalInit proposal found.
    #[error("Multiple ExternalInit proposal found.")]
    MultipleExternalInitProposals,
    /// Found inline Add or Update proposals.
    #[error("Found inline Add or Update proposals.")]
    InvalidInlineProposals,
    // TODO #803: this seems unused
    /// Found multiple inline Remove proposals.
    #[error("Found multiple inline Remove proposals.")]
    MultipleRemoveProposals,
    /// Remove proposal targets the wrong group member.
    #[error("Remove proposal targets the wrong group member.")]
    InvalidRemoveProposal,
    // TODO #803: this seems unused
    /// External Commit has to contain a path.
    #[error("External Commit has to contain a path.")]
    NoPath,
    /// The remove proposal referenced a non-existing member.
    #[error("The remove proposal referenced a non-existing member.")]
    UnknownMemberRemoval,
    /// External commit contains referenced proposal
    #[error("Found a referenced proposal in an External Commit.")]
    ReferencedProposal,
}

/// Create add proposal error
#[derive(Error, Debug, PartialEq, Clone)]
pub enum CreateAddProposalError {
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
    /// See [`LeafNodeValidationError`] for more details.
    #[error(transparent)]
    LeafNodeValidation(#[from] LeafNodeValidationError),
}

// === Crate errors ===

/// Exporter error
#[derive(Error, Debug, PartialEq, Clone)]
pub(crate) enum ExporterError {
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
    #[error("The requested key length is not supported (too large).")]
    KeyLengthTooLong,
}

/// Proposal queue error
#[derive(Error, Debug, PartialEq, Clone)]
pub(crate) enum ProposalQueueError {
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
    /// Not all proposals in the Commit were found locally.
    #[error("Not all proposals in the Commit were found locally.")]
    ProposalNotFound,
    /// See [`SenderError`] for more details.
    #[error(transparent)]
    SenderError(#[from] SenderError),
}

/// Errors that can arise when creating a [`ProposalQueue`] from committed
/// proposals.
#[derive(Error, Debug, PartialEq, Clone)]
pub(crate) enum FromCommittedProposalsError {
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
    /// Not all proposals in the Commit were found locally.
    #[error("Not all proposals in the Commit were found locally.")]
    ProposalNotFound,
    /// The sender of a Commit tried to remove themselves.
    #[error("The sender of a Commit tried to remove themselves.")]
    SelfRemoval,
}

/// Creation proposal queue error
#[derive(Error, Debug, PartialEq, Clone)]
pub(crate) enum CreationProposalQueueError {
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
    /// See [`SenderError`] for more details.
    #[error(transparent)]
    SenderError(#[from] SenderError),
}

// Apply proposals error
#[derive(Error, Debug, PartialEq, Clone)]
pub(crate) enum ApplyProposalsError {
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
}

// Core group build error
#[derive(Error, Debug, PartialEq, Clone)]
pub(crate) enum CoreGroupBuildError<KeyStoreError> {
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
    /// See [`PublicGroupBuildError`] for more details.
    #[error(transparent)]
    PublicGroupBuildError(#[from] PublicGroupBuildError),
    /// See [`PskError`] for more details.
    #[error(transparent)]
    Psk(#[from] PskError),
    /// Error storing leaf private key in key store.
    #[error("Error storing leaf private key in key store.")]
    KeyStoreError(KeyStoreError),
}

// CoreGroup parse message error
#[derive(Error, Debug, PartialEq, Clone)]
pub(crate) enum CoreGroupParseMessageError {
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
    //#[error(transparent)]
    //FramingValidationError(#[from] FramingValidationError),
    /// See [`ValidationError`] for more details.
    #[error(transparent)]
    ValidationError(#[from] ValidationError),
}

/// Create group context ext proposal error
#[derive(Error, Debug, PartialEq, Clone)]
pub(crate) enum CreateGroupContextExtProposalError {
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
    /// See [`KeyPackageExtensionSupportError`] for more details.
    #[error(transparent)]
    KeyPackageExtensionSupport(#[from] KeyPackageExtensionSupportError),
    /// See [`TreeSyncError`] for more details.
    #[error(transparent)]
    TreeSyncError(#[from] TreeSyncError),
    /// See [`ExtensionError`] for more details.
    #[error(transparent)]
    Extension(#[from] ExtensionError),
    /// See [`LeafNodeValidationError`] for more details.
    #[error(transparent)]
    LeafNodeValidation(#[from] LeafNodeValidationError),
}

/// Error merging a commit.
#[derive(Error, Debug, PartialEq, Clone)]
pub enum MergeCommitError<KeyStoreError> {
    /// See [`LibraryError`] for more details.
    #[error(transparent)]
    LibraryError(#[from] LibraryError),
    /// Error accessing the key store.
    #[error("Error accessing the key store.")]
    KeyStoreError(KeyStoreError),
}