// Copyright 2015-2020 Parity Technologies (UK) Ltd.
// This file is part of OpenEthereum.

// OpenEthereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// OpenEthereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with OpenEthereum.  If not, see <http://www.gnu.org/licenses/>.

use ethereum_types::H256;
use ethkey::{Address, Message, Password, Public, Secret, Signature};
use json::{OpaqueKeyFile, Uuid};
use std::{
    cmp::Ordering,
    hash::{Hash, Hasher},
    path::PathBuf,
};
use Error;
use OpaqueSecret;

/// Key directory reference
#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
pub enum SecretVaultRef {
    /// Reference to key in root directory
    Root,
    /// Referenc to key in specific vault
    Vault(String),
}

/// Stored account reference
#[derive(Debug, Clone, PartialEq, Eq, Ord)]
pub struct StoreAccountRef {
    /// Account address
    pub address: Address,
    /// Vault reference
    pub vault: SecretVaultRef,
}

impl PartialOrd for StoreAccountRef {
    fn partial_cmp(&self, other: &StoreAccountRef) -> Option<Ordering> {
        Some(
            self.address
                .cmp(&other.address)
                .then_with(|| self.vault.cmp(&other.vault)),
        )
    }
}

impl ::std::borrow::Borrow<Address> for StoreAccountRef {
    fn borrow(&self) -> &Address {
        &self.address
    }
}

/// Simple Secret Store API
pub trait SimpleSecretStore: Send + Sync {
    /// Inserts new accounts to the store (or vault) with given password.
    fn insert_account(
        &self,
        vault: SecretVaultRef,
        secret: Secret,
        password: &Password,
    ) -> Result<StoreAccountRef, Error>;
    /// Inserts new derived account to the store (or vault) with given password.
    fn insert_derived(
        &self,
        vault: SecretVaultRef,
        account_ref: &StoreAccountRef,
        password: &Password,
        derivation: Derivation,
    ) -> Result<StoreAccountRef, Error>;
    /// Changes accounts password.
    fn change_password(
        &self,
        account: &StoreAccountRef,
        old_password: &Password,
        new_password: &Password,
    ) -> Result<(), Error>;
    /// Exports key details for account.
    fn export_account(
        &self,
        account: &StoreAccountRef,
        password: &Password,
    ) -> Result<OpaqueKeyFile, Error>;
    /// Entirely removes account from the store and underlying storage.
    fn remove_account(&self, account: &StoreAccountRef, password: &Password) -> Result<(), Error>;
    /// Generates new derived account.
    fn generate_derived(
        &self,
        account_ref: &StoreAccountRef,
        password: &Password,
        derivation: Derivation,
    ) -> Result<Address, Error>;
    /// Sign a message with given account.
    fn sign(
        &self,
        account: &StoreAccountRef,
        password: &Password,
        message: &Message,
    ) -> Result<Signature, Error>;
    /// Sign a message with derived account.
    fn sign_derived(
        &self,
        account_ref: &StoreAccountRef,
        password: &Password,
        derivation: Derivation,
        message: &Message,
    ) -> Result<Signature, Error>;
    /// Decrypt a messages with given account.
    fn decrypt(
        &self,
        account: &StoreAccountRef,
        password: &Password,
        shared_mac: &[u8],
        message: &[u8],
    ) -> Result<Vec<u8>, Error>;
    /// Agree on shared key.
    fn agree(
        &self,
        account: &StoreAccountRef,
        password: &Password,
        other: &Public,
    ) -> Result<Secret, Error>;

    /// Returns all accounts in this secret store.
    fn accounts(&self) -> Result<Vec<StoreAccountRef>, Error>;
    /// Get reference to some account with given address.
    /// This method could be removed if we will guarantee that there is max(1) account for given address.
    fn account_ref(&self, address: &Address) -> Result<StoreAccountRef, Error>;

    /// Create new vault with given password
    fn create_vault(&self, name: &str, password: &Password) -> Result<(), Error>;
    /// Open vault with given password
    fn open_vault(&self, name: &str, password: &Password) -> Result<(), Error>;
    /// Close vault
    fn close_vault(&self, name: &str) -> Result<(), Error>;
    /// List all vaults
    fn list_vaults(&self) -> Result<Vec<String>, Error>;
    /// List all currently opened vaults
    fn list_opened_vaults(&self) -> Result<Vec<String>, Error>;
    /// Change vault password
    fn change_vault_password(&self, name: &str, new_password: &Password) -> Result<(), Error>;
    /// Cnage account' vault
    fn change_account_vault(
        &self,
        vault: SecretVaultRef,
        account: StoreAccountRef,
    ) -> Result<StoreAccountRef, Error>;
    /// Get vault metadata string.
    fn get_vault_meta(&self, name: &str) -> Result<String, Error>;
    /// Set vault metadata string.
    fn set_vault_meta(&self, name: &str, meta: &str) -> Result<(), Error>;
}

/// Secret Store API
pub trait SecretStore: SimpleSecretStore {
    /// Returns a raw opaque Secret that can be later used to sign a message.
    fn raw_secret(
        &self,
        account: &StoreAccountRef,
        password: &Password,
    ) -> Result<OpaqueSecret, Error>;

    /// Signs a message with raw secret.
    fn sign_with_secret(
        &self,
        secret: &OpaqueSecret,
        message: &Message,
    ) -> Result<Signature, Error> {
        Ok(::ethkey::sign(&secret.0, message)?)
    }

    /// Imports presale wallet
    fn import_presale(
        &self,
        vault: SecretVaultRef,
        json: &[u8],
        password: &Password,
    ) -> Result<StoreAccountRef, Error>;
    /// Imports existing JSON wallet
    fn import_wallet(
        &self,
        vault: SecretVaultRef,
        json: &[u8],
        password: &Password,
        gen_id: bool,
    ) -> Result<StoreAccountRef, Error>;
    /// Copies account between stores and vaults.
    fn copy_account(
        &self,
        new_store: &dyn SimpleSecretStore,
        new_vault: SecretVaultRef,
        account: &StoreAccountRef,
        password: &Password,
        new_password: &Password,
    ) -> Result<(), Error>;
    /// Checks if password matches given account.
    fn test_password(&self, account: &StoreAccountRef, password: &Password) -> Result<bool, Error>;

    /// Returns a public key for given account.
    fn public(&self, account: &StoreAccountRef, password: &Password) -> Result<Public, Error>;

    /// Returns uuid of an account.
    fn uuid(&self, account: &StoreAccountRef) -> Result<Uuid, Error>;
    /// Returns account's name.
    fn name(&self, account: &StoreAccountRef) -> Result<String, Error>;
    /// Returns account's metadata.
    fn meta(&self, account: &StoreAccountRef) -> Result<String, Error>;

    /// Modifies account metadata.
    fn set_name(&self, account: &StoreAccountRef, name: String) -> Result<(), Error>;
    /// Modifies account name.
    fn set_meta(&self, account: &StoreAccountRef, meta: String) -> Result<(), Error>;

    /// Returns local path of the store.
    fn local_path(&self) -> PathBuf;
}

impl StoreAccountRef {
    /// Create reference to root account with given address
    pub fn root(address: Address) -> Self {
        StoreAccountRef::new(SecretVaultRef::Root, address)
    }

    /// Create reference to vault account with given address
    pub fn vault(vault_name: &str, address: Address) -> Self {
        StoreAccountRef::new(SecretVaultRef::Vault(vault_name.to_owned()), address)
    }

    /// Create new account reference
    pub fn new(vault_ref: SecretVaultRef, address: Address) -> Self {
        StoreAccountRef {
            vault: vault_ref,
            address: address,
        }
    }
}

impl Hash for StoreAccountRef {
    fn hash<H: Hasher>(&self, state: &mut H) {
        self.address.hash(state);
    }
}

/// Node in hierarchical derivation.
pub struct IndexDerivation {
    /// Node is soft (allows proof of parent from parent node).
    pub soft: bool,
    /// Index sequence of the node.
    pub index: u32,
}

/// Derivation scheme for keys
pub enum Derivation {
    /// Hierarchical derivation
    Hierarchical(Vec<IndexDerivation>),
    /// Hash derivation, soft.
    SoftHash(H256),
    /// Hash derivation, hard.
    HardHash(H256),
}