// Copyright 2015-2019 Parity Technologies (UK) Ltd.
// This file is part of Parity Ethereum.

// Parity Ethereum 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.

// Parity Ethereum 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 Parity Ethereum.  If not, see <http://www.gnu.org/licenses/>.

use account_utils::AccountProvider;
use dir::{default_data_path, helpers::replace_home};
use ethcore::{client::Client, miner::Miner};
use ethereum_types::Address;
use ethkey::{Password, Public, Secret};
use parity_runtime::Executor;
use std::{collections::BTreeMap, sync::Arc};
use sync::SyncProvider;

/// This node secret key.
#[derive(Debug, PartialEq, Clone)]
pub enum NodeSecretKey {
    /// Stored as plain text in configuration file.
    Plain(Secret),
    /// Stored as account in key store.
    #[cfg(feature = "accounts")]
    KeyStore(Address),
}

/// Secret store service contract address.
#[derive(Debug, PartialEq, Clone)]
pub enum ContractAddress {
    /// Contract address is read from registry.
    Registry,
    /// Contract address is specified.
    Address(Address),
}

#[derive(Debug, PartialEq, Clone)]
/// Secret store configuration
pub struct Configuration {
    /// Is secret store functionality enabled?
    pub enabled: bool,
    /// Is HTTP API enabled?
    pub http_enabled: bool,
    /// Is auto migrate enabled.
    pub auto_migrate_enabled: bool,
    /// ACL check contract address.
    pub acl_check_contract_address: Option<ContractAddress>,
    /// Service contract address.
    pub service_contract_address: Option<ContractAddress>,
    /// Server key generation service contract address.
    pub service_contract_srv_gen_address: Option<ContractAddress>,
    /// Server key retrieval service contract address.
    pub service_contract_srv_retr_address: Option<ContractAddress>,
    /// Document key store service contract address.
    pub service_contract_doc_store_address: Option<ContractAddress>,
    /// Document key shadow retrieval service contract address.
    pub service_contract_doc_sretr_address: Option<ContractAddress>,
    /// This node secret.
    pub self_secret: Option<NodeSecretKey>,
    /// Other nodes IDs + addresses.
    pub nodes: BTreeMap<Public, (String, u16)>,
    /// Key Server Set contract address. If None, 'nodes' map is used.
    pub key_server_set_contract_address: Option<ContractAddress>,
    /// Interface to listen to
    pub interface: String,
    /// Port to listen to
    pub port: u16,
    /// Interface to listen to
    pub http_interface: String,
    /// Port to listen to
    pub http_port: u16,
    /// Data directory path for secret store
    pub data_path: String,
    /// Administrator public key.
    pub admin_public: Option<Public>,
}

/// Secret store dependencies
pub struct Dependencies<'a> {
    /// Blockchain client.
    pub client: Arc<Client>,
    /// Sync provider.
    pub sync: Arc<dyn SyncProvider>,
    /// Miner service.
    pub miner: Arc<Miner>,
    /// Account provider.
    pub account_provider: Arc<AccountProvider>,
    /// Passed accounts passwords.
    pub accounts_passwords: &'a [Password],
}

#[cfg(not(feature = "secretstore"))]
mod server {
    use super::{Configuration, Dependencies, Executor};

    /// Noop key server implementation
    pub struct KeyServer;

    impl KeyServer {
        /// Create new noop key server
        pub fn new(
            _conf: Configuration,
            _deps: Dependencies,
            _executor: Executor,
        ) -> Result<Self, String> {
            Ok(KeyServer)
        }
    }
}

#[cfg(feature = "secretstore")]
mod server {
    use super::{Configuration, ContractAddress, Dependencies, Executor, NodeSecretKey};
    use ansi_term::Colour::{Red, White};
    use db;
    use ethcore_secretstore;
    use ethkey::KeyPair;
    use std::sync::Arc;

    fn into_service_contract_address(
        address: ContractAddress,
    ) -> ethcore_secretstore::ContractAddress {
        match address {
            ContractAddress::Registry => ethcore_secretstore::ContractAddress::Registry,
            ContractAddress::Address(address) => {
                ethcore_secretstore::ContractAddress::Address(address)
            }
        }
    }

    /// Key server
    pub struct KeyServer {
        _key_server: Box<dyn ethcore_secretstore::KeyServer>,
    }

    impl KeyServer {
        /// Create new key server
        pub fn new(
            mut conf: Configuration,
            deps: Dependencies,
            executor: Executor,
        ) -> Result<Self, String> {
            let self_secret: Arc<dyn ethcore_secretstore::NodeKeyPair> =
                match conf.self_secret.take() {
                    Some(NodeSecretKey::Plain(secret)) => {
                        Arc::new(ethcore_secretstore::PlainNodeKeyPair::new(
                            KeyPair::from_secret(secret)
                                .map_err(|e| format!("invalid secret: {}", e))?,
                        ))
                    }
                    #[cfg(feature = "accounts")]
                    Some(NodeSecretKey::KeyStore(account)) => {
                        // Check if account exists
                        if !deps.account_provider.has_account(account.clone()) {
                            return Err(format!(
                                "Account {} passed as secret store node key is not found",
                                account
                            ));
                        }

                        // Check if any passwords have been read from the password file(s)
                        if deps.accounts_passwords.is_empty() {
                            return Err(format!(
                                "No password found for the secret store node account {}",
                                account
                            ));
                        }

                        // Attempt to sign in the engine signer.
                        let password = deps
                            .accounts_passwords
                            .iter()
                            .find(|p| {
                                deps.account_provider
                                    .sign(account.clone(), Some((*p).clone()), Default::default())
                                    .is_ok()
                            })
                            .ok_or_else(|| {
                                format!(
                                    "No valid password for the secret store node account {}",
                                    account
                                )
                            })?;
                        Arc::new(
                            ethcore_secretstore::KeyStoreNodeKeyPair::new(
                                deps.account_provider,
                                account,
                                password.clone(),
                            )
                            .map_err(|e| format!("{}", e))?,
                        )
                    }
                    None => return Err("self secret is required when using secretstore".into()),
                };

            info!(
                "Starting SecretStore node: {}",
                White.bold().paint(format!("{:?}", self_secret.public()))
            );
            if conf.acl_check_contract_address.is_none() {
                warn!(
                    "Running SecretStore with disabled ACL check: {}",
                    Red.bold().paint("everyone has access to stored keys")
                );
            }

            let key_server_name = format!("{}:{}", conf.interface, conf.port);
            let mut cconf = ethcore_secretstore::ServiceConfiguration {
                listener_address: if conf.http_enabled {
                    Some(ethcore_secretstore::NodeAddress {
                        address: conf.http_interface.clone(),
                        port: conf.http_port,
                    })
                } else {
                    None
                },
                service_contract_address: conf
                    .service_contract_address
                    .map(into_service_contract_address),
                service_contract_srv_gen_address: conf
                    .service_contract_srv_gen_address
                    .map(into_service_contract_address),
                service_contract_srv_retr_address: conf
                    .service_contract_srv_retr_address
                    .map(into_service_contract_address),
                service_contract_doc_store_address: conf
                    .service_contract_doc_store_address
                    .map(into_service_contract_address),
                service_contract_doc_sretr_address: conf
                    .service_contract_doc_sretr_address
                    .map(into_service_contract_address),
                acl_check_contract_address: conf
                    .acl_check_contract_address
                    .map(into_service_contract_address),
                cluster_config: ethcore_secretstore::ClusterConfiguration {
                    listener_address: ethcore_secretstore::NodeAddress {
                        address: conf.interface.clone(),
                        port: conf.port,
                    },
                    nodes: conf
                        .nodes
                        .into_iter()
                        .map(|(p, (ip, port))| {
                            (
                                p,
                                ethcore_secretstore::NodeAddress {
                                    address: ip,
                                    port: port,
                                },
                            )
                        })
                        .collect(),
                    key_server_set_contract_address: conf
                        .key_server_set_contract_address
                        .map(into_service_contract_address),
                    allow_connecting_to_higher_nodes: true,
                    admin_public: conf.admin_public,
                    auto_migrate_enabled: conf.auto_migrate_enabled,
                },
            };

            cconf.cluster_config.nodes.insert(
                self_secret.public().clone(),
                cconf.cluster_config.listener_address.clone(),
            );

            let db = db::open_secretstore_db(&conf.data_path)?;
            let key_server = ethcore_secretstore::start(
                deps.client,
                deps.sync,
                deps.miner,
                self_secret,
                cconf,
                db,
                executor,
            )
            .map_err(|e| format!("Error starting KeyServer {}: {}", key_server_name, e))?;

            Ok(KeyServer {
                _key_server: key_server,
            })
        }
    }
}

pub use self::server::KeyServer;

impl Default for Configuration {
    fn default() -> Self {
        let data_dir = default_data_path();
        Configuration {
            enabled: true,
            http_enabled: true,
            auto_migrate_enabled: true,
            acl_check_contract_address: Some(ContractAddress::Registry),
            service_contract_address: None,
            service_contract_srv_gen_address: None,
            service_contract_srv_retr_address: None,
            service_contract_doc_store_address: None,
            service_contract_doc_sretr_address: None,
            self_secret: None,
            admin_public: None,
            nodes: BTreeMap::new(),
            key_server_set_contract_address: Some(ContractAddress::Registry),
            interface: "127.0.0.1".to_owned(),
            port: 8083,
            http_interface: "127.0.0.1".to_owned(),
            http_port: 8082,
            data_path: replace_home(&data_dir, "$BASE/secretstore"),
        }
    }
}

/// Start secret store-related functionality
pub fn start(
    conf: Configuration,
    deps: Dependencies,
    executor: Executor,
) -> Result<Option<KeyServer>, String> {
    if !conf.enabled {
        return Ok(None);
    }

    KeyServer::new(conf, deps, executor).map(|s| Some(s))
}