// 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/>.

//! Evm input params.
use super::access_list::AccessList;
use bytes::Bytes;
use call_type::CallType;
use ethereum_types::{Address, H256, U256};
use ethjson;
use hash::{keccak, KECCAK_EMPTY};

use std::sync::Arc;

/// Transaction value
#[derive(Clone, Debug)]
pub enum ActionValue {
    /// Value that should be transfered
    Transfer(U256),
    /// Apparent value for transaction (not transfered)
    Apparent(U256),
}

/// Type of the way parameters encoded
#[derive(Clone, Debug)]
pub enum ParamsType {
    /// Parameters are included in code
    Embedded,
    /// Parameters are passed in data section
    Separate,
}

impl ActionValue {
    /// Returns action value as U256.
    pub fn value(&self) -> U256 {
        match *self {
            ActionValue::Transfer(x) | ActionValue::Apparent(x) => x,
        }
    }

    /// Returns the transfer action value of the U256-convertable raw value
    pub fn transfer<T: Into<U256>>(transfer_value: T) -> ActionValue {
        ActionValue::Transfer(transfer_value.into())
    }

    /// Returns the apparent action value of the U256-convertable raw value
    pub fn apparent<T: Into<U256>>(apparent_value: T) -> ActionValue {
        ActionValue::Apparent(apparent_value.into())
    }
}

// TODO: should be a trait, possible to avoid cloning everything from a Transaction(/View).
/// Action (call/create) input params. Everything else should be specified in Externalities.
#[derive(Clone, Debug)]
pub struct ActionParams {
    /// Address of currently executed code.
    pub code_address: Address,
    /// Hash of currently executed code.
    pub code_hash: Option<H256>,
    /// Receive address. Usually equal to code_address,
    /// except when called using CALLCODE.
    pub address: Address,
    /// Sender of current part of the transaction.
    pub sender: Address,
    /// Transaction initiator.
    pub origin: Address,
    /// Gas paid up front for transaction execution
    pub gas: U256,
    /// Gas price.
    pub gas_price: U256,
    /// Transaction value.
    pub value: ActionValue,
    /// Code being executed.
    pub code: Option<Arc<Bytes>>,
    /// Input data.
    pub data: Option<Bytes>,
    /// Type of call
    pub call_type: CallType,
    /// Param types encoding
    pub params_type: ParamsType,
    /// Current access list
    pub access_list: AccessList,
}

impl Default for ActionParams {
    /// Returns default ActionParams initialized with zeros
    fn default() -> ActionParams {
        ActionParams {
            code_address: Address::new(),
            code_hash: Some(KECCAK_EMPTY),
            address: Address::new(),
            sender: Address::new(),
            origin: Address::new(),
            gas: U256::zero(),
            gas_price: U256::zero(),
            value: ActionValue::Transfer(U256::zero()),
            code: None,
            data: None,
            call_type: CallType::None,
            params_type: ParamsType::Separate,
            access_list: AccessList::default(),
        }
    }
}

impl From<ethjson::vm::Transaction> for ActionParams {
    fn from(t: ethjson::vm::Transaction) -> Self {
        let address: Address = t.address.into();
        ActionParams {
            code_address: Address::new(),
            code_hash: Some(keccak(&*t.code)),
            address: address,
            sender: t.sender.into(),
            origin: t.origin.into(),
            code: Some(Arc::new(t.code.into())),
            data: Some(t.data.into()),
            gas: t.gas.into(),
            gas_price: t.gas_price.into(),
            value: ActionValue::Transfer(t.value.into()),
            call_type: match address.is_zero() {
                true => CallType::None,
                false => CallType::Call,
            }, // TODO @debris is this correct?
            params_type: ParamsType::Separate,
            access_list: AccessList::default(),
        }
    }
}