// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "./FinderInterface.sol";

/**
 * @title Financial contract facing Oracle interface.
 * @dev Interface used by financial contracts to interact with the Oracle. Voters will use a different interface.
 */
abstract contract OptimisticOracleV2Interface {
    event RequestPrice(
        address indexed requester,
        bytes32 identifier,
        uint256 timestamp,
        bytes ancillaryData,
        address currency,
        uint256 reward,
        uint256 finalFee
    );
    event ProposePrice(
        address indexed requester,
        address indexed proposer,
        bytes32 identifier,
        uint256 timestamp,
        bytes ancillaryData,
        int256 proposedPrice,
        uint256 expirationTimestamp,
        address currency
    );
    event DisputePrice(
        address indexed requester,
        address indexed proposer,
        address indexed disputer,
        bytes32 identifier,
        uint256 timestamp,
        bytes ancillaryData,
        int256 proposedPrice
    );
    event Settle(
        address indexed requester,
        address indexed proposer,
        address indexed disputer,
        bytes32 identifier,
        uint256 timestamp,
        bytes ancillaryData,
        int256 price,
        uint256 payout
    );
    // Struct representing the state of a price request.
    enum State {
        Invalid, // Never requested.
        Requested, // Requested, no other actions taken.
        Proposed, // Proposed, but not expired or disputed yet.
        Expired, // Proposed, not disputed, past liveness.
        Disputed, // Disputed, but no DVM price returned yet.
        Resolved, // Disputed and DVM price is available.
        Settled // Final price has been set in the contract (can get here from Expired or Resolved).
    }

    struct RequestSettings {
        bool eventBased; // True if the request is set to be event-based.
        bool refundOnDispute; // True if the requester should be refunded their reward on dispute.
        bool callbackOnPriceProposed; // True if callbackOnPriceProposed callback is required.
        bool callbackOnPriceDisputed; // True if callbackOnPriceDisputed callback is required.
        bool callbackOnPriceSettled; // True if callbackOnPriceSettled callback is required.
        uint256 bond; // Bond that the proposer and disputer must pay on top of the final fee.
        uint256 customLiveness; // Custom liveness value set by the requester.
    }

    // Struct representing a price request.
    struct Request {
        address proposer; // Address of the proposer.
        address disputer; // Address of the disputer.
        IERC20 currency; // ERC20 token used to pay rewards and fees.
        bool settled; // True if the request is settled.
        RequestSettings requestSettings; // Custom settings associated with a request.
        int256 proposedPrice; // Price that the proposer submitted.
        int256 resolvedPrice; // Price resolved once the request is settled.
        uint256 expirationTime; // Time at which the request auto-settles without a dispute.
        uint256 reward; // Amount of the currency to pay to the proposer on settlement.
        uint256 finalFee; // Final fee to pay to the Store upon request to the DVM.
    }

    // This value must be <= the Voting contract's `ancillaryBytesLimit` value otherwise it is possible
    // that a price can be requested to this contract successfully, but cannot be disputed because the DVM refuses
    // to accept a price request made with ancillary data length over a certain size.
    uint256 public constant ancillaryBytesLimit = 8192;

    function defaultLiveness() external view virtual returns (uint256);

    function finder() external view virtual returns (FinderInterface);

    function getCurrentTime() external view virtual returns (uint256);

    // Note: this is required so that typechain generates a return value with named fields.
    mapping(bytes32 => Request) public requests;

    /**
     * @notice Requests a new price.
     * @param identifier price identifier being requested.
     * @param timestamp timestamp of the price being requested.
     * @param ancillaryData ancillary data representing additional args being passed with the price request.
     * @param currency ERC20 token used for payment of rewards and fees. Must be approved for use with the DVM.
     * @param reward reward offered to a successful proposer. Will be pulled from the caller. Note: this can be 0,
     *               which could make sense if the contract requests and proposes the value in the same call or
     *               provides its own reward system.
     * @return totalBond default bond (final fee) + final fee that the proposer and disputer will be required to pay.
     * This can be changed with a subsequent call to setBond().
     */
    function requestPrice(
        bytes32 identifier,
        uint256 timestamp,
        bytes memory ancillaryData,
        IERC20 currency,
        uint256 reward
    ) external virtual returns (uint256 totalBond);

    /**
     * @notice Set the proposal bond associated with a price request.
     * @param identifier price identifier to identify the existing request.
     * @param timestamp timestamp to identify the existing request.
     * @param ancillaryData ancillary data of the price being requested.
     * @param bond custom bond amount to set.
     * @return totalBond new bond + final fee that the proposer and disputer will be required to pay. This can be
     * changed again with a subsequent call to setBond().
     */
    function setBond(
        bytes32 identifier,
        uint256 timestamp,
        bytes memory ancillaryData,
        uint256 bond
    ) external virtual returns (uint256 totalBond);

    /**
     * @notice Sets the request to refund the reward if the proposal is disputed. This can help to "hedge" the caller
     * in the event of a dispute-caused delay. Note: in the event of a dispute, the winner still receives the other's
     * bond, so there is still profit to be made even if the reward is refunded.
     * @param identifier price identifier to identify the existing request.
     * @param timestamp timestamp to identify the existing request.
     * @param ancillaryData ancillary data of the price being requested.
     */
    function setRefundOnDispute(
        bytes32 identifier,
        uint256 timestamp,
        bytes memory ancillaryData
    ) external virtual;

    /**
     * @notice Sets a custom liveness value for the request. Liveness is the amount of time a proposal must wait before
     * being auto-resolved.
     * @param identifier price identifier to identify the existing request.
     * @param timestamp timestamp to identify the existing request.
     * @param ancillaryData ancillary data of the price being requested.
     * @param customLiveness new custom liveness.
     */
    function setCustomLiveness(
        bytes32 identifier,
        uint256 timestamp,
        bytes memory ancillaryData,
        uint256 customLiveness
    ) external virtual;

    /**
     * @notice Sets the request to be an "event-based" request.
     * @dev Calling this method has a few impacts on the request:
     *
     * 1. The timestamp at which the request is evaluated is the time of the proposal, not the timestamp associated
     *    with the request.
     *
     * 2. The proposer cannot propose the "too early" value (TOO_EARLY_RESPONSE). This is to ensure that a proposer who
     *    prematurely proposes a response loses their bond.
     *
     * 3. RefundoOnDispute is automatically set, meaning disputes trigger the reward to be automatically refunded to
     *    the requesting contract.
     *
     * @param identifier price identifier to identify the existing request.
     * @param timestamp timestamp to identify the existing request.
     * @param ancillaryData ancillary data of the price being requested.
     */
    function setEventBased(
        bytes32 identifier,
        uint256 timestamp,
        bytes memory ancillaryData
    ) external virtual;

    /**
     * @notice Sets which callbacks should be enabled for the request.
     * @param identifier price identifier to identify the existing request.
     * @param timestamp timestamp to identify the existing request.
     * @param ancillaryData ancillary data of the price being requested.
     * @param callbackOnPriceProposed whether to enable the callback onPriceProposed.
     * @param callbackOnPriceDisputed whether to enable the callback onPriceDisputed.
     * @param callbackOnPriceSettled whether to enable the callback onPriceSettled.
     */
    function setCallbacks(
        bytes32 identifier,
        uint256 timestamp,
        bytes memory ancillaryData,
        bool callbackOnPriceProposed,
        bool callbackOnPriceDisputed,
        bool callbackOnPriceSettled
    ) external virtual;

    /**
     * @notice Proposes a price value on another address' behalf. Note: this address will receive any rewards that come
     * from this proposal. However, any bonds are pulled from the caller.
     * @param proposer address to set as the proposer.
     * @param requester sender of the initial price request.
     * @param identifier price identifier to identify the existing request.
     * @param timestamp timestamp to identify the existing request.
     * @param ancillaryData ancillary data of the price being requested.
     * @param proposedPrice price being proposed.
     * @return totalBond the amount that's pulled from the caller's wallet as a bond. The bond will be returned to
     * the proposer once settled if the proposal is correct.
     */
    function proposePriceFor(
        address proposer,
        address requester,
        bytes32 identifier,
        uint256 timestamp,
        bytes memory ancillaryData,
        int256 proposedPrice
    ) public virtual returns (uint256 totalBond);

    /**
     * @notice Proposes a price value for an existing price request.
     * @param requester sender of the initial price request.
     * @param identifier price identifier to identify the existing request.
     * @param timestamp timestamp to identify the existing request.
     * @param ancillaryData ancillary data of the price being requested.
     * @param proposedPrice price being proposed.
     * @return totalBond the amount that's pulled from the proposer's wallet as a bond. The bond will be returned to
     * the proposer once settled if the proposal is correct.
     */
    function proposePrice(
        address requester,
        bytes32 identifier,
        uint256 timestamp,
        bytes memory ancillaryData,
        int256 proposedPrice
    ) external virtual returns (uint256 totalBond);

    /**
     * @notice Disputes a price request with an active proposal on another address' behalf. Note: this address will
     * receive any rewards that come from this dispute. However, any bonds are pulled from the caller.
     * @param disputer address to set as the disputer.
     * @param requester sender of the initial price request.
     * @param identifier price identifier to identify the existing request.
     * @param timestamp timestamp to identify the existing request.
     * @param ancillaryData ancillary data of the price being requested.
     * @return totalBond the amount that's pulled from the caller's wallet as a bond. The bond will be returned to
     * the disputer once settled if the dispute was value (the proposal was incorrect).
     */
    function disputePriceFor(
        address disputer,
        address requester,
        bytes32 identifier,
        uint256 timestamp,
        bytes memory ancillaryData
    ) public virtual returns (uint256 totalBond);

    /**
     * @notice Disputes a price value for an existing price request with an active proposal.
     * @param requester sender of the initial price request.
     * @param identifier price identifier to identify the existing request.
     * @param timestamp timestamp to identify the existing request.
     * @param ancillaryData ancillary data of the price being requested.
     * @return totalBond the amount that's pulled from the disputer's wallet as a bond. The bond will be returned to
     * the disputer once settled if the dispute was valid (the proposal was incorrect).
     */
    function disputePrice(
        address requester,
        bytes32 identifier,
        uint256 timestamp,
        bytes memory ancillaryData
    ) external virtual returns (uint256 totalBond);

    /**
     * @notice Retrieves a price that was previously requested by a caller. Reverts if the request is not settled
     * or settleable. Note: this method is not view so that this call may actually settle the price request if it
     * hasn't been settled.
     * @param identifier price identifier to identify the existing request.
     * @param timestamp timestamp to identify the existing request.
     * @param ancillaryData ancillary data of the price being requested.
     * @return resolved price.
     */
    function settleAndGetPrice(
        bytes32 identifier,
        uint256 timestamp,
        bytes memory ancillaryData
    ) external virtual returns (int256);

    /**
     * @notice Attempts to settle an outstanding price request. Will revert if it isn't settleable.
     * @param requester sender of the initial price request.
     * @param identifier price identifier to identify the existing request.
     * @param timestamp timestamp to identify the existing request.
     * @param ancillaryData ancillary data of the price being requested.
     * @return payout the amount that the "winner" (proposer or disputer) receives on settlement. This amount includes
     * the returned bonds as well as additional rewards.
     */
    function settle(
        address requester,
        bytes32 identifier,
        uint256 timestamp,
        bytes memory ancillaryData
    ) external virtual returns (uint256 payout);

    /**
     * @notice Gets the current data structure containing all information about a price request.
     * @param requester sender of the initial price request.
     * @param identifier price identifier to identify the existing request.
     * @param timestamp timestamp to identify the existing request.
     * @param ancillaryData ancillary data of the price being requested.
     * @return the Request data structure.
     */
    function getRequest(
        address requester,
        bytes32 identifier,
        uint256 timestamp,
        bytes memory ancillaryData
    ) public view virtual returns (Request memory);

    /**
     * @notice Returns the state of a price request.
     * @param requester sender of the initial price request.
     * @param identifier price identifier to identify the existing request.
     * @param timestamp timestamp to identify the existing request.
     * @param ancillaryData ancillary data of the price being requested.
     * @return the State enum value.
     */
    function getState(
        address requester,
        bytes32 identifier,
        uint256 timestamp,
        bytes memory ancillaryData
    ) public view virtual returns (State);

    /**
     * @notice Checks if a given request has resolved or been settled (i.e the optimistic oracle has a price).
     * @param requester sender of the initial price request.
     * @param identifier price identifier to identify the existing request.
     * @param timestamp timestamp to identify the existing request.
     * @param ancillaryData ancillary data of the price being requested.
     * @return true if price has resolved or settled, false otherwise.
     */
    function hasPrice(
        address requester,
        bytes32 identifier,
        uint256 timestamp,
        bytes memory ancillaryData
    ) public view virtual returns (bool);

    function stampAncillaryData(bytes memory ancillaryData, address requester)
        public
        view
        virtual
        returns (bytes memory);
}