// Source: contracts/executable/AxelarExecutable.sol

pragma solidity ^0.8.0;

// SPDX-License-Identifier: MIT

// File contracts/interfaces/IAxelarGateway.sol

/**
 * @title IAxelarGateway
 * @dev Interface for the Axelar Gateway that supports general message passing and contract call execution.
 */
interface IAxelarGateway {
    /**
     * @notice Emitted when a contract call is made through the gateway.
     * @dev Logs the attempt to call a contract on another chain.
     * @param sender The address of the sender who initiated the contract call.
     * @param destinationChain The name of the destination chain.
     * @param destinationContractAddress The address of the contract on the destination chain.
     * @param payloadHash The keccak256 hash of the sent payload data.
     * @param payload The payload data used for the contract call.
     */
    event ContractCall(
        address indexed sender,
        string destinationChain,
        string destinationContractAddress,
        bytes32 indexed payloadHash,
        bytes payload
    );

    /**
     * @notice Sends a contract call to another chain.
     * @dev Initiates a cross-chain contract call through the gateway to the specified destination chain and contract.
     * @param destinationChain The name of the destination chain.
     * @param contractAddress The address of the contract on the destination chain.
     * @param payload The payload data to be used in the contract call.
     */
    function callContract(
        string calldata destinationChain,
        string calldata contractAddress,
        bytes calldata payload
    ) external;

    /**
     * @notice Checks if a contract call is approved.
     * @dev Determines whether a given contract call, identified by the commandId and payloadHash, is approved.
     * @param commandId The identifier of the command to check.
     * @param sourceChain The name of the source chain.
     * @param sourceAddress The address of the sender on the source chain.
     * @param contractAddress The address of the contract where the call will be executed.
     * @param payloadHash The keccak256 hash of the payload data.
     * @return True if the contract call is approved, false otherwise.
     */
    function isContractCallApproved(
        bytes32 commandId,
        string calldata sourceChain,
        string calldata sourceAddress,
        address contractAddress,
        bytes32 payloadHash
    ) external view returns (bool);

    /**
     * @notice Validates and approves a contract call.
     * @dev Validates the given contract call information and marks it as approved if valid.
     * @param commandId The identifier of the command to validate.
     * @param sourceChain The name of the source chain.
     * @param sourceAddress The address of the sender on the source chain.
     * @param payloadHash The keccak256 hash of the payload data.
     * @return True if the contract call is validated and approved, false otherwise.
     */
    function validateContractCall(
        bytes32 commandId,
        string calldata sourceChain,
        string calldata sourceAddress,
        bytes32 payloadHash
    ) external returns (bool);

    /**
     * @notice Checks if a command has been executed.
     * @dev Determines whether a command, identified by the commandId, has been executed.
     * @param commandId The identifier of the command to check.
     * @return True if the command has been executed, false otherwise.
     */
    function isCommandExecuted(bytes32 commandId) external view returns (bool);
}

// File contracts/interfaces/IAxelarExecutable.sol

/**
 * @title IAxelarExecutable
 * @dev Interface for a contract that is executable by Axelar Gateway's cross-chain message passing.
 * It defines a standard interface to execute commands sent from another chain.
 */
interface IAxelarExecutable {
    /**
     * @dev Thrown when a function is called with an invalid address.
     */
    error InvalidAddress();

    /**
     * @dev Thrown when the call is not approved by the Axelar Gateway.
     */
    error NotApprovedByGateway();

    /**
     * @notice Returns the address of the AxelarGateway contract.
     * @return The Axelar Gateway contract associated with this executable contract.
     */
    function gateway() external view returns (IAxelarGateway);

    /**
     * @notice Executes the specified command sent from another chain.
     * @dev This function is called by the Axelar Gateway to carry out cross-chain commands.
     * Reverts if the call is not approved by the gateway or other checks fail.
     * @param commandId The identifier of the command to execute.
     * @param sourceChain The name of the source chain from where the command originated.
     * @param sourceAddress The address on the source chain that sent the command.
     * @param payload The payload of the command to be executed. This typically includes the function selector and encoded arguments.
     */
    function execute(
        bytes32 commandId,
        string calldata sourceChain,
        string calldata sourceAddress,
        bytes calldata payload
    ) external;
}

// File contracts/executable/AxelarExecutable.sol

/**
 * @title AxelarExecutable
 * @dev Abstract contract to be inherited by contracts that need to execute cross-chain commands via Axelar's Gateway.
 * It implements the IAxelarExecutable interface.
 */
abstract contract AxelarExecutable is IAxelarExecutable {
    /// @dev Reference to the Axelar Gateway contract.
    address internal immutable gatewayAddress;

    /**
     * @dev Contract constructor that sets the Axelar Gateway address.
     * Reverts if the provided address is the zero address.
     * @param gateway_ The address of the Axelar Gateway contract.
     */
    constructor(address gateway_) {
        if (gateway_ == address(0)) revert InvalidAddress();

        gatewayAddress = gateway_;
    }

    /**
     * @notice Executes the cross-chain command after validating it with the Axelar Gateway.
     * @dev This function ensures the call is approved by Axelar Gateway before execution.
     * It uses a hash of the payload for validation and internally calls _execute for the actual command execution.
     * Reverts if the validation fails.
     * @param commandId The unique identifier of the cross-chain message being executed.
     * @param sourceChain The name of the source chain from which the message originated.
     * @param sourceAddress The address on the source chain that sent the message.
     * @param payload The payload of the message payload.
     */
    function execute(
        bytes32 commandId,
        string calldata sourceChain,
        string calldata sourceAddress,
        bytes calldata payload
    ) external virtual {
        bytes32 payloadHash = keccak256(payload);

        if (!gateway().validateContractCall(commandId, sourceChain, sourceAddress, payloadHash))
            revert NotApprovedByGateway();

        _execute(commandId, sourceChain, sourceAddress, payload);
    }

    /**
     * @dev Internal virtual function to be overridden by child contracts to execute the command.
     * It allows child contracts to define their custom command execution logic.
     * @param commandId The identifier of the command to execute.
     * @param sourceChain The name of the source chain from which the command originated.
     * @param sourceAddress The address on the source chain that sent the command.
     * @param payload The payload of the command to be executed.
     */
    function _execute(
        bytes32 commandId,
        string calldata sourceChain,
        string calldata sourceAddress,
        bytes calldata payload
    ) internal virtual;

    /**
     * @notice Returns the address of the AxelarGateway contract.
     * @return The Axelar Gateway instance.
     */
    function gateway() public view returns (IAxelarGateway) {
        return IAxelarGateway(gatewayAddress);
    }
}