// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import { IImplementation } from '../interfaces/IImplementation.sol';
import { IUpgradable } from '../interfaces/IUpgradable.sol';
import { Ownable } from '../utils/Ownable.sol';
import { Implementation } from './Implementation.sol';

/**
 * @title Upgradable Contract
 * @notice This contract provides an interface for upgradable smart contracts and includes the functionality to perform upgrades.
 */
abstract contract Upgradable is Ownable, Implementation, IUpgradable {
    // bytes32(uint256(keccak256('eip1967.proxy.implementation')) - 1)
    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;

    /**
     * @notice Constructor sets the implementation address to the address of the contract itself
     * @dev This is used in the onlyProxy modifier to prevent certain functions from being called directly
     * on the implementation contract itself.
     * @dev The owner is initially set as address(1) because the actual owner is set within the proxy. It is not
     * set as the zero address because Ownable is designed to throw an error for ownership transfers to the zero address.
     */
    constructor() Ownable(address(1)) {}

    /**
     * @notice Returns the address of the current implementation
     * @return implementation_ Address of the current implementation
     */
    function implementation() public view returns (address implementation_) {
        assembly {
            implementation_ := sload(_IMPLEMENTATION_SLOT)
        }
    }

    /**
     * @notice Upgrades the contract to a new implementation
     * @param newImplementation The address of the new implementation contract
     * @param newImplementationCodeHash The codehash of the new implementation contract
     * @param params Optional setup parameters for the new implementation contract
     * @dev This function is only callable by the owner.
     */
    function upgrade(
        address newImplementation,
        bytes32 newImplementationCodeHash,
        bytes calldata params
    ) external override onlyOwner {
        if (IUpgradable(newImplementation).contractId() != IUpgradable(implementation()).contractId())
            revert InvalidImplementation();

        if (newImplementationCodeHash != newImplementation.codehash) revert InvalidCodeHash();

        assembly {
            sstore(_IMPLEMENTATION_SLOT, newImplementation)
        }

        emit Upgraded(newImplementation);

        if (params.length > 0) {
            // slither-disable-next-line controlled-delegatecall
            (bool success, ) = newImplementation.delegatecall(abi.encodeWithSelector(this.setup.selector, params));

            if (!success) revert SetupFailed();
        }
    }

    /**
     * @notice Sets up the contract with initial data
     * @param data Initialization data for the contract
     * @dev This function is only callable by the proxy contract.
     */
    function setup(bytes calldata data) external override(IImplementation, Implementation) onlyProxy {
        _setup(data);
    }

    /**
     * @notice Internal function to set up the contract with initial data
     * @param data Initialization data for the contract
     * @dev This function should be implemented in derived contracts.
     */
    function _setup(bytes calldata data) internal virtual;
}