/*
 * Ethereum Storage Protocol (ESP) - DataPointStorage Contract
 * Copyright (C) 2025 TechnicallyWeb3
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program 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 Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <https://www.gnu.org/licenses/>.
 */

// SPDX-License-Identifier: AGPL-3.0
pragma solidity ^0.8.20;

/// @custom:interface copyright "Copyright (C) 2025 TechnicallyWeb3"
/// @custom:interface build ./interfaces/IDataPointStorage.sol

import "./types/ESPTypes.sol";

/// @title Data Point Storage Contract
/// @notice Provides core storage functionality for data points
/// @dev Basic implementation without collision handling
/// @custom:security ESP_FINGERPRINT_TW3_2025_DPS_v2
contract DataPointStorage {

    mapping(bytes32 => bytes) private dataPointData;
    uint8 public immutable VERSION = 2;

    /// @notice Calculates the storage address for a data point
    /// @param _data The data point to calculate address for
    /// @return _dataPointAddress The calculated storage address
    function calculateAddress(
        bytes memory _data
    ) public pure returns (bytes32 _dataPointAddress) {
        _dataPointAddress = calculateDataPointAddress(_data, VERSION); 
    }

    function dataPointSize(
        bytes32 _dataPointAddress
    ) external view returns (uint256) {
        return dataPointData[_dataPointAddress].length;
    }

    function readDataPoint(
        bytes32 _dataPointAddress
    ) external view returns (bytes memory) {
        return dataPointData[_dataPointAddress];
    }

    /// @notice Stores a new data point with user-specified version
    /// @dev Reverts if the calculated address is already occupied
    /// @param _data The data point to store
    /// @return _dataPointAddress The address where the data point is stored
    function writeDataPoint(
        bytes memory _data
    ) external returns (bytes32 _dataPointAddress) {
        // check that _data is not empty
        if (_data.length == 0) {
            revert InvalidData();
        }

        _dataPointAddress = calculateAddress(_data);
        
        // Check if address is already occupied
        if (dataPointData[_dataPointAddress].length > 0) {
            revert DataExists(_dataPointAddress);
        }
        
        dataPointData[_dataPointAddress] = _data;
        emit DataPointWritten(_dataPointAddress);
        
        return _dataPointAddress;
    }
}