// SPDX-License-Identifier: MIT
pragma solidity ^0.8.19;

/**
 * @title VideoPaymentStorage
 * @dev Storage layout for VideoPayment contract to ensure upgrade compatibility
 */
library VideoPaymentStorage {
    // Storage layout version for upgrade compatibility
    uint256 constant STORAGE_VERSION = 1;

    struct ContentConfig {
        mapping(address => uint256) tokenPrices; // ERC20 token prices
        uint256 nativePrice; // Native coin price
        uint256 viewCount; // View count when purchased
        bool isActive; // Whether content is purchasable
    }

    struct ViewPermission {
        uint256 purchaseTime; // Purchase timestamp
        uint256 remainingViews; // Remaining view count
        bool isValid; // Whether permission is valid
    }

    struct VideoPaymentStorageStruct {
        // Owner and admin management
        address owner;
        mapping(address => bool) isAdmin;
        // Content management
        mapping(uint256 => ContentConfig) contentConfigs;
        // User permissions
        mapping(address => mapping(uint256 => ViewPermission)) userPermissions;
        // Supported payment tokens
        mapping(address => bool) supportedTokens;
        // Token enumeration support
        address[] allSupportedTokens;
        mapping(address => bool) tokenExists;
        mapping(address => uint256) tokenIndexes; // for efficient removal
        // Emergency pause
        bool paused;
        // Contract version
        uint256 version;
        // Treasury management
        address payable treasury;
        // Reserved storage slots for future upgrades
        uint256[47] __gap;
    }
}