└── ERC721


/ERC721:
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  1 | // SPDX-License-Identifier: MIT
  2 | pragma solidity ^0.8.0;
  3 | 
  4 | // Importing OpenZeppelin ERC721 contract
  5 | import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC721/ERC721.sol";
  6 | 
  7 | // Interface for interacting with a submission contract
  8 | interface ISubmission {
  9 |     // Struct representing a haiku
 10 |     struct Haiku {
 11 |         address author; // Address of the haiku author
 12 |         string line1; // First line of the haiku
 13 |         string line2; // Second line of the haiku
 14 |         string line3; // Third line of the haiku
 15 |     }
 16 | 
 17 |     // Function to mint a new haiku
 18 |     function mintHaiku(
 19 |         string memory _line1,
 20 |         string memory _line2,
 21 |         string memory _line3
 22 |     ) external;
 23 | 
 24 |     // Function to get the total number of haikus
 25 |     function counter() external view returns (uint256);
 26 | 
 27 |     // Function to share a haiku with another address
 28 |     function shareHaiku(uint256 _id, address _to) external;
 29 | 
 30 |     // Function to get haikus shared with the caller
 31 |     function getMySharedHaikus() external view returns (Haiku[] memory);
 32 | }
 33 | 
 34 | // Contract for managing Haiku NFTs
 35 | contract HaikuNFT is ERC721, ISubmission {
 36 |     Haiku[] public haikus; // Array to store haikus
 37 |     mapping(address => mapping(uint256 => bool)) public sharedHaikus; // Mapping to track shared haikus
 38 |     uint256 public haikuCounter; // Counter for total haikus minted
 39 | 
 40 |     // Constructor to initialize the ERC721 contract
 41 |     constructor() ERC721("HaikuNFT", "HAIKU") {
 42 |         haikuCounter = 1; // Initialize haiku counter
 43 |     }
 44 | 
 45 |     string salt = "value"; // A private string variable
 46 | 
 47 |     // Function to get the total number of haikus
 48 |     function counter() external view override returns (uint256) {
 49 |         return haikuCounter;
 50 |     }
 51 | 
 52 |     // Function to mint a new haiku
 53 |     function mintHaiku(
 54 |         string memory _line1,
 55 |         string memory _line2,
 56 |         string memory _line3
 57 |     ) external override {
 58 |         // Check if the haiku is unique
 59 |         string[3] memory haikusStrings = [_line1, _line2, _line3];
 60 |         for (uint256 li = 0; li < haikusStrings.length; li++) {
 61 |             string memory newLine = haikusStrings[li];
 62 |             for (uint256 i = 0; i < haikus.length; i++) {
 63 |                 Haiku memory existingHaiku = haikus[i];
 64 |                 string[3] memory existingHaikuStrings = [
 65 |                     existingHaiku.line1,
 66 |                     existingHaiku.line2,
 67 |                     existingHaiku.line3
 68 |                 ];
 69 |                 for (uint256 eHsi = 0; eHsi < 3; eHsi++) {
 70 |                     string memory existingHaikuString = existingHaikuStrings[
 71 |                         eHsi
 72 |                     ];
 73 |                     if (
 74 |                         keccak256(abi.encodePacked(existingHaikuString)) ==
 75 |                         keccak256(abi.encodePacked(newLine))
 76 |                     ) {
 77 |                         revert HaikuNotUnique();
 78 |                     }
 79 |                 }
 80 |             }
 81 |         }
 82 | 
 83 |         // Mint the haiku NFT
 84 |         _safeMint(msg.sender, haikuCounter);
 85 |         haikus.push(Haiku(msg.sender, _line1, _line2, _line3));
 86 |         haikuCounter++;
 87 |     }
 88 | 
 89 |     // Function to share a haiku with another address
 90 |     function shareHaiku(uint256 _id, address _to) external override {
 91 |         require(_id > 0 && _id <= haikuCounter, "Invalid haiku ID");
 92 | 
 93 |         Haiku memory haikuToShare = haikus[_id - 1];
 94 |         require(haikuToShare.author == msg.sender, "NotYourHaiku");
 95 | 
 96 |         sharedHaikus[_to][_id] = true;
 97 |     }
 98 | 
 99 |     // Function to get haikus shared with the caller
100 |     function getMySharedHaikus()
101 |         external
102 |         view
103 |         override
104 |         returns (Haiku[] memory)
105 |     {
106 |         uint256 sharedHaikuCount;
107 |         for (uint256 i = 0; i < haikus.length; i++) {
108 |             if (sharedHaikus[msg.sender][i + 1]) {
109 |                 sharedHaikuCount++;
110 |             }
111 |         }
112 | 
113 |         Haiku[] memory result = new Haiku[](sharedHaikuCount);
114 |         uint256 currentIndex;
115 |         for (uint256 i = 0; i < haikus.length; i++) {
116 |             if (sharedHaikus[msg.sender][i + 1]) {
117 |                 result[currentIndex] = haikus[i];
118 |                 currentIndex++;
119 |             }
120 |         }
121 | 
122 |         if (sharedHaikuCount == 0) {
123 |             revert NoHaikusShared();
124 |         }
125 | 
126 |         return result;
127 |     }
128 | 
129 |     // Custom errors
130 |     error HaikuNotUnique(); // Error for attempting to mint a non-unique haiku
131 |     error NotYourHaiku(); // Error for attempting to share a haiku not owned by the caller
132 |     error NoHaikusShared(); // Error for no haikus shared with the caller
133 | }
134 | 


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