Gearbox Protocol

1// SPDX-License-Identifier: BUSL-1.1
2// Gearbox Protocol. Generalized leverage for DeFi protocols
3// (c) Gearbox Holdings, 2021
4pragma solidity ^0.7.4;
5pragma abicoder v2;
6
7import {EnumerableSet} from "@openzeppelin/contracts/utils/EnumerableSet.sol";
8import {SafeMath} from "@openzeppelin/contracts/math/SafeMath.sol";
9import {Clones} from "@openzeppelin/contracts/proxy/Clones.sol";
10
11import {IAccountFactory} from "../interfaces/IAccountFactory.sol";
12import {IAccountMiner} from "../interfaces/IAccountMiner.sol";
13import {ICreditAccount} from "../interfaces/ICreditAccount.sol";
14import {ICreditManager} from "../interfaces/ICreditManager.sol";
15
16import {AddressProvider} from "./AddressProvider.sol";
17import {ContractsRegister} from "./ContractsRegister.sol";
18import {CreditAccount} from "../credit/CreditAccount.sol";
19import {ACLTrait} from "./ACLTrait.sol";
20import {ReentrancyGuard} from "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
21
22import {DataTypes} from "../libraries/data/Types.sol";
23import {Errors} from "../libraries/helpers/Errors.sol";
24
25/// @title Abstract reusable credit accounts factory
26/// @notice Creates, holds & lend credit accounts to pool contract
27contract AccountFactory is IAccountFactory, ACLTrait, ReentrancyGuard {
28    using EnumerableSet for EnumerableSet.AddressSet;
29
30    //
31    //     head
32    //      ⬇
33    //    -------       -------        -------        -------
34    //   |  VA1  | ->  |  VA2  |  ->  |  VA3  |  ->  |  VA4  |  ->  address(0)
35    //    -------       -------        -------        -------
36    //                                                   ⬆
37    //                                                  tail
38    //
39
40    // Credit accounts connected list
41    mapping(address => address) private _nextCreditAccount;
42
43    // Head on connected list
44    address public override head;
45
46    // Tail of connected list
47    address public override tail;
48
49    // Address of master credit account for cloning
50    address public masterCreditAccount;
51
52    // Credit accounts list
53    EnumerableSet.AddressSet private creditAccountsSet;
54
55    // List of approvals which is needed during account mining campaign
56    DataTypes.MiningApproval[] public miningApprovals;
57
58    // Contracts register
59    ContractsRegister public _contractsRegister;
60
61    // Flag that there is no mining yet
62    bool public isMiningFinished;
63
64    // Contract version
65    uint256 public constant version = 1;
66
67    modifier creditManagerOnly() {
68        require(
69            _contractsRegister.isCreditManager(msg.sender),
70            Errors.REGISTERED_CREDIT_ACCOUNT_MANAGERS_ONLY
71        );
72        _;
73    }
74
75    /**
76     * @dev constructor
77     * After constructor the list should be as following
78     *
79     *     head
80     *      ⬇
81     *    -------
82     *   |  VA1  | ->   address(0)
83     *    -------
84     *      ⬆
85     *     tail
86     *
87     * @param addressProvider Address of address repository
88     */
89    constructor(address addressProvider) ACLTrait(addressProvider) {
90        require(
91            addressProvider != address(0),
92            Errors.ZERO_ADDRESS_IS_NOT_ALLOWED
93        );
94
95        _contractsRegister = ContractsRegister(
96            AddressProvider(addressProvider).getContractsRegister()
97        ); // T:[AF-1]
98
99        masterCreditAccount = address(new CreditAccount()); // T:[AF-1]
100        CreditAccount(masterCreditAccount).initialize(); // T:[AF-1]
101
102        addCreditAccount(); // T:[AF-1]
103        head = tail; // T:[AF-1]
104        _nextCreditAccount[address(0)] = address(0); // T:[AF-1]
105    }
106
107    /**
108     * @dev Provides a new credit account to the pool. Creates a new one, if needed
109     *
110     *   Before:
111     *  ---------
112     *
113     *     head
114     *      ⬇
115     *    -------       -------        -------        -------
116     *   |  VA1  | ->  |  VA2  |  ->  |  VA3  |  ->  |  VA4  |  ->  address(0)
117     *    -------       -------        -------        -------
118     *                                                   ⬆
119     *                                                  tail
120     *
121     *   After:
122     *  ---------
123     *
124     *    head
125     *     ⬇
126     *   -------        -------        -------
127     *  |  VA2  |  ->  |  VA3  |  ->  |  VA4  |  ->  address(0)
128     *   -------        -------        -------
129     *                                    ⬆
130     *                                   tail
131     *
132     *
133     *   -------
134     *  |  VA1  |  ->  address(0)
135     *   -------
136     *
137     *  If had points the last credit account, it adds a new one
138     *
139     *    head
140     *     ⬇
141     *   -------
142     *  |  VA2  |  ->   address(0)     =>    _addNewCreditAccount()
143     *   -------
144     *     ⬆
145     *    tail
146     *
147     * @return Address of credit account
148     */
149    function takeCreditAccount(
150        uint256 _borrowedAmount,
151        uint256 _cumulativeIndexAtOpen
152    )
153        external
154        override
155        creditManagerOnly // T:[AF-12]
156        returns (address)
157    {
158        // Create a new credit account if no one in stock
159        _checkStock(); // T:[AF-3]
160
161        address result = head;
162        head = _nextCreditAccount[head]; // T:[AF-2]
163        _nextCreditAccount[result] = address(0); // T:[AF-2]
164
165        // Initialize creditManager
166        ICreditAccount(result).connectTo(
167            msg.sender,
168            _borrowedAmount,
169            _cumulativeIndexAtOpen
170        ); // T:[AF-11, 14]
171
172        emit InitializeCreditAccount(result, msg.sender); // T:[AF-5]
173        return result; // T:[AF-14]
174    }
175
176    /**
177     * @dev Takes credit account back and adds it to the stock
178     *
179     *   Before:
180     *  ---------
181     *
182     *     head
183     *      ⬇
184     *    -------       -------        -------        -------
185     *   |  VA1  | ->  |  VA2  |  ->  |  VA3  |  ->  |  VA4  |  ->  address(0)
186     *    -------       -------        -------        -------
187     *                                                   ⬆
188     *                                                  tail
189     *
190     *   After:
191     *  ---------
192     *
193     *     head
194     *      ⬇
195     *    -------       -------        -------        -------       ---------------
196     *   |  VA1  | ->  |  VA2  |  ->  |  VA3  |  ->  |  VA4  |  -> |  usedAccount  |  ->  address(0)
197     *    -------       -------        -------        -------       ---------------
198     *                                                                     ⬆
199     *                                                                    tail
200     *
201     *
202     * @param usedAccount Address of used credit account
203     */
204    function returnCreditAccount(address usedAccount)
205        external
206        override
207        creditManagerOnly // T:[AF-12]
208    {
209        require(
210            creditAccountsSet.contains(usedAccount),
211            Errors.AF_EXTERNAL_ACCOUNTS_ARE_FORBIDDEN
212        );
213        require(
214            ICreditAccount(usedAccount).since() != block.number,
215            Errors.AF_CANT_CLOSE_CREDIT_ACCOUNT_IN_THE_SAME_BLOCK
216        ); // T:[CM-20]
217
218        _nextCreditAccount[tail] = usedAccount; // T:[AF-7]
219        tail = usedAccount; // T:[AF-7]
220        emit ReturnCreditAccount(usedAccount); // T:[AF-8]
221    }
222
223    /// @dev Gets next available credit account or address(0) if you are in tail
224    function getNext(address creditAccount)
225        external
226        view
227        override
228        returns (address)
229    {
230        return _nextCreditAccount[creditAccount];
231    }
232
233    /**
234     * @dev Deploys new credit account and adds it to list tail
235     *
236     *   Before:
237     *  ---------
238     *
239     *     head
240     *      ⬇
241     *    -------       -------        -------        -------
242     *   |  VA1  | ->  |  VA2  |  ->  |  VA3  |  ->  |  VA4  |  ->  address(0)
243     *    -------       -------        -------        -------
244     *                                                   ⬆
245     *                                                  tail
246     *
247     *   After:
248     *  ---------
249     *
250     *     head
251     *      ⬇
252     *    -------       -------        -------        -------       --------------
253     *   |  VA1  | ->  |  VA2  |  ->  |  VA3  |  ->  |  VA4  |  -> |  newAccount  |  ->  address(0)
254     *    -------       -------        -------        -------       --------------
255     *                                                                    ⬆
256     *                                                                   tail
257     *
258     *
259     */

JavaScript Tests