foundry project init

.env.example

@@ -0,0 +1,6 @@
+ETH_RPC_URL=
+HOLESKY_RPC_URL=
+ETHERSCAN_API_KEY=
+
+PT_ADDRESS=
+BASE_DISCOUNT_PER_YEAR=

.gitignore

@@ -1,3 +1,5 @@
+.DS_Store
+
 # Compiler files
 cache/
 out/

foundry.toml

@@ -1,6 +1,33 @@
 [profile.default]
+solc = "0.8.19"
+via_ir = true
 src = "src"
 out = "out"
 libs = ["lib"]
+fs_permissions = [{ access = "read-write", path = "./"}]
+gas_reports = ["*"]
+build_info = true
+extra_output = ["storageLayout"]
+
+[rpc_endpoints]
+mainnet = "${ETH_RPC_URL}"
+holesky = "${HOLESKY_RPC_URL}"
+
+[fmt]
+bracket_spacing = false
+int_types = "long"
+line_length = 120
+multiline_func_header = "params_first"
+number_underscore = "thousands"
+quote_style = "double"
+tab_width = 4
+
+[fuzz]
+runs = 4096
+max_test_rejects = 262144
+
+[etherscan]
+mainnet = { key = "${ETHERSCAN_API_KEY}" }
+holesky = { key = "${ETHERSCAN_API_KEY}" }
 
 # See more config options https://github.com/foundry-rs/foundry/blob/master/crates/config/README.md#all-options

script/OjoPointsOracle.s.sol

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+// SPDX-License-Identifier: UNLICENSED
+pragma solidity 0.8.19;
+
+import {Script} from "forge-std/Script.sol";
+import {OjoPointsOracle} from "src/OjoPointsOracle.sol";
+import {console} from "forge-std/console.sol";
+
+contract DeployOjoPointsOracle is Script {
+    function run() external {
+        address _pt = vm.envAddress("PT_ADDRESS");
+        uint256 _baseDiscountPerYear = vm.envUint("BASE_DISCOUNT_PER_YEAR");
+
+        vm.startBroadcast();
+
+        OjoPointsOracle ojoPointsOracle = new OjoPointsOracle(_pt, _baseDiscountPerYear);
+
+        vm.stopBroadcast();
+
+        console.log("OjoPointsOracle Address:", address(ojoPointsOracle));
+    }
+}

src/OjoPointsOracle.sol

@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: SEE LICENSE IN LICENSE
+pragma solidity ^0.8.19;
+
+contract OjoPointsOracle {
+    uint256 private constant SECONDS_PER_YEAR = 365 days;
+    uint256 private constant ONE = 1e18;
+
+    address public immutable PT;
+    uint256 public immutable maturity;
+    uint256 public immutable baseDiscountPerYear; // 100% = 1e18
+
+    constructor(address _pt, uint256 _baseDiscountPerYear) {
+        require(_baseDiscountPerYear <= 1e18, "invalid discount");
+        require(_pt != address(0), "zero address");
+
+        PT = _pt;
+        maturity = PTExpiry(PT).expiry();
+        baseDiscountPerYear = _baseDiscountPerYear;
+    }
+
+    function latestRoundData()
+        external
+        view
+        returns (uint80 roundId, int256 answer, uint256 startedAt, uint256 updatedAt, uint80 answeredInRound)
+    {
+        uint256 timeLeft = (maturity > block.timestamp) ? maturity - block.timestamp : 0;
+        uint256 discount = getDiscount(timeLeft);
+
+        require(discount <= ONE, "discount overflow");
+
+        return (0, int256(ONE - discount), 0, 0, 0);
+    }
+
+    function decimals() external pure returns (uint8) {
+        return 18;
+    }
+
+    function getDiscount(
+        uint256 timeLeft
+    ) public view returns (uint256) {
+        return (timeLeft * baseDiscountPerYear) / SECONDS_PER_YEAR;
+    }
+}
+
+interface PTExpiry {
+    function expiry() external view returns (uint256);
+}