import type { Connection, Signer, TransactionError } from '@solana/web3.js';
import { PublicKey, Transaction } from '@solana/web3.js';
import { TOKEN_2022_PROGRAM_ID, TOKEN_PROGRAM_ID } from '../constants.js';
import { createAmountToUiAmountInstruction } from '../instructions/amountToUiAmount.js';
import { unpackMint } from '../state/mint.js';
import { getInterestBearingMintConfigState } from '../extensions/interestBearingMint/state.js';
/**
* Amount as a string using mint-prescribed decimals
*
* @param connection Connection to use
* @param payer Payer of the transaction fees
* @param mint Mint for the account
* @param amount Amount of tokens to be converted to Ui Amount
* @param programId SPL Token program account
*
* @return Ui Amount generated
*/
export async function amountToUiAmount(
connection: Connection,
payer: Signer,
mint: PublicKey,
amount: number | bigint,
programId = TOKEN_PROGRAM_ID,
): Promise<string | TransactionError | null> {
const transaction = new Transaction().add(createAmountToUiAmountInstruction(mint, amount, programId));
const { returnData, err } = (await connection.simulateTransaction(transaction, [payer], false)).value;
if (returnData?.data) {
return Buffer.from(returnData.data[0], returnData.data[1]).toString('utf-8');
}
return err;
}
/**
* Calculates the exponent for the interest rate formula.
* @param t1 - The start time in seconds.
* @param t2 - The end time in seconds.
* @param r - The interest rate in basis points.
* @returns The calculated exponent.
*/
function calculateExponentForTimesAndRate(t1: number, t2: number, r: number) {
const ONE_IN_BASIS_POINTS = 10000;
const SECONDS_PER_YEAR = 60 * 60 * 24 * 365.24;
const timespan = t2 - t1;
const numerator = r * timespan;
const exponent = numerator / (SECONDS_PER_YEAR * ONE_IN_BASIS_POINTS);
return Math.exp(exponent);
}
/**
* Retrieves the current timestamp from the Solana clock sysvar.
* @param connection - The Solana connection object.
* @returns A promise that resolves to the current timestamp in seconds.
* @throws An error if the sysvar clock cannot be fetched or parsed.
*/
async function getSysvarClockTimestamp(connection: Connection): Promise<number> {
const info = await connection.getParsedAccountInfo(new PublicKey('SysvarC1ock11111111111111111111111111111111'));
if (!info) {
throw new Error('Failed to fetch sysvar clock');
}
if (typeof info.value === 'object' && info.value && 'data' in info.value && 'parsed' in info.value.data) {
return info.value.data.parsed.info.unixTimestamp;
}
throw new Error('Failed to parse sysvar clock');
}
/**
* Convert amount to UiAmount for a mint with interest bearing extension without simulating a transaction
* This implements the same logic as the CPI instruction available in /token/program-2022/src/extension/interest_bearing_mint/mod.rs
* In general to calculate compounding interest over a period of time, the formula is:
* A = P * e^(r * t) where
* A = final amount after interest
* P = principal amount (initial investment)
* r = annual interest rate (as a decimal, e.g., 5% = 0.05)
* t = time in years
* e = mathematical constant (~2.718)
*
* In this case, we are calculating the total scale factor for the interest bearing extension which is the product of two exponential functions:
* totalScale = e^(r1 * t1) * e^(r2 * t2)
* where r1 and r2 are the interest rates before and after the last update, and t1 and t2 are the times in years between
* the initialization timestamp and the last update timestamp, and between the last update timestamp and the current timestamp.
*
* @param amount Amount of tokens to be converted
* @param decimals Number of decimals of the mint
* @param currentTimestamp Current timestamp in seconds
* @param lastUpdateTimestamp Last time the interest rate was updated in seconds
* @param initializationTimestamp Time the interest bearing extension was initialized in seconds
* @param preUpdateAverageRate Interest rate in basis points (1 basis point = 0.01%) before last update
* @param currentRate Current interest rate in basis points
*
* @return Amount scaled by accrued interest as a string with appropriate decimal places
*/
export function amountToUiAmountWithoutSimulation(
amount: bigint,
decimals: number,
currentTimestamp: number, // in seconds
lastUpdateTimestamp: number,
initializationTimestamp: number,
preUpdateAverageRate: number,
currentRate: number,
): string {
// Calculate pre-update exponent
// e^(preUpdateAverageRate * (lastUpdateTimestamp - initializationTimestamp) / (SECONDS_PER_YEAR * ONE_IN_BASIS_POINTS))
const preUpdateExp = calculateExponentForTimesAndRate(
initializationTimestamp,
lastUpdateTimestamp,
preUpdateAverageRate,
);
// Calculate post-update exponent
// e^(currentRate * (currentTimestamp - lastUpdateTimestamp) / (SECONDS_PER_YEAR * ONE_IN_BASIS_POINTS))
const postUpdateExp = calculateExponentForTimesAndRate(lastUpdateTimestamp, currentTimestamp, currentRate);
// Calculate total scale
const totalScale = preUpdateExp * postUpdateExp;
// Scale the amount by the total interest factor
const scaledAmount = Number(amount) * totalScale;
// Calculate the decimal factor (e.g. 100 for 2 decimals)
const decimalFactor = Math.pow(10, decimals);
// Convert to UI amount by:
// 1. Truncating to remove any remaining decimals
// 2. Dividing by decimal factor to get final UI amount
// 3. Converting to string
return (Math.trunc(scaledAmount) / decimalFactor).toString();
}
/**
* Convert amount to UiAmount for a mint without simulating a transaction
* This implements the same logic as `process_amount_to_ui_amount` in /token/program-2022/src/processor.rs
* and `process_amount_to_ui_amount` in /token/program/src/processor.rs
*
* @param connection Connection to use
* @param mint Mint to use for calculations
* @param amount Amount of tokens to be converted to Ui Amount
*
* @return Ui Amount generated
*/
export async function amountToUiAmountForMintWithoutSimulation(
connection: Connection,
mint: PublicKey,
amount: bigint,
): Promise<string> {
const accountInfo = await connection.getAccountInfo(mint);
const programId = accountInfo?.owner;
if (programId !== TOKEN_PROGRAM_ID && programId !== TOKEN_2022_PROGRAM_ID) {
throw new Error('Invalid program ID');
}
const mintInfo = unpackMint(mint, accountInfo, programId);
const interestBearingMintConfigState = getInterestBearingMintConfigState(mintInfo);
if (!interestBearingMintConfigState) {
const amountNumber = Number(amount);
const decimalsFactor = Math.pow(10, mintInfo.decimals);
return (amountNumber / decimalsFactor).toString();
}
const timestamp = await getSysvarClockTimestamp(connection);
return amountToUiAmountWithoutSimulation(
amount,
mintInfo.decimals,
timestamp,
Number(interestBearingMintConfigState.lastUpdateTimestamp),
Number(interestBearingMintConfigState.initializationTimestamp),
interestBearingMintConfigState.preUpdateAverageRate,
interestBearingMintConfigState.currentRate,
);
}
/**
* Convert an amount with interest back to the original amount without interest
* This implements the same logic as the CPI instruction available in /token/program-2022/src/extension/interest_bearing_mint/mod.rs
*
* @param uiAmount UI Amount (principal plus continuously compounding interest) to be converted back to original principal
* @param decimals Number of decimals for the mint
* @param currentTimestamp Current timestamp in seconds
* @param lastUpdateTimestamp Last time the interest rate was updated in seconds
* @param initializationTimestamp Time the interest bearing extension was initialized in seconds
* @param preUpdateAverageRate Interest rate in basis points (hundredths of a percent) before the last update
* @param currentRate Current interest rate in basis points
*
* In general to calculate the principal from the UI amount, the formula is:
* P = A / (e^(r * t)) where
* P = principal
* A = UI amount
* r = annual interest rate (as a decimal, e.g., 5% = 0.05)
* t = time in years
*
* In this case, we are calculating the principal by dividing the UI amount by the total scale factor which is the product of two exponential functions:
* totalScale = e^(r1 * t1) * e^(r2 * t2)
* where r1 is the pre-update average rate, r2 is the current rate, t1 is the time in years between the initialization timestamp and the last update timestamp,
* and t2 is the time in years between the last update timestamp and the current timestamp.
* then to calculate the principal, we divide the UI amount by the total scale factor:
* P = A / totalScale
*
* @return Original amount (principal) without interest
*/
export function uiAmountToAmountWithoutSimulation(
uiAmount: string,
decimals: number,
currentTimestamp: number, // in seconds
lastUpdateTimestamp: number,
initializationTimestamp: number,
preUpdateAverageRate: number,
currentRate: number,
): bigint {
const uiAmountNumber = parseFloat(uiAmount);
const decimalsFactor = Math.pow(10, decimals);
const uiAmountScaled = uiAmountNumber * decimalsFactor;
// Calculate pre-update exponent
const preUpdateExp = calculateExponentForTimesAndRate(
initializationTimestamp,
lastUpdateTimestamp,
preUpdateAverageRate,
);
// Calculate post-update exponent
const postUpdateExp = calculateExponentForTimesAndRate(lastUpdateTimestamp, currentTimestamp, currentRate);
// Calculate total scale
const totalScale = preUpdateExp * postUpdateExp;
// Calculate original principal by dividing the UI amount (principal + interest) by the total scale
const originalPrincipal = uiAmountScaled / totalScale;
return BigInt(Math.trunc(originalPrincipal));
}
/**
* Convert a UI amount back to the raw amount
*
* @param connection Connection to use
* @param mint Mint to use for calculations
* @param uiAmount UI Amount to be converted back to raw amount
*
*
* @return Raw amount
*/
export async function uiAmountToAmountForMintWithoutSimulation(
connection: Connection,
mint: PublicKey,
uiAmount: string,
): Promise<bigint> {
const accountInfo = await connection.getAccountInfo(mint);
const programId = accountInfo?.owner;
if (programId !== TOKEN_PROGRAM_ID && programId !== TOKEN_2022_PROGRAM_ID) {
throw new Error('Invalid program ID');
}
const mintInfo = unpackMint(mint, accountInfo, programId);
const interestBearingMintConfigState = getInterestBearingMintConfigState(mintInfo);
if (!interestBearingMintConfigState) {
const uiAmountScaled = parseFloat(uiAmount) * Math.pow(10, mintInfo.decimals);
return BigInt(Math.trunc(uiAmountScaled));
}
const timestamp = await getSysvarClockTimestamp(connection);
return uiAmountToAmountWithoutSimulation(
uiAmount,
mintInfo.decimals,
timestamp,
Number(interestBearingMintConfigState.lastUpdateTimestamp),
Number(interestBearingMintConfigState.initializationTimestamp),
interestBearingMintConfigState.preUpdateAverageRate,
interestBearingMintConfigState.currentRate,
);
}