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use anchor_lang::prelude::*;
use anchor_spl::token_2022::TransferChecked;
use anchor_spl::token_interface;
use anchor_spl::token_interface::{Mint, TokenAccount, TokenInterface};
use crate::errors::*;
use crate::state::*;
#[derive(AnchorSerialize, AnchorDeserialize, Clone)]
pub struct SpendingLimitUseArgs {
/// Amount of tokens to transfer.
pub amount: u64,
/// Decimals of the token mint. Used for double-checking against incorrect order of magnitude of `amount`.
pub decimals: u8,
/// Memo used for indexing.
pub memo: Option<String>,
}
#[derive(Accounts)]
pub struct SpendingLimitUse<'info> {
/// The multisig account the `spending_limit` is for.
#[account(
seeds = [SEED_PREFIX, SEED_MULTISIG, multisig.create_key.as_ref()],
bump = multisig.bump,
)]
pub multisig: Box<Account<'info, Multisig>>,
pub member: Signer<'info>,
/// The SpendingLimit account to use.
#[account(
mut,
seeds = [
SEED_PREFIX,
multisig.key().as_ref(),
SEED_SPENDING_LIMIT,
spending_limit.create_key.key().as_ref(),
],
bump = spending_limit.bump,
)]
pub spending_limit: Account<'info, SpendingLimit>,
/// Multisig vault account to transfer tokens from.
/// CHECK: All the required checks are done by checking the seeds.
#[account(
mut,
seeds = [
SEED_PREFIX,
multisig.key().as_ref(),
SEED_VAULT,
&spending_limit.vault_index.to_le_bytes(),
],
bump
)]
pub vault: AccountInfo<'info>,
/// Destination account to transfer tokens to.
/// CHECK: We do the checks in `SpendingLimitUse::validate`.
#[account(mut)]
pub destination: AccountInfo<'info>,
/// In case `spending_limit.mint` is SOL.
pub system_program: Option<Program<'info, System>>,
/// The mint of the tokens to transfer in case `spending_limit.mint` is an SPL token.
/// CHECK: We do the checks in `SpendingLimitUse::validate`.
pub mint: Option<InterfaceAccount<'info, Mint>>,
/// Multisig vault token account to transfer tokens from in case `spending_limit.mint` is an SPL token.
#[account(
mut,
token::mint = mint,
token::authority = vault,
)]
pub vault_token_account: Option<InterfaceAccount<'info, TokenAccount>>,
/// Destination token account in case `spending_limit.mint` is an SPL token.
#[account(
mut,
token::mint = mint,
token::authority = destination,
)]
pub destination_token_account: Option<InterfaceAccount<'info, TokenAccount>>,
/// In case `spending_limit.mint` is an SPL token.
pub token_program: Option<Interface<'info, TokenInterface>>,
}
impl SpendingLimitUse<'_> {
fn validate(&self) -> Result<()> {
let Self {
multisig,
member,
spending_limit,
mint,
..
} = self;
// member
require!(
spending_limit.members.contains(&member.key()),
MultisigError::Unauthorized
);
// spending_limit - needs no checking.
// mint
if spending_limit.mint == Pubkey::default() {
// SpendingLimit is for SOL, there should be no mint account in this case.
require!(mint.is_none(), MultisigError::InvalidMint);
} else {
// SpendingLimit is for an SPL token, `mint` must match `spending_limit.mint`.
require!(
spending_limit.mint == mint.as_ref().unwrap().key(),
MultisigError::InvalidMint
);
}
// vault - checked in the #[account] attribute.
// vault_token_account - checked in the #[account] attribute.
// destination
if !spending_limit.destinations.is_empty() {
require!(
spending_limit
.destinations
.contains(&self.destination.key()),
MultisigError::InvalidDestination
);
}
// destination_token_account - checked in the #[account] attribute.
Ok(())
}
/// Use a spending limit to transfer tokens from a multisig vault to a destination account.
#[access_control(ctx.accounts.validate())]
pub fn spending_limit_use(ctx: Context<Self>, args: SpendingLimitUseArgs) -> Result<()> {
let spending_limit = &mut ctx.accounts.spending_limit;
let vault = &mut ctx.accounts.vault;
let destination = &mut ctx.accounts.destination;
let multisig_key = ctx.accounts.multisig.key();
let vault_bump = ctx.bumps.vault;
let now = Clock::get()?.unix_timestamp;
// Reset `spending_limit.remaining_amount` if the `spending_limit.period` has passed.
if let Some(reset_period) = spending_limit.period.to_seconds() {
let passed_since_last_reset = now.checked_sub(spending_limit.last_reset).unwrap();
if passed_since_last_reset > reset_period {
spending_limit.remaining_amount = spending_limit.amount;
let periods_passed = passed_since_last_reset.checked_div(reset_period).unwrap();
// last_reset = last_reset + periods_passed * reset_period,
spending_limit.last_reset = spending_limit
.last_reset
.checked_add(periods_passed.checked_mul(reset_period).unwrap())
.unwrap();
}
}
// Update `spending_limit.remaining_amount`.
// This will also check if `amount` doesn't exceed `spending_limit.remaining_amount`.
spending_limit.remaining_amount = spending_limit
.remaining_amount
.checked_sub(args.amount)
.ok_or(MultisigError::SpendingLimitExceeded)?;
// Transfer tokens.
if spending_limit.mint == Pubkey::default() {
// Transfer using the system_program::transfer.
let system_program = &ctx
.accounts
.system_program
.as_ref()
.ok_or(MultisigError::MissingAccount)?;
// Sanity check for the decimals. Similar to the one in token_interface::transfer_checked.
require!(args.decimals == 9, MultisigError::DecimalsMismatch);
anchor_lang::system_program::transfer(
CpiContext::new_with_signer(
system_program.to_account_info(),
anchor_lang::system_program::Transfer {
from: vault.clone(),
to: destination.clone(),
},
&[&[
SEED_PREFIX,
multisig_key.as_ref(),
SEED_VAULT,
&spending_limit.vault_index.to_le_bytes(),
&[vault_bump],
]],
),
args.amount,
)?
} else {
// Transfer using the token_program::transfer_checked.
let mint = &ctx
.accounts
.mint
.as_ref()
.ok_or(MultisigError::MissingAccount)?;
let vault_token_account = &ctx
.accounts
.vault_token_account
.as_ref()
.ok_or(MultisigError::MissingAccount)?;
let destination_token_account = &ctx
.accounts
.destination_token_account
.as_ref()
.ok_or(MultisigError::MissingAccount)?;
let token_program = &ctx
.accounts
.token_program
.as_ref()
.ok_or(MultisigError::MissingAccount)?;
msg!(
"token_program {} mint {} vault {} destination {} amount {} decimals {}",
&token_program.key,
&mint.key(),
&vault.key,
&destination.key,
&args.amount,
&args.decimals
);
token_interface::transfer_checked(
CpiContext::new_with_signer(
token_program.to_account_info(),
TransferChecked {
from: vault_token_account.to_account_info(),
mint: mint.to_account_info(),
to: destination_token_account.to_account_info(),
authority: vault.clone(),
},
&[&[
SEED_PREFIX,
multisig_key.as_ref(),
SEED_VAULT,
&spending_limit.vault_index.to_le_bytes(),
&[vault_bump],
]],
),
args.amount,
args.decimals,
)?;
}
Ok(())
}
}