;; @contract Stake Pool - Stake xUSD/USDA LP tokens
;; A fixed amount of rewards per block will be distributed across all stakers, according to their size in the pool
;; Rewards will be automatically staked before staking or unstaking.
;; The cumm reward per stake represents the rewards over time, taking into account total staking volume over time
;; When total stake changes, the cumm reward per stake is increased accordingly.
;; @version 1.1
;; (impl-trait .arkadiko-stake-pool-trait-v1.stake-pool-trait)
(use-trait ft-trait 'SP3K8BC0PPEVCV7NZ6QSRWPQ2JE9E5B6N3PA0KBR9.trait-semi-fungible.semi-fungible-trait)
(use-trait stake-registry-trait .arkadiko-stake-registry-trait-v1.stake-registry-trait)
;; Errors
(define-constant ERR-NOT-AUTHORIZED (err u18401))
(define-constant ERR-REWARDS-CALC (err u18001))
(define-constant ERR-WRONG-TOKEN (err u18002))
(define-constant ERR-INSUFFICIENT-STAKE (err u18003))
(define-constant ERR-WRONG-REGISTRY (err u18004))
(define-constant TOKEN-ID u1)
;; Variables
(define-data-var total-staked uint u0)
(define-data-var cumm-reward-per-stake uint u0)
(define-data-var last-reward-increase-block uint u0)
;; ---------------------------------------------------------
;; Stake Functions
;; ---------------------------------------------------------
;; Keep track of total amount staked and last cumm reward per stake
(define-map stakes
{ staker: principal }
{
uamount: uint, ;; micro diko amount staked
cumm-reward-per-stake: uint
}
)
(define-read-only (get-stake-of (staker principal))
(default-to
{ uamount: u0, cumm-reward-per-stake: u0 }
(map-get? stakes { staker: staker })
)
)
;; Get stake info - amount staked
(define-read-only (get-stake-amount-of (staker principal))
(get uamount (get-stake-of staker))
)
;; Get stake info - last rewards block
(define-read-only (get-stake-cumm-reward-per-stake-of (staker principal))
(get cumm-reward-per-stake (get-stake-of staker))
)
;; Get variable total-staked
(define-read-only (get-total-staked)
(var-get total-staked)
)
;; Get variable cumm-reward-per-stake
(define-read-only (get-cumm-reward-per-stake)
(var-get cumm-reward-per-stake)
)
;; Get variable last-reward-increase-block
(define-read-only (get-last-reward-increase-block)
(var-get last-reward-increase-block)
)
;; @desc stake tokens in the pool, used by stake-registry
;; @param registry-trait; current stake registry
;; @param token; token to stake
;; @param staker; user who wants to stake
;; @param amount; amount of tokens to stake
;; @post uint; returns amount of tokens staked
(define-public (stake (registry-trait <stake-registry-trait>) (token <ft-trait>) (staker principal) (amount uint))
(begin
;; Check given registry
(asserts! (is-eq (contract-of registry-trait) (unwrap-panic (contract-call? .arkadiko-dao get-qualified-name-by-name "stake-registry"))) ERR-WRONG-REGISTRY)
(asserts! (is-eq 'SP3K8BC0PPEVCV7NZ6QSRWPQ2JE9E5B6N3PA0KBR9.token-amm-swap-pool (contract-of token)) ERR-WRONG-TOKEN)
;; Save currrent cumm reward per stake
(unwrap-panic (increase-cumm-reward-per-stake registry-trait))
(let (
;; Calculate new stake amount
(stake-amount (get-stake-amount-of staker))
(new-stake-amount (+ stake-amount amount))
)
;; Claim all pending rewards for staker so we can set the new cumm-reward for this user
(try! (claim-pending-rewards registry-trait staker))
;; Update total stake
(var-set total-staked (+ (var-get total-staked) amount))
;; Update cumm reward per stake now that total is updated
(unwrap-panic (increase-cumm-reward-per-stake registry-trait))
;; Transfer LP token to this contract
(try! (contract-call? 'SP3K8BC0PPEVCV7NZ6QSRWPQ2JE9E5B6N3PA0KBR9.token-amm-swap-pool transfer TOKEN-ID amount staker (as-contract tx-sender)))
;; Update sender stake info
(map-set stakes { staker: staker } { uamount: new-stake-amount, cumm-reward-per-stake: (var-get cumm-reward-per-stake) })
(ok amount)
)
)
)
;; @desc unstake tokens in the pool, used by stake-registry
;; @param registry-trait; current stake registry
;; @param token; token to unstake
;; @param staker; user who wants to unstake
;; @param amount; amount of tokens to unstake
;; @post uint; returns amount of tokens unstaked
(define-public (unstake (registry-trait <stake-registry-trait>) (token <ft-trait>) (staker principal) (amount uint))
(let (
;; Staked amount of staker
(stake-amount (get-stake-amount-of staker))
)
;; Check given registry
(asserts! (is-eq (contract-of registry-trait) (unwrap-panic (contract-call? .arkadiko-dao get-qualified-name-by-name "stake-registry"))) ERR-WRONG-REGISTRY)
(asserts! (is-eq 'SP3K8BC0PPEVCV7NZ6QSRWPQ2JE9E5B6N3PA0KBR9.token-amm-swap-pool (contract-of token)) ERR-WRONG-TOKEN)
(asserts! (>= stake-amount amount) ERR-INSUFFICIENT-STAKE)
;; Save currrent cumm reward per stake
(unwrap-panic (increase-cumm-reward-per-stake registry-trait))
(let (
;; Calculate new stake amount
(new-stake-amount (- stake-amount amount))
)
;; Claim all pending rewards for staker so we can set the new cumm-reward for this user
(try! (claim-pending-rewards registry-trait staker))
;; Update total stake
(var-set total-staked (- (var-get total-staked) amount))
;; Update cumm reward per stake now that total is updated
(unwrap-panic (increase-cumm-reward-per-stake registry-trait))
;; Transfer LP token back from this contract to the user
(try! (as-contract (contract-call? 'SP3K8BC0PPEVCV7NZ6QSRWPQ2JE9E5B6N3PA0KBR9.token-amm-swap-pool transfer TOKEN-ID amount tx-sender staker)))
;; Update sender stake info
(map-set stakes { staker: staker } { uamount: new-stake-amount, cumm-reward-per-stake: (var-get cumm-reward-per-stake) })
(ok amount)
)
)
)
;; @desc unstake tokens without claiming rewards
;; @param registry-trait; current stake registry
;; @post uint; returns zero
(define-public (emergency-withdraw (registry-trait <stake-registry-trait>))
(begin
;; Check given registry
(asserts! (is-eq (contract-of registry-trait) (unwrap-panic (contract-call? .arkadiko-dao get-qualified-name-by-name "stake-registry"))) ERR-WRONG-REGISTRY)
;; Save currrent cumm reward per stake
(unwrap-panic (increase-cumm-reward-per-stake registry-trait))
(let (
(stake-amount (get-stake-amount-of tx-sender))
(new-stake-amount u0)
(staker tx-sender)
)
;; Update total stake
(var-set total-staked (- (var-get total-staked) stake-amount))
;; Update cumm reward per stake now that total is updated
(unwrap-panic (increase-cumm-reward-per-stake registry-trait))
;; Transfer LP token back from this contract to the user
(try! (as-contract (contract-call? 'SP3K8BC0PPEVCV7NZ6QSRWPQ2JE9E5B6N3PA0KBR9.token-amm-swap-pool transfer TOKEN-ID stake-amount tx-sender staker)))
;; Update sender stake info
(map-set stakes { staker: tx-sender } { uamount: new-stake-amount, cumm-reward-per-stake: (var-get cumm-reward-per-stake) })
(ok new-stake-amount)
)
)
)
;; @desc get amount of pending rewards for staker
;; @param registry-trait; current stake registry
;; @param staker; user to get pending rewards for
;; @post uint; returns pending rewards
(define-public (get-pending-rewards (registry-trait <stake-registry-trait>) (staker principal))
(let (
(stake-amount (get-stake-amount-of staker))
(amount-owed-per-token (- (unwrap-panic (calculate-cumm-reward-per-stake registry-trait)) (get-stake-cumm-reward-per-stake-of staker)))
(rewards-decimals (* stake-amount amount-owed-per-token))
(rewards (/ rewards-decimals u1000000))
)
(ok rewards)
)
)
;; @desc claim pending rewards for staker, used by stake-registry
;; @param registry-trait; current stake registry
;; @param staker; user to claim rewards for
;; @post uint; returns claimed rewards
(define-public (claim-pending-rewards (registry-trait <stake-registry-trait>) (staker principal))
(begin
;; Check given registry
(asserts! (is-eq (contract-of registry-trait) (unwrap-panic (contract-call? .arkadiko-dao get-qualified-name-by-name "stake-registry"))) ERR-WRONG-REGISTRY)
(unwrap-panic (increase-cumm-reward-per-stake registry-trait))
(let (
(pending-rewards (unwrap! (get-pending-rewards registry-trait staker) ERR-REWARDS-CALC))
(stake-of (get-stake-of staker))
)
;; Only mint if enough pending rewards and amount is positive
(if (>= pending-rewards u1)
(begin
;; Mint DIKO rewards for staker
(try! (contract-call? .arkadiko-dao mint-token .arkadiko-token pending-rewards staker))
(map-set stakes { staker: staker } (merge stake-of { cumm-reward-per-stake: (var-get cumm-reward-per-stake) }))
(ok pending-rewards)
)
(ok u0)
)
)
)
)
;; @desc increase cummulative rewards per stake and save
;; @param registry-trait; current stake registry
;; @post uint; returns saved cummulative rewards per stake
(define-public (increase-cumm-reward-per-stake (registry-trait <stake-registry-trait>))
(let (
;; Calculate new cumm reward per stake
(new-cumm-reward-per-stake (unwrap-panic (calculate-cumm-reward-per-stake registry-trait)))
(last-block-height (get-last-block-height registry-trait))
)
(asserts! (is-eq (contract-of registry-trait) (unwrap-panic (contract-call? .arkadiko-dao get-qualified-name-by-name "stake-registry"))) ERR-WRONG-REGISTRY)
(asserts! (> block-height (var-get last-reward-increase-block)) (ok u0))
(var-set cumm-reward-per-stake new-cumm-reward-per-stake)
(var-set last-reward-increase-block last-block-height)
(ok new-cumm-reward-per-stake)
)
)
;; @desc calculate current cumm reward per stake
;; @param registry-trait; current stake registry
;; @post uint; returns new cummulative rewards per stake
(define-public (calculate-cumm-reward-per-stake (registry-trait <stake-registry-trait>))
(let (
(rewards-per-block (unwrap-panic (contract-call? registry-trait get-rewards-per-block-for-pool .arkadiko-stake-pool-wstx-usda-v1-1)))
(current-total-staked (var-get total-staked))
(last-block-height (get-last-block-height registry-trait))
(block-diff (if (> last-block-height (var-get last-reward-increase-block))
(- last-block-height (var-get last-reward-increase-block))
u0
))
(current-cumm-reward-per-stake (var-get cumm-reward-per-stake))
)
(if (> current-total-staked u0)
(let (
(total-rewards-to-distribute (* rewards-per-block block-diff))
(reward-added-per-token (/ (* total-rewards-to-distribute u1000000) current-total-staked))
(new-cumm-reward-per-stake (+ current-cumm-reward-per-stake reward-added-per-token))
)
(ok new-cumm-reward-per-stake)
)
(ok current-cumm-reward-per-stake)
)
)
)
;; Helper for current-cumm-reward-per-stake
;; Return current block height, or block height when pool was deactivated
(define-private (get-last-block-height (registry-trait <stake-registry-trait>))
(let (
(deactivated-block (unwrap-panic (contract-call? registry-trait get-pool-deactivated-block .arkadiko-stake-pool-wstx-usda-v1-1)))
(pool-active (is-eq deactivated-block u0))
)
(if (is-eq pool-active true)
block-height
deactivated-block
)
)
)
;; Initialize the contract
(begin
(var-set last-reward-increase-block block-height)
)