;; STACKS DEX - Pool Contract V4 (Clarity 3)
;; Features: Bidirectional swaps, LP shares, add/remove liquidity
(use-trait ft-trait .sip-010-trait-ft-standard-v2-c4.sip-010-trait)
;; Fee configuration: 30 basis points = 0.30%
(define-constant FEE_BPS u30)
(define-constant BPS_DENOM u10000)
(define-constant MINIMUM_LIQUIDITY u1000)
;; Error codes
(define-constant ERR_ZERO_INPUT (err u100))
(define-constant ERR_ZERO_RESERVES (err u101))
(define-constant ERR_DEADLINE_EXPIRED (err u102))
(define-constant ERR_SLIPPAGE_EXCEEDED (err u103))
(define-constant ERR_INSUFFICIENT_LIQUIDITY (err u104))
(define-constant ERR_TRANSFER_X_FAILED (err u105))
(define-constant ERR_TRANSFER_Y_FAILED (err u106))
(define-constant ERR_FEE_TRANSFER_FAILED (err u107))
(define-constant ERR_ALREADY_INITIALIZED (err u200))
(define-constant ERR_NOT_INITIALIZED (err u201))
(define-constant ERR_INSUFFICIENT_LP_BALANCE (err u202))
(define-constant ERR_ZERO_SHARES (err u203))
(define-constant ERR_MIN_LIQUIDITY (err u204))
;; State variables
(define-data-var fee-recipient (optional principal) none)
(define-data-var reserve-x uint u0)
(define-data-var reserve-y uint u0)
(define-data-var total-supply uint u0)
(define-data-var total-fees-x uint u0)
(define-data-var total-fees-y uint u0)
;; LP share balances
(define-map lp-balances principal uint)
;; Read-only functions
(define-read-only (get-reserves)
{ x: (var-get reserve-x), y: (var-get reserve-y) })
(define-read-only (get-fee-info)
{ fee-bps: FEE_BPS, denom: BPS_DENOM, recipient: (var-get fee-recipient) })
(define-read-only (get-total-fees)
{ fees-x: (var-get total-fees-x), fees-y: (var-get total-fees-y) })
(define-read-only (get-total-supply)
(var-get total-supply))
(define-read-only (get-lp-balance (user principal))
(default-to u0 (map-get? lp-balances user)))
(define-read-only (get-pool-share (user principal))
(let ((balance (get-lp-balance user))
(supply (var-get total-supply)))
(if (is-eq supply u0)
u0
(/ (* balance u10000) supply))))
(define-read-only (get-user-liquidity (user principal))
(let ((balance (get-lp-balance user))
(supply (var-get total-supply))
(rx (var-get reserve-x))
(ry (var-get reserve-y)))
(if (or (is-eq supply u0) (is-eq balance u0))
{ x: u0, y: u0, shares: u0 }
{ x: (/ (* balance rx) supply),
y: (/ (* balance ry) supply),
shares: balance })))
(define-read-only (quote-x-for-y (dx uint))
(let ((rx (var-get reserve-x)) (ry (var-get reserve-y)))
(asserts! (> dx u0) ERR_ZERO_INPUT)
(asserts! (and (> rx u0) (> ry u0)) ERR_ZERO_RESERVES)
(let ((fee (/ (* dx FEE_BPS) BPS_DENOM))
(dx-to-pool (- dx fee))
(dy (/ (* ry dx-to-pool) (+ rx dx-to-pool))))
(asserts! (< dy ry) ERR_INSUFFICIENT_LIQUIDITY)
(ok { dy: dy, fee: fee }))))
(define-read-only (quote-y-for-x (dy uint))
(let ((rx (var-get reserve-x)) (ry (var-get reserve-y)))
(asserts! (> dy u0) ERR_ZERO_INPUT)
(asserts! (and (> rx u0) (> ry u0)) ERR_ZERO_RESERVES)
(let ((fee (/ (* dy FEE_BPS) BPS_DENOM))
(dy-to-pool (- dy fee))
(dx (/ (* rx dy-to-pool) (+ ry dy-to-pool))))
(asserts! (< dx rx) ERR_INSUFFICIENT_LIQUIDITY)
(ok { dx: dx, fee: fee }))))
(define-read-only (quote-add-liquidity (amount-x uint) (amount-y uint))
(let ((rx (var-get reserve-x))
(ry (var-get reserve-y))
(supply (var-get total-supply)))
(if (is-eq supply u0)
;; First deposit: shares = sqrt(x * y)
(ok { shares: (int-sqrt (* amount-x amount-y)), optimal-x: amount-x, optimal-y: amount-y })
;; Subsequent: calculate optimal amounts
(let ((shares-from-x (/ (* amount-x supply) rx))
(shares-from-y (/ (* amount-y supply) ry))
(shares (if (< shares-from-x shares-from-y) shares-from-x shares-from-y))
(optimal-x (/ (* shares rx) supply))
(optimal-y (/ (* shares ry) supply)))
(ok { shares: shares, optimal-x: optimal-x, optimal-y: optimal-y })))))
(define-read-only (quote-remove-liquidity (shares uint))
(let ((supply (var-get total-supply))
(rx (var-get reserve-x))
(ry (var-get reserve-y)))
(asserts! (> supply u0) ERR_NOT_INITIALIZED)
(asserts! (> shares u0) ERR_ZERO_INPUT)
(ok {
amount-x: (/ (* shares rx) supply),
amount-y: (/ (* shares ry) supply)
})))
;; Integer square root using Newton's method (non-recursive)
;; For simplicity, we use a formula that works for most cases
(define-read-only (int-sqrt (n uint))
(if (<= n u1)
n
(if (<= n u3)
u1
(let ((x0 (/ n u2)))
(let ((x1 (/ (+ x0 (/ n x0)) u2)))
(let ((x2 (/ (+ x1 (/ n x1)) u2)))
(let ((x3 (/ (+ x2 (/ n x2)) u2)))
(let ((x4 (/ (+ x3 (/ n x3)) u2)))
(let ((x5 (/ (+ x4 (/ n x4)) u2)))
(let ((x6 (/ (+ x5 (/ n x5)) u2)))
(let ((x7 (/ (+ x6 (/ n x6)) u2)))
(if (<= (* x7 x7) n) x7 (- x7 u1)))))))))))))
;; Swap X for Y (e.g., ALEX -> USDA)
(define-public (swap-x-for-y
(token-x <ft-trait>)
(token-y <ft-trait>)
(dx uint)
(min-dy uint)
(recipient principal)
(deadline uint))
(let ((rx (var-get reserve-x))
(ry (var-get reserve-y))
(sender tx-sender)
(fee-addr (unwrap! (var-get fee-recipient) ERR_NOT_INITIALIZED)))
(asserts! (<= stacks-block-height deadline) ERR_DEADLINE_EXPIRED)
(asserts! (> dx u0) ERR_ZERO_INPUT)
(asserts! (and (> rx u0) (> ry u0)) ERR_ZERO_RESERVES)
(let ((fee (/ (* dx FEE_BPS) BPS_DENOM))
(dx-to-pool (- dx fee))
(dy (/ (* ry dx-to-pool) (+ rx dx-to-pool))))
(asserts! (>= dy min-dy) ERR_SLIPPAGE_EXCEEDED)
(asserts! (< dy ry) ERR_INSUFFICIENT_LIQUIDITY)
(if (and (> fee u0) (not (is-eq sender fee-addr)))
(unwrap! (contract-call? token-x transfer fee sender fee-addr none) ERR_FEE_TRANSFER_FAILED)
true)
(unwrap! (contract-call? token-x transfer dx-to-pool sender (as-contract tx-sender) none) ERR_TRANSFER_X_FAILED)
(unwrap! (as-contract (contract-call? token-y transfer dy tx-sender recipient none)) ERR_TRANSFER_Y_FAILED)
(var-set reserve-x (+ rx dx-to-pool))
(var-set reserve-y (- ry dy))
(var-set total-fees-x (+ (var-get total-fees-x) fee))
(ok { dx: dx, dy: dy, fee: fee, recipient: recipient }))))
;; Swap Y for X (e.g., USDA -> ALEX)
(define-public (swap-y-for-x
(token-x <ft-trait>)
(token-y <ft-trait>)
(dy uint)
(min-dx uint)
(recipient principal)
(deadline uint))
(let ((rx (var-get reserve-x))
(ry (var-get reserve-y))
(sender tx-sender)
(fee-addr (unwrap! (var-get fee-recipient) ERR_NOT_INITIALIZED)))
(asserts! (<= stacks-block-height deadline) ERR_DEADLINE_EXPIRED)
(asserts! (> dy u0) ERR_ZERO_INPUT)
(asserts! (and (> rx u0) (> ry u0)) ERR_ZERO_RESERVES)
(let ((fee (/ (* dy FEE_BPS) BPS_DENOM))
(dy-to-pool (- dy fee))
(dx (/ (* rx dy-to-pool) (+ ry dy-to-pool))))
(asserts! (>= dx min-dx) ERR_SLIPPAGE_EXCEEDED)
(asserts! (< dx rx) ERR_INSUFFICIENT_LIQUIDITY)
(if (and (> fee u0) (not (is-eq sender fee-addr)))
(unwrap! (contract-call? token-y transfer fee sender fee-addr none) ERR_FEE_TRANSFER_FAILED)
true)
(unwrap! (contract-call? token-y transfer dy-to-pool sender (as-contract tx-sender) none) ERR_TRANSFER_Y_FAILED)
(unwrap! (as-contract (contract-call? token-x transfer dx tx-sender recipient none)) ERR_TRANSFER_X_FAILED)
(var-set reserve-x (- rx dx))
(var-set reserve-y (+ ry dy-to-pool))
(var-set total-fees-y (+ (var-get total-fees-y) fee))
(ok { dx: dx, dy: dy, fee: fee, recipient: recipient }))))
;; Initialize pool with initial liquidity (first LP)
(define-public (initialize-pool
(token-x <ft-trait>)
(token-y <ft-trait>)
(amount-x uint)
(amount-y uint))
(let ((sender tx-sender))
(asserts! (and (is-eq (var-get reserve-x) u0) (is-eq (var-get reserve-y) u0)) ERR_ALREADY_INITIALIZED)
(asserts! (and (> amount-x u0) (> amount-y u0)) ERR_ZERO_INPUT)
(let ((shares (int-sqrt (* amount-x amount-y))))
(asserts! (> shares MINIMUM_LIQUIDITY) ERR_MIN_LIQUIDITY)
(var-set fee-recipient (some sender))
(unwrap! (contract-call? token-x transfer amount-x sender (as-contract tx-sender) none) ERR_TRANSFER_X_FAILED)
(unwrap! (contract-call? token-y transfer amount-y sender (as-contract tx-sender) none) ERR_TRANSFER_Y_FAILED)
(var-set reserve-x amount-x)
(var-set reserve-y amount-y)
(var-set total-supply shares)
(map-set lp-balances sender shares)
(ok { shares: shares, x: amount-x, y: amount-y }))))
;; Add liquidity (subsequent LPs)
(define-public (add-liquidity
(token-x <ft-trait>)
(token-y <ft-trait>)
(amount-x uint)
(amount-y uint)
(min-shares uint))
(let ((rx (var-get reserve-x))
(ry (var-get reserve-y))
(supply (var-get total-supply))
(sender tx-sender))
(asserts! (> supply u0) ERR_NOT_INITIALIZED)
(asserts! (and (> amount-x u0) (> amount-y u0)) ERR_ZERO_INPUT)
;; Calculate shares based on minimum contribution
(let ((shares-from-x (/ (* amount-x supply) rx))
(shares-from-y (/ (* amount-y supply) ry))
(shares (if (< shares-from-x shares-from-y) shares-from-x shares-from-y))
;; Calculate actual amounts to deposit (proportional)
(actual-x (/ (* shares rx) supply))
(actual-y (/ (* shares ry) supply)))
(asserts! (>= shares min-shares) ERR_SLIPPAGE_EXCEEDED)
(asserts! (> shares u0) ERR_ZERO_SHARES)
;; Transfer tokens
(unwrap! (contract-call? token-x transfer actual-x sender (as-contract tx-sender) none) ERR_TRANSFER_X_FAILED)
(unwrap! (contract-call? token-y transfer actual-y sender (as-contract tx-sender) none) ERR_TRANSFER_Y_FAILED)
;; Update state
(var-set reserve-x (+ rx actual-x))
(var-set reserve-y (+ ry actual-y))
(var-set total-supply (+ supply shares))
(map-set lp-balances sender (+ (get-lp-balance sender) shares))
(ok { shares: shares, x: actual-x, y: actual-y }))))
;; Remove liquidity
(define-public (remove-liquidity
(token-x <ft-trait>)
(token-y <ft-trait>)
(shares uint)
(min-x uint)
(min-y uint))
(let ((rx (var-get reserve-x))
(ry (var-get reserve-y))
(supply (var-get total-supply))
(sender tx-sender)
(user-balance (get-lp-balance sender)))
(asserts! (> supply u0) ERR_NOT_INITIALIZED)
(asserts! (> shares u0) ERR_ZERO_INPUT)
(asserts! (>= user-balance shares) ERR_INSUFFICIENT_LP_BALANCE)
;; Calculate amounts to withdraw
(let ((amount-x (/ (* shares rx) supply))
(amount-y (/ (* shares ry) supply)))
(asserts! (>= amount-x min-x) ERR_SLIPPAGE_EXCEEDED)
(asserts! (>= amount-y min-y) ERR_SLIPPAGE_EXCEEDED)
;; Transfer tokens back
(unwrap! (as-contract (contract-call? token-x transfer amount-x tx-sender sender none)) ERR_TRANSFER_X_FAILED)
(unwrap! (as-contract (contract-call? token-y transfer amount-y tx-sender sender none)) ERR_TRANSFER_Y_FAILED)
;; Update state
(var-set reserve-x (- rx amount-x))
(var-set reserve-y (- ry amount-y))
(var-set total-supply (- supply shares))
(map-set lp-balances sender (- user-balance shares))
(ok { shares: shares, x: amount-x, y: amount-y }))))
;; Contract info
(define-read-only (get-contract-info)
{
name: "stacks-dex-pool-v4-c4",
version: "4.0.0",
fee-bps: FEE_BPS,
fee-recipient: (var-get fee-recipient),
reserve-x: (var-get reserve-x),
reserve-y: (var-get reserve-y),
total-supply: (var-get total-supply),
total-fees-x: (var-get total-fees-x),
total-fees-y: (var-get total-fees-y)
})