(use-trait fungible-token 'SP3FBR2AGK5H9QBDH3EEN6DF8EK8JY7RX8QJ5SVTE.sip-010-trait-ft-standard.sip-010-trait)
;; the fee structure is defined by the calling client
(define-trait fees-trait
((get-fees (uint) (response uint uint))
(hold-fees (uint) (response bool uint))
(release-fees (uint) (response bool uint))
(pay-fees (uint) (response bool uint))))
(define-constant expiry u432)
(define-data-var next-id uint u0)
(define-map swaps
uint
{
invader-id: uint,
invader-sender: principal,
ft-amount: uint,
ft-sender: (optional principal),
when: uint,
open: bool,
ft: principal,
fees: principal
}
)
;; helper function to transfer invader from tx-sender to a principal with memo
(define-private (invader-transfer-to (invader-id uint) (to principal) (memo (buff 34)))
(begin
(try! (contract-call? 'SPV8C2N59MA417HYQNG6372GCV0SEQE01EV4Z1RQ.stacks-invaders-v0 transfer
invader-id tx-sender to))
(print memo)
(ok true)))
;; create a public neon INVADER FT
(define-public (offer (invader-id uint) (ft-amount uint) (ft-sender (optional principal)) (ft <fungible-token>) (fees <fees-trait>))
(let ((id (var-get next-id)))
(asserts! (map-insert swaps id
{invader-id: invader-id, invader-sender: tx-sender, ft-amount: ft-amount, ft-sender: ft-sender,
when: block-height, open: true, ft: (contract-of ft), fees: (contract-of fees)}) ERR_INVALID_ID)
(print
{
type: "offer",
ft-amount: ft-amount,
ft: (contract-of ft),
ft-decimals: (unwrap! (contract-call? ft get-decimals) ERR_FT_FAILURE),
invader-id: invader-id,
swap-id: id,
expiration: (+ block-height expiry),
}
)
(var-set next-id (+ id u1))
(try! (contract-call? fees hold-fees invader-id))
(match (invader-transfer-to invader-id (as-contract tx-sender) 0x636174616d6172616e2073776170)
success (ok id)
error (err (* error u100)))))
;; any user can cancle the swap after the expiry period
(define-public (cancel (id uint) (ft <fungible-token>) (fees <fees-trait>))
(let ((swap (unwrap! (map-get? swaps id) ERR_INVALID_ID))
(invader-id (get invader-id swap)))
(asserts! (is-eq (contract-of ft) (get ft swap)) ERR_INVALID_FUNGIBLE_TOKEN)
(asserts! (is-eq (contract-of fees) (get fees swap)) ERR_INVALID_FEES_TRAIT)
(asserts! (< (+ (get when swap) expiry) block-height) ERR_TOO_EARLY) ;; start + 100 < now anyone takes the worm
(asserts! (get open swap) ERR_ALREADY_DONE)
(asserts! (map-set swaps id (merge swap {open: false})) ERR_NATIVE_FAILURE)
(try! (contract-call? fees release-fees invader-id))
(print
{
type: "cancel",
ft-amount: (get ft-amount swap),
ft: (contract-of ft),
ft-decimals: (unwrap! (contract-call? ft get-decimals) ERR_FT_FAILURE),
invader-id: invader-id,
swap-id: id,
}
)
(match (as-contract (invader-transfer-to
invader-id (get invader-sender swap)
0x72657665727420636174616d6172616e2073776170))
success (ok success)
error (err (* error u100)))))
;; invader-sender can cancel the option before expiry
(define-public (revoke (id uint) (ft <fungible-token>) (fees <fees-trait>))
(let ((swap (unwrap! (map-get? swaps id) ERR_INVALID_ID))
(invader-id (get invader-id swap)))
(asserts! (is-eq (contract-of ft) (get ft swap)) ERR_INVALID_FUNGIBLE_TOKEN)
(asserts! (is-eq (contract-of fees) (get fees swap)) ERR_INVALID_FEES_TRAIT)
(asserts! (is-eq tx-sender (get invader-sender swap)) ERR_NOT_INVADER_SENDER)
(asserts! (get open swap) ERR_ALREADY_DONE)
(asserts! (map-set swaps id (merge swap {open: false})) ERR_NATIVE_FAILURE)
(try! (contract-call? fees release-fees invader-id))
(print
{
type: "revoke",
ft-amount: (get ft-amount swap),
ft: (contract-of ft),
ft-decimals: (unwrap! (contract-call? ft get-decimals) ERR_FT_FAILURE),
invader-id: invader-id,
swap-id: id,
}
)
(match (as-contract (invader-transfer-to
invader-id (get invader-sender swap)
0x72657665727420636174616d6172616e2073776170))
success (ok success)
error (err (* error u100)))))
;; any user can submit a tx that contains the swap
(define-public (swap-invader
(id uint)
(ft <fungible-token>)
(fees <fees-trait>))
(let ((swap (unwrap! (map-get? swaps id) ERR_INVALID_ID))
(invader-id (get invader-id swap))
(invader-receiver (default-to tx-sender (get ft-sender swap))))
(asserts! (get open swap) ERR_ALREADY_DONE)
(asserts! (is-eq (contract-of ft) (get ft swap)) ERR_INVALID_FUNGIBLE_TOKEN)
(asserts! (is-eq (contract-of fees) (get fees swap)) ERR_INVALID_FEES_TRAIT)
(asserts! (map-set swaps id (merge swap {open: false})) ERR_NATIVE_FAILURE)
(asserts! (is-eq tx-sender invader-receiver) ERR_INVALID_RECEIVER) ;; assert out if the receiver is predetermined
(try! (contract-call? fees pay-fees invader-id))
(print
{
type: "swap",
ft-amount: (get ft-amount swap),
ft: (contract-of ft),
ft-decimals: (unwrap! (contract-call? ft get-decimals) ERR_FT_FAILURE),
invader-id: invader-id,
swap-id: id,
}
)
(match (contract-call? ft transfer
(get ft-amount swap) invader-receiver (get invader-sender swap) (some 0x636174616d6172616e2073776170))
success-ft (begin
(asserts! success-ft ERR_NATIVE_FAILURE)
(match (as-contract (invader-transfer-to
(get invader-id swap) invader-receiver
0x636174616d6172616e2073776170))
success-stx (ok success-stx)
error-stx (err (* error-stx u100))))
error-ft (err (* error-ft u1000)))))
;; read-only function to get swap details by id
(define-read-only (get-swap (id uint))
(match (map-get? swaps id)
swap (ok swap)
(err ERR_INVALID_ID)))
(define-constant ERR_INVALID_ID (err u3))
(define-constant ERR_TOO_EARLY (err u4))
(define-constant ERR_ALREADY_DONE (err u7))
(define-constant ERR_INVALID_FUNGIBLE_TOKEN (err u8))
(define-constant ERR_INVALID_RECEIVER (err u9))
(define-constant ERR_INVALID_FEES (err u10))
(define-constant ERR_INVALID_FEES_TRAIT (err u11))
(define-constant ERR_NATIVE_FAILURE (err u99))
(define-constant ERR_NOT_INVADER_SENDER (err u12))
(define-constant ERR_FT_FAILURE (err u13))