fix: add draft of redemption contract from ccip-020

contracts/extensions/ccd012-redemtpion-mia.clar

@@ -0,0 +1,186 @@
+;; Title: CCD012 - CityCoin Redemption (MIA)
+;; Version: 1.0.0
+;; Summary: A redemption extension that allows users to redeem CityCoins for a portion of the city treasury.
+;; Description: An extension that provides the ability to claim a portion of the city treasury in exchange for CityCoins.
+
+;; TRAITS
+
+(impl-trait .extension-trait.extension-trait)
+
+;; CONSTANTS
+
+;; error codes
+(define-constant ERR_UNAUTHORIZED (err u12000))
+(define-constant ERR_PANIC (err u12001))
+(define-constant ERR_GETTING_TOTAL_SUPPLY (err u12002))
+(define-constant ERR_GETTING_REDEMPTION_BALANCE (err u12003))
+(define-constant ERR_ALREADY_ENABLED (err u12004))
+(define-constant ERR_NOT_ENABLED (err u12005))
+(define-constant ERR_BALANCE_NOT_FOUND (err u12006))
+(define-constant ERR_NOTHING_TO_REDEEM (err u12007))
+
+;; helpers
+(define-constant MICRO_CITYCOINS (pow u10 u6)) ;; 6 decimal places
+
+;; DATA VARS
+
+(define-data-var redemptionsEnabled bool false)
+(define-data-var blockHeight uint u0)
+(define-data-var totalSupply uint u0)
+(define-data-var contractBalance uint u0)
+(define-data-var redemptionRatio uint u0)
+
+;; DATA MAPS
+
+;; track totals per principal
+(define-map RedemptionClaims
+  principal ;; address
+  uint      ;; total redemption amount
+)
+
+;; PUBLIC FUNCTIONS
+
+(define-public (is-dao-or-extension)
+  (ok (asserts! (or (is-eq tx-sender .base-dao)
+    (contract-call? .base-dao is-extension contract-caller)) ERR_UNAUTHORIZED
+  ))
+)
+
+(define-public (callback (sender principal) (memo (buff 34)))
+  (ok true)
+)
+
+;; initialize contract after deployment to start redemptions
+(define-public (initialize-redemptions)
+  (let
+    (
+      ;; MAINNET: TODO
+      (miaTotalSupplyV1 (unwrap! (contract-call? .miamicoin-token get-total-supply) ERR_PANIC))
+      (miaTotalSupplyV2 (unwrap! (contract-call? .miamicoin-token-v2 get-total-supply) ERR_PANIC))
+      (miaTotalSupply (+ (* miaTotalSupplyV1 MICRO_CITYCOINS) miaTotalSupplyV2))
+      (miaRedemptionBalance (as-contract (stx-get-balance tx-sender)))
+    )
+    ;; check if sender is DAO or extension
+    (try! (is-dao-or-extension))
+    ;; check that total supply is greater than 0
+    (asserts! (and (> miaTotalSupplyV1 u0) (> miaTotalSupplyV2 u0)) ERR_GETTING_TOTAL_SUPPLY)
+    ;; check that redemption balance is greater than 0
+    (asserts! (> miaRedemptionBalance u0) ERR_GETTING_REDEMPTION_BALANCE)
+    ;; check if redemptions are already enabled
+    (asserts! (not (var-get redemptionsEnabled)) ERR_ALREADY_ENABLED)
+    ;; record current block height
+    (var-set blockHeight block-height)
+    ;; record total supply at block height
+    (var-set totalSupply miaTotalSupply)
+    ;; record contract balance at block height
+    (var-set contractBalance miaRedemptionBalance)
+    ;; calculate redemption ratio
+    (var-set redemptionRatio (/ miaRedemptionBalance miaTotalSupply))
+    ;; set redemptionsEnabled to true, can only run once
+    (ok (var-set redemptionsEnabled true))
+  )
+)
+
+(define-public (redeem-mia)
+  (let
+    (
+      (userAddress tx-sender)
+      (balanceV1 (unwrap! (contract-call? .miamicoin-token get-balance userAddress) ERR_BALANCE_NOT_FOUND))
+      (balanceV2 (unwrap! (contract-call? .miamicoin-token-v2 get-balance userAddress) ERR_BALANCE_NOT_FOUND))
+      (totalBalance (+ (* balanceV1 MICRO_CITYCOINS) balanceV2))
+      (redemptionAmount (unwrap! (get-redemption-for-balance totalBalance) ERR_NOTHING_TO_REDEEM))
+      (redemptionClaims (default-to u0 (get-redemption-amount-claimed userAddress)))
+    )
+    ;; check if redemptions are enabled
+    (asserts! (var-get redemptionsEnabled) ERR_NOT_ENABLED)
+    ;; check that redemption amount is > 0
+    (asserts! (> redemptionAmount u0) ERR_NOTHING_TO_REDEEM)
+    ;; burn MIA
+    (and (> u0 balanceV1) (try! (contract-call? .miamicoin-core-v1-patch burn-mia-v1 balanceV1 userAddress)))
+    (and (> u0 balanceV2) (try! (contract-call? .miamicoin-token-v2 burn balanceV2 userAddress)))
+    ;; transfer STX
+    (try! (as-contract (stx-transfer? redemptionAmount tx-sender userAddress)))
+    ;; update redemption claims
+    (map-set RedemptionClaims userAddress (+ redemptionClaims redemptionAmount))
+    ;; return redemption amount
+    (ok redemptionAmount)
+  )
+)
+
+;; READ ONLY FUNCTIONS
+
+(define-read-only (is-redemption-enabled)
+  (var-get redemptionsEnabled)
+)
+
+(define-read-only (get-redemption-block-height)
+  (var-get blockHeight)
+)
+
+(define-read-only (get-redemption-total-supply)
+  (var-get totalSupply)
+)
+
+(define-read-only (get-redemption-contract-balance)
+  (var-get contractBalance)
+)
+
+(define-read-only (get-redemption-ratio)
+  (var-get redemptionRatio)
+)
+
+;; aggregate all exposed vars above
+(define-read-only (get-redemption-info)
+  {
+    redemptionsEnabled: (var-get redemptionsEnabled),
+    blockHeight: (var-get blockHeight),
+    totalSupply: (var-get totalSupply),
+    contractBalance: (var-get contractBalance),
+    redemptionRatio: (var-get redemptionRatio)
+  }
+)
+
+(define-read-only (get-mia-balances)
+  (let
+    (
+      (balanceV1 (unwrap! (contract-call? .miamicoin-token get-balance tx-sender) ERR_BALANCE_NOT_FOUND))
+      (balanceV2 (unwrap! (contract-call? .miamicoin-token-v2 get-balance tx-sender) ERR_BALANCE_NOT_FOUND))
+      (totalBalance (+ (* balanceV1 MICRO_CITYCOINS) balanceV2))
+    )
+    (ok {
+      balanceV1: balanceV1,
+      balanceV2: balanceV2,
+      totalBalance: totalBalance
+    })
+  )
+)
+
+(define-read-only (get-redemption-for-balance (balance uint))
+  (begin
+    (asserts! (var-get redemptionsEnabled) none)
+    (some (* balance (var-get redemptionRatio)))
+  )
+)
+
+(define-read-only (get-redemption-amount-claimed (address principal))
+    (map-get? RedemptionClaims tx-sender)
+)
+
+;; aggregate all exposed vars above
+(define-read-only (get-user-redemption-info)
+  (let
+    (
+      (miaBalances (try! (get-mia-balances)))
+      (redemptionAmount (default-to u0 (get-redemption-for-balance (get totalBalance miaBalances))))
+      (redemptionClaims (default-to u0 (get-redemption-amount-claimed tx-sender)))
+    )
+    (ok {
+      address: tx-sender,
+      miaBalances: miaBalances,
+      redemptionAmount: redemptionAmount,
+      redemptionClaims: redemptionClaims
+    })
+  )
+)
+
+;; PRIVATE FUNCTIONS