;; @contract DIKO Guardian - Get total staking and vault rewards per block
;; @version 2.1
;; Errors
(define-constant ERR-NOT-AUTHORIZED (err u22401))
;; Constants
(define-constant MIN-STAKING-BLOCK-REWARDS u28000000) ;; 28 DIKO
(define-constant STAKING-REWARDS-FIRST-YEAR u25000000000000) ;; 25m with 6 decimals
(define-constant REWARDS-PER-BLOCK-START u320000000) ;;
;; Variables
;; First version of diko-guardian was deployed on Bitcoin block 705573 (Stacks block 34239)
;; https://explorer.hiro.so/txid/0xe8309941311ab8a40b9e1d6ad50a6f59f52e5b4ea4f2441d8ddeecceffbf7406?chain=mainnet
(define-data-var contract-start-block uint u705573)
;; ---------------------------------------------------------
;; Staking
;; ---------------------------------------------------------
;; Get currrent staking rewards per block for all pools
;; The yearly rewards are reduced by half every year
;; During the year, the rewards are reduced every 2 weeks
(define-read-only (get-staking-rewards-per-block)
(let (
;; 26 steps per year (2 week interval)
(steps-per-year u26)
;; 144 blocks per day, 14 days
(blocks-per-step u2016)
(start-block (var-get contract-start-block))
)
(asserts! (>= burn-block-height start-block) u0)
(let (
;; each step is equal to 2 weeks. This calculates the current step we are in, since the start
(step-number (/ (- burn-block-height start-block) blocks-per-step))
;; year we are currently in since start
(year-number (+ (/ step-number steps-per-year) u1))
;; step number in the curent year (instead of since start)
(step-number-current-year (mod step-number steps-per-year))
;; rewards are halved every year because of this devider (1, 2, 4, 8, 16)
(staking-rewards-divider (pow u2 (- year-number u1)))
;; the total rewards to distribute in the current year
(year-rewards (/ STAKING-REWARDS-FIRST-YEAR staking-rewards-divider))
;; avg rewards per step (2 weeks)
(avg-rewards-per-step (/ year-rewards steps-per-year))
;; max-percentage = 1.33333, min-percentage = 0.666666
;; used to linearly decrease rewards per step in a given year
(max-percentage (+ u10000000000 (/ u10000000000 u3)))
(min-percentage (- u10000000000 (/ u10000000000 u3)))
(step-percentage-diff (/ (- max-percentage min-percentage) steps-per-year))
;; based on the avg rewards per step, and the percentages
(actual-step-rewards (* avg-rewards-per-step (- max-percentage (* step-number-current-year step-percentage-diff))))
;; block rewarrds based on step rewards
(actual-block-rewards (/ (/ actual-step-rewards blocks-per-step) u10000000000))
;; Extra multiplier of 98.5% - makes sure we remain below our targets
(block-rewards (/ (* actual-block-rewards u9850000000) u10000000000))
)
;; Min 28 DIKO
(if (>= block-rewards MIN-STAKING-BLOCK-REWARDS)
block-rewards
MIN-STAKING-BLOCK-REWARDS
)
)
)
)