Feat/adjust kandel (#142)

* feat: add adjust kandel

* chore: changeset

* chore: format

---------

Co-authored-by: maxencerb <[email protected]>

.changeset/healthy-ads-shake.md

@@ -0,0 +1,5 @@
+---
+"@mangrovedao/mgv": patch
+---
+
+Add adjust params for kandel

src/lib/kandel/params.ts

@@ -22,6 +22,7 @@ export type RawKandelPositionParams = {
   midPrice: number
   pricePoints: bigint
   market: MarketParams
+  adjust?: boolean | undefined
 }
 
 export type PositionKandelParams = {
@@ -31,22 +32,46 @@ export type PositionKandelParams = {
   pricePoints: bigint
 }
 
+function getTick(price: number, tickSpacing: bigint, adjust: boolean) {
+  const lowerTick = tickFromPrice(price, tickSpacing, false)
+  if (!adjust) return lowerTick
+  const upperTick = tickFromPrice(price, tickSpacing, true)
+
+  if (upperTick === lowerTick) return lowerTick
+
+  const lowerPrice = priceFromTick(lowerTick)
+  const upperPrice = priceFromTick(upperTick)
+
+  const lowerDiff = Math.abs(price - lowerPrice)
+  const upperDiff = Math.abs(price - upperPrice)
+
+  return lowerDiff < upperDiff ? lowerTick : upperTick
+}
+
 export function getKandelPositionRawParams(
   params: RawKandelPositionParams,
 ): PositionKandelParams {
   const { market, pricePoints } = params
-  const baseQuoteTickIndex0 = tickFromPrice(
-    humanPriceToRawPrice(params.minPrice, market),
+  const minPriceRaw = humanPriceToRawPrice(params.minPrice, market)
+  const midPriceRaw = humanPriceToRawPrice(params.midPrice, market)
+  const maxPriceRaw = humanPriceToRawPrice(params.maxPrice, market)
+
+  const baseQuoteTickIndex0 = getTick(
+    minPriceRaw,
     market.tickSpacing,
+    params.adjust ?? false,
   )
-  const midTick = tickFromPrice(
-    humanPriceToRawPrice(params.midPrice, market),
+  const midTick = getTick(
+    midPriceRaw,
     market.tickSpacing,
+    params.adjust ?? false,
   )
-  const maxTick = tickFromPrice(
-    humanPriceToRawPrice(params.maxPrice, market),
+  const maxTick = getTick(
+    maxPriceRaw,
     market.tickSpacing,
+    params.adjust ?? false,
   )
+
   let baseQuoteTickOffset =
     ((maxTick - baseQuoteTickIndex0) /
       (pricePoints - 1n) /

src/lib/tick.test.ts

@@ -3,6 +3,7 @@ import {
   MAX_SAFE_VOLUME,
   inboundFromOutbound,
   outboundFromInbound,
+  tickFromPrice,
   tickFromVolumes,
 } from './tick.js'
 
@@ -44,6 +45,12 @@ describe('ticks', () => {
     assertEq(tickFromVolumes(1000000n * 10n ** 18n, 999999n * 10n ** 18n), 0n)
   })
 
+  test('tickFromPrice', () => {
+    assertEq(tickFromPrice(1), 0n)
+    assertEq(tickFromPrice(1.0001), 1n)
+    assertEq(tickFromPrice(0.9998, 1n, true), -2n)
+  })
+
   test('outboundFromInbound and inboundFromOutbound', () => {
     testPrice(1n, 1n)
     testPrice(2n, 1n)

src/lib/tick.ts

@@ -31,10 +31,16 @@ export function tickInRange(tick: bigint): boolean {
  * Computes the tick value corresponding to the price of the asset.
  * @param price the price of the asset
  * @param tickSpacing the tick spacing of the market @default 1n
+ * @param roundUp round up the result @default false
  * @returns A Tick instance corresponding to the price of the asset.
  */
-export function tickFromPrice(price: number, tickSpacing = 1n): bigint {
-  const rawTick = BigInt(Math.floor(Math.log(price) / Math.log(1.0001)))
+export function tickFromPrice(
+  price: number,
+  tickSpacing = 1n,
+  roundUp = false,
+): bigint {
+  const roundMethod = roundUp ? Math.ceil : Math.floor
+  const rawTick = BigInt(roundMethod(Math.log(price) / Math.log(1.0001)))
   const bin = rawTick / tickSpacing + (rawTick % tickSpacing > 0n ? 1n : 0n)
   return bin * tickSpacing
 }