package uniswap

import (
	"math/big"
	"sync"
)

var (
	// Cached constants to avoid recomputing them
	q96  *big.Int
	q192 *big.Int
	once sync.Once
)

// initConstants initializes the cached constants
func initConstants() {
	once.Do(func() {
		q96 = new(big.Int).Exp(big.NewInt(2), big.NewInt(96), nil)
		q192 = new(big.Int).Exp(big.NewInt(2), big.NewInt(192), nil)
	})
}

// SqrtPriceX96ToPriceCached converts sqrtPriceX96 to a price using cached constants
func SqrtPriceX96ToPriceCached(sqrtPriceX96 *big.Int) *big.Float {
	// Initialize cached constants
	initConstants()

	// price = (sqrtPriceX96 / 2^96)^2
	// price = sqrtPriceX96^2 / 2^192

	// Convert to big.Float for precision
	sqrtPrice := new(big.Float).SetInt(sqrtPriceX96)

	// Calculate sqrtPrice^2
	price := new(big.Float).Mul(sqrtPrice, sqrtPrice)

	// Divide by 2^192 using cached constant
	q192Float := new(big.Float).SetInt(q192)
	price.Quo(price, q192Float)

	return price
}

// PriceToSqrtPriceX96Cached converts a price to sqrtPriceX96 using cached constants
func PriceToSqrtPriceX96Cached(price *big.Float) *big.Int {
	// Initialize cached constants
	initConstants()

	// sqrtPriceX96 = sqrt(price) * 2^96

	// Calculate sqrt(price)
	sqrtPrice := new(big.Float).Sqrt(price)

	// Multiply by 2^96 using cached constant
	q96Float := new(big.Float).SetInt(q96)
	sqrtPrice.Mul(sqrtPrice, q96Float)

	// Convert to big.Int
	sqrtPriceX96 := new(big.Int)
	sqrtPrice.Int(sqrtPriceX96)

	return sqrtPriceX96
}