package utils

import (
	"github.com/shopspring/decimal"
	"math/rand"
	"strconv"
)

// RandInt 生成 [min, max] 范围内的随机整数
func RandInt(min, max int) int {
	if min > max {
		min, max = max, min
	}
	return rand.Intn(max-min+1) + min
}

// StringToInt64 converts a string to int64, returns 0 if failed
func StringToInt64(s string) int64 {
	i, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		return 0
	}
	return i
}

// Int64ToString converts int64 to string
func Int64ToString(i int64) string {
	return strconv.FormatInt(i, 10)
}

// AddFloat64 对浮点数求和
func AddFloat64(places int32, number ...float64) float64 {
	if len(number) == 0 {
		return 0
	}
	result := decimal.NewFromFloat(0)
	for _, n := range number {
		result = result.Add(decimal.NewFromFloat(n))
	}
	return result.Round(places).InexactFloat64()
}

// SubFloat64 对浮点数求差
func SubFloat64(places int32, number ...float64) float64 {
	if len(number) == 0 {
		return 0
	}
	result := decimal.NewFromFloat(number[0])
	for i := 1; i < len(number); i++ {
		result = result.Sub(decimal.NewFromFloat(number[i]))
	}
	return result.Round(places).InexactFloat64()
}

// MulFloat64 对浮点数求积
func MulFloat64(places int32, number ...float64) float64 {
	if len(number) == 0 {
		return 0
	}
	result := decimal.NewFromFloat(1)
	for _, n := range number {
		result = result.Mul(decimal.NewFromFloat(n))
	}
	return result.Round(places).InexactFloat64()
}

// DivFloat64 对浮点数求商
func DivFloat64(places int32, number ...float64) float64 {
	if len(number) == 0 {
		return 0
	}
	result := decimal.NewFromFloat(number[0])
	for i := 1; i < len(number); i++ {
		if number[i] == 0 {
			return 0 // 避免除以零
		}
		result = result.Div(decimal.NewFromFloat(number[i]))
	}
	return result.Round(places).InexactFloat64()
}

// MaxInt32 返回两个 int32 中的较大值
func MaxInt32(a, b int32) int32 {
	if a > b {
		return a
	}
	return b
}

// MinInt32 返回两个 int32 中的较小值
func MinInt32(a, b int32) int32 {
	if a < b {
		return a
	}
	return b
}

// MaxFloat64 返回两个 float64 中的较大值
func MaxFloat64(a, b float64) float64 {
	if a > b {
		return a
	}
	return b
}

// MinFloat64 返回两个 float64 中的较小值
func MinFloat64(a, b float64) float64 {
	if a < b {
		return a
	}
	return b
}