github.com/mysteriumnetwork/node@v0.0.0-20240516044423-365054f76801/money/money.go (about)

     1  /*
     2   * Copyright (C) 2017 The "MysteriumNetwork/node" Authors.
     3   *
     4   * This program is free software: you can redistribute it and/or modify
     5   * it under the terms of the GNU General Public License as published by
     6   * the Free Software Foundation, either version 3 of the License, or
     7   * (at your option) any later version.
     8   *
     9   * This program is distributed in the hope that it will be useful,
    10   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    11   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    12   * GNU General Public License for more details.
    13   *
    14   * You should have received a copy of the GNU General Public License
    15   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    16   */
    17  
    18  package money
    19  
    20  import (
    21  	"fmt"
    22  	"math/big"
    23  
    24  	"github.com/mysteriumnetwork/node/config"
    25  )
    26  
    27  // Money holds the currency type and amount
    28  type Money struct {
    29  	Amount   *big.Int `json:"amount,omitempty"`
    30  	Currency Currency `json:"currency,omitempty"`
    31  }
    32  
    33  // New returns a new instance of Money.
    34  // Expected `amount` value for 1 myst is equal to 1_000_000_000_000_000_000.
    35  // It also allows for an optional currency value to be passed,
    36  // if one is not passed, default config value is used.
    37  func New(amount *big.Int, currency ...Currency) Money {
    38  	m := Money{
    39  		Amount: amount,
    40  	}
    41  
    42  	if len(currency) > 0 {
    43  		m.Currency = currency[0]
    44  	} else {
    45  		m.Currency = Currency(config.GetString(config.FlagDefaultCurrency))
    46  	}
    47  
    48  	return m
    49  }
    50  
    51  // String converts Money struct into a string
    52  // which is represented by a float64 with 6 number precision.
    53  func (value Money) String() string {
    54  	amount := new(big.Float).SetInt(value.Amount)
    55  	size := new(big.Float).SetInt(MystSize)
    56  	val, _ := new(big.Float).Quo(amount, size).Float64()
    57  	return fmt.Sprintf(
    58  		"%.6f%s",
    59  		val,
    60  		value.Currency,
    61  	)
    62  }