add MultiversX chain (#44)

added MultiversX chain

implements part of #16 - MultiversX support

reworked PR #30

README.md

@@ -59,6 +59,7 @@ NOTE: You can get your API Key by signing up [here](https://www.validators.app/u
 18. [Sui](https://sui.io/)
 19. [Pulsechain](https://pulsechain.com/)
 20. [Celestia](https://celestia.org/)
+21. [MultiversX](https://multiversx.com/)
 
 ### Notes
 

core/chains/chain.go

@@ -24,6 +24,7 @@ const (
 	AVAX  Token = "AVAX"
 	BLD   Token = "BLD"
 	BNB   Token = "BNB"
+	EGLD  Token = "EGLD"
 	ETH2  Token = "ETH2"
 	GRT   Token = "GRT"
 	HBAR  Token = "HBAR"
@@ -52,6 +53,8 @@ func (t Token) ChainName() string {
 		return "Agoric"
 	case BNB:
 		return "Binance"
+	case EGLD:
+		return "MultiversX"
 	case ETH2:
 		return "Ethereum Proof-of-Stake"
 	case GRT:
@@ -87,7 +90,7 @@ func (t Token) ChainName() string {
 	}
 }
 
-var Tokens = []Token{ATOM, AVAX, BLD, BNB, ETH2, GRT, HBAR, JUNO, MATIC, MINA, NEAR, OSMO, PLS, REGEN, RUNE, SOL, STARS, SUI, TIA}
+var Tokens = []Token{ATOM, AVAX, BLD, BNB, EGLD, ETH2, GRT, HBAR, JUNO, MATIC, MINA, NEAR, OSMO, PLS, REGEN, RUNE, SOL, STARS, SUI, TIA}
 
 // NewState returns a new fresh state.
 func NewState() ChainState {
@@ -129,6 +132,8 @@ func newValues(token Token) (int, error) {
 		currVal, err = Agoric()
 	case BNB:
 		currVal, err = Binance()
+	case EGLD:
+		currVal, err = MultiversX()
 	case ETH2:
 		currVal, err = Eth2()
 	case GRT:

core/chains/multiversx.go

@@ -0,0 +1,112 @@
+package chains
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"sort"
+
+	"github.com/xenowits/nakamoto-coefficient-calculator/core/utils"
+)
+
+const totalValidatorsUrl = "https://api.multiversx.com/stake"
+const identitiesUrl = "https://api.multiversx.com/identities"
+
+type MultiversXTotalValidatorsResponse struct {
+	TotalValidators int64 `json:"totalValidators"`
+}
+
+type MultiversXIdentitiesResponse []struct {
+	Locked        string `json:"locked"`
+	NumValidators int64  `json:"validators"`
+}
+
+func MultiversX() (int, error) {
+	numValidatorsPerIdentity := make([]int64, 0)
+
+	totalNumberOfValidators, err := getTotalValidatorsNumber()
+	if err != nil {
+		return 0, err
+	}
+
+	identities, err := getIdentities()
+	if err != nil {
+		return 0, err
+	}
+
+	for _, identity := range identities {
+		if identity.Locked == "0" {
+			continue
+		}
+		numValidatorsPerIdentity = append(numValidatorsPerIdentity, identity.NumValidators)
+	}
+
+	sort.Slice(numValidatorsPerIdentity, func(i, j int) bool {
+		return numValidatorsPerIdentity[i] > numValidatorsPerIdentity[j]
+	})
+
+	fmt.Println("Total voting power:", totalNumberOfValidators)
+
+	// there is a fixed number of validator seats in MultiversX - currently 3200
+	// the Nakamoto coefficient can be computed by counting the identities (node operators)
+	// that control more than 33% of the total number of validators
+	nakamotoCoefficient := utils.CalcNakamotoCoefficient(totalNumberOfValidators, numValidatorsPerIdentity)
+	fmt.Println("The Nakamoto coefficient for MultiversX is", nakamotoCoefficient)
+
+	return nakamotoCoefficient, nil
+}
+
+func getTotalValidatorsNumber() (int64, error) {
+	resp, err := http.Get(totalValidatorsUrl)
+	if err != nil {
+		return 0, err
+	}
+
+	defer closeBody(resp)
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return 0, err
+	}
+
+	var response MultiversXTotalValidatorsResponse
+	err = json.Unmarshal(body, &response)
+	if err != nil {
+		return 0, err
+	}
+
+	return response.TotalValidators, nil
+}
+
+func getIdentities() (MultiversXIdentitiesResponse, error) {
+	resp, err := http.Get(identitiesUrl)
+	if err != nil {
+		return nil, err
+	}
+
+	defer closeBody(resp)
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	var response MultiversXIdentitiesResponse
+	err = json.Unmarshal(body, &response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+func closeBody(resp *http.Response) {
+	if resp == nil || resp.Body == nil {
+		return
+	}
+	if closeErr := resp.Body.Close(); closeErr != nil {
+		log.Printf("failed to close response body: %s", closeErr)
+	}
+}