add backend service

Author: CoderZhi

.gitignore

@@ -1,6 +1,8 @@
 # Compiler files
 cache/
 out/
+artifacts/
+.deps/
 
 # Ignores development broadcast logs
 !/broadcast

backend/Dockerfile

@@ -0,0 +1,15 @@
+FROM golang:1.24-alpine AS builder
+RUN apk add --no-cache git
+WORKDIR /app
+COPY go.mod go.sum ./
+RUN go mod download
+COPY . .
+RUN go build -o server main.go
+
+FROM alpine:3.18
+RUN apk add --no-cache ca-certificates
+WORKDIR /app
+COPY --from=builder /app/server .
+EXPOSE 8080
+
+CMD ["./server"]

backend/README.md

@@ -0,0 +1,19 @@
+# build docker image
+`docker build . -t nubila-service`
+
+# start service
+Assume $RPC_URL is the RPC of the blockchain where the contracts are deployed to
+## without vesting manager contract
+Before deploying vesting manager contract, the total supply is the initial supply, 1_000_000_000, and the circulating amount is 0.
+`docker run -p 8080:8080 -e RPC_URL="$RPC_URL" nubila-service`
+
+## with vesting manager contract
+Once we have the vesting manager contract deployed, the service is started as follows:
+`docker run -p 8080:8080 -e MANAGER_ADDRESS="$MANAGER_ADDR" -e RPC_URL="$RPC_URL" nubila-service`
+
+# Query
+## total supply
+localhost:8080/total
+
+## circulating
+localhost:8080/circulating

backend/contract/IERC20.go

@@ -0,0 +1,63 @@
+module github.com/CoderZhi/nubila-token/backend
+
+go 1.24.0
+
+toolchain go1.24.9
+
+require (
+	github.com/ethereum/go-ethereum v1.16.3
+	github.com/gin-gonic/gin v1.11.0
+)
+
+require (
+	github.com/Microsoft/go-winio v0.6.2 // indirect
+	github.com/StackExchange/wmi v1.2.1 // indirect
+	github.com/bits-and-blooms/bitset v1.20.0 // indirect
+	github.com/bytedance/sonic v1.14.0 // indirect
+	github.com/bytedance/sonic/loader v0.3.0 // indirect
+	github.com/cloudwego/base64x v0.1.6 // indirect
+	github.com/consensys/gnark-crypto v0.18.0 // indirect
+	github.com/crate-crypto/go-eth-kzg v1.4.0 // indirect
+	github.com/crate-crypto/go-ipa v0.0.0-20240724233137-53bbb0ceb27a // indirect
+	github.com/deckarep/golang-set/v2 v2.6.0 // indirect
+	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 // indirect
+	github.com/ethereum/c-kzg-4844/v2 v2.1.3 // indirect
+	github.com/ethereum/go-verkle v0.2.2 // indirect
+	github.com/fsnotify/fsnotify v1.6.0 // indirect
+	github.com/gabriel-vasile/mimetype v1.4.8 // indirect
+	github.com/gin-contrib/sse v1.1.0 // indirect
+	github.com/go-ole/go-ole v1.3.0 // indirect
+	github.com/go-playground/locales v0.14.1 // indirect
+	github.com/go-playground/universal-translator v0.18.1 // indirect
+	github.com/go-playground/validator/v10 v10.27.0 // indirect
+	github.com/goccy/go-json v0.10.4 // indirect
+	github.com/goccy/go-yaml v1.18.0 // indirect
+	github.com/google/uuid v1.3.0 // indirect
+	github.com/gorilla/websocket v1.4.2 // indirect
+	github.com/holiman/uint256 v1.3.2 // indirect
+	github.com/json-iterator/go v1.1.12 // indirect
+	github.com/klauspost/cpuid/v2 v2.3.0 // indirect
+	github.com/leodido/go-urn v1.4.0 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421 // indirect
+	github.com/modern-go/reflect2 v1.0.2 // indirect
+	github.com/pelletier/go-toml/v2 v2.2.4 // indirect
+	github.com/quic-go/qpack v0.5.1 // indirect
+	github.com/quic-go/quic-go v0.54.0 // indirect
+	github.com/shirou/gopsutil v3.21.4-0.20210419000835-c7a38de76ee5+incompatible // indirect
+	github.com/supranational/blst v0.3.16-0.20250831170142-f48500c1fdbe // indirect
+	github.com/tklauser/go-sysconf v0.3.12 // indirect
+	github.com/tklauser/numcpus v0.6.1 // indirect
+	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
+	github.com/ugorji/go/codec v1.3.0 // indirect
+	go.uber.org/mock v0.5.0 // indirect
+	golang.org/x/arch v0.20.0 // indirect
+	golang.org/x/crypto v0.40.0 // indirect
+	golang.org/x/mod v0.25.0 // indirect
+	golang.org/x/net v0.42.0 // indirect
+	golang.org/x/sync v0.16.0 // indirect
+	golang.org/x/sys v0.36.0 // indirect
+	golang.org/x/text v0.27.0 // indirect
+	golang.org/x/tools v0.34.0 // indirect
+	google.golang.org/protobuf v1.36.9 // indirect
+)

backend/contract/VestingManager.go

@@ -0,0 +1,99 @@
+package main
+
+import (
+	"math/big"
+	"os"
+	"time"
+
+	"github.com/CoderZhi/nubila-token/backend/contract"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/gin-gonic/gin"
+)
+
+func main() {
+	rpc := os.Getenv("RPC_URL")
+	addr := os.Getenv("MANAGER_ADDRESS")
+	client, err := ethclient.Dial(rpc)
+	if err != nil {
+		panic(err)
+	}
+	var token *contract.IERC20
+	if addr != "" {
+		manager, err := contract.NewVestingManager(common.HexToAddress(addr), client)
+		if err != nil {
+			panic(err)
+		}
+		tokenAddr, err := manager.Token(nil)
+		if err != nil {
+			panic(err)
+		}
+		token, err = contract.NewIERC20(tokenAddr, client)
+		if err != nil {
+			panic(err)
+		}
+	}
+	var (
+		initSupply    = big.NewFloat(1_000_000_000)
+		decimal       = big.NewFloat(1e18)
+		totalSupply   *big.Float
+		withheld      *big.Float
+		totalSupplyTs time.Time
+		withheldTs    time.Time
+	)
+	getTotalSupply := func() (*big.Float, error) {
+		if token == nil {
+			return initSupply, nil
+		}
+		if time.Since(totalSupplyTs) < time.Minute && totalSupply != nil {
+			return totalSupply, nil
+		}
+		supply, err := token.TotalSupply(nil)
+		if err != nil {
+			return nil, err
+		}
+		totalSupply = new(big.Float).Quo(new(big.Float).SetInt(supply), decimal)
+		totalSupplyTs = time.Now()
+		return totalSupply, nil
+	}
+	getWithheld := func() (*big.Float, error) {
+		if token == nil {
+			return initSupply, nil
+		}
+		if time.Since(withheldTs) < time.Minute && withheld != nil {
+			return withheld, nil
+		}
+		balance, err := token.BalanceOf(nil, common.HexToAddress(addr))
+		if err != nil {
+			return nil, err
+		}
+		withheld = new(big.Float).Quo(new(big.Float).SetInt(balance), decimal)
+		withheldTs = time.Now()
+		return withheld, nil
+	}
+
+	r := gin.Default()
+
+	r.GET("/total", func(c *gin.Context) {
+		total, err := getTotalSupply()
+		if err != nil {
+			c.JSON(500, gin.H{"error": err.Error()})
+			return
+		}
+		c.String(200, total.Text('f', 18))
+	})
+	r.GET("/circulating", func(c *gin.Context) {
+		total, err := getTotalSupply()
+		if err != nil {
+			c.JSON(500, gin.H{"error": err.Error()})
+			return
+		}
+		withheld, err := getWithheld()
+		if err != nil {
+			c.JSON(500, gin.H{"error": err.Error()})
+			return
+		}
+		c.String(200, new(big.Float).Sub(total, withheld).Text('f', 18))
+	})
+	r.Run(":8080")
+}