Convert wallet to ledger with sms validation

.github/workflows/ci.yml

@@ -0,0 +1,27 @@
+name: CI
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+jobs:
+  flutter:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: subosito/flutter-action@v2
+        with:
+          channel: stable
+      - run: flutter --version
+      - run: flutter pub get
+        working-directory: android-client
+      - run: flutter test
+        working-directory: android-client
+  go:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-go@v5
+        with:
+          go-version: '1.22'
+      - run: go test ./...
+        working-directory: wallet-plugin-go

README.md

@@ -1,16 +1,4 @@
-# opencongopay
+# Decentralized Payments
 
-A new Flutter project.
-
-## Getting Started
-
-This project is a starting point for a Flutter application.
-
-A few resources to get you started if this is your first Flutter project:
-
-- [Lab: Write your first Flutter app](https://docs.flutter.dev/get-started/codelab)
-- [Cookbook: Useful Flutter samples](https://docs.flutter.dev/cookbook)
-
-For help getting started with Flutter development, view the
-[online documentation](https://docs.flutter.dev/), which offers tutorials,
-samples, guidance on mobile development, and a full API reference.
+Ce monorepo regroupe l'application Flutter et le backend wallet en Go.
+Le plugin `walletd` expose des APIs REST pour crediter un compte via les SMS Mobile Money.

android-client/README.md

@@ -0,0 +1,16 @@
+# opencongopay
+
+A new Flutter project.
+
+## Getting Started
+
+This project is a starting point for a Flutter application.
+
+A few resources to get you started if this is your first Flutter project:
+
+- [Lab: Write your first Flutter app](https://docs.flutter.dev/get-started/codelab)
+- [Cookbook: Useful Flutter samples](https://docs.flutter.dev/cookbook)
+
+For help getting started with Flutter development, view the
+[online documentation](https://docs.flutter.dev/), which offers tutorials,
+samples, guidance on mobile development, and a full API reference.

docs/en/README.md

@@ -0,0 +1 @@
+English docs coming soon

docs/fr/contrat-api.yaml

@@ -0,0 +1,58 @@
+openapi: 3.1.0
+info:
+  title: API Wallet
+  version: "1.0"
+paths:
+  /api/credits:
+    post:
+      summary: Crediter un numero
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                phone:
+                  type: string
+                amount:
+                  type: integer
+                timestamp:
+                  type: string
+                raw_sms:
+                  type: string
+      responses:
+        '200':
+          description: OK
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  id:
+                    type: integer
+  /wallet/{phone}:
+    get:
+      summary: Obtenir le solde
+      parameters:
+        - in: path
+          name: phone
+          required: true
+          schema:
+            type: string
+      responses:
+        '200':
+          description: OK
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  balance:
+                    type: integer
+  /healthz:
+    get:
+      summary: Sante du service
+      responses:
+        '200':
+          description: OK

docs/fr/installation-android.md

@@ -0,0 +1,3 @@
+# Installation Android
+
+Decrivez comment installer l'application Flutter.

docs/fr/installation-server.md

@@ -0,0 +1,3 @@
+# Installation du serveur
+
+Guide pour deployer walletd via Docker.

docs/fr/parsers.md

@@ -0,0 +1,3 @@
+# Formats SMS Operateurs
+
+Liste des regex pour parser les SMS.

wallet-plugin-go/cmd/server/main.go

@@ -0,0 +1,62 @@
+package main
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+	"time"
+
+	"github.com/go-chi/chi/v5"
+	_ "github.com/mattn/go-sqlite3"
+
+	"github.com/example/wallet-plugin-go/internal/wallet"
+)
+
+func main() {
+	store, err := wallet.NewStore("wallet.db")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	r := chi.NewRouter()
+	r.Post("/api/credits", func(w http.ResponseWriter, r *http.Request) {
+		var body struct {
+			Phone     string    `json:"phone"`
+			Amount    int64     `json:"amount"`
+			Timestamp time.Time `json:"timestamp"`
+			RawSMS    string    `json:"raw_sms"`
+		}
+		if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+			w.WriteHeader(http.StatusBadRequest)
+			return
+		}
+		id, err := store.AddCredit(wallet.Transaction{
+			Phone:     body.Phone,
+			Amount:    body.Amount,
+			RawSMS:    body.RawSMS,
+			Timestamp: body.Timestamp,
+		})
+		if err != nil {
+			w.WriteHeader(http.StatusBadRequest)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]any{"id": id})
+	})
+	r.Get("/wallet/{phone}", func(w http.ResponseWriter, r *http.Request) {
+		phone := chi.URLParam(r, "phone")
+		bal, err := store.Balance(phone)
+		if err != nil {
+			w.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]any{"balance": bal})
+	})
+	r.Get("/healthz", func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+	})
+
+	log.Println("listening on :8080")
+	http.ListenAndServe(":8080", r)
+}

wallet-plugin-go/go.mod

@@ -0,0 +1,8 @@
+module github.com/example/wallet-plugin-go
+
+go 1.22
+
+require (
+	github.com/go-chi/chi/v5 v5.0.8
+	github.com/mattn/go-sqlite3 v1.14.18
+)

wallet-plugin-go/go.sum

@@ -0,0 +1,4 @@
+github.com/go-chi/chi/v5 v5.0.8 h1:lD+NLqFcAi1ovnVZpsnObHGW4xb4J8lNmoYVfECH1Y0=
+github.com/go-chi/chi/v5 v5.0.8/go.mod h1:DslCQbL2OYiznFReuXYUmQ2hGd1aDpCnlMNITLSKoi8=
+github.com/mattn/go-sqlite3 v1.14.18 h1:JL0eqdCOq6DJVNPSvArO/bIV9/P7fbGrV00LZHc+5aI=
+github.com/mattn/go-sqlite3 v1.14.18/go.mod h1:2eHXhiwb8IkHr+BDWZGa96P6+rkvnG63S2DGjv9HUNg=

wallet-plugin-go/internal/wallet/store.go

@@ -0,0 +1,96 @@
+package wallet
+
+import (
+	"database/sql"
+	"errors"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+type Store struct {
+	db *sql.DB
+}
+
+type Transaction struct {
+	ID        int64
+	Phone     string
+	Amount    int64
+	RawSMS    string
+	Timestamp time.Time
+}
+
+var amountRx = regexp.MustCompile(`([0-9]+)`)
+
+func NewStore(path string) (*Store, error) {
+	db, err := sql.Open("sqlite3", path)
+	if err != nil {
+		return nil, err
+	}
+	if _, err := db.Exec(`CREATE TABLE IF NOT EXISTS transactions(
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        phone TEXT NOT NULL,
+        amount INTEGER NOT NULL,
+        raw_sms TEXT NOT NULL,
+        ts DATETIME NOT NULL
+    )`); err != nil {
+		return nil, err
+	}
+	return &Store{db: db}, nil
+}
+
+func parseAmount(raw string) (int64, error) {
+	match := amountRx.FindString(raw)
+	if match == "" {
+		return 0, errors.New("amount not found")
+	}
+	return strconv.ParseInt(match, 10, 64)
+}
+
+func (s *Store) AddCredit(txn Transaction) (int64, error) {
+	if txn.Phone == "" || txn.Amount <= 0 || txn.RawSMS == "" {
+		return 0, errors.New("invalid transaction")
+	}
+
+	parsed, err := parseAmount(strings.ReplaceAll(txn.RawSMS, " ", ""))
+	if err != nil {
+		return 0, err
+	}
+	if parsed != txn.Amount {
+		return 0, errors.New("amount mismatch")
+	}
+
+	res, err := s.db.Exec(`INSERT INTO transactions(phone,amount,raw_sms,ts) VALUES(?,?,?,?)`,
+		txn.Phone, txn.Amount, txn.RawSMS, txn.Timestamp)
+	if err != nil {
+		return 0, err
+	}
+	return res.LastInsertId()
+}
+
+func (s *Store) Balance(phone string) (int64, error) {
+	var bal sql.NullInt64
+	err := s.db.QueryRow(`SELECT COALESCE(SUM(amount),0) FROM transactions WHERE phone=?`, phone).Scan(&bal)
+	if err != nil {
+		return 0, err
+	}
+	if !bal.Valid {
+		return 0, nil
+	}
+	return bal.Int64, nil
+}
+
+func (s *Store) LastTransaction(phone string) (*Transaction, error) {
+	row := s.db.QueryRow(`SELECT id, phone, amount, raw_sms, ts FROM transactions WHERE phone=? ORDER BY id DESC LIMIT 1`, phone)
+	var t Transaction
+	if err := row.Scan(&t.ID, &t.Phone, &t.Amount, &t.RawSMS, &t.Timestamp); err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, nil
+		}
+		return nil, err
+	}
+	return &t, nil
+}

wallet-plugin-go/internal/wallet/store_test.go

@@ -0,0 +1,50 @@
+package wallet
+
+import (
+	"path/filepath"
+	"testing"
+	"time"
+)
+
+func TestAddCreditAndBalance(t *testing.T) {
+	dir := t.TempDir()
+	store, err := NewStore(filepath.Join(dir, "test.db"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	sms := "Transfert de 2000 CDF"
+	txn := Transaction{Phone: "+243810000111", Amount: 2000, RawSMS: sms, Timestamp: time.Now()}
+	if _, err := store.AddCredit(txn); err != nil {
+		t.Fatalf("add credit: %v", err)
+	}
+
+	bal, err := store.Balance(txn.Phone)
+	if err != nil {
+		t.Fatalf("balance: %v", err)
+	}
+	if bal != 2000 {
+		t.Fatalf("got balance %d", bal)
+	}
+
+	last, err := store.LastTransaction(txn.Phone)
+	if err != nil {
+		t.Fatalf("last tx: %v", err)
+	}
+	if last == nil || last.Amount != 2000 {
+		t.Fatalf("unexpected last tx: %#v", last)
+	}
+}
+
+func TestAmountMismatch(t *testing.T) {
+	dir := t.TempDir()
+	store, err := NewStore(filepath.Join(dir, "test.db"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	sms := "Transfert de 1000 CDF"
+	txn := Transaction{Phone: "123", Amount: 2000, RawSMS: sms, Timestamp: time.Now()}
+	if _, err := store.AddCredit(txn); err == nil {
+		t.Fatal("expected error on mismatch")
+	}
+}