11 Commits

Author SHA1 Message Date
91997686d1 Added endpoint for shares 2026-03-04 14:23:09 +01:00
2f4e0bb8ce Updated refresh-token property names 2026-03-03 20:07:35 +01:00
56cc1c50a7 Updated refresh-token property names 2026-03-03 19:54:21 +01:00
088d32984c Made some small adjustments to e7da8c9443 2026-03-03 16:29:26 +01:00
e7da8c9443 Removed hardcoded string
- Roles are not hardcoded anymore (closes #4)
2026-03-03 15:55:39 +01:00
0afd5bfc3a Bugfix
- Role is now again listed in jwt when retrieving new access token (closes #3)
2026-03-03 15:45:53 +01:00
ef7ef3cf74 New Endpoint and security enhancement
- Userinfo endpoint is now available
- HTTPS is now required (closes #2)
2026-03-03 15:41:07 +01:00
c75c405200 Added .run dir to .gitignore 2026-03-01 13:49:17 +01:00
c735261f0c Removed comments from Dockerfile 2026-03-01 13:46:16 +01:00
188b238e7d Finished first part of balance calculation 2026-03-01 13:45:49 +01:00
87ae8cc0b9 Added logs 2026-03-01 13:25:27 +01:00
12 changed files with 330 additions and 71 deletions

1
.gitignore vendored
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@@ -2,3 +2,4 @@ appdata
.idea
*.exe
*.cmd
.run

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@@ -1,24 +1,19 @@
# Wir sagen Docker: Der Builder soll IMMER auf der Architektur deines PCs laufen (schnell!)
FROM --platform=$BUILDPLATFORM golang:1.26-alpine AS builder
RUN apk add --no-cache git
WORKDIR /app
# Cache für Module nutzen
COPY go.mod go.sum ./
RUN go mod download
COPY . .
# buildx übergibt diese Variablen automatisch
ARG TARGETOS
ARG TARGETARCH
# Hier passiert die Magie: Go kompiliert NATIV für das Ziel (Cross-Compilation)
RUN CGO_ENABLED=0 GOOS=$TARGETOS GOARCH=$TARGETARCH \
go build -ldflags "-s -w" -o shap-planner-backend .
# Final Stage (bleibt gleich klein)
FROM scratch
COPY --from=builder /app/shap-planner-backend /shap-planner-backend
ENTRYPOINT ["/shap-planner-backend"]

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@@ -1,7 +1,6 @@
package auth
import (
"os"
"time"
"github.com/golang-jwt/jwt/v5"
@@ -13,8 +12,6 @@ type Claims struct {
jwt.RegisteredClaims
}
var secret = os.Getenv("SHAP_JWT_SECRET")
func GenerateJWT(userID, role string, secret []byte) (string, error) {
claims := Claims{
UserID: userID,

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@@ -12,6 +12,8 @@ type Config struct {
HouseholdName string `yaml:"household_name"`
Port string `yaml:"port"`
DatabasePath string `yaml:"database_path"`
CertificatePath string `yaml:"certificate_path"`
PrivateKeyPath string `yaml:"private_key_path"`
}
const configPath = "./appdata/config.yaml"
@@ -36,6 +38,8 @@ func CheckIfExists() error {
Port: "8080",
DatabasePath: "./appdata/database.db",
HouseholdName: "Example-Household",
CertificatePath: "./appdata/cert.pem",
PrivateKeyPath: "./appdata/key.pem",
}
data, err := yaml.Marshal(defaultConfig)

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@@ -18,35 +18,35 @@ var cfg, _ = config.LoadConfig()
func Register(w http.ResponseWriter, r *http.Request) {
var user models.User
if err := json.NewDecoder(r.Body).Decode(&user); err != nil {
log.Println("[api/register] " + r.RemoteAddr + ": " + err.Error())
log.Println("POST [api/register] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Invalid request body", http.StatusBadRequest)
return
}
if user.Username == "" || user.Password == "" {
log.Println("[api/register] " + r.RemoteAddr + ": Username or Password is empty")
log.Println("POST [api/register] " + r.RemoteAddr + ": Username or Password is empty")
http.Error(w, "username and password required", http.StatusBadRequest)
return
}
hashed, err := auth.HashPassword(user.Password)
if err != nil {
log.Println("[api/register] " + r.RemoteAddr + ": " + err.Error())
log.Println("POST [api/register] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "internal error", http.StatusInternalServerError)
return
}
user.Password = hashed
user.ID = utils.GenerateUUID()
user.Role = "user"
user.Role = models.RoleUser
if err := storage.AddUser(&user); err != nil {
log.Println("[api/register] " + r.RemoteAddr + ": " + err.Error())
log.Println("POST [api/register] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "user already exists", http.StatusBadRequest)
return
}
w.WriteHeader(http.StatusCreated)
log.Println("[api/register] " + r.RemoteAddr + ": Successfully created user")
log.Println("POST [api/register] " + r.RemoteAddr + ": Successfully created user")
}
func Login(w http.ResponseWriter, r *http.Request) {
var creds struct {
@@ -54,41 +54,41 @@ func Login(w http.ResponseWriter, r *http.Request) {
Password string `json:"password"`
}
if err := json.NewDecoder(r.Body).Decode(&creds); err != nil {
log.Println("[api/login] " + r.RemoteAddr + ": " + err.Error())
log.Println("POST [api/login] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Invalid request", http.StatusBadRequest)
return
}
user, err := storage.GetUserByUsername(creds.Username)
if err != nil {
log.Println("[api/login] " + r.RemoteAddr + ": " + err.Error())
log.Println("POST [api/login] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Invalid credentials", http.StatusUnauthorized)
return
}
if !auth.CheckPasswordHash(creds.Password, user.Password) {
log.Println("[api/login] " + r.RemoteAddr + ": Invalid credentials")
log.Println("POST [api/login] " + r.RemoteAddr + ": Invalid credentials")
http.Error(w, "Invalid credentials", http.StatusUnauthorized)
return
}
secret := []byte(os.Getenv("SHAP_JWT_SECRET"))
if len(secret) == 0 {
log.Println("[api/login] " + r.RemoteAddr + ": Server misconfiguration")
log.Println("POST [api/login] " + r.RemoteAddr + ": Server misconfiguration")
http.Error(w, "Server misconfiguration", http.StatusInternalServerError)
return
}
accessToken, err := auth.GenerateJWT(user.ID, user.Role, secret)
if err != nil {
log.Println("[api/login] " + r.RemoteAddr + ": " + err.Error())
log.Println("POST [api/login] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Could not generate token", http.StatusInternalServerError)
return
}
refreshTokenPlain, err := utils.GenerateRefreshToken()
if err != nil {
log.Println("[api/login] " + r.RemoteAddr + ": " + err.Error())
log.Println("POST [api/login] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "could not generate refresh token", http.StatusInternalServerError)
return
}
@@ -107,7 +107,7 @@ func Login(w http.ResponseWriter, r *http.Request) {
CreatedAt: time.Now().Unix(),
Revoked: false,
}); err != nil {
log.Println("[api/login] " + r.RemoteAddr + ": " + err.Error())
log.Println("POST [api/login] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "could not save refresh token", http.StatusInternalServerError)
return
}
@@ -127,17 +127,17 @@ func Login(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json")
err = json.NewEncoder(w).Encode(resp)
if err != nil {
log.Println("[api/login] " + r.RemoteAddr + ": " + err.Error())
log.Println("POST [api/login] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Something went wrong", http.StatusInternalServerError)
return
}
log.Println("[api/login] " + r.RemoteAddr + ": Successfully logged in")
log.Println("POST [api/login] " + r.RemoteAddr + ": Successfully logged in")
}
func Logout(w http.ResponseWriter, r *http.Request) {
claims := r.Context().Value(auth.UserContextKey).(*auth.Claims)
err := storage.RevokeAllRefreshTokensForUser(claims.UserID)
if err != nil {
log.Println("[api/logout] " + r.RemoteAddr + ": " + err.Error())
log.Println("GET [api/logout] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Internal server error", http.StatusInternalServerError)
return
}
@@ -150,20 +150,20 @@ func TestHandler(w http.ResponseWriter, r *http.Request) {
err := json.NewEncoder(w).Encode(map[string]interface{}{
"user_id": claims.UserID,
"role": claims.Role,
"msg": "access granted to protected endpoint",
"msg": "Authentication successful",
})
if err != nil {
log.Println("[api/ping] " + r.RemoteAddr + ": " + err.Error())
log.Println("GET [api/ping] " + r.RemoteAddr + ": " + err.Error())
return
}
log.Println("[api/login] " + r.RemoteAddr + ": Successfully tested connection")
log.Println("GET [api/login] " + r.RemoteAddr + ": Successfully tested connection")
}
func RefreshToken(w http.ResponseWriter, r *http.Request) {
var req struct {
RefreshToken string `json:"refresh_token"`
}
if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
log.Println("[api/refresh] " + r.RemoteAddr + ": " + err.Error())
log.Println("POST [api/refresh] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Invalid request", http.StatusBadRequest)
return
}
@@ -172,7 +172,7 @@ func RefreshToken(w http.ResponseWriter, r *http.Request) {
tokenRow, err := storage.GetRefreshToken(hashed)
if err != nil || tokenRow.Revoked || tokenRow.ExpiresAt < time.Now().Unix() {
log.Println("[api/refresh] " + r.RemoteAddr + ": Invalid refresh token")
log.Println("POST [api/refresh] " + r.RemoteAddr + ": Invalid refresh token")
http.Error(w, "Invalid refresh token", http.StatusUnauthorized)
return
}
@@ -195,19 +195,52 @@ func RefreshToken(w http.ResponseWriter, r *http.Request) {
Revoked: false,
DeviceInfo: deviceInfo,
}); err != nil {
log.Println("[api/refresh] " + r.RemoteAddr + ": " + err.Error())
log.Println("POST [api/refresh] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Could not generate new refresh token", http.StatusInternalServerError)
return
}
accessToken, _ := auth.GenerateJWT(tokenRow.UserID, "", []byte(os.Getenv("SHAP_JWT_SECRET")))
user, err := storage.GetUserById(tokenRow.UserID)
if err != nil {
log.Println("POST [api/refresh] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Internal server error", http.StatusInternalServerError)
return
}
accessToken, _ := auth.GenerateJWT(tokenRow.UserID, user.Role, []byte(os.Getenv("SHAP_JWT_SECRET")))
if err = json.NewEncoder(w).Encode(map[string]string{
"access_token": accessToken,
"refresh_token": newToken,
}); err != nil {
log.Println("[api/refresh] " + r.RemoteAddr + ": " + err.Error())
log.Println("POST [api/refresh] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Internal server error", http.StatusInternalServerError)
return
}
log.Println("POST [api/refresh] " + r.RemoteAddr + ": Successfully refreshed token")
}
func UserInfo(w http.ResponseWriter, r *http.Request) {
if r.Method != http.MethodGet {
log.Println("GET [api/userinfo] " + r.RemoteAddr + ": Method " + r.Method + " not allowed")
http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
return
}
query := r.URL.Query()
idParam := query.Get("id")
user, err := storage.GetUserById(idParam)
if err != nil {
log.Println("GET [api/userinfo] " + r.RemoteAddr + ": User " + idParam + " not found")
http.Error(w, "User not found", http.StatusNotFound)
return
}
w.Header().Set("Content-Type", "application/json")
err = json.NewEncoder(w).Encode(map[string]interface{}{
"id": user.ID,
"name": user.Username,
"avatar_url": "",
})
if err != nil {
log.Println("GET [api/userinfo] " + r.RemoteAddr + ": " + err.Error())
return
}
log.Println("GET [api/userinfo] " + r.RemoteAddr + ": Successfully retrieved user info")
}

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@@ -1,12 +1,32 @@
package handlers
import "net/http"
import (
"encoding/json"
"log"
"net/http"
"shap-planner-backend/storage"
)
func GetBalance(w http.ResponseWriter, r *http.Request) {
query := r.URL.Query()
userParam := query.Get("user")
if userParam == "" {
if userParam == "all" {
// TODO: add later
} else {
balance, err := storage.ComputeBalance(userParam)
if err != nil {
log.Println("GET [api/balance] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Invalid request query", http.StatusBadRequest)
return
}
err = json.NewEncoder(w).Encode(map[string]interface{}{
"balance": balance,
})
if err != nil {
log.Println("GET [api/balance] " + r.RemoteAddr + ": " + err.Error())
return
}
log.Println("GET [api/balance] " + r.RemoteAddr + ": Successfully retrieved balance")
}
}

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@@ -2,10 +2,13 @@ package handlers
import (
"encoding/json"
"log"
"net/http"
"shap-planner-backend/models"
"shap-planner-backend/storage"
"shap-planner-backend/utils"
"strings"
"time"
)
func Expenses(w http.ResponseWriter, r *http.Request) {
@@ -13,6 +16,20 @@ func Expenses(w http.ResponseWriter, r *http.Request) {
switch r.Method {
case http.MethodGet: // -> Get Expenses
expenses, err := storage.GetAllExpenses()
if err != nil {
log.Println("GET [api/expense] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Something went wrong", http.StatusInternalServerError)
return
}
err = json.NewEncoder(w).Encode(map[string]interface{}{
"expenses": expenses,
})
if err != nil {
log.Println("GET [api/expense] " + r.RemoteAddr + ": " + err.Error())
return
}
log.Println("GET [api/expense] " + r.RemoteAddr + ": Successfully retrieved expenses")
break
case http.MethodPost: // -> Create Expense
var body struct {
@@ -20,37 +37,54 @@ func Expenses(w http.ResponseWriter, r *http.Request) {
Shares []models.ExpenseShare `json:"shares"`
}
if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
log.Println("POST [api/expense] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Invalid request body", http.StatusBadRequest)
return
}
if claims.UserID != body.Expense.PayerID { // You cannot create an expense in the name of another user
http.Error(w, "Invalid request", http.StatusUnauthorized)
log.Println("POST [api/expense] " + r.RemoteAddr + ": claims.UserID and expense.PayerID does not match")
http.Error(w, "Invalid request", http.StatusBadRequest)
return
}
// Set ExpenseID
if body.Expense.ID != "" {
http.Error(w, "Invalid request", http.StatusUnauthorized)
log.Println("POST [api/expense] " + r.RemoteAddr + ": Expense ID must be empty")
http.Error(w, "Invalid request", http.StatusBadRequest)
return
}
body.Expense.ID = utils.GenerateUUID()
if body.Expense.CreatedAt == 0 {
body.Expense.CreatedAt = time.Now().Unix()
}
if body.Expense.Amount <= 0 {
log.Println("POST [api/expense] " + r.RemoteAddr + ": Amount must be greater than zero")
http.Error(w, "Invalid request", http.StatusBadRequest)
return
}
// Set ShareIDs and save them
for _, share := range body.Shares {
if share.ID != "" {
http.Error(w, "Invalid request", http.StatusUnauthorized)
log.Println("POST [api/expense] " + r.RemoteAddr + ": Share ID must be empty")
http.Error(w, "Invalid request", http.StatusBadRequest)
return
}
if share.ExpenseID != "" {
http.Error(w, "Invalid request", http.StatusUnauthorized)
log.Println("POST [api/expense] " + r.RemoteAddr + ": Expense ID of Share must be empty")
http.Error(w, "Invalid request", http.StatusBadRequest)
return
}
share.ExpenseID = body.Expense.ID
share.ID = utils.GenerateUUID()
err := storage.AddShare(&share)
if err != nil {
log.Println("POST [api/expense] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Error adding expense", http.StatusBadRequest) // Should never happen
return
}
}
err := storage.AddExpense(&body.Expense)
if err != nil {
log.Println("POST [api/expense] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Error adding expense", http.StatusBadRequest)
return
}
@@ -59,13 +93,68 @@ func Expenses(w http.ResponseWriter, r *http.Request) {
"shares": body.Shares,
})
if err != nil {
println(err.Error())
log.Println("POST [api/expense] " + r.RemoteAddr + ": " + err.Error())
return
}
log.Println("POST [api/expense] " + r.RemoteAddr + ": Successfully added expense and its shares")
break
case http.MethodPut: // -> Update Expense
break
case http.MethodDelete: // -> Delete Expense
default:
http.Error(w, "Invalid request method", http.StatusMethodNotAllowed)
}
}
func ExpenseShares(w http.ResponseWriter, r *http.Request) {
switch r.Method {
case http.MethodGet:
query := r.URL.Query()
idParam := query.Get("id")
idTypeParam := strings.ToLower(query.Get("idType"))
if idTypeParam == models.IDTypeEXPENSE {
println(idParam)
shares, err := storage.GetSharesByExpenseId(idParam)
if err != nil {
log.Println("GET [api/shares] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Something went wrong", http.StatusInternalServerError)
return
}
w.Header().Set("Content-Type", "application/json")
err = json.NewEncoder(w).Encode(map[string]interface{}{
"shares": shares,
})
if err != nil {
log.Println("GET [api/shares] " + r.RemoteAddr + ": " + err.Error())
return
}
log.Println("GET [api/shares] " + r.RemoteAddr + ": Successfully retrieved shares")
} else if idTypeParam == models.IDTypeSHARE || idTypeParam == "" {
share, err := storage.GetShareById(idParam)
if err != nil {
log.Println("GET [api/shares] " + r.RemoteAddr + ": " + err.Error())
http.Error(w, "Something went wrong", http.StatusInternalServerError)
return
}
w.Header().Set("Content-Type", "application/json")
err = json.NewEncoder(w).Encode(map[string]interface{}{
"id": share.ID,
"expense_id": share.ExpenseID,
"user_id": share.UserID,
"share_cents": share.ShareCents,
})
if err != nil {
log.Println("GET [api/shares] " + r.RemoteAddr + ": " + err.Error())
return
}
log.Println("GET [api/shares] " + r.RemoteAddr + ": Successfully retrieved shares")
}
break
case http.MethodPut:
break
case http.MethodDelete:
break
default:
http.Error(w, "Invalid request method", http.StatusMethodNotAllowed)
}
}
func AdminPanel(w http.ResponseWriter, r *http.Request) {}

10
main.go
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@@ -7,17 +7,13 @@ import (
)
func main() {
var SERVER = server.InitServer()
var _server = server.InitServer()
err := storage.InitDB(SERVER.DatabasePath)
err := storage.InitDB(_server.DatabasePath)
if err != nil {
log.Fatal(err)
return
}
SERVER.Run()
}
func Setup() {
//TODO: first configuration
_server.Run()
}

14
models/constants.go Normal file
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@@ -0,0 +1,14 @@
package models
// Roles
const (
RoleUser = "user"
RoleAdmin = "admin"
)
// ID-Types
const (
IDTypeSHARE = "share"
IDTypeEXPENSE = "expense"
IDTypeUSER = "user"
)

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@@ -1,11 +1,11 @@
package models
type RefreshToken struct {
ID string `json:id`
UserID string `json:userid`
Token string `json:token`
ExpiresAt int64 `json:expiresat`
CreatedAt int64 `json:createdat`
Revoked bool `json:revoked`
DeviceInfo string `json:deviceinfo`
ID string `json:"id"`
UserID string `json:"user_id"`
Token string `json:"token"`
ExpiresAt int64 `json:"expires_at"`
CreatedAt int64 `json:"created_at"`
Revoked bool `json:"revoked"`
DeviceInfo string `json:"device_info"`
}

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@@ -13,10 +13,10 @@ type Server struct {
Port string
JWTSecret []byte
DatabasePath string
CertificatePath string
PrivateKeyPath string
}
var cfg, _ = config.LoadConfig()
func InitServer() *Server {
err := config.CheckIfExists()
@@ -45,6 +45,8 @@ func InitServer() *Server {
Port: cfg.Port,
JWTSecret: []byte(jwtSecret),
DatabasePath: cfg.DatabasePath,
CertificatePath: cfg.CertificatePath,
PrivateKeyPath: cfg.PrivateKeyPath,
}
}
@@ -60,12 +62,14 @@ func (server *Server) Run() {
// Login required
mux.Handle("/api/expenses", auth.AuthMiddleware(server.JWTSecret)(http.HandlerFunc(handlers.Expenses)))
mux.Handle("/api/shares", auth.AuthMiddleware(server.JWTSecret)(http.HandlerFunc(handlers.ExpenseShares)))
mux.Handle("/api/balance", auth.AuthMiddleware(server.JWTSecret)(http.HandlerFunc(handlers.GetBalance)))
mux.Handle("/api/ping", auth.AuthMiddleware(server.JWTSecret)(http.HandlerFunc(handlers.TestHandler)))
mux.Handle("/api/userinfo", auth.AuthMiddleware(server.JWTSecret)(http.HandlerFunc(handlers.UserInfo)))
// Admin-only
mux.Handle("/api/admin", auth.AuthMiddleware(server.JWTSecret)(auth.RequireRole("admin")(http.HandlerFunc(handlers.AdminPanel))))
log.Printf("Listening on port %s", server.Port)
log.Fatal(http.ListenAndServe(":"+server.Port, mux))
log.Fatal(http.ListenAndServeTLS(":"+server.Port, server.CertificatePath, server.PrivateKeyPath, mux))
}

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@@ -120,7 +120,35 @@ func GetExpensesByUserId(userId string) ([]models.Expense, error) {
return nil, nil
}
func GetAllExpenses() ([]models.Expense, error) {
return nil, nil
query := "SELECT * FROM expenses"
rows, err := DB.Query(query)
if err != nil {
return nil, err
}
defer rows.Close()
var expenses []models.Expense
for rows.Next() {
var expense models.Expense
var attachmentsJSON []byte
err := rows.Scan(&expense.ID, &expense.PayerID, &expense.Amount, &expense.Title, &expense.Description, &attachmentsJSON, &expense.CreatedAt, &expense.LastUpdatedAt)
if err != nil {
return nil, err
}
if len(attachmentsJSON) > 0 {
err := json.Unmarshal(attachmentsJSON, &expense.Attachments)
if err != nil {
return nil, err
}
}
expenses = append(expenses, expense)
}
if err = rows.Err(); err != nil {
return nil, err
}
return expenses, nil
}
// Expense Shares
@@ -132,6 +160,84 @@ func AddShare(share *models.ExpenseShare) error {
share.ShareCents)
return err
}
func GetShareById(id string) (models.ExpenseShare, error) {
row := DB.QueryRow("SELECT * FROM expense_shares WHERE id = ?", id)
var share models.ExpenseShare
err := row.Scan(&share.ID, &share.ExpenseID, &share.UserID, &share.ShareCents)
return share, err
}
func GetSharesByExpenseId(id string) ([]models.ExpenseShare, error) {
query := "SELECT * FROM expense_shares WHERE expense_id = ?"
rows, err := DB.Query(query, id)
if err != nil {
return nil, err
}
defer rows.Close()
var shares []models.ExpenseShare
for rows.Next() {
var share models.ExpenseShare
err := rows.Scan(&share.ID, &share.ExpenseID, &share.UserID, &share.ShareCents)
if err != nil {
return nil, err
}
shares = append(shares, share)
}
if err = rows.Err(); err != nil {
return nil, err
}
return shares, nil
}
// Balances
func ComputeBalance(userId string) (float64, error) {
var balance float64
query := `
SELECT
COALESCE(p.paid, 0) - COALESCE(s.shared, 0) AS balance
FROM (SELECT ? AS id) u
LEFT JOIN (
SELECT payer_id, SUM(amount_cents) AS paid
FROM expenses
WHERE payer_id = ?
GROUP BY payer_id
) p ON u.id = p.payer_id
LEFT JOIN (
SELECT user_id, SUM(share_cents) AS shared
FROM expense_shares
WHERE user_id = ?
GROUP BY user_id
) s ON u.id = s.user_id`
err := DB.QueryRow(query, userId, userId, userId).Scan(&balance)
if err != nil {
return 0, err
}
return balance, nil
}
func ComputeWGBalance() (float64, error) {
var balance float64
query := `SELECT u.id AS user_id,
COALESCE(p.paid_cents,0) - COALESCE(s.share_cents,0) AS balance_cents
FROM users u
LEFT JOIN (
SELECT payer_id, SUM(amount_cents) AS paid_cents
FROM expenses
GROUP BY payer_id
) p ON u.id = p.payer_id
LEFT JOIN (
SELECT es.user_id, SUM(es.share_cents) AS share_cents
FROM expense_shares es
JOIN expenses e ON es.expense_id = e.id
GROUP BY es.user_id
) s ON u.id = s.user_id)`
err := DB.QueryRow(query).Scan(&balance)
if err != nil {
return 0, err
}
return balance, nil
}
// Users
func AddUser(user *models.User) error {