Initial commit

.idea/.gitignore

@@ -0,0 +1,8 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml

.idea/dataSources.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="DataSourceManagerImpl" format="xml" multifile-model="true">
+    <data-source source="LOCAL" name="database.db" uuid="0e462ae0-ce8a-4670-ab47-9f0bf5101c63">
+      <driver-ref>sqlite.xerial</driver-ref>
+      <synchronize>true</synchronize>
+      <jdbc-driver>org.sqlite.JDBC</jdbc-driver>
+      <jdbc-url>jdbc:sqlite:$PROJECT_DIR$/database.db</jdbc-url>
+      <working-dir>$ProjectFileDir$</working-dir>
+    </data-source>
+  </component>
+</project>

.idea/discord.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="DiscordProjectSettings">
+    <option name="show" value="PROJECT_FILES" />
+    <option name="description" value="" />
+  </component>
+</project>

.idea/modules.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/.idea/shap-planner-backend.iml" filepath="$PROJECT_DIR$/.idea/shap-planner-backend.iml" />
+    </modules>
+  </component>
+</project>

.idea/shap-planner-backend.iml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="WEB_MODULE" version="4">
+  <component name="Go" enabled="true" />
+  <component name="NewModuleRootManager">
+    <content url="file://$MODULE_DIR$" />
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

.idea/sqldialects.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="SqlDialectMappings">
+    <file url="file://$PROJECT_DIR$/storage/storage.go" dialect="GenericSQL" />
+    <file url="PROJECT" dialect="SQLite" />
+  </component>
+</project>

.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>

go.mod

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+module shap-planner-backend
+
+go 1.26.0
+
+require (
+	github.com/google/uuid v1.6.0
+	github.com/mattn/go-sqlite3 v1.14.34
+	golang.org/x/crypto v0.48.0
+)

go.sum

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+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/mattn/go-sqlite3 v1.14.34 h1:3NtcvcUnFBPsuRcno8pUtupspG/GM+9nZ88zgJcp6Zk=
+github.com/mattn/go-sqlite3 v1.14.34/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
+golang.org/x/crypto v0.48.0 h1:/VRzVqiRSggnhY7gNRxPauEQ5Drw9haKdM0jqfcCFts=
+golang.org/x/crypto v0.48.0/go.mod h1:r0kV5h3qnFPlQnBSrULhlsRfryS2pmewsg+XfMgkVos=

handlers/account.go

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+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+	"shap-planner-backend/models"
+	"shap-planner-backend/storage"
+	"shap-planner-backend/utils"
+)
+
+func Register(w http.ResponseWriter, r *http.Request) {
+	var user models.User
+	_ = json.NewDecoder(r.Body).Decode(&user)
+	hashed, _ := utils.HashPassword(user.Password)
+	user.Password = hashed
+	user.ID = utils.GenerateUUID()
+
+	err := storage.AddUser(user)
+	if err != nil {
+		http.Error(w, "User exists", http.StatusBadRequest)
+		return
+	}
+	w.WriteHeader(http.StatusCreated)
+}
+
+func Login(w http.ResponseWriter, r *http.Request) {
+	var creds struct {
+		Username string `json:"username"`
+		Password string `json:"password"`
+	}
+	_ = json.NewDecoder(r.Body).Decode(&creds)
+
+	user, err := storage.GetUserByUsername(creds.Username)
+	if err != nil {
+		http.Error(w, "User not found", http.StatusUnauthorized)
+		return
+	}
+
+	if !utils.CheckPasswordHash(creds.Password, user.Password) {
+		http.Error(w, "Wrong password", http.StatusUnauthorized)
+		return
+	}
+
+	// TODO: JWT oder Session-Token erzeugen
+	w.WriteHeader(http.StatusOK)
+	err = json.NewEncoder(w).Encode(user)
+	if err != nil {
+		return
+	}
+}

main.go

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+package shap_planner_backend
+
+import (
+	"log"
+	"net/http"
+	"shap-planner-backend/handlers"
+	"shap-planner-backend/storage"
+)
+
+func main() {
+	err := storage.InitDB("database.db")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	http.HandleFunc("/register", handlers.Register)
+	http.HandleFunc("/login", handlers.Login)
+
+	log.Println("Server läuft auf :8080")
+	log.Fatal(http.ListenAndServe(":8080", nil))
+}

models/models.go

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+package models
+
+type User struct {
+	ID       string `json:"id"`
+	Username string `json:"username"`
+	Password string `json:"password"`
+}
+
+type Expense struct {
+	ID          string `json:"id"`
+	Amount      int    `json:"amt"`
+	Description string `json:"desc"`
+
+	Payer   User   `json:"payer"`
+	Debtors []User `json:"debtors"`
+}

storage/storage.go

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+package storage
+
+import (
+	"database/sql"
+	_ "database/sql"
+	_ "github.com/mattn/go-sqlite3"
+	"shap-planner-backend/models"
+	_ "shap-planner-backend/models"
+)
+
+var DB *sql.DB
+
+func InitDB(filepath string) error {
+	var err error
+	DB, err = sql.Open("sqlite3", filepath)
+	if err != nil {
+		return err
+	}
+
+	//Create Users-Table
+	_, err = DB.Exec(`CREATE TABLE IF NOT EXISTS users(
+    	id TEXT PRIMARY KEY,
+    	username TEXT UNIQUE,
+    	password TEXT
+	);`)
+	if err != nil {
+		return err
+	}
+
+	//Create Expenses-Table
+	_, err = DB.Exec(`CREATE TABLE IF NOT EXISTS expenses(
+    	id TEXT PRIMARY KEY
+        
+	)`)
+	return err
+}
+
+func AddUser(user models.User) error {
+	_, err := DB.Exec("INSERT INTO users(id, username, password) VALUES (?, ?, ?)", user.ID, user.Username, user.Password)
+	return err
+}
+
+func GetUserByUsername(username string) (models.User, error) {
+	row := DB.QueryRow("SELECT * FROM users WHERE username = ?", username)
+	var user models.User
+	err := row.Scan(&user.ID, &user.Username, &user.Password)
+	return user, err
+}
+
+func GetUserById(id string) (models.User, error) {
+	row := DB.QueryRow("SELECT * FROM users WHERE id = ?", id)
+	var user models.User
+	err := row.Scan(&user.ID, &user.Username, &user.Password)
+	return user, err
+}

utils/util.go

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+package utils
+
+import (
+	"github.com/google/uuid"
+	"golang.org/x/crypto/bcrypt"
+)
+
+func HashPassword(password string) (string, error) {
+	bytes, err := bcrypt.GenerateFromPassword([]byte(password), 14)
+	return string(bytes), err
+}
+
+func CheckPasswordHash(password, hash string) bool {
+	err := bcrypt.CompareHashAndPassword([]byte(hash), []byte(password))
+	return err == nil
+}
+
+func GenerateUUID() string {
+	return uuid.New().String()
+}