init

backend/.dockerignore

@@ -0,0 +1,8 @@
+.git
+.gitignore
+node_modules
+tmp
+dist
+coverage
+.env
+*.log

backend/.env.example

@@ -0,0 +1,16 @@
+SERVER_PORT=8080
+JWT_SECRET=replace-with-a-long-random-secret
+
+MYSQL_DATABASE=social_raiting
+MYSQL_USER=social_raiting
+MYSQL_PASSWORD=change-db-password
+MYSQL_ROOT_PASSWORD=change-root-password
+
+DB_HOST=mysql
+DB_PORT=3306
+DB_NAME=social_raiting
+DB_USER=social_raiting
+DB_PASSWORD=change-db-password
+
+DEFAULT_ADMIN_EMAIL=admin@example.com
+DEFAULT_ADMIN_PASSWORD=change-admin-password

backend/Dockerfile

@@ -0,0 +1,24 @@
+FROM golang:1.25.6-alpine AS builder
+
+WORKDIR /app
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+RUN CGO_ENABLED=0 GOOS=linux go build -o /social-raiting-backend .
+
+FROM alpine:3.22
+
+WORKDIR /app
+
+RUN adduser -D -H -u 10001 appuser
+
+COPY --from=builder /social-raiting-backend /app/social-raiting-backend
+COPY docs /app/docs
+
+EXPOSE 8080
+
+USER appuser
+
+CMD ["/app/social-raiting-backend"]

backend/docs/swagger.yaml

@@ -0,0 +1,431 @@
+openapi: 3.0.3
+info:
+  title: Social Raiting API
+  version: 1.0.0
+  description: |
+    API for authentication, user management, and social rating operations.
+
+    Social rating values are allowed to go below zero. Decrease operations continue
+    subtracting from the current score without applying a lower bound.
+servers:
+  - url: http://localhost:8080
+    description: Local backend
+tags:
+  - name: Health
+  - name: Auth
+  - name: Social Rating
+paths:
+  /ping:
+    get:
+      tags:
+        - Health
+      summary: Health check
+      operationId: ping
+      responses:
+        '200':
+          description: Backend is healthy
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/PingResponse'
+
+  /api/auth/login:
+    post:
+      tags:
+        - Auth
+      summary: Login user
+      operationId: loginUser
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/LoginRequest'
+      responses:
+        '200':
+          description: Login successful
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/AuthResponse'
+        '400':
+          description: Invalid request body
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+        '401':
+          description: Invalid credentials
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+
+  /api/auth/me:
+    get:
+      tags:
+        - Auth
+      summary: Get current user
+      operationId: getCurrentUser
+      security:
+        - bearerAuth: []
+      responses:
+        '200':
+          description: Current authenticated user
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/UserResponse'
+        '401':
+          description: Missing or invalid token
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+        '404':
+          description: User not found
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+
+  /api/auth/register:
+    post:
+      tags:
+        - Auth
+      summary: Register user
+      description: Only authenticated admin users may create new users.
+      operationId: registerUser
+      security:
+        - bearerAuth: []
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/RegisterRequest'
+      responses:
+        '201':
+          description: User created
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/UserResponse'
+        '400':
+          description: Invalid request body
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+        '401':
+          description: Missing or invalid token
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+        '403':
+          description: Admin access required
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+        '409':
+          description: Email already exists
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+
+  /api/social-rating/increase:
+    post:
+      tags:
+        - Social Rating
+      summary: Increase social rating
+      operationId: increaseSocialRating
+      description: Adds a positive amount to the target user's current social rating.
+      security:
+        - bearerAuth: []
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/ChangeSocialRatingRequest'
+      responses:
+        '200':
+          description: Social rating increased
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ChangeSocialRatingResponse'
+        '400':
+          description: Invalid request body
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+        '401':
+          description: Missing or invalid token
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+        '404':
+          description: Target or actor user not found
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+
+  /api/social-rating/decrease:
+    post:
+      tags:
+        - Social Rating
+      summary: Decrease social rating
+      operationId: decreaseSocialRating
+      description: |
+        Subtracts a positive amount from the target user's current social rating.
+        The resulting score may be negative.
+      security:
+        - bearerAuth: []
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/ChangeSocialRatingRequest'
+      responses:
+        '200':
+          description: Social rating decreased
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ChangeSocialRatingResponse'
+        '400':
+          description: Invalid request body
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+        '401':
+          description: Missing or invalid token
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+        '404':
+          description: Target or actor user not found
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+
+components:
+  securitySchemes:
+    bearerAuth:
+      type: http
+      scheme: bearer
+      bearerFormat: JWT
+
+  schemas:
+    PingResponse:
+      type: object
+      properties:
+        message:
+          type: string
+          example: ok
+      required:
+        - message
+
+    ErrorResponse:
+      type: object
+      properties:
+        error:
+          type: string
+          example: invalid credentials
+      required:
+        - error
+
+    LoginRequest:
+      type: object
+      properties:
+        email:
+          type: string
+          format: email
+          example: admin@example.com
+        password:
+          type: string
+          format: password
+          example: strong-password
+      required:
+        - email
+        - password
+
+    RegisterRequest:
+      type: object
+      properties:
+        email:
+          type: string
+          format: email
+          example: user@example.com
+        password:
+          type: string
+          format: password
+          minLength: 8
+          example: strong-password
+        isAdmin:
+          type: boolean
+          example: false
+      required:
+        - email
+        - password
+
+    ChangeSocialRatingRequest:
+      type: object
+      properties:
+        targetUserId:
+          type: integer
+          format: uint64
+          example: 2
+        amount:
+          type: integer
+          minimum: 1
+          default: 1
+          example: 3
+        reason:
+          type: string
+          example: helpful review
+        source:
+          type: string
+          example: api
+      required:
+        - targetUserId
+
+    AuthResponse:
+      type: object
+      properties:
+        token:
+          type: string
+          example: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...
+        user:
+          $ref: '#/components/schemas/User'
+      required:
+        - token
+        - user
+
+    UserResponse:
+      type: object
+      properties:
+        user:
+          $ref: '#/components/schemas/User'
+      required:
+        - user
+
+    User:
+      type: object
+      properties:
+        id:
+          type: integer
+          format: uint64
+          example: 1
+        email:
+          type: string
+          format: email
+          example: admin@example.com
+        isAdmin:
+          type: boolean
+          example: true
+        socialRating:
+          $ref: '#/components/schemas/UserSocialRating'
+        createdAt:
+          type: string
+          format: date-time
+        updatedAt:
+          type: string
+          format: date-time
+      required:
+        - id
+        - email
+        - isAdmin
+        - createdAt
+        - updatedAt
+
+    UserSocialRating:
+      type: object
+      properties:
+        userId:
+          type: integer
+          format: uint64
+          example: 2
+        score:
+          type: integer
+          example: -4
+        lastOperationId:
+          type: integer
+          format: uint64
+          nullable: true
+          example: 15
+        createdAt:
+          type: string
+          format: date-time
+        updatedAt:
+          type: string
+          format: date-time
+      required:
+        - userId
+        - score
+        - createdAt
+        - updatedAt
+
+    SocialRatingOperation:
+      type: object
+      properties:
+        id:
+          type: integer
+          format: uint64
+          example: 15
+        targetUserId:
+          type: integer
+          format: uint64
+          example: 2
+        actorUserId:
+          type: integer
+          format: uint64
+          nullable: true
+          example: 1
+        delta:
+          type: integer
+          example: -3
+        operationType:
+          type: string
+          example: decrease
+        reason:
+          type: string
+          example: spam
+        source:
+          type: string
+          example: api
+        balanceAfter:
+          type: integer
+          example: -4
+        createdAt:
+          type: string
+          format: date-time
+      required:
+        - id
+        - targetUserId
+        - delta
+        - operationType
+        - balanceAfter
+        - createdAt
+
+    ChangeSocialRatingResponse:
+      type: object
+      properties:
+        operation:
+          $ref: '#/components/schemas/SocialRatingOperation'
+        currentRating:
+          $ref: '#/components/schemas/UserSocialRating'
+      required:
+        - operation
+        - currentRating

backend/go.mod

@@ -0,0 +1,47 @@
+module social-raiting.nekiiinkognito.ru
+
+go 1.25.6
+
+require (
+	github.com/gin-contrib/cors v1.7.6
+	github.com/gin-gonic/gin v1.12.0
+	github.com/golang-jwt/jwt/v5 v5.3.0
+	golang.org/x/crypto v0.48.0
+	gorm.io/driver/mysql v1.6.0
+	gorm.io/gorm v1.31.1
+)
+
+require (
+	filippo.io/edwards25519 v1.1.0 // indirect
+	github.com/bytedance/gopkg v0.1.3 // indirect
+	github.com/bytedance/sonic v1.15.0 // indirect
+	github.com/bytedance/sonic/loader v0.5.0 // indirect
+	github.com/cloudwego/base64x v0.1.6 // indirect
+	github.com/gabriel-vasile/mimetype v1.4.12 // indirect
+	github.com/gin-contrib/sse v1.1.0 // 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 v10.30.1 // indirect
+	github.com/go-sql-driver/mysql v1.8.1 // indirect
+	github.com/goccy/go-json v0.10.5 // indirect
+	github.com/goccy/go-yaml v1.19.2 // indirect
+	github.com/jinzhu/inflection v1.0.0 // indirect
+	github.com/jinzhu/now v1.1.5 // 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 v0.0.0-20180306012644-bacd9c7ef1dd // 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 v0.6.0 // indirect
+	github.com/quic-go/quic-go v0.59.0 // indirect
+	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
+	github.com/ugorji/go/codec v1.3.1 // indirect
+	go.mongodb.org/mongo-driver/v2 v2.5.0 // indirect
+	golang.org/x/arch v0.22.0 // indirect
+	golang.org/x/net v0.51.0 // indirect
+	golang.org/x/sys v0.41.0 // indirect
+	golang.org/x/text v0.34.0 // indirect
+	google.golang.org/protobuf v1.36.10 // indirect
+)

backend/go.sum

@@ -0,0 +1,105 @@
+filippo.io/edwards25519 v1.1.0 h1:FNf4tywRC1HmFuKW5xopWpigGjJKiJSV0Cqo0cJWDaA=
+filippo.io/edwards25519 v1.1.0/go.mod h1:BxyFTGdWcka3PhytdK4V28tE5sGfRvvvRV7EaN4VDT4=
+github.com/bytedance/gopkg v0.1.3 h1:TPBSwH8RsouGCBcMBktLt1AymVo2TVsBVCY4b6TnZ/M=
+github.com/bytedance/gopkg v0.1.3/go.mod h1:576VvJ+eJgyCzdjS+c4+77QF3p7ubbtiKARP3TxducM=
+github.com/bytedance/sonic v1.15.0 h1:/PXeWFaR5ElNcVE84U0dOHjiMHQOwNIx3K4ymzh/uSE=
+github.com/bytedance/sonic v1.15.0/go.mod h1:tFkWrPz0/CUCLEF4ri4UkHekCIcdnkqXw9VduqpJh0k=
+github.com/bytedance/sonic/loader v0.5.0 h1:gXH3KVnatgY7loH5/TkeVyXPfESoqSBSBEiDd5VjlgE=
+github.com/bytedance/sonic/loader v0.5.0/go.mod h1:AR4NYCk5DdzZizZ5djGqQ92eEhCCcdf5x77udYiSJRo=
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backend/internal/auth/admin_middleware.go

@@ -0,0 +1,39 @@
+package auth
+
+import (
+	"errors"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
+
+	"social-raiting.nekiiinkognito.ru/internal/models"
+)
+
+func RequireAdmin(db *gorm.DB) gin.HandlerFunc {
+	return func(ctx *gin.Context) {
+		userID, exists := ctx.Get("userID")
+		if !exists {
+			ctx.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "missing user context"})
+			return
+		}
+
+		var user models.User
+		if err := db.First(&user, "id = ?", userID).Error; err != nil {
+			if errors.Is(err, gorm.ErrRecordNotFound) {
+				ctx.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "user not found"})
+				return
+			}
+
+			ctx.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"error": "failed to load user"})
+			return
+		}
+
+		if !user.IsAdmin {
+			ctx.AbortWithStatusJSON(http.StatusForbidden, gin.H{"error": "admin access required"})
+			return
+		}
+
+		ctx.Next()
+	}
+}

backend/internal/auth/handler.go

@@ -0,0 +1,123 @@
+package auth
+
+import (
+	"errors"
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+	"golang.org/x/crypto/bcrypt"
+	"gorm.io/gorm"
+
+	"social-raiting.nekiiinkognito.ru/internal/models"
+)
+
+type Handler struct {
+	DB        *gorm.DB
+	JWTSecret string
+}
+
+func NewHandler(db *gorm.DB, jwtSecret string) Handler {
+	return Handler{
+		DB:        db,
+		JWTSecret: jwtSecret,
+	}
+}
+
+func (h Handler) Register(ctx *gin.Context) {
+	var req RegisterRequest
+	if err := ctx.ShouldBindJSON(&req); err != nil {
+		ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	email := strings.ToLower(strings.TrimSpace(req.Email))
+	passwordHash, err := bcrypt.GenerateFromPassword([]byte(req.Password), bcrypt.DefaultCost)
+	if err != nil {
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": "failed to hash password"})
+		return
+	}
+
+	user := models.User{
+		Email:        email,
+		PasswordHash: string(passwordHash),
+		IsAdmin:      req.IsAdmin,
+	}
+
+	if err := h.DB.Create(&user).Error; err != nil {
+		if isDuplicateEmailError(err) {
+			ctx.JSON(http.StatusConflict, gin.H{"error": "email is already registered"})
+			return
+		}
+
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": "failed to create user"})
+		return
+	}
+
+	ctx.JSON(http.StatusCreated, UserResponse{User: user})
+}
+
+func (h Handler) Login(ctx *gin.Context) {
+	var req LoginRequest
+	if err := ctx.ShouldBindJSON(&req); err != nil {
+		ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	var user models.User
+	if err := h.DB.Where("email = ?", strings.ToLower(strings.TrimSpace(req.Email))).First(&user).Error; err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			ctx.JSON(http.StatusUnauthorized, gin.H{"error": "invalid credentials"})
+			return
+		}
+
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": "failed to load user"})
+		return
+	}
+
+	if err := bcrypt.CompareHashAndPassword([]byte(user.PasswordHash), []byte(req.Password)); err != nil {
+		ctx.JSON(http.StatusUnauthorized, gin.H{"error": "invalid credentials"})
+		return
+	}
+
+	token, err := GenerateToken(user.ID, h.JWTSecret, TokenOptions{})
+	if err != nil {
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": "failed to create token"})
+		return
+	}
+
+	ctx.JSON(http.StatusOK, AuthResponse{
+		Token: token,
+		User:  user,
+	})
+}
+
+func (h Handler) Me(ctx *gin.Context) {
+	userID, exists := ctx.Get("userID")
+	if !exists {
+		ctx.JSON(http.StatusUnauthorized, gin.H{"error": "missing user context"})
+		return
+	}
+
+	var user models.User
+	if err := h.DB.First(&user, "id = ?", userID).Error; err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			ctx.JSON(http.StatusNotFound, gin.H{"error": "user not found"})
+			return
+		}
+
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": "failed to load user"})
+		return
+	}
+
+	ctx.JSON(http.StatusOK, UserResponse{User: user})
+}
+
+func isDuplicateEmailError(err error) bool {
+	if err == nil {
+		return false
+	}
+
+	errText := strings.ToLower(err.Error())
+	return strings.Contains(errText, "duplicate") || strings.Contains(errText, "1062")
+}

backend/internal/auth/jwt.go

@@ -0,0 +1,28 @@
+package auth
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+)
+
+func GenerateToken(userID uint, jwtSecret string, options TokenOptions) (string, error) {
+	ttl := options.TTL
+	if ttl <= 0 {
+		ttl = 24 * time.Hour
+	}
+
+	now := time.Now()
+	claims := JWTClaims{
+		UserID: userID,
+		RegisteredClaims: jwt.RegisteredClaims{
+			Subject:   fmt.Sprintf("%d", userID),
+			IssuedAt:  jwt.NewNumericDate(now),
+			ExpiresAt: jwt.NewNumericDate(now.Add(ttl)),
+		},
+	}
+
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	return token.SignedString([]byte(jwtSecret))
+}

backend/internal/auth/middleware.go

@@ -0,0 +1,42 @@
+package auth
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+	"github.com/golang-jwt/jwt/v5"
+)
+
+func Middleware(jwtSecret string) gin.HandlerFunc {
+	return func(ctx *gin.Context) {
+		header := strings.TrimSpace(ctx.GetHeader("Authorization"))
+		if header == "" {
+			ctx.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "missing authorization header"})
+			return
+		}
+
+		parts := strings.SplitN(header, " ", 2)
+		if len(parts) != 2 || !strings.EqualFold(parts[0], "Bearer") {
+			ctx.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "invalid authorization header"})
+			return
+		}
+
+		claims := &JWTClaims{}
+		token, err := jwt.ParseWithClaims(parts[1], claims, func(token *jwt.Token) (any, error) {
+			if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
+				return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
+			}
+
+			return []byte(jwtSecret), nil
+		})
+		if err != nil || !token.Valid {
+			ctx.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "invalid token"})
+			return
+		}
+
+		ctx.Set("userID", claims.UserID)
+		ctx.Next()
+	}
+}

backend/internal/auth/types.go

@@ -0,0 +1,38 @@
+package auth
+
+import (
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+
+	"social-raiting.nekiiinkognito.ru/internal/models"
+)
+
+type RegisterRequest struct {
+	Email    string `json:"email" binding:"required,email"`
+	Password string `json:"password" binding:"required,min=8"`
+	IsAdmin  bool   `json:"isAdmin"`
+}
+
+type LoginRequest struct {
+	Email    string `json:"email" binding:"required,email"`
+	Password string `json:"password" binding:"required"`
+}
+
+type AuthResponse struct {
+	Token string      `json:"token"`
+	User  models.User `json:"user"`
+}
+
+type JWTClaims struct {
+	UserID uint `json:"userId"`
+	jwt.RegisteredClaims
+}
+
+type UserResponse struct {
+	User models.User `json:"user"`
+}
+
+type TokenOptions struct {
+	TTL time.Duration
+}

backend/internal/config/config.go

@@ -0,0 +1,52 @@
+package config
+
+import (
+	"log"
+	"os"
+	"strings"
+)
+
+type Config struct {
+	ServerPort           string
+	JWTSecret            string
+	DBUser               string
+	DBPassword           string
+	DBHost               string
+	DBPort               string
+	DBName               string
+	DefaultAdminEmail    string
+	DefaultAdminPassword string
+}
+
+func Load() Config {
+	cfg := Config{
+		ServerPort:           getEnv("SERVER_PORT", "8080"),
+		JWTSecret:            getEnv("JWT_SECRET", "change-me-in-production"),
+		DBUser:               getEnv("DB_USER", "root"),
+		DBPassword:           getEnv("DB_PASSWORD", ""),
+		DBHost:               getEnv("DB_HOST", "127.0.0.1"),
+		DBPort:               getEnv("DB_PORT", "3306"),
+		DBName:               getEnv("DB_NAME", "social_raiting"),
+		DefaultAdminEmail:    getEnv("DEFAULT_ADMIN_EMAIL", "admin@example.com"),
+		DefaultAdminPassword: getEnv("DEFAULT_ADMIN_PASSWORD", "change-admin-password"),
+	}
+
+	if cfg.JWTSecret == "change-me-in-production" {
+		log.Println("warning: JWT_SECRET is using the default development value")
+	}
+
+	if cfg.DefaultAdminPassword == "change-admin-password" {
+		log.Println("warning: DEFAULT_ADMIN_PASSWORD is using the default development value")
+	}
+
+	return cfg
+}
+
+func getEnv(key, fallback string) string {
+	value := strings.TrimSpace(os.Getenv(key))
+	if value == "" {
+		return fallback
+	}
+
+	return value
+}

backend/internal/database/mysql.go

@@ -0,0 +1,94 @@
+package database
+
+import (
+	"fmt"
+	"log"
+	"strings"
+	"time"
+
+	"golang.org/x/crypto/bcrypt"
+	"social-raiting.nekiiinkognito.ru/internal/config"
+	"social-raiting.nekiiinkognito.ru/internal/models"
+
+	"gorm.io/driver/mysql"
+	"gorm.io/gorm"
+)
+
+func Connect(cfg config.Config) *gorm.DB {
+	dsn := fmt.Sprintf(
+		"%s:%s@tcp(%s:%s)/%s?charset=utf8mb4&parseTime=True&loc=Local",
+		cfg.DBUser,
+		cfg.DBPassword,
+		cfg.DBHost,
+		cfg.DBPort,
+		cfg.DBName,
+	)
+
+	db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{})
+	if err != nil {
+		log.Fatalf("failed to connect to mysql: %v", err)
+	}
+
+	sqlDB, err := db.DB()
+	if err != nil {
+		log.Fatalf("failed to create sql database handle: %v", err)
+	}
+
+	sqlDB.SetConnMaxLifetime(5 * time.Minute)
+	sqlDB.SetMaxIdleConns(10)
+	sqlDB.SetMaxOpenConns(25)
+
+	if err := sqlDB.Ping(); err != nil {
+		log.Fatalf("failed to ping mysql: %v", err)
+	}
+
+	if err := db.AutoMigrate(&models.User{}); err != nil {
+		log.Fatalf("failed to migrate database: %v", err)
+	}
+
+	if err := db.AutoMigrate(&models.UserSocialRating{}, &models.SocialRatingOperation{}); err != nil {
+		log.Fatalf("failed to migrate database: %v", err)
+	}
+
+	ensureDefaultAdmin(db, cfg)
+
+	return db
+}
+
+func ensureDefaultAdmin(db *gorm.DB, cfg config.Config) {
+	email := strings.ToLower(strings.TrimSpace(cfg.DefaultAdminEmail))
+	password := strings.TrimSpace(cfg.DefaultAdminPassword)
+	if email == "" || password == "" {
+		log.Println("skipping default admin bootstrap because admin credentials are empty")
+		return
+	}
+
+	var user models.User
+	err := db.Where("email = ?", email).First(&user).Error
+	if err == nil {
+		if !user.IsAdmin {
+			if updateErr := db.Model(&user).Update("is_admin", true).Error; updateErr != nil {
+				log.Fatalf("failed to promote default admin user: %v", updateErr)
+			}
+		}
+		return
+	}
+
+	if err != gorm.ErrRecordNotFound {
+		log.Fatalf("failed to check default admin user: %v", err)
+	}
+
+	passwordHash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
+	if err != nil {
+		log.Fatalf("failed to hash default admin password: %v", err)
+	}
+
+	user = models.User{
+		Email:        email,
+		PasswordHash: string(passwordHash),
+		IsAdmin:      true,
+	}
+	if err := db.Create(&user).Error; err != nil {
+		log.Fatalf("failed to create default admin user: %v", err)
+	}
+}

backend/internal/models/social_rating.go

@@ -0,0 +1,26 @@
+package models
+
+import "time"
+
+type SocialRatingOperation struct {
+	ID            uint      `json:"id" gorm:"primaryKey"`
+	TargetUserID  uint      `json:"targetUserId" gorm:"not null;index"`
+	TargetUser    User      `json:"-" gorm:"foreignKey:TargetUserID;constraint:OnUpdate:CASCADE,OnDelete:CASCADE"`
+	ActorUserID   *uint     `json:"actorUserId,omitempty" gorm:"index"`
+	ActorUser     *User     `json:"-" gorm:"foreignKey:ActorUserID;constraint:OnUpdate:CASCADE,OnDelete:SET NULL"`
+	Delta         int       `json:"delta" gorm:"not null"`
+	OperationType string    `json:"operationType" gorm:"size:32;not null;index"`
+	Reason        string    `json:"reason,omitempty" gorm:"size:255"`
+	Source        string    `json:"source,omitempty" gorm:"size:64;index"`
+	BalanceAfter  int       `json:"balanceAfter" gorm:"not null"`
+	CreatedAt     time.Time `json:"createdAt"`
+}
+
+type UserSocialRating struct {
+	UserID          uint      `json:"userId" gorm:"primaryKey"`
+	User            User      `json:"-" gorm:"foreignKey:UserID;constraint:OnUpdate:CASCADE,OnDelete:CASCADE"`
+	Score           int       `json:"score" gorm:"not null;default:0;index"`
+	LastOperationID *uint     `json:"lastOperationId,omitempty" gorm:"index"`
+	CreatedAt       time.Time `json:"createdAt"`
+	UpdatedAt       time.Time `json:"updatedAt"`
+}

backend/internal/models/user.go

@@ -0,0 +1,23 @@
+package models
+
+import (
+	"time"
+
+	"gorm.io/gorm"
+)
+
+type User struct {
+	ID           uint              `json:"id" gorm:"primaryKey"`
+	Email        string            `json:"email" gorm:"size:255;uniqueIndex;not null"`
+	PasswordHash string            `json:"-" gorm:"size:255;not null"`
+	IsAdmin      bool              `json:"isAdmin" gorm:"not null;default:false;index"`
+	SocialRating *UserSocialRating `json:"socialRating,omitempty" gorm:"foreignKey:UserID"`
+	CreatedAt    time.Time         `json:"createdAt"`
+	UpdatedAt    time.Time         `json:"updatedAt"`
+}
+
+func (u *User) AfterCreate(tx *gorm.DB) error {
+	return tx.FirstOrCreate(&UserSocialRating{}, UserSocialRating{
+		UserID: u.ID,
+	}).Error
+}

backend/internal/server/router.go

@@ -0,0 +1,49 @@
+package server
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/gin-contrib/cors"
+	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
+
+	"social-raiting.nekiiinkognito.ru/internal/auth"
+	"social-raiting.nekiiinkognito.ru/internal/config"
+	"social-raiting.nekiiinkognito.ru/internal/socialrating"
+)
+
+func NewRouter(db *gorm.DB, cfg config.Config) *gin.Engine {
+	router := gin.Default()
+	router.Use(cors.New(cors.Config{
+		AllowOrigins:     []string{"http://localhost:5173", "http://127.0.0.1:5173", "http://localhost:8081", "http://127.0.0.1:8081", "https://social-rating.nekiiinkognito.ru/"},
+		AllowMethods:     []string{"GET", "POST", "PUT", "PATCH", "DELETE", "OPTIONS"},
+		AllowHeaders:     []string{"Origin", "Content-Type", "Accept", "Authorization"},
+		ExposeHeaders:    []string{"Content-Length"},
+		AllowCredentials: true,
+		MaxAge:           12 * time.Hour,
+	}))
+
+	router.GET("/ping", func(ctx *gin.Context) {
+		ctx.JSON(http.StatusOK, gin.H{"message": "ok"})
+	})
+	router.StaticFile("/swagger.yaml", "./docs/swagger.yaml")
+
+	authHandler := auth.NewHandler(db, cfg.JWTSecret)
+	socialRatingHandler := socialrating.NewHandler(socialrating.NewService(db))
+
+	api := router.Group("/api")
+	api.POST("/auth/login", authHandler.Login)
+
+	protected := api.Group("/")
+	protected.Use(auth.Middleware(cfg.JWTSecret))
+	protected.GET("/auth/me", authHandler.Me)
+	protected.POST("/social-rating/increase", socialRatingHandler.Increase)
+	protected.POST("/social-rating/decrease", socialRatingHandler.Decrease)
+
+	admin := protected.Group("/")
+	admin.Use(auth.RequireAdmin(db))
+	admin.POST("/auth/register", authHandler.Register)
+
+	return router
+}

backend/internal/socialrating/handler.go

@@ -0,0 +1,99 @@
+package socialrating
+
+import (
+	"errors"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
+
+	"social-raiting.nekiiinkognito.ru/internal/models"
+)
+
+type Handler struct {
+	Service Service
+}
+
+type ChangeRequest struct {
+	TargetUserID uint   `json:"targetUserId" binding:"required"`
+	Amount       int    `json:"amount"`
+	Reason       string `json:"reason"`
+	Source       string `json:"source"`
+}
+
+type ChangeResponse struct {
+	Operation     models.SocialRatingOperation `json:"operation"`
+	CurrentRating models.UserSocialRating      `json:"currentRating"`
+}
+
+func NewHandler(service Service) Handler {
+	return Handler{Service: service}
+}
+
+func (h Handler) Increase(ctx *gin.Context) {
+	h.applySignedChange(ctx, "increase", 1)
+}
+
+func (h Handler) Decrease(ctx *gin.Context) {
+	h.applySignedChange(ctx, "decrease", -1)
+}
+
+func (h Handler) applySignedChange(ctx *gin.Context, operationType string, direction int) {
+	var req ChangeRequest
+	if err := ctx.ShouldBindJSON(&req); err != nil {
+		ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	actorUserID, ok := getActorUserID(ctx)
+	if !ok {
+		ctx.JSON(http.StatusUnauthorized, gin.H{"error": "missing user context"})
+		return
+	}
+
+	amount := req.Amount
+	if amount == 0 {
+		amount = 1
+	}
+	if amount < 0 {
+		ctx.JSON(http.StatusBadRequest, gin.H{"error": "amount must be greater than zero"})
+		return
+	}
+
+	operation, currentRating, err := h.Service.ApplyChange(ChangeInput{
+		TargetUserID:  req.TargetUserID,
+		ActorUserID:   &actorUserID,
+		Delta:         amount * direction,
+		OperationType: operationType,
+		Reason:        req.Reason,
+		Source:        req.Source,
+	})
+	if err != nil {
+		handleApplyChangeError(ctx, err)
+		return
+	}
+
+	ctx.JSON(http.StatusOK, ChangeResponse{
+		Operation:     operation,
+		CurrentRating: currentRating,
+	})
+}
+
+func getActorUserID(ctx *gin.Context) (uint, bool) {
+	value, exists := ctx.Get("userID")
+	if !exists {
+		return 0, false
+	}
+
+	userID, ok := value.(uint)
+	return userID, ok
+}
+
+func handleApplyChangeError(ctx *gin.Context, err error) {
+	switch {
+	case errors.Is(err, gorm.ErrRecordNotFound):
+		ctx.JSON(http.StatusNotFound, gin.H{"error": "user not found"})
+	default:
+		ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+	}
+}

backend/internal/socialrating/service.go

@@ -0,0 +1,97 @@
+package socialrating
+
+import (
+	"errors"
+	"strings"
+
+	"gorm.io/gorm"
+
+	"social-raiting.nekiiinkognito.ru/internal/models"
+)
+
+type Service struct {
+	DB *gorm.DB
+}
+
+type ChangeInput struct {
+	TargetUserID  uint
+	ActorUserID   *uint
+	Delta         int
+	OperationType string
+	Reason        string
+	Source        string
+}
+
+func NewService(db *gorm.DB) Service {
+	return Service{DB: db}
+}
+
+func (s Service) ApplyChange(input ChangeInput) (models.SocialRatingOperation, models.UserSocialRating, error) {
+	var operation models.SocialRatingOperation
+	var currentRating models.UserSocialRating
+
+	if err := validateChangeInput(input); err != nil {
+		return operation, currentRating, err
+	}
+
+	err := s.DB.Transaction(func(tx *gorm.DB) error {
+		if err := ensureUserExists(tx, input.TargetUserID); err != nil {
+			return err
+		}
+
+		if input.ActorUserID != nil {
+			if err := ensureUserExists(tx, *input.ActorUserID); err != nil {
+				return err
+			}
+		}
+
+		currentRating = models.UserSocialRating{UserID: input.TargetUserID}
+		if err := tx.FirstOrCreate(&currentRating, models.UserSocialRating{
+			UserID: input.TargetUserID,
+		}).Error; err != nil {
+			return err
+		}
+
+		// Social rating is allowed to go below zero, so no lower bound is applied here.
+		currentRating.Score += input.Delta
+
+		operation = models.SocialRatingOperation{
+			TargetUserID:  input.TargetUserID,
+			ActorUserID:   input.ActorUserID,
+			Delta:         input.Delta,
+			OperationType: strings.TrimSpace(input.OperationType),
+			Reason:        strings.TrimSpace(input.Reason),
+			Source:        strings.TrimSpace(input.Source),
+			BalanceAfter:  currentRating.Score,
+		}
+		if err := tx.Create(&operation).Error; err != nil {
+			return err
+		}
+
+		currentRating.LastOperationID = &operation.ID
+		return tx.Save(&currentRating).Error
+	})
+
+	return operation, currentRating, err
+}
+
+func validateChangeInput(input ChangeInput) error {
+	if input.TargetUserID == 0 {
+		return errors.New("target user id is required")
+	}
+
+	if strings.TrimSpace(input.OperationType) == "" {
+		return errors.New("operation type is required")
+	}
+
+	if input.Delta == 0 {
+		return errors.New("delta must not be zero")
+	}
+
+	return nil
+}
+
+func ensureUserExists(tx *gorm.DB, userID uint) error {
+	var user models.User
+	return tx.First(&user, "id = ?", userID).Error
+}

backend/main.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"log"
+
+	"social-raiting.nekiiinkognito.ru/internal/config"
+	"social-raiting.nekiiinkognito.ru/internal/database"
+	"social-raiting.nekiiinkognito.ru/internal/server"
+)
+
+func main() {
+	cfg := config.Load()
+	db := database.Connect(cfg)
+	router := server.NewRouter(db, cfg)
+
+	log.Printf("backend listening on :%s", cfg.ServerPort)
+	if err := router.Run(":" + cfg.ServerPort); err != nil {
+		log.Fatalf("failed to start server: %v", err)
+	}
+}