# Story 2.2: Identity Service - User Management

## Metadata
- **Story ID**: 2.2
- **Title**: Identity Service - User Management
- **Epic**: 2 - Core Services (Authentication & Authorization)
- **Status**: Pending
- **Priority**: High
- **Estimated Time**: 10-12 hours
- **Dependencies**: 1.1, 1.2, 1.5, 1.7

## Goal
Implement Identity Service as an independent microservice for user CRUD operations, password management, and email verification. The service exposes a gRPC server, manages its own database connection with User entity, and registers with Consul service registry.

## Description
This story implements the Identity Service as a separate, independently deployable microservice. It includes user registration, email verification, password reset/change, and user profile management via gRPC. The service has its own entry point, database connection with User entity schema, and service registration.

## Deliverables

### 1. Service Entry Point (`cmd/identity-service/main.go`)
- Independent service entry point
- Bootstrap with core kernel services
- Register with Consul service registry
- Start gRPC server on configured port (default: 8082)
- Graceful shutdown with service deregistration

### 2. gRPC Service Definition (`api/proto/identity.proto`)
- `CreateUserRequest` / `CreateUserResponse` - User registration
- `GetUserRequest` / `GetUserResponse` - Get user by ID
- `GetUserByEmailRequest` / `GetUserByEmailResponse` - Get user by email
- `UpdateUserRequest` / `UpdateUserResponse` - Update user profile
- `DeleteUserRequest` / `DeleteUserResponse` - Delete user
- `VerifyEmailRequest` / `VerifyEmailResponse` - Email verification
- `RequestPasswordResetRequest` / `RequestPasswordResetResponse` - Password reset request
- `ResetPasswordRequest` / `ResetPasswordResponse` - Password reset
- `ChangePasswordRequest` / `ChangePasswordResponse` - Password change
- `IdentityService` gRPC service definition

### 3. gRPC Server Implementation (`services/identity/internal/api/server.go`)
- gRPC server implementation
- Handlers for all user operations
- Integration with Identity Service business logic

### 4. Identity Service Implementation (`services/identity/internal/service/user_service.go`)
- User registration with email verification token generation
- Email verification flow
- Password reset flow (token-based, time-limited)
- Password change with old password verification
- User profile updates
- User deletion (soft delete option)
- Password hashing (argon2id)
- Email uniqueness validation

### 5. User Repository (`services/identity/internal/repository/user_repo.go`)
- CRUD operations using Ent
- User lookup by ID and email
- User search and pagination
- Ent schema integration

### 6. Database Connection and Schema (`services/identity/ent/schema/user.go`)
- Identity Service database connection (schema: `identity`)
- User entity schema:
  - ID, email, password_hash, verified, created_at, updated_at
  - Email verification token, password reset token
- Migration support
- Per-service connection pool

### 7. Service Client Integration
- Uses `AuditServiceClient` to log user operations
- Service discovery via Consul

### 8. Service Registration
- Register with Consul on startup
- Health check endpoint for Consul
- Service metadata (name: `identity-service`, port: 8082)
- Deregister on shutdown

## Acceptance Criteria
- [x] Identity Service is independently deployable
- [x] Service entry point exists at `cmd/identity-service/main.go`
- [x] Service registers with Consul on startup
- [x] gRPC server starts on configured port (8082)
- [x] CreateUser RPC registers new users with password hashing
- [x] GetUser/GetUserByEmail RPCs retrieve user data
- [x] UpdateUser RPC updates user profiles
- [x] VerifyEmail RPC verifies email addresses
- [x] Password reset flow works via RPCs
- [x] Service has its own database connection (identity schema)
- [x] User entity schema is defined and migrated
- [x] Service uses AuditServiceClient for logging
- [x] Service can be discovered by other services via Consul
- [x] Health check endpoint works for Consul

## Related ADRs
- [ADR-0018: Password Hashing](../../adr/0018-password-hashing.md)
- [ADR-0029: Microservices Architecture](../../adr/0029-microservices-architecture.md)
- [ADR-0030: Service Communication Strategy](../../adr/0030-service-communication-strategy.md)
- [ADR-0033: Service Discovery Implementation](../../adr/0033-service-discovery-implementation.md)

## Testing
```bash
# Test Identity Service
go test ./services/identity/...

# Test service startup
go run cmd/identity-service/main.go

# Test gRPC service
grpcurl -plaintext localhost:8082 list
grpcurl -plaintext -d '{"email":"user@example.com","password":"password"}' \
  localhost:8082 identity.IdentityService/CreateUser
```

## Files to Create/Modify
- `cmd/identity-service/main.go` - Service entry point
- `api/proto/identity.proto` - gRPC service definition
- `services/identity/internal/api/server.go` - gRPC server implementation
- `services/identity/internal/service/user_service.go` - User service logic
- `services/identity/internal/repository/user_repo.go` - User repository
- `services/identity/ent/schema/user.go` - User entity schema
- `config/default.yaml` - Add identity service configuration