# 账户域 (Account Domain)

## 一、领域概述

账户域负责管理银行账户的完整生命周期，包括实体账户（对应真实银行账户）和虚拟子账户（在实体账户下创建的逻辑账户）。

## 二、核心实体

### 2.1 实体账户 (PhysicalAccount)

实体账户对应真实的银行账户，是资金管理的基础单元。

```rust
pub struct PhysicalAccount {
    pub id: i64,                           // 账户ID
    pub account_no: String,                // 银行账号
    pub bank_code: String,                 // 银行代码
    pub bank_name: Option<String>,         // 银行名称
    pub consistency_mode: ConsistencyMode, // 一致性模式
    pub outbound_control: OutboundControl, // 出金管控模式
    pub status: AccountStatus,             // 账户状态
    pub created_at: DateTime<Utc>,         // 创建时间
    pub updated_at: DateTime<Utc>,         // 更新时间
}
```

**核心方法**：
- `is_active()` - 检查账户是否可用
- `can_outbound()` - 检查是否允许出金

### 2.2 虚拟子账户 (VirtualSubAccount)

虚拟子账户是在实体账户下创建的逻辑账户，用于资金隔离和管理。

```rust
pub struct VirtualSubAccount {
    pub id: i64,                             // 子账户ID
    pub physical_account_id: i64,            // 所属实体账户ID
    pub account_code: String,                // 子账户编号
    pub account_type: SubAccountType,        // 子账户类型
    pub valid_from: Option<DateTime<Utc>>,   // 有效期开始
    pub valid_to: Option<DateTime<Utc>>,     // 有效期结束
    pub status: AccountStatus,               // 账户状态
    pub created_at: DateTime<Utc>,           // 创建时间
    pub updated_at: DateTime<Utc>,           // 更新时间
}
```

**核心方法**：
- `is_active()` - 检查账户是否可用（考虑有效期）
- `is_temporary()` - 是否为临时账户
- `is_expired()` - 临时账户是否过期

### 2.3 账户控制 (AccountControl)

账户控制配置，用于设置对账频率和银行对接配置。

```rust
pub struct AccountControl {
    pub id: i64,
    pub physical_account_id: i64,
    pub reconciliation_interval: i32,        // 对账频率（分钟）
    pub direct_connect_config: Option<Value>, // 银企直连配置
    pub third_party_config: Option<Value>,    // 第三方支付配置
}
```

### 2.4 临时账户池 (SubAccountPool)

管理临时子账户的池，支持批量创建和自动销户。

```rust
pub struct SubAccountPool {
    pub id: i64,
    pub physical_account_id: i64,
    pub name: String,
    pub valid_from: DateTime<Utc>,
    pub valid_to: DateTime<Utc>,
    pub auto_close_rule: Option<Value>,  // 自动销户规则
}
```

## 三、枚举类型

### 3.1 账户状态 (AccountStatus)

```rust
pub enum AccountStatus {
    Active,  // 正常
    Frozen,  // 冻结
    Closed,  // 已关闭
}
```

**状态转移规则**：
```
Active ──► Frozen ──► Active
   │                    │
   └──────► Closed ◄────┘
```

### 3.2 一致性模式 (ConsistencyMode)

```rust
pub enum ConsistencyMode {
    Strong,   // 强一致性 - 交易需等待银行确认
    Eventual, // 最终一致性 - 先记账后对账
}
```

| 模式 | 特点 | 适用场景 |
|------|------|----------|
| Strong | 实时确认，响应慢 | 大额转账 |
| Eventual | 异步确认，响应快 | 小额高频 |

### 3.3 出金管控模式 (OutboundControl)

```rust
pub enum OutboundControl {
    ReceiveOnly, // 只收不付
    OnlineBank,  // 网银控制
    Token,       // 令牌控制
}
```

| 模式 | 说明 | 使用场景 |
|------|------|----------|
| ReceiveOnly | 禁止出金 | 归集账户 |
| OnlineBank | 网银审批出金 | 常规账户 |
| Token | 令牌验证出金 | 高安全账户 |

### 3.4 账户类型 (AccountType)

```rust
pub enum AccountType {
    Physical, // 实体账户
    Virtual,  // 虚拟账户
}
```

### 3.5 子账户类型 (SubAccountType)

```rust
pub enum SubAccountType {
    Settlement,  // 结算子账户
    Management,  // 管理子账户
    Temporary,   // 临时子账户
}
```

| 类型 | 说明 | 特点 |
|------|------|------|
| Settlement | 结算账户 | 长期使用，用于日常结算 |
| Management | 管理账户 | 内部管理，资金归集 |
| Temporary | 临时账户 | 有有效期，自动销户 |

## 四、领域服务

### 4.1 AccountService

账户域的核心服务，提供账户管理功能。

```rust
impl AccountService {
    // 创建实体账户
    pub async fn create_physical_account(&self, req: CreatePhysicalAccountRequest) -> Result<PhysicalAccount>;
    
    // 获取实体账户
    pub async fn get_physical_account(&self, id: i64) -> Result<PhysicalAccount>;
    
    // 获取实体账户列表（分页）
    pub async fn list_physical_accounts_paginated(
        &self, 
        status: Option<AccountStatus>,
        keyword: Option<String>,
        page: i32,
        page_size: i32
    ) -> Result<(Vec<PhysicalAccount>, i64)>;
    
    // 冻结实体账户
    pub async fn freeze_physical_account(&self, id: i64) -> Result<()>;
    
    // 解冻实体账户
    pub async fn unfreeze_physical_account(&self, id: i64) -> Result<()>;
    
    // 创建虚拟子账户
    pub async fn create_sub_account(&self, req: CreateVirtualSubAccountRequest) -> Result<VirtualSubAccount>;
    
    // 批量创建子账户
    pub async fn batch_create_sub_accounts(&self, req: BatchCreateSubAccountRequest) -> Result<Vec<VirtualSubAccount>>;
    
    // 关闭子账户
    pub async fn close_sub_account(&self, id: i64) -> Result<()>;
    
    // 获取实体账户下的子账户列表
    pub async fn list_sub_accounts(&self, physical_account_id: i64) -> Result<Vec<VirtualSubAccount>>;
}
```

## 五、仓储接口

### 5.1 PhysicalAccountRepository

```rust
#[async_trait]
pub trait PhysicalAccountRepository: Send + Sync {
    async fn create(&self, account: &PhysicalAccount) -> Result<i64>;
    async fn find_by_id(&self, id: i64) -> Result<Option<PhysicalAccount>>;
    async fn find_by_account_no(&self, account_no: &str) -> Result<Option<PhysicalAccount>>;
    async fn find_all(&self) -> Result<Vec<PhysicalAccount>>;
    async fn find_paginated(&self, status: Option<AccountStatus>, keyword: Option<String>, offset: i64, limit: i64) -> Result<Vec<PhysicalAccount>>;
    async fn count(&self, status: Option<AccountStatus>, keyword: Option<String>) -> Result<i64>;
    async fn update_status(&self, id: i64, status: AccountStatus) -> Result<()>;
}
```

### 5.2 VirtualSubAccountRepository

```rust
#[async_trait]
pub trait VirtualSubAccountRepository: Send + Sync {
    async fn create(&self, account: &VirtualSubAccount) -> Result<i64>;
    async fn find_by_id(&self, id: i64) -> Result<Option<VirtualSubAccount>>;
    async fn find_by_physical_account(&self, physical_account_id: i64) -> Result<Vec<VirtualSubAccount>>;
    async fn find_expired_temporary(&self) -> Result<Vec<VirtualSubAccount>>;
    async fn update_status(&self, id: i64, status: AccountStatus) -> Result<()>;
    async fn batch_create(&self, accounts: &[VirtualSubAccount]) -> Result<Vec<i64>>;
}
```

## 六、业务规则

### 6.1 账户创建规则

1. 银行账号必须唯一
2. 实体账户必须关联有效的银行代码
3. 子账户编号在同一实体账户下必须唯一
4. 临时账户必须设置有效期

### 6.2 账户状态规则

1. 只有 `Active` 状态的账户可以进行交易
2. `Frozen` 状态只影响出金，入金正常
3. `Closed` 状态不可进行任何交易
4. 账户关闭前必须余额为零

### 6.3 出金管控规则

1. `ReceiveOnly` 模式禁止任何出金操作
2. `OnlineBank` 模式需要通过网银审批
3. `Token` 模式需要提供有效令牌

## 七、API 接口

| 方法 | 路径 | 说明 |
|------|------|------|
| POST | /api/v1/physical-accounts | 创建实体账户 |
| GET | /api/v1/physical-accounts | 获取实体账户列表 |
| GET | /api/v1/physical-accounts/:id | 获取实体账户详情 |
| POST | /api/v1/physical-accounts/:id/freeze | 冻结实体账户资金 |
| POST | /api/v1/physical-accounts/:id/unfreeze | 解冻实体账户资金 |
| POST | /api/v1/sub-accounts | 创建虚拟子账户 |
| GET | /api/v1/sub-accounts/:id | 获取子账户详情 |
| GET | /api/v1/sub-accounts/:id/balance | 获取子账户余额 |
| POST | /api/v1/sub-accounts/:id/freeze | 冻结子账户资金 |
| POST | /api/v1/sub-accounts/:id/unfreeze | 解冻子账户资金 |
| POST | /api/v1/sub-accounts/:id/close | 关闭子账户 |
| GET | /api/v1/physical-accounts/:id/sub-accounts | 获取实体账户下的子账户列表 |

## 八、数据库表结构

### 8.1 physical_account 表

```sql
CREATE TABLE physical_account (
    id BIGINT PRIMARY KEY AUTO_INCREMENT,
    account_no VARCHAR(64) NOT NULL UNIQUE,
    account_name VARCHAR(128),
    bank_code VARCHAR(32) NOT NULL,
    bank_name VARCHAR(128),
    consistency_mode VARCHAR(32) DEFAULT 'eventual',
    outbound_control VARCHAR(32) DEFAULT 'online_bank',
    status VARCHAR(32) DEFAULT 'active',
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
    INDEX idx_bank_code (bank_code),
    INDEX idx_status (status)
);
```

### 8.2 virtual_sub_account 表

```sql
CREATE TABLE virtual_sub_account (
    id BIGINT PRIMARY KEY AUTO_INCREMENT,
    physical_account_id BIGINT NOT NULL,
    account_code VARCHAR(64) NOT NULL,
    account_type VARCHAR(32) DEFAULT 'settlement',
    valid_from TIMESTAMP NULL,
    valid_to TIMESTAMP NULL,
    status VARCHAR(32) DEFAULT 'active',
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
    FOREIGN KEY (physical_account_id) REFERENCES physical_account(id),
    UNIQUE INDEX idx_account_code (physical_account_id, account_code),
    INDEX idx_status (status),
    INDEX idx_valid_to (valid_to)
);
```

## 九、使用示例

### 9.1 创建实体账户

```rust
let req = CreatePhysicalAccountRequest {
    account_no: "6222021234567890123".to_string(),
    bank_code: "ICBC".to_string(),
    bank_name: Some("中国工商银行".to_string()),
    consistency_mode: Some(ConsistencyMode::Eventual),
    outbound_control: Some(OutboundControl::OnlineBank),
};

let account = account_service.create_physical_account(req).await?;
```

### 9.2 创建子账户

```rust
let req = CreateVirtualSubAccountRequest {
    physical_account_id: 1,
    account_code: "SUB001".to_string(),
    account_type: SubAccountType::Settlement,
    valid_from: None,
    valid_to: None,
};

let sub_account = account_service.create_sub_account(req).await?;
```

### 9.3 批量创建临时账户

```rust
let req = BatchCreateSubAccountRequest {
    physical_account_id: 1,
    account_type: SubAccountType::Temporary,
    prefix: "TEMP".to_string(),
    count: 100,
    valid_from: Some(Utc::now()),
    valid_to: Some(Utc::now() + Duration::days(30)),
};

let accounts = account_service.batch_create_sub_accounts(req).await?;
```