# Design Document: 知识库租户分组展示 (knowledge-tenant-view)

## Overview

本设计将知识库管理页面从扁平列表改造为两层结构：第一层按 `tenant_id` 分组展示租户汇总卡片，第二层展示某租户下的知识条目列表。改造涉及三个层面：

1. **后端 API 层** — 在 `knowledge_bp` 中新增租户汇总端点 `/api/knowledge/tenants`，并为现有 `/api/knowledge` 和 `/api/knowledge/stats` 端点增加 `tenant_id` 查询参数支持。
2. **业务逻辑层** — 在 `KnowledgeManager` 中新增 `get_tenant_summary()` 方法，并为 `get_knowledge_paginated()`、`search_knowledge()`、`get_knowledge_stats()` 方法增加 `tenant_id` 过滤参数。`add_knowledge_entry()` 方法也需接受 `tenant_id` 参数。
3. **前端展示层** — 在 `dashboard.js` 中实现 `Tenant_List_View` 和 `Tenant_Detail_View` 两个视图状态的切换逻辑，包括面包屑导航、统计面板上下文切换、搜索范围限定。

数据模型 `KnowledgeEntry` 已有 `tenant_id` 字段（`String(50)`, indexed），无需数据库迁移。

## Architecture

```mermaid
graph TD
    subgraph Frontend["前端 (dashboard.js)"]
        TLV[Tenant_List_View<br/>租户卡片列表]
        TDV[Tenant_Detail_View<br/>租户知识条目列表]
        Stats[统计面板<br/>全局/租户统计切换]
        Breadcrumb[面包屑导航]
    end

    subgraph API["Flask Blueprint (knowledge_bp)"]
        EP1["GET /api/knowledge/tenants"]
        EP2["GET /api/knowledge?tenant_id=X"]
        EP3["GET /api/knowledge/stats?tenant_id=X"]
        EP4["GET /api/knowledge/search?q=...&tenant_id=X"]
        EP5["POST /api/knowledge (含 tenant_id)"]
    end

    subgraph Service["KnowledgeManager"]
        M1[get_tenant_summary]
        M2[get_knowledge_paginated<br/>+tenant_id filter]
        M3[get_knowledge_stats<br/>+tenant_id filter]
        M4[search_knowledge<br/>+tenant_id filter]
        M5[add_knowledge_entry<br/>+tenant_id param]
    end

    subgraph DB["SQLAlchemy"]
        KE[KnowledgeEntry<br/>tenant_id indexed]
    end

    TLV -->|点击租户卡片| TDV
    TDV -->|面包屑返回| TLV
    TLV --> EP1
    TDV --> EP2
    TDV --> EP4
    Stats --> EP3
    TDV --> EP5

    EP1 --> M1
    EP2 --> M2
    EP3 --> M3
    EP4 --> M4
    EP5 --> M5

    M1 --> KE
    M2 --> KE
    M3 --> KE
    M4 --> KE
    M5 --> KE
```

### 设计决策

- **不引入新模型/表**：`tenant_id` 已存在于 `KnowledgeEntry`，聚合查询通过 `GROUP BY` 实现，无需额外的 Tenant 表。
- **视图状态管理在前端**：使用 JS 变量 `currentTenantId` 控制当前视图层级，避免引入前端路由框架。
- **统计面板复用**：同一个统计面板根据 `currentTenantId` 是否为 `null` 决定请求全局或租户级统计。
- **搜索范围自动限定**：当处于 `Tenant_Detail_View` 时，搜索请求自动附加 `tenant_id` 参数。

## Components and Interfaces

### 1. KnowledgeManager 新增/修改方法

```python
# 新增方法
def get_tenant_summary(self) -> List[Dict[str, Any]]:
    """
    按 tenant_id 聚合活跃知识条目，返回租户汇总列表。
    返回格式: [
        {
            "tenant_id": "market_a",
            "entry_count": 42,
            "verified_count": 30,
            "category_distribution": {"FAQ": 20, "故障排查": 22}
        }, ...
    ]
    按 entry_count 降序排列。
    """

# 修改方法签名
def get_knowledge_paginated(
    self, page=1, per_page=10,
    category_filter='', verified_filter='',
    tenant_id: Optional[str] = None  # 新增
) -> Dict[str, Any]

def search_knowledge(
    self, query: str, top_k=3,
    verified_only=True,
    tenant_id: Optional[str] = None  # 新增
) -> List[Dict[str, Any]]

def get_knowledge_stats(
    self,
    tenant_id: Optional[str] = None  # 新增
) -> Dict[str, Any]

def add_knowledge_entry(
    self, question, answer, category,
    confidence_score=0.5, is_verified=False,
    tenant_id: Optional[str] = None  # 新增，默认取 config
) -> bool
```

### 2. Knowledge API 新增/修改端点

| 端点 | 方法 | 变更 | 说明 |
|------|------|------|------|
| `/api/knowledge/tenants` | GET | 新增 | 返回租户汇总数组 |
| `/api/knowledge` | GET | 修改 | 增加 `tenant_id` 查询参数 |
| `/api/knowledge/stats` | GET | 修改 | 增加 `tenant_id` 查询参数 |
| `/api/knowledge/search` | GET | 修改 | 增加 `tenant_id` 查询参数 |
| `/api/knowledge` | POST | 修改 | 请求体增加 `tenant_id` 字段 |

### 3. 前端组件

| 组件 | 职责 |
|------|------|
| `loadTenantList()` | 请求 `/api/knowledge/tenants`，渲染租户卡片 |
| `loadTenantDetail(tenantId, page)` | 请求 `/api/knowledge?tenant_id=X`，渲染知识条目列表 |
| `renderBreadcrumb(tenantId)` | 渲染面包屑 "知识库 > {tenant_id}" |
| `loadKnowledgeStats(tenantId)` | 根据 tenantId 是否为 null 请求全局/租户统计 |
| `searchKnowledge()` | 搜索时自动附加 `currentTenantId` |

## Data Models

### KnowledgeEntry（现有，无变更）

```python
class KnowledgeEntry(Base):
    __tablename__ = "knowledge_entries"
    id = Column(Integer, primary_key=True)
    tenant_id = Column(String(50), nullable=False, default="default", index=True)
    question = Column(Text, nullable=False)
    answer = Column(Text, nullable=False)
    category = Column(String(100), nullable=False)
    confidence_score = Column(Float, default=0.0)
    usage_count = Column(Integer, default=0)
    created_at = Column(DateTime, default=datetime.now)
    updated_at = Column(DateTime, default=datetime.now, onupdate=datetime.now)
    is_active = Column(Boolean, default=True)
    is_verified = Column(Boolean, default=False)
    verified_by = Column(String(100))
    verified_at = Column(DateTime)
    vector_embedding = Column(Text)
    search_frequency = Column(Integer, default=0)
    last_accessed = Column(DateTime)
    relevance_score = Column(Float)
```

### Tenant Summary（API 响应结构，非持久化）

```json
{
    "tenant_id": "market_a",
    "entry_count": 42,
    "verified_count": 30,
    "category_distribution": {
        "FAQ": 20,
        "故障排查": 22
    }
}
```

### Stats 响应结构（扩展）

```json
{
    "total_entries": 100,
    "active_entries": 80,
    "category_distribution": {"FAQ": 40, "故障排查": 60},
    "average_confidence": 0.85,
    "tenant_id": "market_a"  // 新增，仅当按租户筛选时返回
}
```


## Correctness Properties

*A property is a characteristic or behavior that should hold true across all valid executions of a system — essentially, a formal statement about what the system should do. Properties serve as the bridge between human-readable specifications and machine-verifiable correctness guarantees.*

### Property 1: Tenant summary correctly aggregates active entries

*For any* set of `KnowledgeEntry` records with mixed `is_active` and `tenant_id` values, calling `get_tenant_summary()` should return a list where each element's `entry_count` equals the number of active entries for that `tenant_id`, each `verified_count` equals the number of active+verified entries for that `tenant_id`, and each `category_distribution` correctly reflects the category counts of active entries for that `tenant_id`.

**Validates: Requirements 1.1, 1.2**

### Property 2: Tenant summary sorted by entry_count descending

*For any* result returned by `get_tenant_summary()`, the list should be sorted such that for every consecutive pair of elements `(a, b)`, `a.entry_count >= b.entry_count`.

**Validates: Requirements 1.3**

### Property 3: Knowledge entry filtering by tenant, category, and verified status

*For any* combination of `tenant_id`, `category_filter`, and `verified_filter` parameters, all entries returned by `get_knowledge_paginated()` should satisfy all specified filter conditions simultaneously. Specifically: every returned entry's `tenant_id` matches the requested `tenant_id`, every returned entry's `category` matches `category_filter` (if provided), and every returned entry's `is_verified` matches `verified_filter` (if provided).

**Validates: Requirements 2.1, 2.3**

### Property 4: Pagination consistency with tenant filter

*For any* `tenant_id` and valid `page`/`per_page` values, the entries returned by `get_knowledge_paginated(tenant_id=X, page=P, per_page=N)` should be a correct slice of the full filtered result set. The `total` field should equal the count of all matching entries, `total_pages` should equal `ceil(total / per_page)`, and the number of returned entries should equal `min(per_page, total - (page-1)*per_page)` when `page <= total_pages`.

**Validates: Requirements 2.2**

### Property 5: New entry tenant association

*For any* valid `tenant_id` and valid entry data (question, answer, category), calling `add_knowledge_entry(tenant_id=X, ...)` should result in the newly created `KnowledgeEntry` record having `tenant_id == X`. If `tenant_id` is not provided, it should default to the configured `get_config().server.tenant_id`.

**Validates: Requirements 5.2**

### Property 6: Search results scoped to tenant

*For any* search query and `tenant_id`, all results returned by `search_knowledge(query=Q, tenant_id=X)` should have `tenant_id == X`. The result set should be a subset of what `search_knowledge(query=Q)` returns (without tenant filter).

**Validates: Requirements 6.2**

### Property 7: Stats scoped to tenant

*For any* `tenant_id`, the statistics returned by `get_knowledge_stats(tenant_id=X)` should reflect only entries with `tenant_id == X`. Specifically, `total_entries` should equal the count of active entries for that tenant, and `average_confidence` should equal the mean confidence of those entries. When `tenant_id` is omitted, the stats should aggregate across all tenants.

**Validates: Requirements 7.3, 7.4**

## Error Handling

### API 层错误处理

所有 API 端点已使用 `@handle_api_errors` 装饰器，该装饰器捕获以下异常：

| 异常类型 | HTTP 状态码 | 说明 |
|----------|------------|------|
| `ValueError` | 400 | 参数校验失败（如 `page < 1`） |
| `PermissionError` | 403 | 权限不足 |
| `Exception` | 500 | 数据库查询失败等未预期错误 |

### 业务逻辑层错误处理

- `get_tenant_summary()` — 数据库异常时返回空列表 `[]`，记录 error 日志。
- `get_knowledge_paginated()` — 异常时返回空结构 `{"knowledge": [], "total": 0, ...}`（现有行为保持不变）。
- `get_knowledge_stats()` — 异常时返回空字典 `{}`（现有行为保持不变）。
- `add_knowledge_entry()` — 异常时返回 `False`，记录 error 日志。

### 前端错误处理

- API 请求失败时通过 `showNotification(message, 'error')` 展示错误提示。
- 网络超时或断连时显示通用错误消息。
- 批量操作部分失败时显示成功/失败计数。

## Testing Strategy

### 测试框架

- **单元测试**: `pytest`
- **属性测试**: `hypothesis`（Python property-based testing 库）
- **每个属性测试最少运行 100 次迭代**

### 属性测试（Property-Based Tests）

每个 Correctness Property 对应一个属性测试，使用 `hypothesis` 的 `@given` 装饰器生成随机输入。

测试标签格式: `Feature: knowledge-tenant-view, Property {number}: {property_text}`

| Property | 测试描述 | 生成策略 |
|----------|---------|---------|
| Property 1 | 生成随机 KnowledgeEntry 列表（混合 tenant_id、is_active），验证 `get_tenant_summary()` 聚合正确性 | `st.lists(st.builds(KnowledgeEntry, tenant_id=st.sampled_from([...]), is_active=st.booleans()))` |
| Property 2 | 验证 `get_tenant_summary()` 返回列表按 entry_count 降序 | 复用 Property 1 的生成策略 |
| Property 3 | 生成随机 tenant_id + category + verified 组合，验证过滤结果一致性 | `st.sampled_from(tenant_ids)`, `st.sampled_from(categories)`, `st.sampled_from(['true','false',''])` |
| Property 4 | 生成随机 page/per_page，验证分页切片正确性 | `st.integers(min_value=1, max_value=10)` for page/per_page |
| Property 5 | 生成随机 tenant_id 和条目数据，验证新建条目的 tenant_id | `st.text(min_size=1, max_size=50)` for tenant_id |
| Property 6 | 生成随机搜索词和 tenant_id，验证搜索结果范围 | `st.text()` for query, `st.sampled_from(tenant_ids)` |
| Property 7 | 生成随机 tenant_id，验证统计数据与手动聚合一致 | `st.sampled_from(tenant_ids)` + `st.none()` |

### 单元测试（Unit Tests）

单元测试聚焦于边界情况和具体示例：

- **边界**: 无活跃条目时 `get_tenant_summary()` 返回空数组
- **边界**: 不存在的 `tenant_id` 查询返回空列表 + `total=0`
- **示例**: 数据库异常时 API 返回 500
- **示例**: `add_knowledge_entry` 不传 `tenant_id` 时使用配置默认值
- **集成**: 前端 `loadTenantList()` → API → Manager 完整链路

### 测试配置

```python
from hypothesis import settings

@settings(max_examples=100)
```

每个属性测试函数头部添加注释引用设计文档中的 Property 编号，例如：

```python
# Feature: knowledge-tenant-view, Property 1: Tenant summary correctly aggregates active entries
@given(entries=st.lists(knowledge_entry_strategy(), min_size=0, max_size=50))
def test_tenant_summary_aggregation(entries):
    ...
```