# Inbox Messages 协议

本文档定义 `/api/v1/inbox/messages` 的收件箱消息协议。

Base URL: `/api/v1/inbox/messages`

---

## 端点

| 方法 | 路径 | 说明 |
|---|---|---|
| GET | `` | 获取消息列表 |
| PATCH | `/{message_id}/read` | 标记消息为已读 |
| GET | `/stream` | 订阅收件箱实时事件（SSE） |

---

## 枚举类型

### InboxMessageType

| 值 | 说明 |
|---|---|
| `friend_request` | 好友申请 |
| `calendar` | 日历消息 |
| `system` | 系统消息 |
| `group` | 群组消息 |

### InboxMessageStatus

| 值 | 说明 |
|---|---|
| `pending` | 待处理 |
| `accepted` | 已接受 |
| `rejected` | 已拒绝 |
| `dismissed` | 已忽略 |

---

## 消息内容类型

### CalendarInviteContent (schema_version=2)

```json
{
  "type": "invite",
  "schema_version": 2,
  "item": {
    "id": "uuid",
    "title": "string",
    "description": "string | null",
    "start_at": "datetime",
    "end_at": "datetime | null",
    "timezone": "string"
  },
  "actor": {
    "user_id": "uuid",
    "username": "string",
    "phone": "string | null"
  },
  "summary": "string",
  "permission": "int (1=view, 2=invite, 4=edit, 8=delete, 15=owner)",
  "action": "pending"
}
```

说明：`description/start_at/end_at/timezone/actor.phone` 为 `invite` 类型的扩展字段，
用于前端展示邀请详情（邀请人、联系电话、时间区间、描述）。

### CalendarUpdateContent (schema_version=2)

```json
{
  "type": "updated",
  "schema_version": 2,
  "item": {
    "id": "uuid",
    "title": "string"
  },
  "actor": {
    "user_id": "uuid",
    "username": "string"
  },
  "summary": "string",
  "changes": [
    {
      "field": "title | description | start_at | end_at | timezone | status",
      "label": "string",
      "before": "any | null",
      "after": "any | null",
      "display_before": "string | null",
      "display_after": "string | null",
      "change_type": "added | removed | modified"
    }
  ],
  "action": "updated"
}
```

### CalendarDeleteContent (schema_version=2)

```json
{
  "type": "deleted",
  "schema_version": 2,
  "item": {
    "id": "uuid",
    "title": "string"
  },
  "actor": {
    "user_id": "uuid",
    "username": "string"
  },
  "summary": "string",
  "changes": [],
  "action": "deleted"
}
```

### FriendshipContent

```json
{
  "type": "request",
  "message": "string | null"
}
```

---

## 数据结构

### InboxMessageResponse

```json
{
  "id": "uuid",
  "recipient_id": "uuid",
  "sender_id": "uuid | null",
  "message_type": "InboxMessageType",
  "schedule_item_id": "uuid | null",
  "friendship_id": "uuid | null",
  "content": "CalendarInviteContent | CalendarUpdateContent | CalendarDeleteContent | FriendshipContent | null",
  "is_read": "boolean",
  "status": "InboxMessageStatus",
  "created_at": "datetime"
}
```

---

## 1) GET `/`

获取消息列表。

### Query Parameters

- `is_read`: boolean | null（可选，筛选已读/未读状态）

### Response

`InboxMessageResponse` 对象数组。

---

## 2) PATCH `/{message_id}/read`

标记指定消息为已读。

### Path Parameters

- `message_id`: 消息 UUID

### Response

`InboxMessageResponse` 对象。

---

## 3) GET `/stream` (SSE)

订阅当前登录用户的 inbox 实时增量事件。

### Headers

- `Accept: text/event-stream`
- `Last-Event-ID`（可选）：断点续流游标，格式 `\d+-\d+`

### Query Parameters

- `idle_limit`: `1..3600`（可选，默认 `300`），连续空轮询上限，超过后服务端主动结束连接。

### SSE 事件帧

```text
id: 1743313300000-0
event: INBOX_MESSAGE_CREATED
data: {"event_id":"6f0d...","occurred_at":"2026-03-30T07:00:00Z","user_id":"...","message_id":"...","op":"created","version":1743313300000,"data":{"message":{...}}}

```

### 事件类型

- `INBOX_MESSAGE_CREATED`
- `INBOX_MESSAGE_READ_CHANGED`
- `INBOX_MESSAGE_STATUS_CHANGED`
- `INBOX_SNAPSHOT_REQUIRED`

### Event Envelope

```json
{
  "event_id": "uuid",
  "occurred_at": "datetime",
  "user_id": "uuid",
  "message_id": "uuid",
  "op": "created | read_changed | status_changed | snapshot_required",
  "version": 1743313300000,
  "data": {}
}
```

### Delta 约定

- `created`:

```json
{
  "message": {
    "id": "uuid",
    "recipient_id": "uuid",
    "sender_id": "uuid | null",
    "message_type": "InboxMessageType",
    "schedule_item_id": "uuid | null",
    "friendship_id": "uuid | null",
    "content": {},
    "is_read": false,
    "status": "pending",
    "created_at": "datetime"
  }
}
```

- `read_changed`:

```json
{
  "is_read": true
}
```

- `status_changed`:

```json
{
  "status": "accepted"
}
```

- `snapshot_required`:

```json
{}
```

### 幂等与补偿策略

- 客户端按 `message_id + version` 做幂等合并；旧版本事件必须丢弃。
- 若检测到版本跳跃或本地状态不可信，客户端应回退到 `GET /api/v1/inbox/messages` 全量快照。
- `id` 字段可用于 `Last-Event-ID` 断点续流。

### 前端渲染约束（强制）

- 对 `message_type=calendar`，前端必须按 `content.type` 严格分发：`invite | updated | deleted`。
- 若 `content` 缺少协议必填字段（`schema_version/item/actor/summary`，以及 `updated` 的 `changes`），前端必须进入协议异常展示路径。
- 禁止将协议异常消息兜底渲染为“默认日历邀请”或其他正常业务消息。