%% 坐席端截图+拍照功能 — 时序图
%% 文件: docs/03-技术架构/sequence-diagram.mermaid
%% 包含 4 个关键流程：截图、拍照、图文发送、初始化与资源清理

%% ============================================
%% 流程 1：截图完整流程
%% ============================================
sequenceDiagram
    participant User as 用户
    participant RB as ReplyBox.vue
    participant USC as useScreenCapture
    participant SC as ScreenCapture.vue
    participant UPI as usePendingImages
    participant PIP as PendingImagePreview.vue

    User->>RB: 点击截图按钮
    RB->>RB: handleScreenshot()
    RB->>USC: captureScreenAsCanvas()
    
    Note over USC: 浏览器弹出 getDisplayMedia 选择器
    User->>USC: 选择屏幕/窗口/标签页
    
    USC->>USC: getDisplayMedia() 获取视频流
    USC->>USC: video.play() → canvas.drawImage() 捕获一帧
    USC->>USC: stream.getTracks().stop() 停止共享
    USC-->>RB: 返回 HTMLCanvasElement
    
    RB->>RB: screenshotCanvas = canvas
    RB->>RB: showScreenCapture = true
    
    Note over SC: 组件挂载，显示全屏遮罩
    SC->>SC: 初始化：底图 Canvas + 遮罩 Canvas
    SC->>SC: drawMask() 绘制半透明遮罩
    
    User->>SC: 鼠标拖拽框选区域
    SC->>SC: 更新 box {x, y, w, h}
    SC->>SC: drawMask() 清除选区内遮罩
    
    User->>SC: 选择马赛克工具
    User->>SC: 在选区内拖拽涂抹
    SC->>SC: saveHistory() 保存当前状态
    SC->>SC: drawMosaic() 像素化处理
    
    User->>SC: 选择箭头工具
    User->>SC: 拖拽绘制箭头
    SC->>SC: saveHistory() 保存当前状态
    SC->>SC: drawArrow() 绘制箭头线段
    
    User->>SC: 点击撤销
    SC->>SC: historyIndex--
    SC->>SC: ctx.putImageData() 恢复上一状态
    
    User->>SC: 点击确认 ✓
    SC->>SC: 从编辑 Canvas 裁剪选区
    SC->>SC: canvas.toBlob() 转 Blob
    SC-->>RB: emit('confirm', blob)
    
    RB->>RB: showScreenCapture = false
    RB->>UPI: addImage(blob, 'screenshot')
    
    UPI->>UPI: URL.createObjectURL(blob) 生成预览URL
    UPI->>UPI: images.push({ id, blob, previewUrl, source })
    UPI-->>RB: 队列已更新
    
    RB->>PIP: 响应式传递 images
    PIP->>PIP: 渲染缩略图 + × 删除按钮
    PIP-->>User: 显示待发送图片预览

%% ============================================
%% 流程 2：拍照完整流程
%% ============================================
sequenceDiagram
    participant User as 用户
    participant RB as ReplyBox.vue
    participant CC as CameraCapture.vue
    participant UC as useCamera
    participant UPI as usePendingImages

    User->>RB: 点击拍照按钮
    RB->>RB: handleCamera()
    RB->>RB: showCameraDialog = true
    RB->>CC: 挂载组件（v-model=true）
    
    CC->>CC: ElMessage.info('即将请求摄像头权限...')
    CC->>UC: startCamera()
    
    UC->>UC: getUserMedia({ video: { facingMode: 'user' } })
    Note over UC: 浏览器弹出权限请求
    User->>UC: 允许摄像头访问
    
    UC->>UC: stream 赋值到 video.srcObject
    UC->>UC: video.play()
    UC-->>CC: 摄像头预览已启动
    CC-->>User: 显示实时摄像头预览
    
    User->>CC: 点击拍照按钮
    CC->>UC: captureFrame()
    UC->>UC: canvas.drawImage(video, 0, 0)
    UC->>UC: canvas.toDataURL('image/png')
    UC-->>CC: 返回图片 dataURL
    CC->>CC: capturedImage = dataURL
    CC->>CC: 隐藏 video，显示 img 静态画面
    CC-->>User: 显示拍照结果 + 重拍/确认按钮
    
    alt 用户点击重拍
        User->>CC: 点击重拍
        CC->>CC: capturedImage = null
        CC->>CC: 恢复 video 实时预览
        CC-->>User: 回到实时预览状态
    else 用户点击确认
        User->>CC: 点击确认 ✓
        CC->>UC: captureFrame()
        CC->>CC: dataURL → Blob 转换
        CC->>UC: stopCamera() 停止摄像头
        CC-->>RB: emit('confirm', blob)
        CC-->>RB: emit('update:modelValue', false)
    end
    
    RB->>RB: showCameraDialog = false
    RB->>UPI: addImage(blob, 'camera')
    UPI->>UPI: 生成 previewUrl，加入队列
    UPI-->>RB: 队列已更新
    RB-->>User: 输入区显示拍照缩略图

%% ============================================
%% 流程 3：图文组合发送流程
%% ============================================
sequenceDiagram
    participant User as 用户
    participant RB as ReplyBox.vue
    participant UPI as usePendingImages
    participant API_U as uploadFile()
    participant API_M as sendMessage()
    participant Store as conversationStore

    User->>RB: 输入文字 + 有待发送图片
    User->>RB: 点击发送 / 按 Enter
    
    RB->>RB: handleSend()
    RB->>RB: content = inputText.trim()
    RB->>RB: hasImages = pendingImages.count > 0
    RB->>RB: hasText = content.length > 0
    
    alt 无图片且无文字
        RB->>RB: return（不发送）
    else 有图片
        RB->>RB: ElMessage.info('发送中...')
        RB->>UPI: 获取 images 数组
        
        loop 遍历每张图片
            RB->>API_U: uploadFile(image.blob)
            API_U-->>RB: { url, filename, file_size }
            
            RB->>API_M: sendMessage(convId, '[图片]', 'image', { media_url, file_name, file_size })
            API_M-->>RB: 返回新消息 Message
            RB->>Store: messages.push(newMsg)
        end
        
        RB->>UPI: clearAll() 清空图片队列
        RB->>RB: URL.revokeObjectURL() 释放预览URL
    end
    
    opt 有文字
        RB->>RB: emit('send', content)
        RB->>RB: inputText = ''
    end
    
    RB->>RB: textareaHeight = 60
    RB-->>User: 发送完成，输入区清空

%% ============================================
%% 流程 4：组件初始化与资源清理
%% ============================================
sequenceDiagram
    participant RB as ReplyBox
    participant SC as ScreenCapture
    participant CC as CameraCapture
    participant UPI as usePendingImages

    Note over RB: 组件挂载 onMounted
    RB->>RB: 注册全局快捷键
    
    Note over RB: 用户触发截图
    RB->>SC: v-if="showScreenCapture" 挂载
    SC->>SC: onMounted → 初始化 Canvas、事件监听
    SC->>SC: drawMask() 绘制初始遮罩
    
    Note over RB: 截图取消/确认
    RB->>SC: v-if=false 卸载
    SC->>SC: onUnmounted → 移除事件监听、清空 history
    
    Note over RB: 用户触发拍照
    RB->>CC: v-model=true 挂载
    CC->>CC: onMounted → startCamera()
    
    Note over RB: 拍照取消/确认
    RB->>CC: v-model=false 卸载
    CC->>CC: onUnmounted → stopCamera() 停止流
    
    Note over RB: ReplyBox 卸载
    RB->>RB: onUnmounted
    RB->>UPI: clearAll() → revokeObjectURL 释放内存
    RB->>RB: 移除快捷键监听