✨ 添加下载管理和 metalink 解析

src-tauri/src/utils/download_manager.rs

@@ -0,0 +1,178 @@
+use std::collections::HashMap;
+use std::sync::Mutex;
+use crate::models::download::{DownloadStatus, DownloadTask};
+use crate::utils::metalink::parse_metalink;
+use crate::handlers::server::get_json_server_url;
+use crate::utils::{format_icon_url, UA};
+
+pub struct DownloadManager {
+    queue: Mutex<HashMap<String, DownloadTask>>,
+}
+
+impl DownloadManager {
+    pub fn new() -> Self {
+        DownloadManager {
+            queue: Mutex::new(HashMap::new()),
+        }
+    }
+
+    // 获取所有下载任务
+    pub fn get_downloads(&self) -> Result<Vec<DownloadTask>, String> {
+        let downloads = self.queue.lock().map_err(|e| e.to_string())?;
+        Ok(downloads.values().cloned().collect())
+    }
+
+    // 检查是否有正在下载的任务
+    fn has_downloading_task(&self) -> Result<bool, String> {
+        let downloads = self.queue.lock().map_err(|e| e.to_string())?;
+        Ok(downloads.values().any(|task| matches!(task.status, DownloadStatus::Downloading)))
+    }
+
+    // 获取下一个等待下载的任务
+    fn get_next_queued_task(&self) -> Result<Option<String>, String> {
+        let downloads = self.queue.lock().map_err(|e| e.to_string())?;
+        Ok(downloads
+            .iter()
+            .find(|(_, task)| matches!(task.status, DownloadStatus::Queued))
+            .map(|(task_id, _)| task_id.clone()))
+    }
+
+    // 开始下载下一个任务
+    fn start_next_download(&self) -> Result<(), String> {
+        let mut downloads = self.queue.lock().map_err(|e| e.to_string())?;
+        if let Some(task_id) = self.get_next_queued_task()? {
+            if let Some(task) = downloads.get_mut(&task_id) {
+                task.status = DownloadStatus::Downloading;
+            }
+        }
+        Ok(())
+    }
+
+    // 添加下载任务
+    pub async fn add_download(&self, category: String, pkgname: String, filename: String, name: String) -> Result<(), String> {
+        let task_id = format!("{}/{}", category, pkgname);
+        
+        // 获取metalink文件URL和内容（在获取锁之前完成）
+        let json_server_url = get_json_server_url();
+        let metalink_url = format!("{}{}/{}/{}.metalink", json_server_url, category, pkgname, filename);
+        
+        // 发送请求获取metalink文件
+        let client = reqwest::Client::new();
+        let response = client
+            .get(&metalink_url)
+            .header("User-Agent", UA)
+            .send()
+            .await
+            .map_err(|e| format!("获取metalink文件失败: {}", e))?;
+            
+        // 检查响应状态
+        if !response.status().is_success() {
+            return Err(format!("获取metalink文件失败: HTTP {}", response.status()));
+        }
+
+        // 解析 metalink 内容
+        let metalink_content = response.text().await
+            .map_err(|e| format!("读取metalink内容失败: {}", e))?;
+        
+        let metalink_data = parse_metalink(&metalink_content)?;
+
+        println!("{:?}", metalink_data);
+        
+        // 获取一次锁，完成所有状态更新操作
+        let mut downloads = self.queue.lock().map_err(|e| e.to_string())?;
+        
+        // 检查任务是否已存在
+        if downloads.contains_key(&task_id) {
+            return Ok(());
+        }
+        
+        // 检查是否有正在下载的任务
+        let has_downloading = downloads.values().any(|task| matches!(task.status, DownloadStatus::Downloading));
+        let initial_status = if has_downloading {
+            DownloadStatus::Queued
+        } else {
+            DownloadStatus::Downloading
+        };
+        
+        // 创建下载任务
+        let task = DownloadTask {
+            category: category.clone(),
+            pkgname: pkgname.clone(),
+            filename,
+            name,
+            icon: format_icon_url(&category, &pkgname),
+            status: initial_status,
+            progress: 0.0,
+            speed: None,
+            size: None,
+            metalink: metalink_data,
+        };
+        
+        // 添加任务到队列
+        downloads.insert(task_id, task);
+        
+        Ok(())
+    }
+
+    // 暂停下载任务
+    pub fn pause_download(&self, category: String, pkgname: String) -> Result<(), String> {
+        let mut downloads = self.queue.lock().map_err(|e| e.to_string())?;
+        let task_id = format!("{}/{}", category, pkgname);
+        
+        if let Some(task) = downloads.get_mut(&task_id) {
+            let old_status = task.status.clone();
+            task.status = DownloadStatus::Paused;
+            if matches!(old_status, DownloadStatus::Downloading) {
+                self.start_next_download()?;
+            }
+        }
+        Ok(())
+    }
+
+    // 恢复下载任务
+    pub fn resume_download(&self, category: String, pkgname: String) -> Result<(), String> {
+        let mut downloads = self.queue.lock().map_err(|e| e.to_string())?;
+        let task_id = format!("{}/{}", category, pkgname);
+        
+        // 先检查任务是否存在且处于暂停状态
+        let should_resume = downloads
+            .get(&task_id)
+            .map(|task| matches!(task.status, DownloadStatus::Paused))
+            .unwrap_or(false);
+        
+        if should_resume {
+            // 检查是否有其他正在下载的任务
+            let has_downloading = self.has_downloading_task()?;
+            
+            // 更新任务状态
+            if let Some(task) = downloads.get_mut(&task_id) {
+                task.status = if has_downloading {
+                    DownloadStatus::Queued
+                } else {
+                    DownloadStatus::Downloading
+                };
+            }
+        }
+        
+        Ok(())
+    }
+
+    // 取消下载任务
+    pub fn cancel_download(&self, category: String, pkgname: String) -> Result<(), String> {
+        let mut downloads = self.queue.lock().map_err(|e| e.to_string())?;
+        let task_id = format!("{}/{}", category, pkgname);
+        
+        let was_downloading = downloads
+            .get(&task_id)
+            .map(|task| matches!(task.status, DownloadStatus::Downloading))
+            .unwrap_or(false);
+        
+        downloads.remove(&task_id);
+        
+        if was_downloading {
+            self.start_next_download()?;
+        }
+        
+        Ok(())
+    }
+}