split transmission adapter helpers

2026-10-12 00:06:37 +08:00 · 2026-06-27 01:35:23 +08:00
parent ad1c3e55ba
commit 9f22e4060b
3 changed files with 233 additions and 219 deletions
@@ -0,0 +1,133 @@
+package service
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+)
+
+// transmissionRPCRequest 是 Transmission RPC 请求的通用结构。
+type transmissionRPCRequest struct {
+	Method    string                 `json:"method"`
+	Arguments map[string]interface{} `json:"arguments"`
+	Tag       int                    `json:"tag,omitempty"`
+}
+
+// transmissionRPCResponse 是 Transmission RPC 响应的通用结构。
+type transmissionRPCResponse struct {
+	Result    string                 `json:"result"`
+	Arguments map[string]interface{} `json:"arguments"`
+	Tag       int                    `json:"tag"`
+}
+
+// Initialize 配置并初始化 Transmission RPC 连接。
+func (a *TransmissionAdapter) Initialize(ctx context.Context, cfg DownloadClientConfig) error {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	endpoint, err := normalizeDownloadClientEndpoint("transmission", cfg.Host)
+	if err != nil {
+		return err
+	}
+	cfg.Host = endpoint
+	a.cfg = cfg
+	a.sessionID = ""
+	a.tag = 0
+	return a.pingLocked(ctx)
+}
+
+// Ping 测试连接。
+func (a *TransmissionAdapter) Ping(ctx context.Context) error {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.pingLocked(ctx)
+}
+
+// pingLocked 内部 ping 实现（调用者必须持有锁）。
+func (a *TransmissionAdapter) pingLocked(ctx context.Context) error {
+	rpcURL, err := downloadClientRPCURL("transmission", a.cfg.Host)
+	if err != nil {
+		return err
+	}
+	req, err := newDownloadClientHTTPRequest(ctx, http.MethodGet, rpcURL, nil)
+	if err != nil {
+		return err
+	}
+	if a.cfg.Username != "" {
+		req.SetBasicAuth(a.cfg.Username, a.cfg.Password)
+	}
+	resp, err := a.client.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	_, _ = io.Copy(io.Discard, resp.Body)
+	if resp.StatusCode == 409 {
+		// 正常：需要 CSRF token
+		a.sessionID = resp.Header.Get("X-Transmission-Session-Id")
+		return nil
+	}
+	if resp.StatusCode >= 400 {
+		return fmt.Errorf("transmission rpc: %d", resp.StatusCode)
+	}
+	return nil
+}
+
+// rpcLocked 发送 RPC 请求（调用者必须持有锁）。
+func (a *TransmissionAdapter) rpcLocked(ctx context.Context, method string, args map[string]interface{}) (*transmissionRPCResponse, error) {
+	rpcURL, err := downloadClientRPCURL("transmission", a.cfg.Host)
+	if err != nil {
+		return nil, err
+	}
+
+	a.tag++
+	body, err := json.Marshal(transmissionRPCRequest{
+		Method:    method,
+		Arguments: args,
+		Tag:       a.tag,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	for attempt := 0; attempt < 2; attempt++ {
+		req, err := newDownloadClientHTTPRequest(ctx, http.MethodPost, rpcURL, bytes.NewReader(body))
+		if err != nil {
+			return nil, err
+		}
+		req.Header.Set("Content-Type", "application/json")
+		if a.sessionID != "" {
+			req.Header.Set("X-Transmission-Session-Id", a.sessionID)
+		}
+		if a.cfg.Username != "" {
+			req.SetBasicAuth(a.cfg.Username, a.cfg.Password)
+		}
+
+		resp, err := a.client.Do(req)
+		if err != nil {
+			return nil, err
+		}
+		defer resp.Body.Close()
+
+		if resp.StatusCode == 409 {
+			a.sessionID = resp.Header.Get("X-Transmission-Session-Id")
+			continue
+		}
+		if resp.StatusCode >= 400 {
+			raw, _ := io.ReadAll(resp.Body)
+			return nil, fmt.Errorf("transmission rpc error: %d: %s", resp.StatusCode, string(raw))
+		}
+
+		var result transmissionRPCResponse
+		if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+			return nil, err
+		}
+		if result.Result != "success" {
+			return nil, fmt.Errorf("transmission rpc result: %s", result.Result)
+		}
+		return &result, nil
+	}
+	return nil, fmt.Errorf("transmission: failed after CSRF retry")
+}