feat(service): 实现阶段 4 业务逻辑 — Agent、Runner、Assembler、ChatService

internal/service/runner.go

@@ -1 +1,68 @@
 package service
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"ai-agent-scaffold-go/internal/model"
+)
+
+// RunnerImpl Runner 的默认实现
+type RunnerImpl struct {
+	appName string
+	agent   model.Agent
+}
+
+// NewRunner 创建 Runner
+func NewRunner(appName string, agent model.Agent) *RunnerImpl {
+	return &RunnerImpl{
+		appName: appName,
+		agent:   agent,
+	}
+}
+
+// CreateSession 创建会话 ID
+func (r *RunnerImpl) CreateSession(userID string) (string, error) {
+	if strings.TrimSpace(userID) == "" {
+		return "", fmt.Errorf("user id is required")
+	}
+	next := sessionCounter.Add(1)
+	return fmt.Sprintf("%s:%s:%d", r.appName, userID, next), nil
+}
+
+// Run 同步执行
+func (r *RunnerImpl) Run(userID, sessionID string, content model.ChatContent) ([]string, error) {
+	if strings.TrimSpace(userID) == "" || strings.TrimSpace(sessionID) == "" {
+		return nil, fmt.Errorf("user id and session id are required")
+	}
+	output, err := r.agent.Run(context.Background(), content)
+	if err != nil {
+		return nil, err
+	}
+	if output == "" {
+		return []string{}, nil
+	}
+	return []string{output}, nil
+}
+
+// Stream 流式执行
+func (r *RunnerImpl) Stream(userID, sessionID string, content model.ChatContent) (<-chan string, <-chan error) {
+	outputs := make(chan string, 8)
+	errs := make(chan error, 1)
+
+	go func() {
+		defer close(outputs)
+		defer close(errs)
+
+		if strings.TrimSpace(userID) == "" || strings.TrimSpace(sessionID) == "" {
+			errs <- fmt.Errorf("user id and session id are required")
+			return
+		}
+		if err := r.agent.Stream(context.Background(), content, outputs); err != nil {
+			errs <- err
+		}
+	}()
+
+	return outputs, errs
+}