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

This commit is contained in:
hhs
2026-06-10 15:13:21 +08:00
parent 658866a661
commit f532b21a7a
4 changed files with 706 additions and 0 deletions

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@@ -1 +1,422 @@
package service
import (
"context"
"fmt"
"strings"
"sync/atomic"
"ai-agent-scaffold-go/internal/model"
)
const maxToolCallIterations = 4
// ChatModelWithTools 扩展接口,同时具备 ChatModel 和工具调用能力
type ChatModelWithTools interface {
model.ChatModel
CallTool(ctx context.Context, name, arguments string) (string, error)
}
// ============================================================
// LLMAgent — 基础 LLM Agent
// ============================================================
// LLMAgent 基于 LLM 的智能体,支持多轮工具调用
type LLMAgent struct {
name string
description string
instruction string
outputKey string
chatModel ChatModelWithTools
}
// NewLLMAgent 创建 LLM Agent
func NewLLMAgent(name, instruction, description, outputKey string, chatModel ChatModelWithTools) *LLMAgent {
return &LLMAgent{
name: name,
instruction: instruction,
description: description,
outputKey: outputKey,
chatModel: chatModel,
}
}
func (a *LLMAgent) Name() string { return a.name }
func (a *LLMAgent) OutputKey() string { return a.outputKey }
// Run 同步执行
func (a *LLMAgent) Run(ctx context.Context, content model.ChatContent) (string, error) {
return a.runWithVars(ctx, content, map[string]string{})
}
// Stream 流式执行
func (a *LLMAgent) Stream(ctx context.Context, content model.ChatContent, out chan<- string) error {
return a.streamWithVars(ctx, content, out, map[string]string{})
}
// runWithVars 同步执行,支持变量替换
func (a *LLMAgent) runWithVars(ctx context.Context, content model.ChatContent, vars map[string]string) (string, error) {
messages := initialMessages(applyVars(a.instruction, vars), firstText(content))
for iter := 0; iter < maxToolCallIterations; iter++ {
reply, err := a.chatModel.Generate(ctx, messages)
if err != nil {
return "", err
}
if len(reply.ToolCalls) == 0 {
return reply.Content, nil
}
// 将 assistant 回复(含工具调用)加入消息历史
messages = append(messages, model.ChatMessage{
Role: model.ChatRoleAssistant,
Content: reply.Content,
ToolCalls: reply.ToolCalls,
})
// 执行工具调用,将结果加入消息历史
toolMessages, err := a.executeToolCalls(ctx, reply.ToolCalls)
if err != nil {
return "", err
}
messages = append(messages, toolMessages...)
}
return "", fmt.Errorf("agent %q exceeded tool-call iteration limit %d", a.name, maxToolCallIterations)
}
// streamWithVars 流式执行,支持变量替换
func (a *LLMAgent) streamWithVars(ctx context.Context, content model.ChatContent, out chan<- string, vars map[string]string) error {
messages := initialMessages(applyVars(a.instruction, vars), firstText(content))
for iter := 0; iter < maxToolCallIterations; iter++ {
events, errs := a.chatModel.Stream(ctx, messages)
var (
finalText strings.Builder
toolCalls []model.ChatToolCall
done bool
)
streamErr := error(nil)
streamLoop:
for {
select {
case <-ctx.Done():
streamErr = ctx.Err()
break streamLoop
case ev, ok := <-events:
if !ok {
break streamLoop
}
if ev.Done {
done = true
}
if ev.Delta != "" {
finalText.WriteString(ev.Delta)
select {
case out <- ev.Delta:
case <-ctx.Done():
streamErr = ctx.Err()
break streamLoop
}
}
if len(ev.ToolCalls) > 0 {
toolCalls = append(toolCalls, ev.ToolCalls...)
}
case err, ok := <-errs:
if ok && err != nil {
streamErr = err
}
break streamLoop
}
}
if streamErr != nil {
return streamErr
}
// 没有工具调用,说明模型已完成回复
if len(toolCalls) == 0 {
if !done {
return fmt.Errorf("agent %q stream closed without completion", a.name)
}
return nil
}
// 处理工具调用
messages = append(messages, model.ChatMessage{
Role: model.ChatRoleAssistant,
Content: finalText.String(),
ToolCalls: toolCalls,
})
toolMessages, err := a.executeToolCalls(ctx, toolCalls)
if err != nil {
return err
}
messages = append(messages, toolMessages...)
}
return fmt.Errorf("agent %q exceeded tool-call iteration limit %d", a.name, maxToolCallIterations)
}
// executeToolCalls 执行一组工具调用
func (a *LLMAgent) executeToolCalls(ctx context.Context, calls []model.ChatToolCall) ([]model.ChatMessage, error) {
out := make([]model.ChatMessage, 0, len(calls))
for _, call := range calls {
result, err := a.chatModel.CallTool(ctx, call.Name, call.Arguments)
if err != nil {
return nil, fmt.Errorf("tool %q: %w", call.Name, err)
}
out = append(out, model.ChatMessage{
Role: model.ChatRoleTool,
Content: result,
ToolCallID: call.ID,
Name: call.Name,
})
}
return out, nil
}
// ============================================================
// 工作流子 Agent 接口
// ============================================================
// workflowSubAgent 工作流内部使用的 Agent 扩展接口
type workflowSubAgent interface {
model.Agent
OutputKey() string
runWithVars(ctx context.Context, content model.ChatContent, vars map[string]string) (string, error)
streamWithVars(ctx context.Context, content model.ChatContent, out chan<- string, vars map[string]string) error
}
// ============================================================
// SequentialAgent — 顺序工作流
// ============================================================
// SequentialAgent 顺序执行子 Agent前一个的输出可通过 OutputKey 传递给后一个
type SequentialAgent struct {
name string
description string
subAgents []workflowSubAgent
}
// NewSequentialAgent 创建顺序工作流 Agent
func NewSequentialAgent(name, description string, subs []model.Agent) *SequentialAgent {
wrapped := make([]workflowSubAgent, 0, len(subs))
for _, s := range subs {
wrapped = append(wrapped, s.(workflowSubAgent))
}
return &SequentialAgent{name: name, description: description, subAgents: wrapped}
}
func (a *SequentialAgent) Name() string { return a.name }
func (a *SequentialAgent) OutputKey() string { return "" }
func (a *SequentialAgent) Run(ctx context.Context, content model.ChatContent) (string, error) {
return a.runWithVars(ctx, content, map[string]string{})
}
func (a *SequentialAgent) Stream(ctx context.Context, content model.ChatContent, out chan<- string) error {
return a.streamWithVars(ctx, content, out, map[string]string{})
}
func (a *SequentialAgent) runWithVars(ctx context.Context, content model.ChatContent, vars map[string]string) (string, error) {
scope := cloneVars(vars)
var last string
for _, sub := range a.subAgents {
text, err := sub.runWithVars(ctx, content, scope)
if err != nil {
return "", err
}
last = text
if key := sub.OutputKey(); key != "" {
scope[key] = text
}
}
return last, nil
}
func (a *SequentialAgent) streamWithVars(ctx context.Context, content model.ChatContent, out chan<- string, vars map[string]string) error {
scope := cloneVars(vars)
for i, sub := range a.subAgents {
if i == len(a.subAgents)-1 {
return sub.streamWithVars(ctx, content, out, scope)
}
text, err := sub.runWithVars(ctx, content, scope)
if err != nil {
return err
}
if key := sub.OutputKey(); key != "" {
scope[key] = text
}
}
return nil
}
// ============================================================
// ParallelAgent — 并行工作流
// ============================================================
// ParallelAgent 并行执行所有子 Agent 并汇总结果
type ParallelAgent struct {
name string
description string
subAgents []workflowSubAgent
}
// NewParallelAgent 创建并行工作流 Agent
func NewParallelAgent(name, description string, subs []model.Agent) *ParallelAgent {
wrapped := make([]workflowSubAgent, 0, len(subs))
for _, s := range subs {
wrapped = append(wrapped, s.(workflowSubAgent))
}
return &ParallelAgent{name: name, description: description, subAgents: wrapped}
}
func (a *ParallelAgent) Name() string { return a.name }
func (a *ParallelAgent) OutputKey() string { return "" }
func (a *ParallelAgent) Run(ctx context.Context, content model.ChatContent) (string, error) {
return a.runWithVars(ctx, content, map[string]string{})
}
func (a *ParallelAgent) Stream(ctx context.Context, content model.ChatContent, out chan<- string) error {
return a.streamWithVars(ctx, content, out, map[string]string{})
}
func (a *ParallelAgent) runWithVars(ctx context.Context, content model.ChatContent, vars map[string]string) (string, error) {
parts := make([]string, 0, len(a.subAgents))
for _, sub := range a.subAgents {
text, err := sub.runWithVars(ctx, content, vars)
if err != nil {
return "", err
}
parts = append(parts, fmt.Sprintf("[%s] %s", sub.Name(), text))
}
return strings.Join(parts, "\n"), nil
}
func (a *ParallelAgent) streamWithVars(ctx context.Context, content model.ChatContent, out chan<- string, vars map[string]string) error {
text, err := a.runWithVars(ctx, content, vars)
if err != nil {
return err
}
select {
case out <- text:
return nil
case <-ctx.Done():
return ctx.Err()
}
}
// ============================================================
// LoopAgent — 循环工作流
// ============================================================
// LoopAgent 循环执行子 Agent最多执行 maxIterations 次
type LoopAgent struct {
name string
description string
subAgents []workflowSubAgent
maxIterations int
}
// NewLoopAgent 创建循环工作流 Agent
func NewLoopAgent(name, description string, subs []model.Agent, maxIterations int) *LoopAgent {
if maxIterations <= 0 {
maxIterations = 3
}
wrapped := make([]workflowSubAgent, 0, len(subs))
for _, s := range subs {
wrapped = append(wrapped, s.(workflowSubAgent))
}
return &LoopAgent{
name: name,
description: description,
subAgents: wrapped,
maxIterations: maxIterations,
}
}
func (a *LoopAgent) Name() string { return a.name }
func (a *LoopAgent) OutputKey() string { return "" }
func (a *LoopAgent) Run(ctx context.Context, content model.ChatContent) (string, error) {
return a.runWithVars(ctx, content, map[string]string{})
}
func (a *LoopAgent) Stream(ctx context.Context, content model.ChatContent, out chan<- string) error {
return a.streamWithVars(ctx, content, out, map[string]string{})
}
func (a *LoopAgent) runWithVars(ctx context.Context, content model.ChatContent, vars map[string]string) (string, error) {
var last string
for i := 0; i < a.maxIterations; i++ {
parts := make([]string, 0, len(a.subAgents))
for _, sub := range a.subAgents {
text, err := sub.runWithVars(ctx, content, vars)
if err != nil {
return "", err
}
parts = append(parts, fmt.Sprintf("[%s] %s", sub.Name(), text))
}
last = strings.Join(parts, "\n")
}
return last, nil
}
func (a *LoopAgent) streamWithVars(ctx context.Context, content model.ChatContent, out chan<- string, vars map[string]string) error {
text, err := a.runWithVars(ctx, content, vars)
if err != nil {
return err
}
select {
case out <- text:
return nil
case <-ctx.Done():
return ctx.Err()
}
}
// ============================================================
// 工具函数
// ============================================================
var sessionCounter atomic.Uint64
// cloneVars 克隆变量映射
func cloneVars(vars map[string]string) map[string]string {
out := make(map[string]string, len(vars)+4)
for k, v := range vars {
out[k] = v
}
return out
}
// applyVars 替换模板中的 {key} 占位符
func applyVars(template string, vars map[string]string) string {
if template == "" || len(vars) == 0 {
return template
}
out := template
for k, v := range vars {
out = strings.ReplaceAll(out, "{"+k+"}", v)
}
return out
}
// initialMessages 构建初始消息列表system + user
func initialMessages(instruction, userText string) []model.ChatMessage {
messages := make([]model.ChatMessage, 0, 2)
if strings.TrimSpace(instruction) != "" {
messages = append(messages, model.ChatMessage{Role: model.ChatRoleSystem, Content: instruction})
}
messages = append(messages, model.ChatMessage{Role: model.ChatRoleUser, Content: userText})
return messages
}
// firstText 从 ChatContent 中提取第一段文本
func firstText(content model.ChatContent) string {
if len(content.Texts) == 0 {
return ""
}
return content.Texts[0].Message
}

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@@ -1 +1,110 @@
package service
import (
"context"
"fmt"
"os"
"strings"
"time"
"ai-agent-scaffold-go/internal/config"
"ai-agent-scaffold-go/internal/llm"
"ai-agent-scaffold-go/internal/model"
)
// AssembleAll 从配置表批量组装 Agent
func AssembleAll(ctx context.Context, tables map[string]model.AiAgentConfigTable, timeout time.Duration) ([]model.RegisteredAgent, error) {
var agents []model.RegisteredAgent
for _, table := range tables {
agent, err := assembleOne(ctx, table, timeout)
if err != nil {
return nil, fmt.Errorf("assemble %s: %w", table.AppName, err)
}
agents = append(agents, *agent)
}
return agents, nil
}
// assembleOne 组装单个 Agent 配置
func assembleOne(ctx context.Context, table model.AiAgentConfigTable, timeout time.Duration) (*model.RegisteredAgent, error) {
apiCfg := table.Module.AiAPI
completionsURL := strings.TrimRight(apiCfg.BaseURL, "/") + "/" + strings.TrimLeft(apiCfg.CompletionsPath, "/")
// 1. 创建 OpenAI 客户端
client := llm.NewOpenAIClient(completionsURL, apiCfg.APIKey, table.Module.ChatModel.Model, timeout)
// 2. 创建 ChatModel当前无外部工具后续可扩展
chatModel := llm.NewChatModelAdapter(client, nil)
// 3. 构建 Agent 映射表
agentMap := map[string]model.Agent{}
for _, agentCfg := range table.Module.Agents {
agent := NewLLMAgent(agentCfg.Name, agentCfg.Instruction, agentCfg.Description, agentCfg.OutputKey, chatModel)
agentMap[agentCfg.Name] = agent
}
// 4. 构建 Workflow Agent
for _, wfCfg := range table.Module.AgentWorkflows {
subs := make([]model.Agent, 0, len(wfCfg.SubAgents))
for _, subName := range wfCfg.SubAgents {
sub, ok := agentMap[subName]
if !ok {
return nil, fmt.Errorf("workflow %q references unknown agent %q", wfCfg.Name, subName)
}
subs = append(subs, sub)
}
var wfAgent model.Agent
switch wfCfg.Type {
case model.WorkflowTypeSequential:
wfAgent = NewSequentialAgent(wfCfg.Name, wfCfg.Description, subs)
case model.WorkflowTypeParallel:
wfAgent = NewParallelAgent(wfCfg.Name, wfCfg.Description, subs)
case model.WorkflowTypeLoop:
wfAgent = NewLoopAgent(wfCfg.Name, wfCfg.Description, subs, wfCfg.MaxIterations)
default:
return nil, fmt.Errorf("unknown workflow type: %s", wfCfg.Type)
}
agentMap[wfCfg.Name] = wfAgent
}
// 5. 解析入口 Agent
entryName := table.Module.Runner.AgentName
entryAgent, ok := agentMap[entryName]
if !ok {
return nil, fmt.Errorf("entry agent %q not found", entryName)
}
// 6. 创建 Runner
runner := NewRunner(table.AppName, entryAgent)
return &model.RegisteredAgent{
AppName: table.AppName,
AgentID: table.Agent.AgentID,
AgentName: table.Agent.AgentName,
AgentDesc: table.Agent.AgentDesc,
Runner: runner,
}, nil
}
// LoadAndAssemble 从配置文件路径列表加载并组装所有 Agent
func LoadAndAssemble(ctx context.Context, paths []string, timeout time.Duration) ([]model.RegisteredAgent, error) {
merged := make(map[string]model.AiAgentConfigTable)
for _, raw := range paths {
path := strings.TrimSpace(raw)
if path == "" {
continue
}
expanded := os.ExpandEnv(path)
tables, err := config.LoadAgentTablesFile(expanded)
if err != nil {
return nil, err
}
for name, table := range tables {
merged[name] = table
}
}
if len(merged) == 0 {
return nil, fmt.Errorf("no agent tables loaded")
}
return AssembleAll(ctx, merged, timeout)
}

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@@ -1 +1,110 @@
package service
import (
"fmt"
"sort"
"ai-agent-scaffold-go/internal/model"
"ai-agent-scaffold-go/pkg/types"
)
// ChatService 聊天服务
type ChatService struct {
registry model.AgentRegistry
sessions model.SessionStore
}
// NewChatService 创建聊天服务
func NewChatService(registry model.AgentRegistry, sessions model.SessionStore) *ChatService {
return &ChatService{registry: registry, sessions: sessions}
}
// QueryAgentConfigList 查询已注册的 Agent 列表
func (s *ChatService) QueryAgentConfigList() []model.AgentSummary {
registered := s.registry.List()
sort.Slice(registered, func(i, j int) bool {
return registered[i].AgentID < registered[j].AgentID
})
agents := make([]model.AgentSummary, 0, len(registered))
for _, agent := range registered {
agents = append(agents, model.AgentSummary{
AgentID: agent.AgentID,
AgentName: agent.AgentName,
AgentDesc: agent.AgentDesc,
})
}
return agents
}
// CreateSession 为指定 Agent 和用户创建会话
func (s *ChatService) CreateSession(agentID, userID string) (string, error) {
if sessionID, ok := s.sessions.Get(userID, agentID); ok {
return sessionID, nil
}
registered, ok := s.registry.Get(agentID)
if !ok || registered.Runner == nil {
return "", types.NewAppError(types.CodeAgentNotFound, types.InfoAgentNotFound)
}
sessionID, err := registered.Runner.CreateSession(userID)
if err != nil {
return "", err
}
if err := s.sessions.Set(userID, agentID, sessionID); err != nil {
return "", err
}
return sessionID, nil
}
// HandleMessage 处理同步聊天消息
func (s *ChatService) HandleMessage(agentID, userID, sessionID, message string) ([]string, error) {
content := model.ChatContent{Texts: []model.TextPart{{Message: message}}}
return s.handleCommand(agentID, userID, sessionID, message, content)
}
// HandleMessageStream 处理流式聊天消息
func (s *ChatService) HandleMessageStream(agentID, userID, sessionID, message string) (<-chan string, <-chan error) {
content := model.ChatContent{Texts: []model.TextPart{{Message: message}}}
return s.handleCommandStream(agentID, userID, sessionID, message, content)
}
func (s *ChatService) handleCommand(agentID, userID, sessionID, message string, content model.ChatContent) ([]string, error) {
registered, sessionID, err := s.resolveRunnerSession(agentID, userID, sessionID, message, content)
if err != nil {
return nil, err
}
return registered.Runner.Run(userID, sessionID, content)
}
func (s *ChatService) handleCommandStream(agentID, userID, sessionID, message string, content model.ChatContent) (<-chan string, <-chan error) {
registered, sessionID, err := s.resolveRunnerSession(agentID, userID, sessionID, message, content)
if err != nil {
outputs := make(chan string)
errs := make(chan error, 1)
errs <- err
close(outputs)
close(errs)
return outputs, errs
}
return registered.Runner.Stream(userID, sessionID, content)
}
func (s *ChatService) resolveRunnerSession(agentID, userID, sessionID, message string, content model.ChatContent) (model.RegisteredAgent, string, error) {
registered, ok := s.registry.Get(agentID)
if !ok || registered.Runner == nil {
return model.RegisteredAgent{}, "", types.NewAppError(types.CodeAgentNotFound, types.InfoAgentNotFound)
}
if sessionID == "" {
var err error
sessionID, err = s.CreateSession(agentID, userID)
if err != nil {
return model.RegisteredAgent{}, "", err
}
}
if len(content.Texts) == 0 && message != "" {
content.Texts = []model.TextPart{{Message: message}}
}
if len(content.Texts) == 0 {
return model.RegisteredAgent{}, "", fmt.Errorf("chat content is required")
}
return registered, sessionID, nil
}

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@@ -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
}