// ai/agent/types.go
const (
    EventTypePhaseChange = "phase_change"  // 阶段变化
    EventTypeProgress    = "progress"      // 进度更新
)

type PhaseChangeData struct {
    Phase        string   `json:"phase"`         // analyzing, planning, retrieving, synthesizing
    EstimatedMs  int      `json:"estimated_ms"`  // 预估剩余毫秒
    ToolsPlanned []string `json:"tools_planned"` // 计划执行的工具
}

type ProgressData struct {
    Phase           string   `json:"phase"`
    Progress        int      `json:"progress"`         // 0-100
    SubPhase        string   `json:"sub_phase"`        // 子阶段描述
    ToolsInProgress []string `json:"tools_in_progress"`
    ToolsCompleted  []string `json:"tools_completed"`
}

func (p *AmazingParrot) ExecuteWithCallback(...) error {
    // Phase 1: Analyzing
    callback(EventTypePhaseChange, &PhaseChangeData{
        Phase: "analyzing",
        EstimatedMs: 500,
    })
    
    plan, err := p.planRetrieval(ctx, userInput, history, callback)
    
    // Phase 2: Retrieving
    callback(EventTypePhaseChange, &PhaseChangeData{
        Phase: "retrieving",
        ToolsPlanned: plan.GetToolNames(),
        EstimatedMs: 1000,
    })
    
    // 每个工具完成时发送进度
    for i, tool := range tools {
        result := tool.Execute(ctx)
        callback(EventTypeProgress, &ProgressData{
            Phase:           "retrieving",
            Progress:        (i + 1) * 100 / len(tools),
            ToolsCompleted:  completedTools,
            ToolsInProgress: remainingTools,
        })
    }
    
    // Phase 3: Synthesizing
    callback(EventTypePhaseChange, &PhaseChangeData{
        Phase: "synthesizing",
        EstimatedMs: 2000,
    })
    // ...
}