package runtime

import (
	"context"
	"fmt"

	"chat-agent-system/internal/projectinstance"
	"chat-agent-system/internal/workflowdef"
)

// TaskResolution 从冻结实例解析的运行时任务绑定。
type TaskResolution struct {
	ProjectID       int64
	WorkflowInstID  int64
	StageKey        string
	TaskKey         string
	DocTaskInstID   int64
	ExecutorKey     string
	QualityGateKey  string
	TemplateAsset   string
	TemplateVersion int
	AuthorUserID    int64
	ReviewerUserID  int64
	ApproverUserID  int64
}

// Orchestrator 只读冻结快照编排（禁止 flatten 旁路）。
type Orchestrator struct {
	instSvc *projectinstance.Service
}

func NewOrchestrator(instSvc *projectinstance.Service) *Orchestrator {
	return &Orchestrator{instSvc: instSvc}
}

// ResolveDocTask 由 doc_task_instance_id 解析 executor/模板/三权。
func (o *Orchestrator) ResolveDocTask(ctx context.Context, projectID, docTaskInstID int64) (*TaskResolution, error) {
	if o == nil || o.instSvc == nil || !o.instSvc.Available() {
		return nil, fmt.Errorf("orchestrator unavailable")
	}
	detail, version, err := o.instSvc.GetLiveInstanceDetail(ctx, projectID)
	if err != nil {
		return nil, err
	}
	plan := detail.Instance.ConfigSnapshot
	for _, st := range detail.Stages {
		for _, dt := range st.DocTasks {
			if dt.ID != docTaskInstID {
				continue
			}
			res := &TaskResolution{
				ProjectID:      projectID,
				WorkflowInstID: detail.Instance.ID,
				StageKey:       st.StageKey,
				TaskKey:        dt.TaskKey,
				DocTaskInstID:  dt.ID,
			}
			if def := lookupTaskDef(&version.Definition, st.StageKey, dt.TaskKey); def != nil {
				res.ExecutorKey = def.ExecutorKey
				res.QualityGateKey = def.QualityGateKey
				if def.Template != nil {
					res.TemplateAsset = def.Template.AssetKey
					res.TemplateVersion = def.Template.Version
				} else {
					res.TemplateAsset = def.TemplateAssetKey
					res.TemplateVersion = def.TemplateVersion
				}
			}
			for _, stPlan := range plan.Stages {
				if stPlan.StageKey != st.StageKey {
					continue
				}
				for _, dtPlan := range stPlan.DocTasks {
					if dtPlan.TaskKey != dt.TaskKey {
						continue
					}
					res.AuthorUserID = dtPlan.Duties.AuthorUserID
					res.ReviewerUserID = dtPlan.Duties.ReviewerUserID
					res.ApproverUserID = dtPlan.Duties.ApproverUserID
				}
			}
			return res, nil
		}
	}
	return nil, fmt.Errorf("doc task instance not in live snapshot")
}

func lookupTaskDef(def *workflowdef.VersionDefinition, stageKey, taskKey string) *workflowdef.DocTaskDef {
	if def == nil {
		return nil
	}
	for _, st := range def.Stages {
		if st.Key != stageKey {
			continue
		}
		for i := range st.DocTasks {
			if st.DocTasks[i].Key == taskKey {
				return &st.DocTasks[i]
			}
		}
	}
	return nil
}