package intent

import "strings"

// branchToRelation 将三分支映射为 ExpectationRelation
func mapQueryProgressSubtype(topic string) string {
	switch topic {
	case "risk":
		return "risk"
	case "testing_analysis", "technical_design":
		return "technical"
	case "talk_script":
		return "communication"
	case "progress":
		return "status"
	default:
		return topic
	}
}

func branchToRelation(branch ResolutionBranch, cand *CandidateIntent) ExpectationRelation {
	switch branch {
	case BranchExpectationHit:
		if cand != nil && cand.IsDecline {
			return RelationExpectationDecline
		}
		if cand != nil && len(cand.PatchSlots) > 0 {
			return RelationExpectationPatch
		}
		return RelationExpectationHit
	case BranchAmbiguousFallback:
		return RelationUnresolvedReference
	default:
		return RelationNew
	}
}

// BuildIntentFrameV2 从 Legacy 候选意图构建 V2 语义帧
func BuildIntentFrameV2(res *IntentRecognitionResult, registry *ActionRegistry) *IntentFrameV2 {
	if res == nil || res.TopIntent == nil {
		return nil
	}
	if registry == nil {
		registry = DefaultRegistry()
	}
	top := res.TopIntent
	spec, ok := registry.GetByLegacyIntent(top.Intent)
	frame := &IntentFrameV2{
		Version:      IntentFrameV2Version,
		LegacyIntent: top.Intent,
		Relation:     branchToRelation(res.Branch, top),
		Score:        top.Confidence,
		Margin:       res.ShadowMargin,
		DialogueAct:  detectDialogueAct(res.RawInput),
		MissingSlots: append([]string(nil), top.MissingSlots...),
	}
	if len(res.Candidates) >= 2 {
		frame.Margin = res.Candidates[0].Confidence - res.Candidates[1].Confidence
	}
	if ok {
		frame.ActionKey = spec.Key
		frame.Domain = spec.Domain
		frame.Object = spec.Object
		frame.Goal = spec.Goal
	} else {
		frame.ActionKey = "unknown." + strings.ToLower(string(top.Intent))
		frame.Domain = "unknown"
		frame.Object = "unknown"
		frame.Goal = GoalConverse
	}
	if top.FilledSlots != nil {
		frame.Slots = make(map[string]SlotValue, len(top.FilledSlots))
		for k, v := range top.FilledSlots {
			frame.Slots[k] = SlotValue{Value: v, Source: "rule"}
		}
	}
	if top.FilledSlots != nil {
		switch top.Intent {
		case IntentQueryProgress:
			if topic, ok := top.FilledSlots[SlotQueryTopic]; ok {
				frame.Subtype = mapQueryProgressSubtype(topic)
			}
		case IntentSupplementInfo:
			if action, ok := top.FilledSlots[SlotSupplementAction]; ok {
				frame.Subtype = action
			}
		}
	}
	frame.Evidence = buildEvidenceFromCandidate(top, res)
	return frame
}

func buildEvidenceFromCandidate(top *CandidateIntent, res *IntentRecognitionResult) []IntentEvidence {
	var ev []IntentEvidence
	if top.Reasoning != "" {
		ev = append(ev, IntentEvidence{Kind: "rule_match", Detail: top.Reasoning, Weight: top.Confidence})
	}
	if res.ShadowDialogueAct != "" {
		ev = append(ev, IntentEvidence{Kind: "dialogue_act", Detail: res.ShadowDialogueAct, Weight: 0.1})
	}
	if strings.Contains(top.Reasoning, "权限不符") {
		ev = append(ev, IntentEvidence{Kind: "policy_hint", Detail: "permission_mismatch_l1", Weight: 0.0})
	}
	if len(top.MissingSlots) > 0 {
		ev = append(ev, IntentEvidence{Kind: "missing_slots", Detail: strings.Join(top.MissingSlots, ","), Weight: 0.0})
	}
	return ev
}

// BuildRankedIntentSet 从识别结果构建排序候选帧集合
func BuildRankedIntentSet(res *IntentRecognitionResult, registry *ActionRegistry) *RankedIntentSet {
	if res == nil || len(res.Candidates) == 0 {
		return nil
	}
	if registry == nil {
		registry = DefaultRegistry()
	}
	set := &RankedIntentSet{TopMargin: res.ShadowMargin}
	if len(res.Candidates) >= 2 {
		set.TopMargin = res.Candidates[0].Confidence - res.Candidates[1].Confidence
	}
	for i := range res.Candidates {
		c := res.Candidates[i]
		tmp := &IntentRecognitionResult{
			RawInput:   res.RawInput,
			Branch:     res.Branch,
			TopIntent:  &c,
			Candidates: res.Candidates,
		}
		if fr := BuildIntentFrameV2(tmp, registry); fr != nil {
			set.Candidates = append(set.Candidates, *fr)
		}
	}
	if len(res.Candidates) >= 2 {
		top := res.Candidates[0]
		second := res.Candidates[1]
		margin := top.Confidence - second.Confidence
		if margin < 0.05 && ((isWriteIntent(top.Intent) && isQueryIntent(second.Intent)) ||
			(isQueryIntent(top.Intent) && isWriteIntent(second.Intent))) {
			set.Conflicts = append(set.Conflicts, CandidateConflict{
				Kind:         "write_vs_query",
				TopAction:    string(top.Intent),
				SecondAction: string(second.Intent),
				Margin:       margin,
			})
		}
	}
	return set
}

// LegacyIntentFromFrame 从 V2 帧还原 Legacy TopIntent（契约测试与灰度回退）
func LegacyIntentFromFrame(frame *IntentFrameV2) IntentType {
	if frame == nil {
		return IntentCasualChat
	}
	if frame.LegacyIntent != "" {
		return frame.LegacyIntent
	}
	if spec, ok := DefaultRegistry().Get(frame.ActionKey); ok {
		return spec.LegacyIntent
	}
	return IntentCasualChat
}

// AttachIntentFrameV2 为识别结果附加 V2 双写字段（不改变 TopIntent 路由）
func AttachIntentFrameV2(res *IntentRecognitionResult) {
	if res == nil {
		return
	}
	res.IntentFrameV2 = BuildIntentFrameV2(res, DefaultRegistry())
	res.RankedFrames = BuildRankedIntentSet(res, DefaultRegistry())
}