package domain

import (
	"strings"
	"time"

	"git.cin.su/m/Assistant/contracts/epistemics"
	"git.cin.su/m/Assistant/contracts/interaction"
	"git.cin.su/m/Assistant/contracts/situation"
	"git.cin.su/m/Assistant/platform/ids"
)

type SemanticResult struct {
	Interpretation interaction.UtteranceInterpretation
	Projects       []interaction.ProjectReference
	Relations      []interaction.InteractionRelation
	ActiveFocus    *situation.ActiveProjectFocus
	Reply          string
	NeedsCognition bool
}

func InterpretUtterance(utterance interaction.HumanUtterance, projects []situation.ProjectDescriptor, previousFocus *situation.ActiveProjectFocus, now time.Time) (SemanticResult, error) {
	act := ClassifySpeechAct(utterance.Content, utterance.CorrectsUtteranceID)
	interpretationID, err := ids.New()
	if err != nil {
		return SemanticResult{}, err
	}
	millis := now.UnixMilli()
	result := SemanticResult{
		Interpretation: interaction.UtteranceInterpretation{
			ID:                    interaction.InterpretationID(interpretationID),
			UtteranceID:           utterance.ID,
			SpeechAct:             act,
			ConfidenceMillis:      confidenceFor(act),
			Source:                "deterministic-v1",
			AssertionVerification: string(epistemics.VerificationUnverified),
			RequestedOutcome:      requestedOutcome(utterance.Content, act),
			Clarification:         interaction.ClarificationNotRequired,
			RecordedAtUnixMillis:  millis,
		},
		NeedsCognition: NeedsCognition(act),
	}
	explicitFocus := explicitProjectFocus(utterance.Content, projects)
	projectRefs, err := projectReferences(utterance, projects, explicitFocus, previousFocus, millis)
	if err != nil {
		return SemanticResult{}, err
	}
	result.Projects = projectRefs
	if explicitFocus != nil {
		result.ActiveFocus = &situation.ActiveProjectFocus{
			ActorID:             utterance.ActorID,
			PrincipalID:         utterance.PrincipalID,
			ProjectID:           explicitFocus.ProjectID,
			ProjectDisplayName:  explicitFocus.ProjectDisplayName,
			Provenance:          situation.ProjectResolutionExplicit,
			ConfidenceMillis:    explicitFocus.ConfidenceMillis,
			SourceUtteranceID:   string(utterance.ID),
			UpdatedAtUnixMillis: millis,
		}
	}
	if isAmbiguousDestructive(act, utterance.Content, result.Projects) {
		result.Interpretation.Clarification = interaction.ClarificationRequired
		result.Reply = "Уточните проект и цель: это потенциально разрушительное изменение, а текущая ссылка недостаточно надёжна."
		return result, nil
	}
	if act == interaction.SpeechActCorrection {
		relations, err := correctionRelations(utterance, millis)
		if err != nil {
			return SemanticResult{}, err
		}
		result.Relations = append(result.Relations, relations...)
	}
	result.Reply = semanticReply(utterance.Content, result, previousFocus)
	if isCurrentFocusQuestion(utterance.Content, act) && previousFocus != nil {
		result.NeedsCognition = false
	}
	return result, nil
}

func explicitProjectFocus(message string, projects []situation.ProjectDescriptor) *interaction.ProjectReference {
	lower := strings.ToLower(message)
	if !(strings.Contains(lower, "работаем с") || strings.Contains(lower, "вернемся к") || strings.Contains(lower, "вернёмся к") || strings.HasPrefix(strings.TrimSpace(lower), "теперь ")) {
		return nil
	}
	for _, project := range projects {
		for _, alias := range projectAliases(project) {
			if strings.Contains(lower, alias) {
				return &interaction.ProjectReference{ProjectID: project.ID, ProjectDisplayName: project.DisplayName, Provenance: situation.ProjectResolutionExplicit, ConfidenceMillis: 980}
			}
		}
	}
	return nil
}

func projectReferences(utterance interaction.HumanUtterance, projects []situation.ProjectDescriptor, explicit *interaction.ProjectReference, previousFocus *situation.ActiveProjectFocus, millis int64) ([]interaction.ProjectReference, error) {
	if explicit != nil {
		ref, err := newProjectReference(utterance.ID, explicit.ProjectID, explicit.ProjectDisplayName, interaction.ProjectRolePrimary, explicit.Provenance, explicit.ConfidenceMillis, millis)
		return []interaction.ProjectReference{ref}, err
	}
	lower := strings.ToLower(utterance.Content)
	var refs []interaction.ProjectReference
	for _, project := range projects {
		for _, alias := range projectAliases(project) {
			if strings.Contains(lower, alias) {
				role := projectRoleForAlias(lower, alias)
				ref, err := newProjectReference(utterance.ID, project.ID, project.DisplayName, role, situation.ProjectResolutionEntityReference, 850, millis)
				if err != nil {
					return nil, err
				}
				refs = append(refs, ref)
				break
			}
		}
	}
	if len(refs) == 0 && previousFocus != nil && inheritedFocusAllowed(utterance.SpeechAct, utterance.Content) {
		ref, err := newProjectReference(utterance.ID, previousFocus.ProjectID, previousFocus.ProjectDisplayName, interaction.ProjectRolePrimary, situation.ProjectResolutionInheritedFocus, 700, millis)
		if err != nil {
			return nil, err
		}
		refs = append(refs, ref)
	}
	if len(refs) > 1 {
		hasPrimary := false
		for _, ref := range refs {
			hasPrimary = hasPrimary || ref.Role == interaction.ProjectRolePrimary
		}
		if !hasPrimary {
			refs[len(refs)-1].Role = interaction.ProjectRolePrimary
		}
	}
	return refs, nil
}

func projectRoleForAlias(lower string, alias string) interaction.ProjectReferenceRole {
	aliasIndex := strings.Index(lower, alias)
	if aliasIndex < 0 {
		return interaction.ProjectRoleRelated
	}
	before := strings.TrimSpace(lower[:aliasIndex])
	afterStart := aliasIndex + len(alias)
	after := ""
	if afterStart < len(lower) {
		after = strings.TrimSpace(lower[afterStart:])
	}
	if strings.Contains(before, "как") || strings.Contains(before, "посмотри") || strings.Contains(after, "как источник") {
		return interaction.ProjectRoleReferenceSource
	}
	targetMarkers := []string{"сделай", "добавь", "измени", "поменяй", "перенеси", "используй", "настрой", "в "}
	for _, marker := range targetMarkers {
		if strings.Contains(before, marker) {
			return interaction.ProjectRolePrimary
		}
	}
	return interaction.ProjectRoleRelated
}

func newProjectReference(utteranceID interaction.HumanUtteranceID, projectID situation.ProjectID, display string, role interaction.ProjectReferenceRole, provenance situation.ProjectResolutionProvenance, confidence int64, millis int64) (interaction.ProjectReference, error) {
	id, err := ids.New()
	if err != nil {
		return interaction.ProjectReference{}, err
	}
	return interaction.ProjectReference{ID: interaction.ProjectReferenceID(id), UtteranceID: utteranceID, ProjectID: projectID, ProjectDisplayName: display, Role: role, Provenance: provenance, ConfidenceMillis: confidence, RecordedAtUnixMillis: millis}, nil
}

func projectAliases(project situation.ProjectDescriptor) []string {
	values := []string{strings.ToLower(project.DisplayName), strings.ToLower(string(project.ID))}
	for _, alias := range project.Aliases {
		values = append(values, strings.ToLower(string(alias)))
	}
	return values
}

func correctionRelations(utterance interaction.HumanUtterance, millis int64) ([]interaction.InteractionRelation, error) {
	if utterance.CorrectsUtteranceID == "" {
		return nil, nil
	}
	id, err := ids.New()
	if err != nil {
		return nil, err
	}
	return []interaction.InteractionRelation{{ID: interaction.InteractionRelationID(id), FromUtteranceID: utterance.ID, ToUtteranceID: utterance.CorrectsUtteranceID, Kind: interaction.RelationSupersedes, RecordedAtUnixMillis: millis}}, nil
}

func confidenceFor(act interaction.SpeechAct) int64 {
	if act == interaction.SpeechActUnknown {
		return 300
	}
	return 800
}

func requestedOutcome(message string, act interaction.SpeechAct) string {
	if act == interaction.SpeechActDirective || act == interaction.SpeechActDecision || act == interaction.SpeechActRequestToInvestigate {
		return strings.TrimSpace(message)
	}
	return ""
}

func inheritedFocusAllowed(act interaction.SpeechAct, message string) bool {
	lower := strings.ToLower(message)
	if act == interaction.SpeechActUnknown {
		return false
	}
	if strings.Contains(lower, "туда") || strings.Contains(lower, "там") || strings.Contains(lower, "в этом проекте") {
		return true
	}
	if act == interaction.SpeechActQuestion || act == interaction.SpeechActRequestToInvestigate {
		return strings.Contains(lower, "база") || strings.Contains(lower, "сервер") || strings.Contains(lower, "почему тормозит") || strings.Contains(lower, "что там")
	}
	return false
}

func isAmbiguousDestructive(act interaction.SpeechAct, message string, projects []interaction.ProjectReference) bool {
	lower := strings.ToLower(message)
	destructive := strings.Contains(lower, "удали") || strings.Contains(lower, "снеси") || strings.Contains(lower, "удалить")
	if !destructive || act != interaction.SpeechActDirective {
		return false
	}
	if len(projects) == 0 {
		return true
	}
	return projects[0].Provenance == situation.ProjectResolutionInheritedFocus || projects[0].Provenance == situation.ProjectResolutionInferred
}

func semanticReply(message string, result SemanticResult, previousFocus *situation.ActiveProjectFocus) string {
	if result.ActiveFocus != nil {
		return "Фокус переключён: " + result.ActiveFocus.ProjectDisplayName + "."
	}
	switch result.Interpretation.SpeechAct {
	case interaction.SpeechActAssertion:
		return "Записал как утверждение человека. Это пока не проверенный факт."
	case interaction.SpeechActDirective:
		return "Записал просьбу как намерение пользователя. Ничего не выполнено без отдельного подтверждённого действия."
	case interaction.SpeechActDecision:
		return "Записал это как явное решение пользователя для дальнейшей обработки."
	case interaction.SpeechActCorrection:
		return "Исправление записано новым сообщением; прежняя история сохранена."
	case interaction.SpeechActQuestion:
		lower := strings.ToLower(message)
		if previousFocus != nil && (strings.Contains(lower, "сейчас") || strings.Contains(lower, "что мы") || strings.Contains(lower, "делаем")) {
			return "Сейчас в фокусе: " + previousFocus.ProjectDisplayName + "."
		}
	}
	return FallbackText(result.Interpretation.SpeechAct)
}

func isCurrentFocusQuestion(message string, act interaction.SpeechAct) bool {
	if act != interaction.SpeechActQuestion {
		return false
	}
	lower := strings.ToLower(message)
	return strings.Contains(lower, "сейчас") || strings.Contains(lower, "что мы") || strings.Contains(lower, "делаем")
}