package orchestration

import (
	"context"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"errors"
	"fmt"
	"strings"
	"time"

	"data-terminal-cloud/internal/billing"
	"data-terminal-cloud/internal/conversation"
	"data-terminal-cloud/internal/deviceauth"
	"data-terminal-cloud/internal/firmwareversion"
	"data-terminal-cloud/internal/retrieval"

	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgconn"
)

var (
	ErrDeviceNotBound            = errors.New("device is not bound to an active subject")
	ErrConsentRequired           = errors.New("voice chat consent is required")
	ErrFirmwareUpdateRequired    = errors.New("device firmware does not satisfy the minimum version")
	ErrConversationAlreadyActive = errors.New("device already has an unfinished conversation")
	ErrConversationNotFound      = errors.New("conversation was not found for device")
	ErrConversationStateConflict = errors.New("conversation state does not allow operation")
	ErrAllocationExpired         = errors.New("room allocation expired")
	ErrRTCIdentityMismatch       = errors.New("RTC room or user does not match allocation")
	ErrConfigVersionConflict     = errors.New("device configuration revision is stale")
	ErrRuntimeConfigUnavailable  = errors.New("published runtime routing configuration is unavailable")
	ErrContextPreparationFailed  = errors.New("authorized subject context preparation failed")
	ErrUsageQuotaExceeded        = billing.ErrQuotaExceeded
)

const contextPreparationFailureCode = "context_preparation_failed"

type AllocationOptions struct {
	Now                     time.Time
	AllocationExpires       time.Time
	TokenExpires            time.Time
	RTCAppID                string
	VoiceProvider           string
	EngineMode              string
	HeartbeatInterval       int
	MemoryQueryVector       string
	MemoryPolicy            string
	RequirePublishedRouting bool
}

type Repository struct{}

type ActivationResult struct {
	Response        ActivateResponse
	InternalID      string
	ProviderTaskRef string
	StartRequested  bool
}

type StopResult struct {
	Response        StopResponse
	InternalID      string
	ProviderTaskRef string
	StopRequested   bool
}

func NewRepository() *Repository { return &Repository{} }

func (r *Repository) Stop(
	ctx context.Context,
	tx pgx.Tx,
	identity deviceauth.Identity,
	conversationPublicID, requestID string,
	input StopInput,
	now time.Time,
) (StopResult, error) {
	var internalID, providerTaskRef string
	var status conversation.Status
	err := tx.QueryRow(ctx, `
		SELECT c.id::text, c.status, c.provider_task_ref
		FROM conversation c JOIN rtc_task r ON r.conversation_id=c.id
		WHERE c.public_id=$1::uuid AND c.device_id=$2::uuid AND c.tenant_id=$3::uuid
		FOR UPDATE OF c, r`, conversationPublicID, identity.ID, identity.TenantID,
	).Scan(&internalID, &status, &providerTaskRef)
	if errors.Is(err, pgx.ErrNoRows) {
		return StopResult{}, ErrConversationNotFound
	}
	if err != nil {
		return StopResult{}, fmt.Errorf("read conversation stop state: %w", err)
	}
	result := StopResult{
		Response:   StopResponse{ConversationID: conversationPublicID, Status: status, AcceptedAt: now},
		InternalID: internalID, ProviderTaskRef: providerTaskRef,
	}
	if conversation.IsTerminal(status) {
		return result, nil
	}
	if status == conversation.StatusStopping {
		_, err := tx.Exec(ctx, `
			UPDATE conversation SET stop_reason=COALESCE(stop_reason,$2),
				last_heartbeat_seq=GREATEST(last_heartbeat_seq,$3), updated_at=$4
			WHERE id=$1::uuid`, internalID, input.Reason, input.LastHeartbeatSequence, now)
		if err != nil {
			return StopResult{}, fmt.Errorf("refresh repeated stop: %w", err)
		}
		return result, nil
	}
	if status == conversation.StatusRoomIssued {
		if err := conversation.ValidateTransition(status, conversation.StatusExpired); err != nil {
			return StopResult{}, err
		}
		_, err := tx.Exec(ctx, `
			UPDATE conversation SET status='EXPIRED', stop_reason=$2, ended_at=$3,
				lease_expires_at=NULL, last_heartbeat_seq=GREATEST(last_heartbeat_seq,$4),
				version=version+1, updated_at=$3 WHERE id=$1::uuid AND status='ROOM_ISSUED'`,
			internalID, input.Reason, now, input.LastHeartbeatSequence)
		if err == nil {
			_, err = tx.Exec(ctx, `UPDATE rtc_task SET status='COMPLETED', lease_expires_at=NULL,
				last_checked_at=$2, updated_at=$2 WHERE conversation_id=$1::uuid`, internalID, now)
		}
		if err == nil {
			_, err = tx.Exec(ctx, `
				INSERT INTO conversation_state_history (
					conversation_id, from_status, to_status, reason, source, request_id
				) VALUES ($1::uuid, 'ROOM_ISSUED', 'EXPIRED', 'device stopped before activation', 'device', NULLIF($2,''))`,
				internalID, requestID)
		}
		if err != nil {
			return StopResult{}, fmt.Errorf("expire unactivated conversation: %w", err)
		}
		result.Response.Status = conversation.StatusExpired
		return result, nil
	}
	if status != conversation.StatusStartingAgent && status != conversation.StatusActive {
		return StopResult{}, ErrConversationStateConflict
	}
	if err := conversation.ValidateTransition(status, conversation.StatusStopping); err != nil {
		return StopResult{}, err
	}
	_, err = tx.Exec(ctx, `
		UPDATE conversation SET status='STOPPING', stop_reason=$2,
			lease_expires_at=NULL, last_heartbeat_seq=GREATEST(last_heartbeat_seq,$3),
			version=version+1, updated_at=$4 WHERE id=$1::uuid AND status=$5`,
		internalID, input.Reason, input.LastHeartbeatSequence, now, status)
	if err == nil {
		_, err = tx.Exec(ctx, `
			UPDATE rtc_task SET status='STOPPING', lease_expires_at=NULL, updated_at=$2
			WHERE conversation_id=$1::uuid`, internalID, now)
	}
	if err == nil {
		_, err = tx.Exec(ctx, `
			INSERT INTO conversation_state_history (
				conversation_id, from_status, to_status, reason, source, request_id
			) VALUES ($1::uuid, $2, 'STOPPING', 'device requested conversation stop', 'device', NULLIF($3,''))`,
			internalID, status, requestID)
	}
	if err != nil {
		return StopResult{}, fmt.Errorf("stop active conversation: %w", err)
	}
	result.Response.Status = conversation.StatusStopping
	result.StopRequested = true
	return result, nil
}

func (r *Repository) Activate(
	ctx context.Context,
	tx pgx.Tx,
	identity deviceauth.Identity,
	conversationPublicID, requestID string,
	input ActivateInput,
	now time.Time,
) (ActivationResult, error) {
	var internalID, providerTaskRef, roomID, rtcUserID string
	var status conversation.Status
	var allocationExpires time.Time
	var desiredRevision int64
	err := tx.QueryRow(ctx, `
		SELECT c.id::text, c.status, c.allocation_expires_at, c.provider_task_ref,
			r.room_id, r.device_rtc_user_id, dt.desired_revision
		FROM conversation c
		JOIN rtc_task r ON r.conversation_id = c.id
		JOIN device_twin dt ON dt.device_id = c.device_id AND dt.tenant_id = c.tenant_id
		JOIN device_binding b ON b.device_id = c.device_id AND b.tenant_id = c.tenant_id
			AND b.subject_id = c.subject_id AND b.unbound_at IS NULL
		WHERE c.public_id = $1::uuid AND c.device_id = $2::uuid AND c.tenant_id = $3::uuid
		FOR UPDATE OF c, r`, conversationPublicID, identity.ID, identity.TenantID,
	).Scan(&internalID, &status, &allocationExpires, &providerTaskRef, &roomID, &rtcUserID, &desiredRevision)
	if errors.Is(err, pgx.ErrNoRows) {
		return ActivationResult{}, ErrConversationNotFound
	}
	if err != nil {
		return ActivationResult{}, fmt.Errorf("read conversation activation state: %w", err)
	}
	if input.RoomID != roomID || input.RTCUserID != rtcUserID {
		return ActivationResult{}, ErrRTCIdentityMismatch
	}
	if input.RTCJoinResult != "success" || input.JoinedAt.IsZero() || input.JoinedAt.After(now.Add(5*time.Minute)) {
		return ActivationResult{}, ErrRTCIdentityMismatch
	}
	if input.ConfigRevision != desiredRevision {
		return ActivationResult{}, ErrConfigVersionConflict
	}
	result := ActivationResult{
		Response:   ActivateResponse{ConversationID: conversationPublicID, Status: status, AcceptedAt: now},
		InternalID: internalID, ProviderTaskRef: providerTaskRef,
	}
	if status == conversation.StatusStartingAgent || status == conversation.StatusActive {
		return result, nil
	}
	if status != conversation.StatusRoomIssued {
		return ActivationResult{}, ErrConversationStateConflict
	}
	if !allocationExpires.After(now) {
		return ActivationResult{}, ErrAllocationExpired
	}
	if err := conversation.ValidateTransition(status, conversation.StatusStartingAgent); err != nil {
		return ActivationResult{}, err
	}
	tag, err := tx.Exec(ctx, `
		UPDATE conversation
		SET status='STARTING_AGENT', version=version+1, updated_at=$2
		WHERE id=$1::uuid AND status='ROOM_ISSUED'`, internalID, now)
	if err != nil {
		return ActivationResult{}, fmt.Errorf("start conversation activation: %w", err)
	}
	if tag.RowsAffected() != 1 {
		return ActivationResult{}, ErrConversationStateConflict
	}
	_, err = tx.Exec(ctx, `
		UPDATE rtc_task SET status='STARTING', updated_at=$2
		WHERE conversation_id=$1::uuid AND status='ALLOCATED'`, internalID, now)
	if err != nil {
		return ActivationResult{}, fmt.Errorf("mark RTC task starting: %w", err)
	}
	_, err = tx.Exec(ctx, `
		INSERT INTO conversation_state_history (
			conversation_id, from_status, to_status, reason, source, request_id
		) VALUES ($1::uuid, 'ROOM_ISSUED', 'STARTING_AGENT', 'device confirmed RTC join', 'device', NULLIF($2,''))`,
		internalID, requestID)
	if err != nil {
		return ActivationResult{}, fmt.Errorf("record activation state: %w", err)
	}
	result.Response.Status = conversation.StatusStartingAgent
	result.StartRequested = true
	return result, nil
}

func (r *Repository) Create(
	ctx context.Context,
	tx pgx.Tx,
	identity deviceauth.Identity,
	input CreateInput,
	options AllocationOptions,
) (CreateResponse, string, error) {
	if options.VoiceProvider == "" {
		options.VoiceProvider = "mock"
	}
	var householdID, householdPublicID, subjectID, subjectPublicID, subjectName string
	var profileDataJSON, conversationPreferencesJSON json.RawMessage
	var minimumFirmwareVersion, currentFirmwareVersion *string
	var profileVersion int64
	err := tx.QueryRow(ctx, `
		SELECT b.household_id::text, h.public_id::text, b.subject_id::text,
			s.public_id::text, s.preferred_name, s.profile_data, s.conversation_preferences, s.profile_version,
			d.minimum_firmware_version, dt.firmware_version
		FROM device d
		JOIN device_twin dt ON dt.device_id=d.id AND dt.tenant_id=d.tenant_id
		JOIN device_binding b ON b.device_id = d.id AND b.tenant_id = d.tenant_id AND b.unbound_at IS NULL
		JOIN household h ON h.id = b.household_id AND h.tenant_id = b.tenant_id AND h.status = 'active'
		JOIN subject_profile s ON s.id = b.subject_id AND s.tenant_id = b.tenant_id AND s.status = 'active'
		WHERE d.id = $1::uuid AND d.tenant_id = $2::uuid AND d.status = 'registered'
		FOR UPDATE OF d, b, s, dt`, identity.ID, identity.TenantID,
	).Scan(&householdID, &householdPublicID, &subjectID, &subjectPublicID, &subjectName,
		&profileDataJSON, &conversationPreferencesJSON, &profileVersion, &minimumFirmwareVersion, &currentFirmwareVersion)
	if errors.Is(err, pgx.ErrNoRows) {
		return CreateResponse{}, "", ErrDeviceNotBound
	}
	if err != nil {
		return CreateResponse{}, "", fmt.Errorf("read active device binding: %w", err)
	}
	if minimumFirmwareVersion != nil && (currentFirmwareVersion == nil || !firmwareversion.AtLeast(*currentFirmwareVersion, *minimumFirmwareVersion)) {
		return CreateResponse{}, "", ErrFirmwareUpdateRequired
	}
	var activeConversationExists bool
	if err := tx.QueryRow(ctx, `
		SELECT EXISTS(
			SELECT 1 FROM conversation
			WHERE device_id=$1::uuid AND status NOT IN ('COMPLETED','FAILED','EXPIRED')
		)`, identity.ID).Scan(&activeConversationExists); err != nil {
		return CreateResponse{}, "", fmt.Errorf("check active device conversation: %w", err)
	}
	if activeConversationExists {
		return CreateResponse{}, "", ErrConversationAlreadyActive
	}
	budgetSnapshot, err := billing.CheckQuotaTx(ctx, tx, identity, options.Now)
	if err != nil {
		return CreateResponse{}, "", fmt.Errorf("check usage quota: %w", err)
	}
	engineMode := options.EngineMode
	promptBundleVersion := "minimal-v2"
	publishedConfigID, configuredEngineMode, err := selectRuntimeConfigurationTx(ctx, tx, identity.TenantID, subjectID, identity.ID, identity.PublicID)
	if err == nil {
		if configuredEngineMode != "s2s_pure" && configuredEngineMode != "s2s_hybrid" && configuredEngineMode != "cascade" {
			return CreateResponse{}, "", fmt.Errorf("published routing configuration contains an invalid engine mode")
		}
		engineMode = configuredEngineMode
		promptBundleVersion = "cfg:" + publishedConfigID
	} else if !errors.Is(err, pgx.ErrNoRows) {
		return CreateResponse{}, "", fmt.Errorf("read published runtime configuration: %w", err)
	} else if options.RequirePublishedRouting {
		return CreateResponse{}, "", ErrRuntimeConfigUnavailable
	}

	var sourceConsentPublicID string
	var snapshotVersion int64
	var effectiveConsents, sourceConsentIDs json.RawMessage
	err = tx.QueryRow(ctx, `
		SELECT public_id::text, snapshot_version, effective_consents, source_consent_ids
		FROM consent_snapshot
		WHERE tenant_id = $1::uuid AND subject_id = $2::uuid
		  AND effective_consents @> '{"voice_chat":true}'::jsonb
		ORDER BY created_at DESC, id DESC
		LIMIT 1`, identity.TenantID, subjectID,
	).Scan(&sourceConsentPublicID, &snapshotVersion, &effectiveConsents, &sourceConsentIDs)
	if errors.Is(err, pgx.ErrNoRows) {
		return CreateResponse{}, "", ErrConsentRequired
	}
	if err != nil {
		return CreateResponse{}, "", fmt.Errorf("read effective consent: %w", err)
	}

	consentSnapshotID := uuid.NewString()
	consentSnapshotPublicID := uuid.NewString()
	traceSources, _ := json.Marshal([]string{sourceConsentPublicID})
	_, err = tx.Exec(ctx, `
		INSERT INTO consent_snapshot (
			id, public_id, tenant_id, subject_id, snapshot_version,
			effective_consents, source_consent_ids
		) VALUES ($1::uuid, $2::uuid, $3::uuid, $4::uuid, $5, $6::jsonb, $7::jsonb)`,
		consentSnapshotID, consentSnapshotPublicID, identity.TenantID, subjectID,
		snapshotVersion, effectiveConsents, traceSources,
	)
	if err != nil {
		return CreateResponse{}, "", fmt.Errorf("freeze consent snapshot: %w", err)
	}

	var memories []retrieval.Memory
	if options.MemoryPolicy == "" {
		memories, err = retrieval.SelectMemoryForContext(ctx, tx, identity.TenantID, subjectID, subjectName+" "+input.RequestedGoal, 5)
	} else if options.MemoryQueryVector != "" {
		memories, err = retrieval.SelectMemoryForContextVector(ctx, tx, identity.TenantID, subjectID, options.MemoryQueryVector, 5)
	}
	if err != nil {
		return CreateResponse{}, "", fmt.Errorf("retrieve conversation memory: %w", err)
	}
	memoryVersionsJSON, _ := json.Marshal(memories)
	memoryContents := make([]string, 0, len(memories))
	for _, memory := range memories {
		memoryContents = append(memoryContents, truncateContextText(memory.Content, 300))
	}
	profileContext, err := authorizedProfileContext(profileDataJSON, conversationPreferencesJSON)
	if err != nil {
		return r.createContextPreparationFailure(ctx, tx, identity, householdID, subjectID, profileVersion,
			consentSnapshotID, memoryVersionsJSON, promptBundleVersion, engineMode,
			privacyFromConsent(effectiveConsents), options)
	}
	contextSummary := buildContextSummary(subjectName, profileContext)
	if len(memoryContents) > 0 {
		contextSummary += "；已确认记忆：" + strings.Join(memoryContents, "；")
	}
	contextValue := struct {
		SubjectID       string                   `json:"subject_id"`
		PreferredName   string                   `json:"preferred_name"`
		ProfileVersion  int64                    `json:"profile_version"`
		RequestedGoal   string                   `json:"requested_goal"`
		ProfileContext  authorizedSubjectContext `json:"profile_context"`
		MemoryContents  []string                 `json:"memory_contents"`
		RetrievalPolicy string                   `json:"retrieval_policy"`
	}{subjectPublicID, subjectName, profileVersion, input.RequestedGoal, profileContext, memoryContents, retrievalPolicy(options.MemoryPolicy)}
	contextJSON, _ := json.Marshal(contextValue)
	contextDigest := sha256.Sum256(contextJSON)
	contextSnapshotID := uuid.NewString()
	contextSnapshotPublicID := uuid.NewString()
	_, err = tx.Exec(ctx, `
		INSERT INTO context_snapshot (
			id, public_id, tenant_id, subject_id, profile_version, consent_snapshot_id,
			memory_versions, prompt_bundle_version, engine_mode, content_digest, sanitized_summary
		) VALUES ($1::uuid, $2::uuid, $3::uuid, $4::uuid, $5, $6::uuid,
			$7::jsonb, $8, $9, $10, $11)`,
		contextSnapshotID, contextSnapshotPublicID, identity.TenantID, subjectID, profileVersion,
		consentSnapshotID, memoryVersionsJSON, promptBundleVersion, engineMode, hex.EncodeToString(contextDigest[:]), contextSummary,
	)
	if err != nil {
		return CreateResponse{}, "", fmt.Errorf("create context snapshot: %w", err)
	}

	conversationID := uuid.NewString()
	conversationPublicID := uuid.NewString()
	providerTaskRef := "voice-task-" + uuid.NewString()
	roomID := "r_" + strings.ReplaceAll(uuid.NewString(), "-", "")
	deviceRTCUserID := "d_" + strings.ReplaceAll(identity.PublicID, "-", "")
	agentRTCUserID := "a_" + strings.ReplaceAll(conversationPublicID, "-", "")
	privacy := privacyFromConsent(effectiveConsents)
	_, err = tx.Exec(ctx, `
		INSERT INTO conversation (
			id, public_id, tenant_id, household_id, subject_id, device_id,
			consent_snapshot_id, context_snapshot_id, provider_task_ref,
			engine_mode, retention_mode, rtc_credential_renewal_supported,
			status, allocation_expires_at, created_at, updated_at
		) VALUES (
			$1::uuid, $2::uuid, $3::uuid, $4::uuid, $5::uuid, $6::uuid,
			$7::uuid, $8::uuid, $9, $10, $11, COALESCE($12, false), 'PREPARING', $13, $14, $14
		)`, conversationID, conversationPublicID, identity.TenantID, householdID, subjectID, identity.ID,
		consentSnapshotID, contextSnapshotID, providerTaskRef, engineMode,
		privacy.RetentionMode, input.Capabilities.RTCCredentialRenewal, options.AllocationExpires, options.Now,
	)
	if err != nil {
		var postgresError *pgconn.PgError
		if errors.As(err, &postgresError) && postgresError.ConstraintName == "conversation_one_active_per_device" {
			return CreateResponse{}, "", ErrConversationAlreadyActive
		}
		return CreateResponse{}, "", fmt.Errorf("create conversation: %w", err)
	}
	if err = billing.FreezeBudgetTx(ctx, tx, conversationID, identity.TenantID, budgetSnapshot); err != nil {
		return CreateResponse{}, "", fmt.Errorf("freeze conversation usage budget: %w", err)
	}
	_, err = tx.Exec(ctx, `
		INSERT INTO conversation_state_history (conversation_id, from_status, to_status, reason, source)
		VALUES ($1::uuid, NULL, 'PREPARING', 'create request accepted', 'device')`, conversationID)
	if err != nil {
		return CreateResponse{}, "", fmt.Errorf("record preparing state: %w", err)
	}
	_, err = tx.Exec(ctx, `
		INSERT INTO rtc_task (
			conversation_id, provider, provider_task_ref, room_id,
			device_rtc_user_id, agent_rtc_user_id, status, lease_expires_at,
			credential_issued_at, credential_expires_at
		) VALUES ($1::uuid, $2, $3, $4, $5, $6, 'ALLOCATED', $7, $8, $9)`,
		conversationID, options.VoiceProvider, providerTaskRef, roomID, deviceRTCUserID, agentRTCUserID,
		options.AllocationExpires, options.Now, options.TokenExpires,
	)
	if err != nil {
		return CreateResponse{}, "", fmt.Errorf("allocate RTC task: %w", err)
	}
	_, err = tx.Exec(ctx, `
		UPDATE conversation SET status = 'ROOM_ISSUED', version = version + 1, updated_at = $2
		WHERE id = $1::uuid AND status = 'PREPARING'`, conversationID, options.Now)
	if err != nil {
		return CreateResponse{}, "", fmt.Errorf("issue conversation room: %w", err)
	}
	_, err = tx.Exec(ctx, `
		INSERT INTO conversation_state_history (conversation_id, from_status, to_status, reason, source)
		VALUES ($1::uuid, 'PREPARING', 'ROOM_ISSUED', 'room credentials allocated', 'platform')`, conversationID)
	if err != nil {
		return CreateResponse{}, "", fmt.Errorf("record room issued state: %w", err)
	}

	_ = householdPublicID
	return CreateResponse{
		ConversationID: conversationPublicID,
		Status:         conversation.StatusRoomIssued,
		RTC: RTCGrant{
			AppID: options.RTCAppID, RoomID: roomID, UserID: deviceRTCUserID,
			AgentUserID: agentRTCUserID, ExpiresAt: options.TokenExpires,
		},
		Privacy: privacy,
		Session: Session{
			EngineMode: engineMode, HeartbeatIntervalSecond: options.HeartbeatInterval,
			AllocationExpiresAt: options.AllocationExpires,
		},
	}, conversationID, nil
}

func selectRuntimeConfigurationTx(ctx context.Context, tx pgx.Tx, tenantID, subjectID, deviceID, devicePublicID string) (string, string, error) {
	// Rollouts already bind an immutable configuration version and its business
	// type. ConfigKey is an operator-defined version family, not a runtime
	// discriminator: filtering on a reserved key would make a successfully
	// published custom Agent bundle silently ineffective. Prefer the newest
	// matching Agent bundle at the most specific scope, then retain any direct
	// ROUTING rollout as the compatibility path for installations that have not
	// adopted bundles yet.
	var configID, engineMode string
	err := tx.QueryRow(ctx, `
		SELECT bundle.public_id::text,routing.payload->>'default_engine_mode'
		FROM runtime_config_rollout rr
		JOIN runtime_config_version bundle
		  ON bundle.id=rr.config_version_id AND bundle.tenant_id=rr.tenant_id
		JOIN runtime_config_version routing
		  ON routing.tenant_id=bundle.tenant_id
		 AND routing.public_id::text=bundle.payload->>'routing_version_id'
		 AND routing.config_kind='ROUTING'
		 AND routing.status IN ('PUBLISHED','RETIRED')
		WHERE rr.tenant_id=$1::uuid
		  AND rr.status='ACTIVE'
		  AND bundle.config_kind='AGENT_BUNDLE'
		  AND bundle.status='PUBLISHED'
		  AND (
		    rr.scope_type='TENANT'
		    OR (rr.scope_type='SUBJECT' AND rr.subject_id=$2::uuid)
		    OR (
		      rr.scope_type='DEVICE_GROUP'
		      AND EXISTS (
		        SELECT 1 FROM ops_device_group_member dgm
		        JOIN ops_device_group dg ON dg.id=dgm.group_id AND dg.tenant_id=dgm.tenant_id
		        WHERE dgm.group_id=rr.device_group_id AND dgm.tenant_id=rr.tenant_id
		          AND dgm.device_id=$3::uuid AND dg.status='ACTIVE'
		      )
		    )
		  )
		  AND (
		    rr.rollout_percent=100
		    OR mod((hashtextextended($4,rr.cohort_seed::bigint) & 9223372036854775807),100) < rr.rollout_percent
		  )
		  AND (
		    SELECT count(*) FROM conversation active_conversation
		    JOIN context_snapshot active_snapshot ON active_snapshot.id=active_conversation.context_snapshot_id
		    WHERE active_conversation.tenant_id=rr.tenant_id
		      AND active_conversation.status IN ('PREPARING','ROOM_ISSUED','STARTING_AGENT','ACTIVE','STOPPING')
		      AND active_snapshot.prompt_bundle_version='cfg:' || bundle.public_id::text
		  ) < rr.max_concurrent_calls
		ORDER BY CASE rr.scope_type WHEN 'SUBJECT' THEN 1 WHEN 'DEVICE_GROUP' THEN 2 ELSE 3 END,
		         rr.activated_at DESC,rr.id DESC
		LIMIT 1`, tenantID, subjectID, deviceID, devicePublicID).Scan(&configID, &engineMode)
	if err == nil {
		return configID, engineMode, nil
	}
	if !errors.Is(err, pgx.ErrNoRows) {
		return "", "", err
	}
	err = tx.QueryRow(ctx, `
		SELECT routing.public_id::text,routing.payload->>'default_engine_mode'
		FROM runtime_config_rollout rr
		JOIN runtime_config_version routing
		  ON routing.id=rr.config_version_id AND routing.tenant_id=rr.tenant_id
		WHERE rr.tenant_id=$1::uuid
		  AND rr.status='ACTIVE'
		  AND routing.config_kind='ROUTING'
		  AND routing.status='PUBLISHED'
		  AND (
		    rr.scope_type='TENANT'
		    OR (rr.scope_type='SUBJECT' AND rr.subject_id=$2::uuid)
		    OR (
		      rr.scope_type='DEVICE_GROUP'
		      AND EXISTS (
		        SELECT 1 FROM ops_device_group_member dgm
		        JOIN ops_device_group dg ON dg.id=dgm.group_id AND dg.tenant_id=dgm.tenant_id
		        WHERE dgm.group_id=rr.device_group_id AND dgm.tenant_id=rr.tenant_id
		          AND dgm.device_id=$3::uuid AND dg.status='ACTIVE'
		      )
		    )
		  )
		  AND (
		    rr.rollout_percent=100
		    OR mod((hashtextextended($4,rr.cohort_seed::bigint) & 9223372036854775807),100) < rr.rollout_percent
		  )
		  AND (
		    SELECT count(*) FROM conversation active_conversation
		    JOIN context_snapshot active_snapshot ON active_snapshot.id=active_conversation.context_snapshot_id
		    WHERE active_conversation.tenant_id=rr.tenant_id
		      AND active_conversation.status IN ('PREPARING','ROOM_ISSUED','STARTING_AGENT','ACTIVE','STOPPING')
		      AND active_snapshot.prompt_bundle_version='cfg:' || routing.public_id::text
		  ) < rr.max_concurrent_calls
		ORDER BY CASE rr.scope_type WHEN 'SUBJECT' THEN 1 WHEN 'DEVICE_GROUP' THEN 2 ELSE 3 END,
		         rr.activated_at DESC,rr.id DESC
		LIMIT 1`, tenantID, subjectID, deviceID, devicePublicID).Scan(&configID, &engineMode)
	return configID, engineMode, err
}

func (r *Repository) createContextPreparationFailure(
	ctx context.Context,
	tx pgx.Tx,
	identity deviceauth.Identity,
	householdID, subjectID string,
	profileVersion int64,
	consentSnapshotID string,
	memoryVersionsJSON json.RawMessage,
	promptBundleVersion, engineMode string,
	privacy Privacy,
	options AllocationOptions,
) (CreateResponse, string, error) {
	failureValue := struct {
		FailureCode    string `json:"failure_code"`
		ProfileVersion int64  `json:"profile_version"`
		PromptVersion  string `json:"prompt_bundle_version"`
	}{contextPreparationFailureCode, profileVersion, promptBundleVersion}
	failureJSON, _ := json.Marshal(failureValue)
	digest := sha256.Sum256(failureJSON)
	contextSnapshotID := uuid.NewString()
	contextSnapshotPublicID := uuid.NewString()
	_, err := tx.Exec(ctx, `
		INSERT INTO context_snapshot (
			id, public_id, tenant_id, subject_id, profile_version, consent_snapshot_id,
			memory_versions, prompt_bundle_version, engine_mode, content_digest, sanitized_summary,
			preparation_status, preparation_failure_code
		) VALUES ($1::uuid, $2::uuid, $3::uuid, $4::uuid, $5, $6::uuid,
			$7::jsonb, $8, $9, $10, $11, 'FAILED', $12)`,
		contextSnapshotID, contextSnapshotPublicID, identity.TenantID, subjectID, profileVersion,
		consentSnapshotID, memoryVersionsJSON, promptBundleVersion, engineMode,
		hex.EncodeToString(digest[:]), "背景资料准备失败，未创建房间", contextPreparationFailureCode)
	if err != nil {
		return CreateResponse{}, "", fmt.Errorf("create failed context snapshot: %w", err)
	}

	conversationID := uuid.NewString()
	conversationPublicID := uuid.NewString()
	providerTaskRef := "context-failed-" + uuid.NewString()
	_, err = tx.Exec(ctx, `
		INSERT INTO conversation (
			id, public_id, tenant_id, household_id, subject_id, device_id,
			consent_snapshot_id, context_snapshot_id, provider_task_ref,
			engine_mode, retention_mode, status, allocation_expires_at,
			ended_at, failure_code, created_at, updated_at
		) VALUES (
			$1::uuid, $2::uuid, $3::uuid, $4::uuid, $5::uuid, $6::uuid,
			$7::uuid, $8::uuid, $9, $10, $11, 'FAILED', $12,
			$13, $14, $13, $13
		)`, conversationID, conversationPublicID, identity.TenantID, householdID, subjectID, identity.ID,
		consentSnapshotID, contextSnapshotID, providerTaskRef, engineMode, privacy.RetentionMode,
		options.AllocationExpires, options.Now, contextPreparationFailureCode)
	if err != nil {
		return CreateResponse{}, "", fmt.Errorf("create failed conversation: %w", err)
	}
	_, err = tx.Exec(ctx, `
		INSERT INTO conversation_state_history (conversation_id, from_status, to_status, reason, source)
		VALUES
			($1::uuid, NULL, 'PREPARING', 'create request accepted', 'device'),
			($1::uuid, 'PREPARING', 'FAILED', 'authorized subject context preparation failed', 'platform')`, conversationID)
	if err != nil {
		return CreateResponse{}, "", fmt.Errorf("record context preparation failure: %w", err)
	}
	return CreateResponse{
		ConversationID: conversationPublicID,
		Status:         conversation.StatusFailed,
		FailureCode:    contextPreparationFailureCode,
		Privacy:        privacy,
		Session: Session{
			EngineMode: engineMode, HeartbeatIntervalSecond: options.HeartbeatInterval,
			AllocationExpiresAt: options.AllocationExpires,
		},
	}, conversationID, nil
}

func retrievalPolicy(policy string) string {
	if policy == "" {
		return "pgvector-normal-v1"
	}
	return policy
}

func truncateContextText(value string, limit int) string {
	runes := []rune(strings.TrimSpace(value))
	if len(runes) <= limit {
		return string(runes)
	}
	return string(runes[:limit]) + "…"
}

type authorizedSubjectContext struct {
	Background       string   `json:"background,omitempty"`
	Interests        []string `json:"interests,omitempty"`
	ConversationGoal string   `json:"conversation_goal,omitempty"`
	Pace             string   `json:"pace,omitempty"`
	PreferredTopics  []string `json:"preferred_topics,omitempty"`
}

func authorizedProfileContext(profileDataJSON, preferencesJSON json.RawMessage) (authorizedSubjectContext, error) {
	var profileData, preferences map[string]any
	if err := json.Unmarshal(profileDataJSON, &profileData); err != nil {
		return authorizedSubjectContext{}, fmt.Errorf("decode profile data: %w", err)
	}
	if err := json.Unmarshal(preferencesJSON, &preferences); err != nil {
		return authorizedSubjectContext{}, fmt.Errorf("decode conversation preferences: %w", err)
	}
	background, err := strictContextString(profileData, "background", 500)
	if err != nil {
		return authorizedSubjectContext{}, err
	}
	interests, err := strictContextStringList(profileData, "interests", 8, 50)
	if err != nil {
		return authorizedSubjectContext{}, err
	}
	goal, err := strictContextString(preferences, "conversation_goal", 200)
	if err != nil {
		return authorizedSubjectContext{}, err
	}
	pace, err := strictContextString(preferences, "pace", 24)
	if err != nil {
		return authorizedSubjectContext{}, err
	}
	preferredTopics, err := strictContextStringList(preferences, "preferred_topics", 8, 50)
	if err != nil {
		return authorizedSubjectContext{}, err
	}
	if pace != "slow" && pace != "normal" && pace != "lively" {
		pace = ""
	}
	return authorizedSubjectContext{
		Background:       background,
		Interests:        interests,
		ConversationGoal: goal,
		Pace:             pace,
		PreferredTopics:  preferredTopics,
	}, nil
}

func buildContextSummary(preferredName string, profile authorizedSubjectContext) string {
	parts := []string{"称呼：" + truncateContextText(preferredName, 120)}
	if profile.Background != "" {
		parts = append(parts, "背景资料："+profile.Background)
	}
	if len(profile.Interests) > 0 {
		parts = append(parts, "兴趣："+strings.Join(profile.Interests, "、"))
	}
	goal := profile.ConversationGoal
	if goal == "" {
		goal = "进行一次自然、尊重的陪伴交流"
	}
	parts = append(parts, "本次交流目标："+goal)
	if profile.Pace != "" {
		paceLabels := map[string]string{"slow": "放慢语速并留出回应时间", "normal": "自然语速", "lively": "轻快但保持清晰"}
		parts = append(parts, "交流节奏："+paceLabels[profile.Pace])
	}
	if len(profile.PreferredTopics) > 0 {
		parts = append(parts, "优先话题："+strings.Join(profile.PreferredTopics, "、"))
	}
	return strings.Join(parts, "；")
}

func strictContextString(values map[string]any, key string, limit int) (string, error) {
	raw, exists := values[key]
	if !exists || raw == nil {
		return "", nil
	}
	value, ok := raw.(string)
	if !ok {
		return "", fmt.Errorf("%s must be a string", key)
	}
	return truncateContextText(value, limit), nil
}

func strictContextStringList(values map[string]any, key string, maxItems, itemLimit int) ([]string, error) {
	raw, exists := values[key]
	if !exists || raw == nil {
		return nil, nil
	}
	rawItems, ok := raw.([]any)
	if !ok {
		return nil, fmt.Errorf("%s must be an array of strings", key)
	}
	items := make([]string, 0, min(len(rawItems), maxItems))
	for _, raw := range rawItems {
		value, ok := raw.(string)
		if !ok {
			return nil, fmt.Errorf("%s must contain only strings", key)
		}
		value = truncateContextText(value, itemLimit)
		if value == "" {
			continue
		}
		items = append(items, value)
		if len(items) == maxItems {
			break
		}
	}
	return items, nil
}

func privacyFromConsent(consents json.RawMessage) Privacy {
	values := map[string]bool{}
	_ = json.Unmarshal(consents, &values)
	privacy := Privacy{
		RecordNear:    values["raw_audio_storage"] || values["audio_recording"],
		RecordFar:     values["raw_audio_storage"] || values["audio_recording"],
		UploadAllowed: values["raw_audio_storage"] || values["audio_recording"], RetentionMode: "none",
	}
	if values["transcript_storage"] || values["transcript"] {
		privacy.RetentionMode = "transcript_only"
	}
	if values["raw_audio_storage"] || values["audio_recording"] {
		privacy.RetentionMode = "transcript_and_audio"
	}
	return privacy
}