package callmemory

import (
	"context"
	"encoding/json"
	"errors"
	"strings"
	"time"

	"data-terminal-cloud/internal/companionopening"
	"github.com/jackc/pgx/v5"
)

// Only bounded template keys are retained for opening rotation, without facts.
// These describe what was selected, not what the elder heard or discussed.
type directOpeningMetadata struct {
	Version  string `json:"version"`
	ID       string `json:"id"`
	TopicKey string `json:"topic_key"`
	Category string `json:"category"`
}

func (s *Service) selectDirectOpening(ctx context.Context, tx pgx.Tx, subject, bot, sid, device string, generation, epoch int64, memory bool) (string, *directOpeningMetadata, error) {
	var welcome, timezone string
	var profileRaw, preferencesRaw []byte
	err := tx.QueryRow(ctx, `SELECT COALESCE(a.agent_config->>'WelcomeMessage',''),p.timezone,p.profile_data,p.conversation_preferences FROM subject_voice_agent a JOIN subject_profile p ON p.id=a.subject_id WHERE a.subject_id=$1::uuid AND a.bot_id=$2 AND a.status='READY'`, subject, bot).Scan(&welcome, &timezone, &profileRaw, &preferencesRaw)
	if errors.Is(err, pgx.ErrNoRows) {
		return "", nil, &Error{409, "VOICE_AGENT_NOT_READY", "该老人的智能体尚未创建成功，请重试创建", "NONE"}
	}
	if err != nil {
		return "", nil, err
	}
	welcome = strings.TrimSpace(welcome)
	if welcome == "" {
		welcome = "你好，今天想聊些什么？"
	}
	// Onboarding belongs to this binding, independently of personalized-memory
	// permission, privacy epochs, and the last five rotation entries. Existing
	// bindings without this guide receive it once on rollout. A normal, fully
	// stopped call completes the guide session; this is not a playback receipt.
	if s.direct.PrepareWithWelcome != nil {
		intro := companionopening.Introduction()
		var established bool
		err = tx.QueryRow(ctx, `SELECT EXISTS(SELECT 1 FROM call_session c WHERE c.device_id=$1::uuid AND c.subject_id=$2::uuid AND c.binding_generation=$3 AND c.budget_snapshot->>'protocol'='DIRECT-CHAT-1' AND c.budget_snapshot->'opening'->>'id'=$4 AND c.call_state='ENDED' AND c.ended_at IS NOT NULL AND c.local_audio_off AND c.sdk_stopped)`, device, subject, generation, intro.ID).Scan(&established)
		if err != nil {
			return "", nil, err
		}
		if !established {
			return intro.Text, openingMetadata(intro), nil
		}
	}
	var preferences struct {
		DynamicOpening bool     `json:"dynamic_opening"`
		Preferred      []string `json:"preferred_topics"`
		Avoided        []string `json:"avoided_topics"`
	}
	// Malformed or unsupported preferences keep the original welcome. The pilot
	// also requires an updater that accepts the same text given to the device.
	if json.Unmarshal(preferencesRaw, &preferences) != nil || !preferences.DynamicOpening || s.direct.PrepareWithWelcome == nil {
		return welcome, nil, nil
	}
	input := companionopening.Input{Now: s.now(), Timezone: timezone, SessionID: sid, AvoidedTopics: preferences.Avoided}
	transcripts := false
	if memory {
		transcripts, err = transcriptPermission(ctx, tx, subject)
		if err != nil {
			return "", nil, err
		}
	}
	if memory {
		var profile struct {
			Interests []string `json:"interests"`
		}
		if json.Unmarshal(profileRaw, &profile) == nil {
			input.AuthorizedInterests = append(profile.Interests, preferences.Preferred...)
		}
	}
	// History is scoped to this binding and current privacy epoch. Transcript content is
	// never loaded: only the existence of both sides of a real conversation.
	rows, err := tx.Query(ctx, `SELECT COALESCE(c.budget_snapshot->'opening'->>'id',''),COALESCE(c.budget_snapshot->'opening'->>'topic_key',''),c.created_at,c.ended_at,
	 $3 AND EXISTS(SELECT 1 FROM call_utterance u WHERE u.session_id=c.id AND u.speaker='USER' AND u.text_content NOT IN ('','[deleted]')),
	 $3 AND EXISTS(SELECT 1 FROM call_utterance u WHERE u.session_id=c.id AND u.speaker='ASSISTANT' AND u.text_content NOT IN ('','[deleted]'))
	 FROM call_session c WHERE c.subject_id=$1::uuid AND c.privacy_epoch=$2 AND c.device_id=$4::uuid AND c.binding_generation=$5 AND c.budget_snapshot->>'protocol'='DIRECT-CHAT-1' ORDER BY c.created_at DESC,c.id DESC LIMIT 5`, subject, epoch, transcripts, device, generation)
	if err != nil {
		return "", nil, err
	}
	defer rows.Close()
	for rows.Next() {
		var previous companionopening.RecentOpening
		var ended *time.Time
		if err = rows.Scan(&previous.ID, &previous.TopicKey, &previous.StartedAt, &ended, &previous.HasUserSubtitle, &previous.HasAssistantSubtitle); err != nil {
			return "", nil, err
		}
		if ended != nil {
			previous.EndedAt = *ended
		}
		input.Recent = append(input.Recent, previous)
	}
	if err = rows.Err(); err != nil {
		return "", nil, err
	}
	selected := companionopening.Select(input)
	return selected.Text, openingMetadata(selected), nil
}

func openingMetadata(selected companionopening.Selection) *directOpeningMetadata {
	return &directOpeningMetadata{Version: "companion-opening-v2", ID: selected.ID, TopicKey: selected.TopicKey, Category: selected.Category}
}