package service

import (
	"context"
	"errors"
	"fmt"
	"sort"
	"strconv"
	"strings"
	"time"

	"github.com/gochat/gochat/internal/model"
	"gorm.io/gorm"
)

type AnalyticsTimeseriesPoint struct {
	Value     float64 `json:"value"`
	Timestamp int64   `json:"timestamp"`
	Count     int64   `json:"count,omitempty"`
}

func (s *AnalyticsService) analyticsDB() (*gorm.DB, error) {
	if s == nil || s.db == nil {
		return nil, errors.New("analytics database is required")
	}
	return s.db, nil
}

func (s *AnalyticsService) EnsureRollupsForRange(ctx context.Context, accountID uint, since, until time.Time) error {
	if s == nil || s.rollups == nil || s.db == nil || since.IsZero() || until.IsZero() {
		return nil
	}
	start := dayStart(since)
	end := dayStart(until)
	if until.After(end) {
		end = end.AddDate(0, 0, 1)
	}
	for d := start; d.Before(end); d = d.AddDate(0, 0, 1) {
		var count int64
		if err := s.db.WithContext(ctx).Model(&model.ReportingEventsRollup{}).Where("account_id = ? AND date = ?", accountID, d).Count(&count).Error; err != nil {
			return err
		}
		if count > 0 {
			continue
		}
		if err := s.rollups.ComputeDailyRollup(ctx, accountID, d); err != nil {
			return err
		}
	}
	return nil
}

func (s *AnalyticsService) GetTimeseries(ctx context.Context, accountID uint, metric string, since, until time.Time, reportType string, id uint, groupBy string, timezoneOffset float64, businessHours bool) ([]AnalyticsTimeseriesPoint, error) {
	if strings.TrimSpace(groupBy) == "" {
		groupBy = "day"
	}
	if reportType == "" {
		reportType = "account"
	}
	loc := timeseriesLocation(timezoneOffset)
	if err := s.EnsureRollupsForRange(ctx, accountID, since, until); err != nil {
		return nil, err
	}
	switch metric {
	case "conversations_count":
		return s.conversationCountTimeseries(ctx, accountID, since, until, reportType, id, groupBy, loc, false)
	case "resolutions_count":
		return s.conversationCountTimeseries(ctx, accountID, since, until, reportType, id, groupBy, loc, true)
	case "incoming_messages_count":
		return s.messageCountTimeseries(ctx, accountID, since, until, reportType, id, groupBy, loc, model.MessageTypeIncoming)
	case "outgoing_messages_count":
		return s.messageCountTimeseries(ctx, accountID, since, until, reportType, id, groupBy, loc, model.MessageTypeOutgoing)
	case "avg_first_response_time":
		return s.eventTimeseries(ctx, accountID, since, until, reportType, id, groupBy, loc, []string{model.MetricNameFirstResponse}, true, businessHours, "")
	case "avg_resolution_time":
		return s.eventTimeseries(ctx, accountID, since, until, reportType, id, groupBy, loc, []string{"conversation_resolved", model.MetricNameResolutionTime}, true, businessHours, "")
	case "reply_time":
		return s.eventTimeseries(ctx, accountID, since, until, reportType, id, groupBy, loc, []string{model.MetricNameReplyTime}, true, businessHours, "")
	case "bot_resolutions_count":
		return s.eventTimeseries(ctx, accountID, since, until, reportType, id, groupBy, loc, []string{"conversation_bot_resolved", model.MetricNameBotResolutionsCount}, false, businessHours, "exclude_bot_handoffs")
	case "bot_handoffs_count":
		return s.eventTimeseries(ctx, accountID, since, until, reportType, id, groupBy, loc, []string{"conversation_bot_handoff", model.MetricNameBotHandoffsCount}, false, businessHours, "distinct_conversation")
	default:
		return nil, fmt.Errorf("unsupported report metric %q", metric)
	}
}

func (s *AnalyticsService) liveConversationMetrics(ctx context.Context, accountID uint, teamID uint) (*ConversationMetrics, error) {
	db, err := s.analyticsDB()
	if err != nil {
		return nil, err
	}
	base := func() *gorm.DB {
		q := db.WithContext(ctx).Model(&model.Conversation{}).Where("account_id = ?", accountID)
		if teamID > 0 {
			q = q.Where("team_id = ?", teamID)
		}
		return q
	}
	var result ConversationMetrics
	if err := base().Where("status = ?", string(model.ConversationStatusOpen)).Count(&result.OpenCount).Error; err != nil {
		return nil, err
	}
	if err := base().Where("status = ? AND (first_reply_created_at IS NULL OR waiting_since IS NOT NULL)", string(model.ConversationStatusOpen)).Count(&result.UnattendedCount).Error; err != nil {
		return nil, err
	}
	if err := base().Where("status = ? AND assignee_id IS NULL", string(model.ConversationStatusOpen)).Count(&result.UnassignedCount).Error; err != nil {
		return nil, err
	}
	if err := base().Where("status = ?", string(model.ConversationStatusPending)).Count(&result.PendingCount).Error; err != nil {
		return nil, err
	}
	return &result, nil
}

func (s *AnalyticsService) conversationCountTimeseries(ctx context.Context, accountID uint, since, until time.Time, reportType string, id uint, groupBy string, loc *time.Location, resolved bool) ([]AnalyticsTimeseriesPoint, error) {
	db, err := s.analyticsDB()
	if err != nil {
		return nil, err
	}
	var conversations []model.Conversation
	q := db.WithContext(ctx).Model(&model.Conversation{}).Where("account_id = ?", accountID)
	if resolved {
		q = q.Where("resolved_at IS NOT NULL AND resolved_at >= ? AND resolved_at < ?", since, until)
	} else {
		q = q.Where("created_at >= ? AND created_at < ?", since, until)
	}
	q = applyConversationDimension(q, reportType, id)
	if err := q.Find(&conversations).Error; err != nil {
		return nil, err
	}
	buckets := seedTimeseriesBuckets(since, until, groupBy, loc)
	for _, conversation := range conversations {
		t := conversation.CreatedAt
		if resolved && conversation.ResolvedAt != nil {
			t = *conversation.ResolvedAt
		}
		bucket := bucketStart(t, groupBy, loc)
		point := ensureTimeseriesBucket(buckets, bucket)
		point.Value++
	}
	return sortedTimeseries(buckets), nil
}

func (s *AnalyticsService) messageCountTimeseries(ctx context.Context, accountID uint, since, until time.Time, reportType string, id uint, groupBy string, loc *time.Location, messageType model.MessageType) ([]AnalyticsTimeseriesPoint, error) {
	db, err := s.analyticsDB()
	if err != nil {
		return nil, err
	}
	var messages []model.Message
	q := db.WithContext(ctx).Model(&model.Message{}).Where("messages.account_id = ? AND messages.message_type = ? AND messages.created_at >= ? AND messages.created_at < ?", accountID, string(messageType), since, until)
	q = applyMessageDimension(q, reportType, id)
	if err := q.Find(&messages).Error; err != nil {
		return nil, err
	}
	buckets := seedTimeseriesBuckets(since, until, groupBy, loc)
	for _, message := range messages {
		point := ensureTimeseriesBucket(buckets, bucketStart(message.CreatedAt, groupBy, loc))
		point.Value++
	}
	return sortedTimeseries(buckets), nil
}

func (s *AnalyticsService) eventTimeseries(ctx context.Context, accountID uint, since, until time.Time, reportType string, id uint, groupBy string, loc *time.Location, names []string, average bool, businessHours bool, countStrategy string) ([]AnalyticsTimeseriesPoint, error) {
	db, err := s.analyticsDB()
	if err != nil {
		return nil, err
	}
	var events []model.ReportingEvent
	q := db.WithContext(ctx).Model(&model.ReportingEvent{}).Where("account_id = ? AND name IN ? AND created_at >= ? AND created_at < ?", accountID, names, since, until)
	q = applyEventDimension(q, reportType, id)
	if !average && countStrategy == "exclude_bot_handoffs" {
		var handoffIDs []uint
		handoffQ := db.WithContext(ctx).Model(&model.ReportingEvent{}).
			Where("account_id = ? AND name IN ? AND created_at >= ? AND created_at < ? AND conversation_id IS NOT NULL", accountID, []string{"conversation_bot_handoff", model.MetricNameBotHandoffsCount}, since, until)
		handoffQ = applyEventDimension(handoffQ, reportType, id)
		if err := handoffQ.Distinct("conversation_id").Pluck("conversation_id", &handoffIDs).Error; err != nil {
			return nil, err
		}
		if len(handoffIDs) > 0 {
			q = q.Where("conversation_id NOT IN ?", handoffIDs)
		}
	}
	if err := q.Find(&events).Error; err != nil {
		return nil, err
	}
	buckets := seedTimeseriesBuckets(since, until, groupBy, loc)
	distinctConversationsByBucket := map[time.Time]map[uint]struct{}{}
	for _, event := range events {
		bucket := bucketStart(event.CreatedAt, groupBy, loc)
		point := ensureTimeseriesBucket(buckets, bucket)
		value := event.Value
		if businessHours {
			value = event.ValueInBusinessHours
		}
		if average {
			point.Value += value
			point.Count++
		} else if countStrategy == "distinct_conversation" {
			if event.ConversationID == nil {
				continue
			}
			if distinctConversationsByBucket[bucket] == nil {
				distinctConversationsByBucket[bucket] = map[uint]struct{}{}
			}
			if _, exists := distinctConversationsByBucket[bucket][*event.ConversationID]; exists {
				continue
			}
			distinctConversationsByBucket[bucket][*event.ConversationID] = struct{}{}
			point.Value++
		} else {
			point.Value++
		}
	}
	if average {
		for _, point := range buckets {
			if point.Count > 0 {
				point.Value = point.Value / float64(point.Count)
			}
		}
	}
	return sortedTimeseries(buckets), nil
}

func applyConversationDimension(query *gorm.DB, reportType string, id uint) *gorm.DB {
	switch reportType {
	case "inbox":
		if id > 0 {
			query = query.Where("inbox_id = ?", id)
		}
	case "agent":
		if id > 0 {
			query = query.Where("assignee_id = ?", id)
		}
	case "team":
		if id > 0 {
			query = query.Where("team_id = ?", id)
		}
	case "label":
		if id > 0 {
			query = query.Joins("INNER JOIN conversation_labels ON conversation_labels.conversation_id = conversations.id").Where("conversation_labels.tag_id = ?", id)
		}
	}
	return query
}

func applyMessageDimension(query *gorm.DB, reportType string, id uint) *gorm.DB {
	switch reportType {
	case "inbox":
		if id > 0 {
			query = query.Where("messages.inbox_id = ?", id)
		}
	case "agent":
		if id > 0 {
			query = query.Where("messages.sender_type = ? AND messages.sender_id = ?", "User", id)
		}
	case "team":
		if id > 0 {
			query = query.Joins("INNER JOIN conversations ON conversations.id = messages.conversation_id").Where("conversations.team_id = ?", id)
		}
	case "label":
		if id > 0 {
			query = query.Joins("INNER JOIN conversation_labels ON conversation_labels.conversation_id = messages.conversation_id").Where("conversation_labels.tag_id = ?", id)
		}
	}
	return query
}

func applyEventDimension(query *gorm.DB, reportType string, id uint) *gorm.DB {
	switch reportType {
	case "inbox":
		if id > 0 {
			query = query.Where("inbox_id = ?", id)
		}
	case "agent":
		if id > 0 {
			query = query.Where("user_id = ?", id)
		}
	case "team":
		if id > 0 {
			query = query.Joins("INNER JOIN conversations ON conversations.id = reporting_events.conversation_id").Where("conversations.team_id = ?", id)
		}
	case "label":
		if id > 0 {
			query = query.Joins("INNER JOIN conversation_labels ON conversation_labels.conversation_id = reporting_events.conversation_id").Where("conversation_labels.tag_id = ?", id)
		}
	}
	return query
}

func dayStart(t time.Time) time.Time {
	return time.Date(t.Year(), t.Month(), t.Day(), 0, 0, 0, 0, time.UTC)
}

func bucketStart(t time.Time, groupBy string, loc *time.Location) time.Time {
	if loc == nil {
		loc = time.UTC
	}
	t = t.In(loc)
	switch groupBy {
	case "hour":
		return time.Date(t.Year(), t.Month(), t.Day(), t.Hour(), 0, 0, 0, loc)
	case "week":
		start := time.Date(t.Year(), t.Month(), t.Day(), 0, 0, 0, 0, loc)
		return start.AddDate(0, 0, -int(start.Weekday()))
	case "month":
		return time.Date(t.Year(), t.Month(), 1, 0, 0, 0, 0, loc)
	case "year":
		return time.Date(t.Year(), 1, 1, 0, 0, 0, 0, loc)
	default:
		return time.Date(t.Year(), t.Month(), t.Day(), 0, 0, 0, 0, loc)
	}
}

func timeseriesLocation(offsetHours float64) *time.Location {
	return time.FixedZone("report", int(offsetHours*3600))
}

func seedTimeseriesBuckets(since, until time.Time, groupBy string, loc *time.Location) map[time.Time]*AnalyticsTimeseriesPoint {
	buckets := map[time.Time]*AnalyticsTimeseriesPoint{}
	if since.IsZero() || until.IsZero() || !since.Before(until) {
		return buckets
	}
	for bucket := bucketStart(since, groupBy, loc); bucket.Before(until.In(loc)); bucket = nextBucketStart(bucket, groupBy) {
		ensureTimeseriesBucket(buckets, bucket)
	}
	return buckets
}

func nextBucketStart(bucket time.Time, groupBy string) time.Time {
	switch groupBy {
	case "hour":
		return bucket.Add(time.Hour)
	case "week":
		return bucket.AddDate(0, 0, 7)
	case "month":
		return bucket.AddDate(0, 1, 0)
	case "year":
		return bucket.AddDate(1, 0, 0)
	default:
		return bucket.AddDate(0, 0, 1)
	}
}

func ensureTimeseriesBucket(buckets map[time.Time]*AnalyticsTimeseriesPoint, bucket time.Time) *AnalyticsTimeseriesPoint {
	point := buckets[bucket]
	if point == nil {
		point = &AnalyticsTimeseriesPoint{Timestamp: bucket.Unix()}
		buckets[bucket] = point
	}
	return point
}

func sortedTimeseries(buckets map[time.Time]*AnalyticsTimeseriesPoint) []AnalyticsTimeseriesPoint {
	keys := make([]time.Time, 0, len(buckets))
	for key := range buckets {
		keys = append(keys, key)
	}
	sort.Slice(keys, func(i, j int) bool { return keys[i].Before(keys[j]) })
	result := make([]AnalyticsTimeseriesPoint, 0, len(keys))
	for _, key := range keys {
		result = append(result, *buckets[key])
	}
	return result
}

func parseReportDimensionID(raw string) uint {
	if strings.TrimSpace(raw) == "" {
		return 0
	}
	parsed, err := strconv.ParseUint(raw, 10, 64)
	if err != nil {
		return 0
	}
	return uint(parsed)
}

func (s *AnalyticsService) groupedLiveConversationMetrics(ctx context.Context, accountID uint, groupBy string, teamID uint) ([]map[string]interface{}, error) {
	if groupBy != "team_id" && groupBy != "assignee_id" {
		return nil, errors.New("invalid group_by")
	}
	db, err := s.analyticsDB()
	if err != nil {
		return nil, err
	}
	type row struct {
		GroupID *uint
		Count   int64
	}
	load := func(where string) (map[uint]int64, error) {
		var rows []row
		q := db.WithContext(ctx).Model(&model.Conversation{}).
			Select(groupBy+" AS group_id, COUNT(*) AS count").
			Where("account_id = ? AND status = ? "+where, accountID, string(model.ConversationStatusOpen))
		if teamID > 0 {
			q = q.Where("team_id = ?", teamID)
		}
		if err := q.Group(groupBy).Scan(&rows).Error; err != nil {
			return nil, err
		}
		counts := map[uint]int64{}
		for _, row := range rows {
			if row.GroupID == nil {
				counts[0] += row.Count
				continue
			}
			counts[*row.GroupID] += row.Count
		}
		return counts, nil
	}
	open, err := load("")
	if err != nil {
		return nil, err
	}
	unattended, err := load("AND (first_reply_created_at IS NULL OR waiting_since IS NOT NULL)")
	if err != nil {
		return nil, err
	}
	unassigned, err := load("AND assignee_id IS NULL")
	if err != nil {
		return nil, err
	}
	ids := make([]uint, 0, len(open))
	for id := range open {
		ids = append(ids, id)
	}
	sort.Slice(ids, func(i, j int) bool { return ids[i] < ids[j] })
	result := make([]map[string]interface{}, 0, len(ids))
	for _, id := range ids {
		metric := map[string]interface{}{
			groupBy:      id,
			"open":       open[id],
			"unattended": unattended[id],
			"unassigned": unassigned[id],
		}
		if id == 0 {
			metric[groupBy] = nil
		}
		result = append(result, metric)
	}
	return result, nil
}

func (s *AnalyticsService) botSummaryCounts(ctx context.Context, accountID uint, since, until time.Time, reportType string, id uint) (*BotSummaryResponse, error) {
	result := &BotSummaryResponse{}
	resolutions, err := s.aggregateEventCount(ctx, accountID, since, until, reportType, id, []string{"conversation_bot_resolved", model.MetricNameBotResolutionsCount}, "exclude_bot_handoffs")
	if err != nil {
		return nil, err
	}
	handoffs, err := s.aggregateEventCount(ctx, accountID, since, until, reportType, id, []string{"conversation_bot_handoff", model.MetricNameBotHandoffsCount}, "distinct_conversation")
	if err != nil {
		return nil, err
	}
	result.BotResolutionsCount = resolutions
	result.BotHandoffsCount = handoffs
	return result, nil
}

func (s *AnalyticsService) reportSummaryCounts(ctx context.Context, accountID uint, since, until time.Time, reportType string, id uint, businessHours bool) (*ReportSummaryResponse, error) {
	conversations, err := s.aggregateConversationCount(ctx, accountID, since, until, reportType, id, false)
	if err != nil {
		return nil, err
	}
	incoming, err := s.aggregateMessageCount(ctx, accountID, since, until, reportType, id, model.MessageTypeIncoming)
	if err != nil {
		return nil, err
	}
	outgoing, err := s.aggregateMessageCount(ctx, accountID, since, until, reportType, id, model.MessageTypeOutgoing)
	if err != nil {
		return nil, err
	}
	resolutions, err := s.aggregateEventCount(ctx, accountID, since, until, reportType, id, []string{"conversation_resolved", model.MetricNameResolutionTime}, "")
	if err != nil {
		return nil, err
	}
	firstResponse, err := s.aggregateEventAverage(ctx, accountID, since, until, reportType, id, []string{model.MetricNameFirstResponse}, businessHours)
	if err != nil {
		return nil, err
	}
	resolutionTime, err := s.aggregateEventAverage(ctx, accountID, since, until, reportType, id, []string{"conversation_resolved", model.MetricNameResolutionTime}, businessHours)
	if err != nil {
		return nil, err
	}
	replyTime, err := s.aggregateEventAverage(ctx, accountID, since, until, reportType, id, []string{model.MetricNameReplyTime}, businessHours)
	if err != nil {
		return nil, err
	}
	return &ReportSummaryResponse{
		ConversationsCount:    conversations,
		IncomingMessagesCount: incoming,
		OutgoingMessagesCount: outgoing,
		AvgFirstResponseTime:  firstResponse,
		AvgResolutionTime:     resolutionTime,
		ResolutionsCount:      resolutions,
		ReplyTime:             replyTime,
	}, nil
}

func (s *AnalyticsService) aggregateConversationCount(ctx context.Context, accountID uint, since, until time.Time, reportType string, id uint, resolved bool) (int64, error) {
	db, err := s.analyticsDB()
	if err != nil {
		return 0, err
	}
	q := db.WithContext(ctx).Model(&model.Conversation{}).Where("account_id = ?", accountID)
	if resolved {
		q = q.Where("resolved_at IS NOT NULL AND resolved_at >= ? AND resolved_at < ?", since, until)
	} else {
		q = q.Where("created_at >= ? AND created_at < ?", since, until)
	}
	q = applyConversationDimension(q, reportType, id)
	var count int64
	if err := q.Count(&count).Error; err != nil {
		return 0, err
	}
	return count, nil
}

func (s *AnalyticsService) aggregateMessageCount(ctx context.Context, accountID uint, since, until time.Time, reportType string, id uint, messageType model.MessageType) (int64, error) {
	db, err := s.analyticsDB()
	if err != nil {
		return 0, err
	}
	q := db.WithContext(ctx).Model(&model.Message{}).Where("messages.account_id = ? AND messages.message_type = ? AND messages.created_at >= ? AND messages.created_at < ?", accountID, string(messageType), since, until)
	q = applyMessageDimension(q, reportType, id)
	var count int64
	if err := q.Count(&count).Error; err != nil {
		return 0, err
	}
	return count, nil
}

func (s *AnalyticsService) aggregateEventAverage(ctx context.Context, accountID uint, since, until time.Time, reportType string, id uint, names []string, businessHours bool) (float64, error) {
	db, err := s.analyticsDB()
	if err != nil {
		return 0, err
	}
	valueColumn := "value"
	if businessHours {
		valueColumn = "value_in_business_hours"
	}
	var row struct {
		Value float64
		Count int64
	}
	q := db.WithContext(ctx).Model(&model.ReportingEvent{}).
		Select("COALESCE(SUM("+valueColumn+"), 0) AS value, COUNT(*) AS count").
		Where("account_id = ? AND name IN ? AND created_at >= ? AND created_at < ?", accountID, names, since, until)
	q = applyEventDimension(q, reportType, id)
	if err := q.Scan(&row).Error; err != nil {
		return 0, err
	}
	if row.Count == 0 {
		return 0, nil
	}
	return row.Value / float64(row.Count), nil
}

func (s *AnalyticsService) aggregateEventCount(ctx context.Context, accountID uint, since, until time.Time, reportType string, id uint, names []string, countStrategy string) (int64, error) {
	db, err := s.analyticsDB()
	if err != nil {
		return 0, err
	}
	q := db.WithContext(ctx).Model(&model.ReportingEvent{}).
		Where("account_id = ? AND name IN ? AND created_at >= ? AND created_at < ?", accountID, names, since, until)
	q = applyEventDimension(q, reportType, id)
	if countStrategy == "exclude_bot_handoffs" {
		var handoffIDs []uint
		handoffQ := db.WithContext(ctx).Model(&model.ReportingEvent{}).
			Where("account_id = ? AND name IN ? AND created_at >= ? AND created_at < ? AND conversation_id IS NOT NULL", accountID, []string{"conversation_bot_handoff", model.MetricNameBotHandoffsCount}, since, until)
		handoffQ = applyEventDimension(handoffQ, reportType, id)
		if err := handoffQ.Distinct("conversation_id").Pluck("conversation_id", &handoffIDs).Error; err != nil {
			return 0, err
		}
		if len(handoffIDs) > 0 {
			q = q.Where("conversation_id IS NULL OR conversation_id NOT IN ?", handoffIDs)
		}
	}
	var count int64
	if countStrategy == "distinct_conversation" {
		if err := q.Where("conversation_id IS NOT NULL").Distinct("conversation_id").Count(&count).Error; err != nil {
			return 0, err
		}
		return count, nil
	}
	if err := q.Count(&count).Error; err != nil {
		return 0, err
	}
	return count, nil
}

func (s *AnalyticsService) conversationMetricsByType(ctx context.Context, accountID uint, reportType string, page int) (interface{}, error) {
	if reportType == "account" {
		return s.liveConversationMetrics(ctx, accountID, 0)
	}
	return s.agentConversationMetrics(ctx, accountID, page)
}

func (s *AnalyticsService) agentConversationMetrics(ctx context.Context, accountID uint, page int) ([]ReportAgentConversationMetric, error) {
	db, err := s.analyticsDB()
	if err != nil {
		return nil, err
	}
	if page < 1 {
		page = 1
	}
	const perPage = 25

	var accountUsers []model.AccountUser
	if err := db.WithContext(ctx).
		Preload("User").
		Where("account_id = ?", accountID).
		Order("id ASC").
		Limit(perPage).
		Offset((page - 1) * perPage).
		Find(&accountUsers).Error; err != nil {
		return nil, err
	}

	result := make([]ReportAgentConversationMetric, 0, len(accountUsers))
	for _, accountUser := range accountUsers {
		metric, metricErr := s.liveConversationMetricsForAssignee(ctx, accountID, accountUser.UserID)
		if metricErr != nil {
			return nil, metricErr
		}
		result = append(result, ReportAgentConversationMetric{
			ID:           accountUser.User.ID,
			Name:         accountUser.User.Name,
			Email:        accountUser.User.Email,
			Thumbnail:    accountUser.User.AvatarURL,
			Availability: accountUser.Availability,
			Metric:       metric,
		})
	}
	sort.SliceStable(result, func(i, j int) bool {
		return result[i].Metric["open"] > result[j].Metric["open"]
	})
	return result, nil
}

func (s *AnalyticsService) liveConversationMetricsForAssignee(ctx context.Context, accountID uint, assigneeID uint) (map[string]int64, error) {
	db, err := s.analyticsDB()
	if err != nil {
		return nil, err
	}
	base := func() *gorm.DB {
		return db.WithContext(ctx).Model(&model.Conversation{}).
			Where("account_id = ? AND assignee_id = ? AND status = ?", accountID, assigneeID, string(model.ConversationStatusOpen))
	}
	var openCount int64
	var unattendedCount int64
	if err := base().Count(&openCount).Error; err != nil {
		return nil, err
	}
	if err := base().Where("first_reply_created_at IS NULL OR waiting_since IS NOT NULL").Count(&unattendedCount).Error; err != nil {
		return nil, err
	}
	return map[string]int64{"open": openCount, "unattended": unattendedCount}, nil
}

func (s *AnalyticsService) conversationSummary(ctx context.Context, accountID uint, since, until time.Time) (map[string]interface{}, error) {
	db, err := s.analyticsDB()
	if err != nil {
		return nil, err
	}
	countConversations := func(where string, args ...interface{}) (int64, error) {
		var count int64
		q := db.WithContext(ctx).Model(&model.Conversation{}).Where("account_id = ?", accountID).Where(where, args...)
		err := q.Count(&count).Error
		return count, err
	}
	countMessages := func(messageType model.MessageType) (int64, error) {
		var count int64
		err := db.WithContext(ctx).Model(&model.Message{}).
			Where("account_id = ? AND message_type = ? AND created_at >= ? AND created_at < ?", accountID, string(messageType), since, until).
			Count(&count).Error
		return count, err
	}
	conversations, err := countConversations("created_at >= ? AND created_at < ?", since, until)
	if err != nil {
		return nil, err
	}
	incoming, err := countMessages(model.MessageTypeIncoming)
	if err != nil {
		return nil, err
	}
	outgoing, err := countMessages(model.MessageTypeOutgoing)
	if err != nil {
		return nil, err
	}
	resolutions, err := countConversations("resolved_at IS NOT NULL AND resolved_at >= ? AND resolved_at < ?", since, until)
	if err != nil {
		return nil, err
	}
	firstResponse, _ := s.averageEventValue(ctx, accountID, []string{model.MetricNameFirstResponse}, since, until)
	resolutionTime, _ := s.averageEventValue(ctx, accountID, []string{"conversation_resolved", model.MetricNameResolutionTime}, since, until)
	replyTime, _ := s.averageEventValue(ctx, accountID, []string{model.MetricNameReplyTime}, since, until)
	return map[string]interface{}{
		"conversations_count":     conversations,
		"incoming_messages_count": incoming,
		"outgoing_messages_count": outgoing,
		"avg_first_response_time": firstResponse,
		"avg_resolution_time":     resolutionTime,
		"resolutions_count":       resolutions,
		"reply_time":              replyTime,
	}, nil
}

func (s *AnalyticsService) botMetrics(ctx context.Context, accountID uint, since, until time.Time) (map[string]interface{}, error) {
	db, err := s.analyticsDB()
	if err != nil {
		return nil, err
	}
	var inboxIDs []uint
	if db.Migrator().HasTable(&model.AgentBotInbox{}) {
		if err := db.WithContext(ctx).Model(&model.AgentBotInbox{}).
			Where("status = ?", model.AgentBotInboxActive).
			Where("account_id = ? OR account_id IS NULL", accountID).
			Distinct("inbox_id").Pluck("inbox_id", &inboxIDs).Error; err != nil {
			return nil, err
		}
	}
	conversationIDs := []uint{}
	messageCount := int64(0)
	if len(inboxIDs) > 0 {
		if err := db.WithContext(ctx).Model(&model.Conversation{}).
			Where("account_id = ? AND inbox_id IN ? AND created_at >= ? AND created_at < ?", accountID, inboxIDs, since, until).
			Pluck("id", &conversationIDs).Error; err != nil {
			return nil, err
		}
		if len(conversationIDs) > 0 {
			if err := db.WithContext(ctx).Model(&model.Message{}).
				Where("account_id = ? AND conversation_id IN ? AND message_type = ? AND created_at >= ? AND created_at < ?", accountID, conversationIDs, string(model.MessageTypeOutgoing), since, until).
				Count(&messageCount).Error; err != nil {
				return nil, err
			}
		}
	}
	conversationCount := int64(len(conversationIDs))
	resolutions, handoffs, err := s.botMetricDistinctCounts(ctx, db, accountID, since, until)
	if err != nil {
		return nil, err
	}
	resolutionRate := 0
	handoffRate := 0
	if conversationCount > 0 {
		resolutionRate = int(float64(resolutions) / float64(conversationCount) * 100)
		handoffRate = int(float64(handoffs) / float64(conversationCount) * 100)
	}
	return map[string]interface{}{
		"conversation_count": conversationCount,
		"message_count":      messageCount,
		"resolution_rate":    resolutionRate,
		"handoff_rate":       handoffRate,
	}, nil
}

func (s *AnalyticsService) botMetricDistinctCounts(ctx context.Context, db *gorm.DB, accountID uint, since, until time.Time) (int64, int64, error) {
	handoffIDs := []uint{}
	if err := db.WithContext(ctx).Model(&model.ReportingEvent{}).
		Where("account_id = ? AND name = ? AND created_at >= ? AND created_at < ? AND conversation_id IS NOT NULL", accountID, "conversation_bot_handoff", since, until).
		Distinct("conversation_id").Pluck("conversation_id", &handoffIDs).Error; err != nil {
		return 0, 0, err
	}
	resolutionQ := db.WithContext(ctx).Model(&model.ReportingEvent{}).
		Where("account_id = ? AND name = ? AND created_at >= ? AND created_at < ? AND conversation_id IS NOT NULL", accountID, "conversation_bot_resolved", since, until)
	if len(handoffIDs) > 0 {
		resolutionQ = resolutionQ.Where("conversation_id NOT IN ?", handoffIDs)
	}
	var resolutions int64
	if err := resolutionQ.Distinct("conversation_id").Count(&resolutions).Error; err != nil {
		return 0, 0, err
	}
	return resolutions, int64(len(handoffIDs)), nil
}

func (s *AnalyticsService) inboxLabelMatrix(ctx context.Context, accountID uint, filter InboxLabelMatrixFilter) (map[string]interface{}, error) {
	db, err := s.analyticsDB()
	if err != nil {
		return nil, err
	}
	var inboxes []model.Inbox
	inboxQ := db.WithContext(ctx).Where("account_id = ?", accountID)
	if len(filter.InboxIDs) > 0 {
		inboxQ = inboxQ.Where("id IN ?", filter.InboxIDs)
	}
	if err := inboxQ.Order("name ASC").Find(&inboxes).Error; err != nil {
		return nil, err
	}
	var tags []model.Tag
	tagQ := db.WithContext(ctx).Where("account_id = ?", accountID)
	if len(filter.LabelIDs) > 0 {
		tagQ = tagQ.Where("id IN ?", filter.LabelIDs)
	}
	if err := tagQ.Order("name ASC").Find(&tags).Error; err != nil {
		return nil, err
	}
	type countRow struct {
		InboxID uint
		TagID   uint
		Count   int64
	}
	var rows []countRow
	if len(inboxes) > 0 && len(tags) > 0 {
		inboxIDs := make([]uint, 0, len(inboxes))
		for _, inbox := range inboxes {
			inboxIDs = append(inboxIDs, inbox.ID)
		}
		labelIDs := make([]uint, 0, len(tags))
		for _, tag := range tags {
			labelIDs = append(labelIDs, tag.ID)
		}
		countsQ := db.WithContext(ctx).Table("conversation_labels").
			Select("conversations.inbox_id AS inbox_id, conversation_labels.tag_id AS tag_id, COUNT(*) AS count").
			Joins("INNER JOIN conversations ON conversations.id = conversation_labels.conversation_id").
			Where("conversation_labels.account_id = ? AND conversations.account_id = ?", accountID, accountID).
			Where("conversations.inbox_id IN ? AND conversation_labels.tag_id IN ?", inboxIDs, labelIDs)
		if !filter.Since.IsZero() && !filter.Until.IsZero() {
			countsQ = countsQ.Where("conversations.created_at >= ? AND conversations.created_at < ?", filter.Since, filter.Until)
		}
		if err := countsQ.Group("conversations.inbox_id, conversation_labels.tag_id").Scan(&rows).Error; err != nil {
			return nil, err
		}
	}
	counts := map[uint]map[uint]int64{}
	for _, row := range rows {
		if counts[row.InboxID] == nil {
			counts[row.InboxID] = map[uint]int64{}
		}
		counts[row.InboxID][row.TagID] = row.Count
	}
	inboxPayload := make([]map[string]interface{}, 0, len(inboxes))
	for _, inbox := range inboxes {
		inboxPayload = append(inboxPayload, map[string]interface{}{"id": inbox.ID, "name": inbox.Name})
	}
	labelPayload := make([]map[string]interface{}, 0, len(tags))
	for _, tag := range tags {
		labelPayload = append(labelPayload, map[string]interface{}{"id": tag.ID, "title": tag.Name})
	}
	matrix := make([][]int64, 0, len(inboxes))
	for _, inbox := range inboxes {
		row := make([]int64, 0, len(tags))
		for _, tag := range tags {
			row = append(row, counts[inbox.ID][tag.ID])
		}
		matrix = append(matrix, row)
	}
	return map[string]interface{}{"inboxes": inboxPayload, "labels": labelPayload, "matrix": matrix}, nil
}

func (s *AnalyticsService) firstResponseTimeDistribution(ctx context.Context, accountID uint, since, until time.Time) (map[string]map[string]int64, error) {
	db, err := s.analyticsDB()
	if err != nil {
		return nil, err
	}
	var events []model.ReportingEvent
	eventQ := db.WithContext(ctx).Where("account_id = ? AND name = ?", accountID, model.MetricNameFirstResponse)
	if !since.IsZero() && !until.IsZero() {
		eventQ = eventQ.Where("created_at >= ? AND created_at < ?", since, until)
	}
	if err := eventQ.Find(&events).Error; err != nil {
		return nil, err
	}
	inboxIDs := make([]uint, 0, len(events))
	for _, event := range events {
		if event.InboxID != nil {
			inboxIDs = append(inboxIDs, *event.InboxID)
		}
	}
	var inboxes []model.Inbox
	if len(inboxIDs) > 0 {
		if err := db.WithContext(ctx).Where("account_id = ? AND id IN ?", accountID, inboxIDs).Find(&inboxes).Error; err != nil {
			return nil, err
		}
	}
	channelTypes := map[uint]string{}
	for _, inbox := range inboxes {
		channelTypes[inbox.ID] = inbox.ChannelType
	}
	result := map[string]map[string]int64{}
	for _, event := range events {
		if event.InboxID == nil {
			continue
		}
		channelType := channelTypes[*event.InboxID]
		if channelType == "" {
			continue
		}
		if result[channelType] == nil {
			result[channelType] = map[string]int64{"0-1h": 0, "1-4h": 0, "4-8h": 0, "8-24h": 0, "24h+": 0}
		}
		switch {
		case event.Value < 3600:
			result[channelType]["0-1h"]++
		case event.Value < 14400:
			result[channelType]["1-4h"]++
		case event.Value < 28800:
			result[channelType]["4-8h"]++
		case event.Value < 86400:
			result[channelType]["8-24h"]++
		default:
			result[channelType]["24h+"]++
		}
	}
	return result, nil
}

func (s *AnalyticsService) outgoingMessagesCount(ctx context.Context, accountID uint, since, until time.Time, groupBy string) ([]map[string]interface{}, error) {
	if groupBy == "" {
		groupBy = "agent"
	}
	db, err := s.analyticsDB()
	if err != nil {
		return nil, err
	}
	switch groupBy {
	case "agent":
		return s.outgoingMessagesByAgent(ctx, db, accountID, since, until)
	case "team":
		return s.outgoingMessagesByConversationField(ctx, db, accountID, since, until, "team_id", "teams")
	case "inbox":
		return s.outgoingMessagesByInbox(ctx, db, accountID, since, until)
	case "label":
		return s.outgoingMessagesByLabel(ctx, db, accountID, since, until)
	default:
		return nil, errors.New("invalid group_by")
	}
}

func (s *AnalyticsService) averageEventValue(ctx context.Context, accountID uint, names []string, since, until time.Time) (float64, error) {
	db, err := s.analyticsDB()
	if err != nil {
		return 0, err
	}
	var row struct {
		Value float64
		Count int64
	}
	err = db.WithContext(ctx).Model(&model.ReportingEvent{}).
		Select("COALESCE(SUM(value), 0) AS value, COUNT(*) AS count").
		Where("account_id = ? AND name IN ? AND created_at >= ? AND created_at < ?", accountID, names, since, until).
		Scan(&row).Error
	if err != nil || row.Count == 0 {
		return 0, err
	}
	return row.Value / float64(row.Count), nil
}

type outgoingCountRow struct {
	ID    uint
	Name  string
	Count int64
}

func (s *AnalyticsService) outgoingMessagesByAgent(ctx context.Context, db *gorm.DB, accountID uint, since, until time.Time) ([]map[string]interface{}, error) {
	var rows []outgoingCountRow
	err := db.WithContext(ctx).Table("messages").
		Select("messages.sender_id AS id, users.name AS name, COUNT(*) AS count").
		Joins("LEFT JOIN users ON users.id = messages.sender_id").
		Where("messages.account_id = ? AND messages.message_type = ? AND messages.sender_type = ? AND messages.sender_id IS NOT NULL AND messages.created_at >= ? AND messages.created_at < ?", accountID, string(model.MessageTypeOutgoing), "User", since, until).
		Group("messages.sender_id, users.name").Scan(&rows).Error
	return outgoingRows(rows, "agent"), err
}

func (s *AnalyticsService) outgoingMessagesByConversationField(ctx context.Context, db *gorm.DB, accountID uint, since, until time.Time, field, table string) ([]map[string]interface{}, error) {
	var rows []outgoingCountRow
	err := db.WithContext(ctx).Table("messages").
		Select("conversations."+field+" AS id, "+table+".name AS name, COUNT(*) AS count").
		Joins("INNER JOIN conversations ON conversations.id = messages.conversation_id").
		Joins("LEFT JOIN "+table+" ON "+table+".id = conversations."+field).
		Where("messages.account_id = ? AND messages.message_type = ? AND conversations."+field+" IS NOT NULL AND messages.created_at >= ? AND messages.created_at < ?", accountID, string(model.MessageTypeOutgoing), since, until).
		Group("conversations." + field + ", " + table + ".name").Scan(&rows).Error
	return outgoingRows(rows, strings.TrimSuffix(field, "_id")), err
}

func (s *AnalyticsService) outgoingMessagesByInbox(ctx context.Context, db *gorm.DB, accountID uint, since, until time.Time) ([]map[string]interface{}, error) {
	var rows []outgoingCountRow
	err := db.WithContext(ctx).Table("messages").
		Select("messages.inbox_id AS id, inboxes.name AS name, COUNT(*) AS count").
		Joins("LEFT JOIN inboxes ON inboxes.id = messages.inbox_id").
		Where("messages.account_id = ? AND messages.message_type = ? AND messages.created_at >= ? AND messages.created_at < ?", accountID, string(model.MessageTypeOutgoing), since, until).
		Group("messages.inbox_id, inboxes.name").Scan(&rows).Error
	return outgoingRows(rows, "inbox"), err
}

func (s *AnalyticsService) outgoingMessagesByLabel(ctx context.Context, db *gorm.DB, accountID uint, since, until time.Time) ([]map[string]interface{}, error) {
	type labelRow struct {
		Name  string
		Count int64
	}
	var rows []labelRow
	err := db.WithContext(ctx).Table("messages").
		Select("tags.name AS name, COUNT(*) AS count").
		Joins("INNER JOIN conversations ON conversations.id = messages.conversation_id").
		Joins("INNER JOIN conversation_labels ON conversation_labels.conversation_id = conversations.id").
		Joins("INNER JOIN tags ON tags.id = conversation_labels.tag_id").
		Where("messages.account_id = ? AND messages.message_type = ? AND messages.created_at >= ? AND messages.created_at < ?", accountID, string(model.MessageTypeOutgoing), since, until).
		Group("tags.name").Scan(&rows).Error
	if err != nil {
		return nil, err
	}
	names := make([]string, 0, len(rows))
	for _, row := range rows {
		names = append(names, row.Name)
	}
	var labels []model.Tag
	if len(names) > 0 {
		if err := db.WithContext(ctx).Where("account_id = ? AND name IN ?", accountID, names).Find(&labels).Error; err != nil {
			return nil, err
		}
	}
	labelIDs := map[string]uint{}
	for _, label := range labels {
		labelIDs[label.Name] = label.ID
	}
	result := make([]map[string]interface{}, 0, len(rows))
	for _, row := range rows {
		var id interface{}
		if labelID, ok := labelIDs[row.Name]; ok {
			id = labelID
		}
		result = append(result, map[string]interface{}{"id": id, "name": row.Name, "outgoing_messages_count": row.Count})
	}
	return result, nil
}

func outgoingRows(rows []outgoingCountRow, _ string) []map[string]interface{} {
	result := make([]map[string]interface{}, 0, len(rows))
	for _, row := range rows {
		result = append(result, map[string]interface{}{"id": row.ID, "name": row.Name, "outgoing_messages_count": row.Count})
	}
	return result
}