package isphere

import (
	"sort"
	"strings"
)

type Group struct {
	GroupID     string
	DisplayName string
	Source      string
	Confidence  float64
	RawRef      string
}

type SearchGroupsQuery struct {
	Query string
	Limit int
}

type SearchGroupsResult struct {
	Groups []Group
}

func SearchGroupsFromMessages(messages []Message, query SearchGroupsQuery) SearchGroupsResult {
	unique := map[string]Group{}
	for _, message := range messages {
		if strings.EqualFold(message.ConversationType, "groupchat") {
			addMessageGroup(unique, message.SenderID)
			addMessageGroup(unique, message.ReceiverID)
			continue
		}
		if isLikelyGroupJID(message.SenderID) {
			addMessageGroup(unique, message.SenderID)
		}
		if isLikelyGroupJID(message.ReceiverID) {
			addMessageGroup(unique, message.ReceiverID)
		}
	}

	queryText := strings.ToLower(strings.TrimSpace(query.Query))
	ids := make([]string, 0, len(unique))
	for id := range unique {
		if queryText == "" || strings.Contains(strings.ToLower(id), queryText) || strings.Contains(strings.ToLower(unique[id].DisplayName), queryText) {
			ids = append(ids, id)
		}
	}
	sort.Strings(ids)

	limit := query.Limit
	if limit <= 0 || limit > len(ids) {
		limit = len(ids)
	}
	groups := make([]Group, 0, limit)
	for _, id := range ids[:limit] {
		groups = append(groups, unique[id])
	}
	return SearchGroupsResult{Groups: groups}
}

func addMessageGroup(unique map[string]Group, id string) {
	trimmed := strings.TrimSpace(id)
	if trimmed == "" || !isLikelyGroupJID(trimmed) {
		return
	}
	if _, exists := unique[trimmed]; exists {
		return
	}
	unique[trimmed] = Group{
		GroupID:     trimmed,
		DisplayName: trimmed,
		Source:      "local_readonly",
		Confidence:  0.6,
		RawRef:      "groupchat_jid",
	}
}

func isLikelyGroupJID(id string) bool {
	lower := strings.ToLower(strings.TrimSpace(id))
	return strings.Contains(lower, "conference") || strings.Contains(lower, "muc") || strings.Contains(lower, "group")
}