package admin

import (
	"context"
	"strings"

	"tug/internal/storage"
)

func split(users []storage.User) (enabled, disabled []storage.User) {
	for _, u := range users {
		if u.Disabled {
			disabled = append(disabled, u)
		} else {
			enabled = append(enabled, u)
		}
	}
	return enabled, disabled
}

func membersOf(users []storage.User) []Member {
	out := make([]Member, 0, len(users))
	for _, u := range users {
		out = append(out, Member{ID: u.ID, Username: u.Username, DisplayName: u.DisplayName})
	}
	return out
}

func (s *Service) GroupCandidates(ctx context.Context, groupID, query string) ([]Member, error) {
	g, err := s.store.GroupByID(ctx, groupID)
	if err != nil {
		return nil, target("read group", err)
	}
	needle := strings.ToLower(strings.TrimSpace(query))
	if needle == "" || g.Name == s.primaryGroup {
		return nil, nil
	}
	members, err := s.members(ctx, g)
	if err != nil {
		return nil, err
	}
	in := make(map[string]bool, len(members))
	for _, u := range members {
		in[u.ID] = true
	}
	users, err := s.store.ListUsers(ctx)
	if err != nil {
		return nil, failed("list users", err)
	}
	var found []storage.User
	for _, u := range users {
		if !in[u.ID] && matches(u, needle) {
			found = append(found, u)
			if len(found) == CandidatesShown {
				break
			}
		}
	}
	return membersOf(found), nil
}