package logic

import (
	"context"

	"spark-server/internal/module/group/entity"
	"spark-server/internal/pkg/errs"
	"spark-server/internal/pkg/i18n"
	"spark-server/internal/pkg/reqctx"
	"spark-server/internal/pkg/validate"
)

type InviteInput struct {
	UIDs []int64 `json:"uids" validate:"required,min=1,max=199,dive,gt=0" label:"field.member_uids" errmsg:"required:validate.group.members_required;min:validate.group.members_required;max:validate.group.members_invalid"`
}

func (s *Service) Invite(ctx context.Context, actorID, groupID int64, in *InviteInput) (*View, error) {
	if !s.ready() || actorID <= 0 {
		return nil, errs.ErrUnauthorized
	}
	if in == nil {
		return nil, errs.ErrInvalidArgument
	}
	if err := validate.StructLang(reqctx.Lang(ctx), in); err != nil {
		return nil, err
	}
	g, err := s.loadActive(ctx, groupID)
	if err != nil {
		return nil, err
	}
	if _, err := s.requireMember(ctx, groupID, actorID); err != nil {
		return nil, err
	}
	added, err := s.newMembers(ctx, g, actorID, in.UIDs)
	if err != nil {
		return nil, err
	}
	if err := s.repo.AddMembers(ctx, groupID, added); err != nil {
		return nil, err
	}
	g.MemberCount += len(added)
	s.invalidateMembers(g.ConversationID)
	ids := make([]int64, 0, len(added))
	for _, mem := range added {
		ids = append(ids, mem.UserID)
	}
	_ = s.notice(ctx, g, actorID, entity.SystemKindInvite, ids)
	mem, err := s.requireMember(ctx, groupID, actorID)
	if err != nil {
		return viewOf(g, entity.RoleMember), nil
	}
	return viewOf(g, mem.Role), nil
}

func (s *Service) newMembers(ctx context.Context, g *entity.Group, actorID int64, uids []int64) ([]*entity.Member, error) {
	lang := reqctx.Lang(ctx)
	now := nowMS()
	added := make([]*entity.Member, 0, len(uids))
	for _, uid := range entity.UniqueUIDs(uids) {
		if uid == actorID {
			continue
		}
		if _, err := s.repo.GetMember(ctx, g.ID, uid); err == nil {
			continue
		}
		if err := s.activeUser(ctx, uid); err != nil {
			return nil, err
		}
		if err := s.requireFriend(ctx, actorID, uid); err != nil {
			return nil, err
		}
		added = append(added, &entity.Member{GroupID: g.ID, UserID: uid, Role: entity.RoleMember, JoinedAtMS: now})
	}
	if len(added) == 0 {
		return nil, errs.ErrDuplicate.WithMsg(i18n.T(lang, i18n.KeyGroupAlreadyMember, nil))
	}
	if g.MemberCount+len(added) > entity.MaxMembers {
		return nil, errs.ErrInvalidArgument.WithMsg(i18n.T(lang, i18n.KeyGroupFull, nil))
	}
	return added, nil
}