gochat/backend/internal/repository/conversation_label_repo.go

package repository

import (
	"context"

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

// ConversationLabelRepo provides data access for the ConversationLabel join table.
type ConversationLabelRepo struct {
	db *gorm.DB
}

func NewConversationLabelRepo(db *gorm.DB) *ConversationLabelRepo {
	return &ConversationLabelRepo{db: db}
}

// AddLabel attaches a tag to a conversation.
func (r *ConversationLabelRepo) AddLabel(ctx context.Context, cl *model.ConversationLabel) error {
	return r.db.WithContext(ctx).Create(cl).Error
}

// AddLabels attaches multiple tags to a conversation in a single transaction.
func (r *ConversationLabelRepo) AddLabels(ctx context.Context, labels []model.ConversationLabel) error {
	return r.db.WithContext(ctx).CreateInBatches(labels, 100).Error
}

// RemoveLabel detaches a specific tag from a conversation.
func (r *ConversationLabelRepo) RemoveLabel(ctx context.Context, conversationID, tagID uint) error {
	return r.db.WithContext(ctx).
		Where("conversation_id = ? AND tag_id = ?", conversationID, tagID).
		Delete(&model.ConversationLabel{}).Error
}

// RemoveAllLabels detaches all tags from a conversation.
func (r *ConversationLabelRepo) RemoveAllLabels(ctx context.Context, conversationID uint) error {
	return r.db.WithContext(ctx).
		Where("conversation_id = ?", conversationID).
		Delete(&model.ConversationLabel{}).Error
}

// FindByConversationID returns all labels attached to a conversation, with tag details preloaded.
func (r *ConversationLabelRepo) FindByConversationID(ctx context.Context, conversationID uint) ([]model.ConversationLabel, error) {
	var labels []model.ConversationLabel
	if err := r.db.WithContext(ctx).
		Preload("Tag").
		Where("conversation_id = ?", conversationID).
		Find(&labels).Error; err != nil {
		return nil, err
	}
	return labels, nil
}

// FindByTagID returns all conversations that have a specific tag, with pagination.
func (r *ConversationLabelRepo) FindByTagID(ctx context.Context, accountID, tagID uint, offset, limit int) ([]model.ConversationLabel, int64, error) {
	var labels []model.ConversationLabel
	var count int64
	db := r.db.WithContext(ctx).Model(&model.ConversationLabel{}).
		Where("account_id = ? AND tag_id = ?", accountID, tagID)
	db.Count(&count)
	if err := db.Preload("Conversation").Preload("Tag").
		Offset(offset).Limit(limit).
		Find(&labels).Error; err != nil {
		return nil, 0, err
	}
	return labels, count, nil
}

// FindByAccountID returns all unique tags used in an account (with usage counts).
func (r *ConversationLabelRepo) FindByAccountID(ctx context.Context, accountID uint) ([]model.ConversationLabel, error) {
	var labels []model.ConversationLabel
	if err := r.db.WithContext(ctx).
		Preload("Tag").
		Where("account_id = ?", accountID).
		Find(&labels).Error; err != nil {
		return nil, err
	}
	return labels, nil
}

// BatchAddLabels adds labels to multiple conversations at once.
func (r *ConversationLabelRepo) BatchAddLabels(ctx context.Context, conversationIDs []uint, tagID uint, accountID uint) error {
	labels := make([]model.ConversationLabel, len(conversationIDs))
	for i, convID := range conversationIDs {
		labels[i] = model.ConversationLabel{
			ConversationID: convID,
			TagID:          tagID,
			AccountID:      accountID,
		}
	}
	return r.db.WithContext(ctx).CreateInBatches(labels, 100).Error
}

// BatchRemoveLabels removes a tag from multiple conversations at once.
func (r *ConversationLabelRepo) BatchRemoveLabels(ctx context.Context, conversationIDs []uint, tagID uint) error {
	return r.db.WithContext(ctx).
		Where("conversation_id IN ? AND tag_id = ?", conversationIDs, tagID).
		Delete(&model.ConversationLabel{}).Error
}

// Exists checks if a specific label is already attached to a conversation.
func (r *ConversationLabelRepo) Exists(ctx context.Context, conversationID, tagID uint) (bool, error) {
	var count int64
	if err := r.db.WithContext(ctx).Model(&model.ConversationLabel{}).
		Where("conversation_id = ? AND tag_id = ?", conversationID, tagID).
		Count(&count).Error; err != nil {
		return false, err
	}
	return count > 0, nil
}

// ReplaceLabels replaces all labels on a conversation with the given set of tag IDs.
func (r *ConversationLabelRepo) ReplaceLabels(ctx context.Context, conversationID, accountID uint, tagIDs []uint) error {
	// Remove all existing labels
	if err := r.RemoveAllLabels(ctx, conversationID); err != nil {
		return err
	}
	// Add new labels
	if len(tagIDs) == 0 {
		return nil
	}
	labels := make([]model.ConversationLabel, len(tagIDs))
	for i, tagID := range tagIDs {
		labels[i] = model.ConversationLabel{
			ConversationID: conversationID,
			TagID:          tagID,
			AccountID:      accountID,
		}
	}
	return r.db.WithContext(ctx).CreateInBatches(labels, 100).Error
}