feat(posts): add post reference/internal linking functionality

Add support for referencing other posts within messages through a new post_ref segment type. Includes new PostReference model to track relationships, PostRefService for processing references, and new endpoints for post suggestions, related posts, and reference click tracking.

internal/repository/post_ref_repo.go

@@ -0,0 +1,97 @@
+package repository
+
+import (
+	"context"
+
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+
+	"with_you/internal/model"
+)
+
+type PostRefRepository interface {
+	BatchUpsert(ctx context.Context, sourcePostID string, targetPostIDs []string) error
+	DeleteBySourcePostID(ctx context.Context, sourcePostID string) error
+	GetSourcesByTargetPostID(ctx context.Context, targetPostID string, page, pageSize int) ([]model.PostReference, int64, error)
+	GetTargetsBySourcePostID(ctx context.Context, sourcePostID string) ([]model.PostReference, error)
+	MarkStatusByTargetPostID(ctx context.Context, targetPostID string, status model.PostReferenceStatus) error
+	IncrementClickCount(ctx context.Context, sourcePostID, targetPostID string) error
+}
+
+type postRefRepository struct {
+	db *gorm.DB
+}
+
+func NewPostRefRepository(db *gorm.DB) PostRefRepository {
+	return &postRefRepository{db: db}
+}
+
+func (r *postRefRepository) BatchUpsert(ctx context.Context, sourcePostID string, targetPostIDs []string) error {
+	if len(targetPostIDs) == 0 {
+		return nil
+	}
+	refs := make([]model.PostReference, 0, len(targetPostIDs))
+	for _, targetID := range targetPostIDs {
+		refs = append(refs, model.PostReference{
+			SourcePostID: sourcePostID,
+			TargetPostID: targetID,
+			Status:       model.PostRefActive,
+		})
+	}
+	return r.db.WithContext(ctx).Clauses(clause.OnConflict{
+		Columns:   []clause.Column{{Name: "source_post_id"}, {Name: "target_post_id"}},
+		DoUpdates: clause.AssignmentColumns([]string{"status", "updated_at"}),
+	}).Create(&refs).Error
+}
+
+func (r *postRefRepository) DeleteBySourcePostID(ctx context.Context, sourcePostID string) error {
+	return r.db.WithContext(ctx).Where("source_post_id = ?", sourcePostID).Delete(&model.PostReference{}).Error
+}
+
+func (r *postRefRepository) GetSourcesByTargetPostID(ctx context.Context, targetPostID string, page, pageSize int) ([]model.PostReference, int64, error) {
+	var refs []model.PostReference
+	var total int64
+
+	if err := r.db.WithContext(ctx).Model(&model.PostReference{}).
+		Where("target_post_id = ? AND status = ?", targetPostID, model.PostRefActive).
+		Count(&total).Error; err != nil {
+		return nil, 0, err
+	}
+
+	offset := (page - 1) * pageSize
+	if err := r.db.WithContext(ctx).
+		Where("target_post_id = ? AND status = ?", targetPostID, model.PostRefActive).
+		Preload("SourcePost").
+		Preload("SourcePost.User").
+		Order("created_at DESC").
+		Offset(offset).Limit(pageSize).
+		Find(&refs).Error; err != nil {
+		return nil, 0, err
+	}
+
+	return refs, total, nil
+}
+
+func (r *postRefRepository) GetTargetsBySourcePostID(ctx context.Context, sourcePostID string) ([]model.PostReference, error) {
+	var refs []model.PostReference
+	if err := r.db.WithContext(ctx).
+		Where("source_post_id = ?", sourcePostID).
+		Preload("TargetPost").
+		Preload("TargetPost.User").
+		Find(&refs).Error; err != nil {
+		return nil, err
+	}
+	return refs, nil
+}
+
+func (r *postRefRepository) MarkStatusByTargetPostID(ctx context.Context, targetPostID string, status model.PostReferenceStatus) error {
+	return r.db.WithContext(ctx).Model(&model.PostReference{}).
+		Where("target_post_id = ?", targetPostID).
+		Update("status", status).Error
+}
+
+func (r *postRefRepository) IncrementClickCount(ctx context.Context, sourcePostID, targetPostID string) error {
+	return r.db.WithContext(ctx).Model(&model.PostReference{}).
+		Where("source_post_id = ? AND target_post_id = ?", sourcePostID, targetPostID).
+		UpdateColumn("click_count", gorm.Expr("click_count + 1")).Error
+}