Add unified post storage (#3)

Adds one post creation path for roots and replies, recursive thread loading, body-only updates, root listings, and root-only voting across PostgreSQL and the in-memory store. Co-authored-by: codegirl-007 <s.raide@gmail.com>
2026-08-27 07:43:25 +00:00
parent c5ef15ae1f
commit e86c2072ea
11 changed files with 1764 additions and 30 deletions
@@ -0,0 +1,372 @@
+package store
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5/pgconn"
+
+	"plumber/internal/pacific"
+	"plumber/internal/store/sqlc"
+)
+
+var (
+	ErrInvalidPost    = errors.New("invalid post")
+	ErrPostNotVotable = errors.New("post not votable")
+)
+
+type PostState string
+
+const (
+	PostStateVisible PostState = "visible"
+	PostStateHidden  PostState = "hidden"
+	PostStateLocked  PostState = "locked"
+)
+
+// Post is either a root question (ParentID nil) or a reply to another post.
+type Post struct {
+	ID         string
+	ParentID   *string
+	AuthorID   string
+	AuthorName string
+	AuthorRole Role
+	Title      string
+	Body       string
+	City       string
+	PostDate   string
+	PostState  PostState
+	CreatedAt  string
+	UpdatedAt  string
+	Score      int
+	Answered   bool
+	UserVote   int
+	Replies    []*Post
+	db         *sql.DB
+}
+
+// NewPost returns a post bound to db.
+func NewPost(db *sql.DB) *Post {
+	return &Post{db: db}
+}
+
+// Create inserts a root post or reply according to ParentID.
+func (p *Post) Create(ctx context.Context) error {
+	if p == nil || p.db == nil {
+		return fmt.Errorf("post: no database")
+	}
+	if err := preparePost(p); err != nil {
+		return err
+	}
+	err := sqlc.New(p.db).CreatePost(ctx, sqlc.CreatePostParams{
+		ID:        p.ID,
+		ParentID:  nullableParentID(p.ParentID),
+		AuthorID:  p.AuthorID,
+		Title:     p.Title,
+		Body:      p.Body,
+		City:      p.City,
+		PostDate:  p.PostDate,
+		PostState: string(p.PostState),
+		CreatedAt: p.CreatedAt,
+		UpdatedAt: p.UpdatedAt,
+	})
+	return mapPostCreateError(err)
+}
+
+// Update changes only the post body and update timestamp.
+func (p *Post) Update(ctx context.Context) error {
+	if p == nil || p.db == nil {
+		return fmt.Errorf("post: no database")
+	}
+	p.Body = strings.TrimSpace(p.Body)
+	if p.Body == "" {
+		return fmt.Errorf("%w: body is required", ErrInvalidPost)
+	}
+	p.UpdatedAt = time.Now().UTC().Format(time.RFC3339Nano)
+	n, err := sqlc.New(p.db).UpdatePost(ctx, sqlc.UpdatePostParams{
+		ID:        p.ID,
+		Body:      p.Body,
+		UpdatedAt: p.UpdatedAt,
+	})
+	if err != nil {
+		return err
+	}
+	if n == 0 {
+		return sql.ErrNoRows
+	}
+	return nil
+}
+
+func preparePost(p *Post) error {
+	p.ID = strings.TrimSpace(p.ID)
+	p.AuthorID = strings.TrimSpace(p.AuthorID)
+	p.Title = strings.TrimSpace(p.Title)
+	p.Body = strings.TrimSpace(p.Body)
+	p.City = strings.TrimSpace(p.City)
+	p.PostDate = strings.TrimSpace(p.PostDate)
+	if p.PostState == "" {
+		p.PostState = PostStateVisible
+	}
+	switch p.PostState {
+	case PostStateVisible, PostStateHidden, PostStateLocked:
+	default:
+		return fmt.Errorf("%w: invalid post state", ErrInvalidPost)
+	}
+	if p.AuthorID == "" {
+		return fmt.Errorf("%w: author is required", ErrInvalidPost)
+	}
+	if p.Body == "" {
+		return fmt.Errorf("%w: body is required", ErrInvalidPost)
+	}
+	if p.ParentID == nil {
+		if p.Title == "" {
+			return fmt.Errorf("%w: root title is required", ErrInvalidPost)
+		}
+		if p.PostDate == "" {
+			p.PostDate = pacific.Today()
+		}
+	} else {
+		parentID := strings.TrimSpace(*p.ParentID)
+		if parentID == "" {
+			return fmt.Errorf("%w: parent is required", ErrInvalidPost)
+		}
+		p.ParentID = &parentID
+		if p.Title != "" || p.City != "" || p.PostDate != "" || p.PostState != PostStateVisible {
+			return fmt.Errorf("%w: reply contains root-only fields", ErrInvalidPost)
+		}
+	}
+	if p.ID == "" {
+		p.ID = uuid.NewString()
+	}
+	now := time.Now().UTC().Format(time.RFC3339Nano)
+	if p.CreatedAt == "" {
+		p.CreatedAt = now
+	}
+	if p.UpdatedAt == "" {
+		p.UpdatedAt = p.CreatedAt
+	}
+	return nil
+}
+
+func nullableParentID(parentID *string) sql.NullString {
+	if parentID == nil {
+		return sql.NullString{}
+	}
+	return sql.NullString{String: *parentID, Valid: true}
+}
+
+func parentIDFromNull(parentID sql.NullString) *string {
+	if !parentID.Valid {
+		return nil
+	}
+	id := parentID.String
+	return &id
+}
+
+func mapPostCreateError(err error) error {
+	if err == nil {
+		return nil
+	}
+	var pgErr *pgconn.PgError
+	if errors.As(err, &pgErr) {
+		switch pgErr.Code {
+		case "23503", "23505", "23514":
+			return fmt.Errorf("%w: %v", ErrInvalidPost, err)
+		}
+	}
+	return err
+}
+
+func postFromValues(
+	db *sql.DB,
+	id string,
+	parentID sql.NullString,
+	authorID, authorName, authorRole, title, body, city, postDate string,
+	postState string,
+	createdAt, updatedAt string,
+) Post {
+	return Post{
+		ID:         id,
+		ParentID:   parentIDFromNull(parentID),
+		AuthorID:   authorID,
+		AuthorName: authorName,
+		AuthorRole: Role(authorRole),
+		Title:      title,
+		Body:       body,
+		City:       city,
+		PostDate:   postDate,
+		PostState:  PostState(postState),
+		CreatedAt:  createdAt,
+		UpdatedAt:  updatedAt,
+		db:         db,
+	}
+}
+
+// GetPost returns one post without loading its replies.
+func GetPost(ctx context.Context, db *sql.DB, id string) (*Post, error) {
+	r, err := sqlc.New(db).GetPost(ctx, id)
+	if err != nil {
+		return nil, err
+	}
+	p := postFromValues(
+		db,
+		r.ID,
+		r.ParentID,
+		r.AuthorID,
+		r.AuthorName,
+		r.AuthorRole,
+		r.Title,
+		r.Body,
+		r.City,
+		r.PostDate,
+		r.PostState,
+		r.CreatedAt,
+		r.UpdatedAt,
+	)
+	return &p, nil
+}
+
+// GetPostThread returns a root post with all descendants nested under Replies.
+func GetPostThread(ctx context.Context, db *sql.DB, rootID string) (*Post, error) {
+	rows, err := sqlc.New(db).ListPostThread(ctx, rootID)
+	if err != nil {
+		return nil, err
+	}
+	posts := make([]Post, 0, len(rows))
+	for _, r := range rows {
+		posts = append(posts, postFromValues(
+			db,
+			r.ID,
+			r.ParentID,
+			r.AuthorID,
+			r.AuthorName,
+			r.AuthorRole,
+			r.Title,
+			r.Body,
+			r.City,
+			r.PostDate,
+			r.PostState,
+			r.CreatedAt,
+			r.UpdatedAt,
+		))
+	}
+	return buildPostTree(posts, rootID)
+}
+
+func buildPostTree(posts []Post, rootID string) (*Post, error) {
+	byID := make(map[string]*Post, len(posts))
+	for i := range posts {
+		posts[i].Replies = nil
+		byID[posts[i].ID] = &posts[i]
+	}
+	root, ok := byID[rootID]
+	if !ok || root.ParentID != nil {
+		return nil, sql.ErrNoRows
+	}
+	for i := range posts {
+		post := &posts[i]
+		if post.ID == rootID {
+			continue
+		}
+		if post.ParentID == nil {
+			return nil, fmt.Errorf("post %s is not in thread %s", post.ID, rootID)
+		}
+		parent, ok := byID[*post.ParentID]
+		if !ok {
+			return nil, fmt.Errorf("post %s has missing parent %s", post.ID, *post.ParentID)
+		}
+		parent.Replies = append(parent.Replies, post)
+	}
+	var sortReplies func(*Post)
+	sortReplies = func(post *Post) {
+		sort.Slice(post.Replies, func(i, j int) bool {
+			if post.Replies[i].CreatedAt != post.Replies[j].CreatedAt {
+				return post.Replies[i].CreatedAt < post.Replies[j].CreatedAt
+			}
+			return post.Replies[i].ID < post.Replies[j].ID
+		})
+		for _, reply := range post.Replies {
+			sortReplies(reply)
+		}
+	}
+	sortReplies(root)
+	return root, nil
+}
+
+// ListRootPosts returns visible root posts for a post date.
+func ListRootPosts(ctx context.Context, db *sql.DB, postDate, viewerID string) ([]Post, error) {
+	rows, err := sqlc.New(db).ListRootPosts(ctx, sqlc.ListRootPostsParams{
+		ViewerID:    viewerID,
+		RowLimit:    HuntListLimit,
+		PostDate:    postDate,
+		HiddenState: string(PostStateHidden),
+	})
+	if err != nil {
+		return nil, err
+	}
+	posts := make([]Post, 0, len(rows))
+	for _, r := range rows {
+		post := postFromValues(
+			db,
+			r.ID,
+			r.ParentID,
+			r.AuthorID,
+			r.AuthorName,
+			r.AuthorRole,
+			r.Title,
+			r.Body,
+			r.City,
+			r.PostDate,
+			r.PostState,
+			r.CreatedAt,
+			r.UpdatedAt,
+		)
+		post.Score = int(r.Score)
+		post.Answered = r.Answered
+		post.UserVote = int(r.UserVote)
+		posts = append(posts, post)
+	}
+	return posts, nil
+}
+
+// SetPostVote sets value to 1, -1, or 0 on a visible root post.
+func SetPostVote(ctx context.Context, db *sql.DB, userID, postID string, value int) error {
+	if value != 1 && value != -1 && value != 0 {
+		return fmt.Errorf("invalid vote")
+	}
+	q := sqlc.New(db)
+	if value == 0 {
+		visible, err := q.PostIsVisibleRoot(ctx, sqlc.PostIsVisibleRootParams{
+			ID:          postID,
+			HiddenState: string(PostStateHidden),
+		})
+		if err != nil {
+			return err
+		}
+		if !visible {
+			return ErrPostNotVotable
+		}
+		return q.DeletePostVote(ctx, sqlc.DeletePostVoteParams{
+			UserID: userID,
+			PostID: postID,
+		})
+	}
+	n, err := q.UpsertPostVoteOnVisibleRoot(ctx, sqlc.UpsertPostVoteOnVisibleRootParams{
+		UserID:      userID,
+		PostID:      postID,
+		Value:       int32(value),
+		HiddenState: string(PostStateHidden),
+	})
+	if err != nil {
+		return err
+	}
+	if n == 0 {
+		return ErrPostNotVotable
+	}
+	return nil
+}