[GEM-52] - Add Article to Collections Endpoint (#17)

app/article/collection_handlers.go

@@ -133,6 +133,66 @@ func getOwnCollectionsHandler(w http.ResponseWriter, r *http.Request) {
 	app.WriteHttpBodyJson(w, http.StatusOK, collections)
 }
 
+func getAddedCollectionsHandler(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+
+	creator, ok := ctx.Value(auth.UserInfoCtx).(auth.User)
+	if !ok {
+		app.WriteHttpError(w, http.StatusUnauthorized, auth.ErrInvalidAccessToken)
+		return
+	}
+
+	articleId := chi.URLParam(r, "articleId")
+
+	collections, err := getAddedCollections(ctx, creator.Id, articleId)
+	if err != nil {
+		switch {
+		case errors.As(err, &ErrInvalidArticleId):
+			app.WriteHttpError(w, http.StatusBadRequest, err)
+		case errors.Is(err, ErrArticleDoesNotExist):
+			app.WriteHttpError(w, http.StatusNotFound, err)
+		default:
+			app.WriteHttpInternalServerError(w)
+		}
+		return
+	}
+
+	app.WriteHttpBodyJson(w, http.StatusOK, collections)
+}
+
+func addArticleToCollectionsHandler(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+
+	creator, ok := ctx.Value(auth.UserInfoCtx).(auth.User)
+	if !ok {
+		app.WriteHttpError(w, http.StatusUnauthorized, auth.ErrInvalidAccessToken)
+		return
+	}
+
+	articleId := chi.URLParam(r, "articleId")
+
+	var body addArticleToCollectionsReq
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		app.WriteHttpError(w, http.StatusBadRequest, err)
+		return
+	}
+
+	collections, err := addArticleToCollections(ctx, creator.Id, articleId, body.CollectionIds)
+	if err != nil {
+		switch {
+		case errors.As(err, &ErrInvalidArticleId):
+			app.WriteHttpError(w, http.StatusBadRequest, err)
+		case errors.Is(err, ErrArticleDoesNotExist):
+			app.WriteHttpError(w, http.StatusNotFound, err)
+		default:
+			app.WriteHttpInternalServerError(w)
+		}
+		return
+	}
+
+	app.WriteHttpBodyJson(w, http.StatusOK, collections)
+}
+
 func getPublicCollectionsHandler(w http.ResponseWriter, r *http.Request) {
 	ctx := r.Context()
 

app/article/collection_repo.go

@@ -3,6 +3,8 @@ package article
 import (
 	"context"
 	"errors"
+	"fmt"
+	"time"
 
 	"github.com/georgysavva/scany/v2/pgxscan"
 	"github.com/jackc/pgx/v5"
@@ -138,6 +140,103 @@ func findCollectionsByCreatorId(ctx context.Context, tx pgx.Tx, creatorId ulid.U
 	return collections, nil
 }
 
+func findAddedCollectionsByArticleIdAndCreatorId(ctx context.Context, tx pgx.Tx, articleId, creatorId ulid.ULID) (collections []*Collection, err error) {
+	if _, err := findArticleById(ctx, tx, articleId); err != nil {
+		return collections, err
+	}
+
+	q := `
+	SELECT c.*
+	FROM collections c
+	WHERE EXISTS (
+	  SELECT ca.id
+	  FROM collection_articles ca
+	  WHERE EXISTS (
+		SELECT a.id
+		FROM articles a
+		WHERE
+		  a.id = $2 AND
+		  a.id = ca.article_id AND
+		  a.deleted_at IS NULL
+	  ) AND
+	    c.id = ca.collection_id AND
+		ca.deleted_at IS NULL
+	) AND EXISTS (
+	  SELECT u.id
+	  FROM users u
+	  WHERE 
+	    u.id = $1 AND
+		u.id = c.creator_id AND
+		u.deleted_at IS NULL
+	) AND
+	  c.deleted_at IS NULL
+	ORDER BY c.created_at DESC
+	`
+
+	collections = []*Collection{}
+	if err = pgxscan.Select(ctx, tx, &collections, q, creatorId, articleId); err != nil {
+		log.Err(err).Msg("Failed to find added collections by article id and creator id")
+		return
+	}
+
+	return collections, nil
+}
+
+func createCollectionArticles(ctx context.Context, tx pgx.Tx, articleId, creatorId ulid.ULID, collectionIds []ulid.ULID) (collections []*Collection, err error) {
+	if _, err := findArticleById(ctx, tx, articleId); err != nil {
+		return collections, err
+	}
+
+	q := `
+	UPDATE collection_articles ca
+	SET deleted_at = $3
+	FROM collections c, users u
+	WHERE 
+	  ca.collection_id = c.id AND
+	  ca.article_id = $1 AND
+	  c.creator_id = u.id AND
+	  u.id = $2 AND
+	  ca.deleted_at IS NULL
+	`
+
+	now := time.Now()
+
+	if _, err = tx.Exec(ctx, q, articleId, creatorId, now); err != nil {
+		log.Err(err).Msg("Failed to create collection articles")
+		return
+	}
+
+	if len(collectionIds) > 0 {
+		q = "INSERT INTO collection_articles (id, collection_id, article_id, created_at) VALUES"
+
+		params := []any{articleId, now}
+		paramCount := 3
+		for i, collectionId := range collectionIds {
+			q += fmt.Sprintf("\n($%d, $%d, $1, $2)", paramCount, paramCount+1)
+			if i+1 < len(collectionIds) {
+				q += ","
+			}
+
+			params = append(params, ulid.Make(), collectionId)
+			paramCount += 2
+		}
+
+		q += "\nON CONFLICT DO NOTHING"
+
+		if _, err = tx.Exec(ctx, q, params...); err != nil {
+			log.Err(err).Msg("Failed to create collection articles")
+			return
+		}
+	}
+
+	collections, err = findAddedCollectionsByArticleIdAndCreatorId(ctx, tx, articleId, creatorId)
+	if err != nil {
+		return
+	}
+
+	return collections, nil
+}
+
 func findPublicCollections(ctx context.Context, tx pgx.Tx) (collections []*CollectionMetadata, err error) {
 	q := `
 	SELECT c.*, u.name creator_name, COUNT(1) number_of_articles
@@ -158,4 +257,4 @@ func findPublicCollections(ctx context.Context, tx pgx.Tx) (collections []*Colle
 	}
 
 	return collections, nil
-}
+}

app/article/collection_service.go

@@ -142,6 +142,60 @@ func getOwnCollections(ctx context.Context, creatorId ulid.ULID) (collections []
 	return collections, nil
 }
 
+func getAddedCollections(ctx context.Context, creatorId ulid.ULID, articleIdStr string) (collections []*Collection, err error) {
+	articleId, err := validateArticleId(articleIdStr)
+	if err != nil {
+		return
+	}
+
+	tx, err := pool.Begin(ctx)
+	if err != nil {
+		log.Err(err).Msg("Failed to get added collections")
+		return
+	}
+
+	defer tx.Rollback(ctx)
+
+	collections, err = findAddedCollectionsByArticleIdAndCreatorId(ctx, tx, articleId, creatorId)
+	if err != nil {
+		return
+	}
+
+	if err = tx.Commit(ctx); err != nil {
+		log.Err(err).Msg("Failed to get added collections")
+		return
+	}
+
+	return collections, nil
+}
+
+func addArticleToCollections(ctx context.Context, creatorId ulid.ULID, articleIdStr string, collectionIds []ulid.ULID) (collections []*Collection, err error) {
+	articleId, err := validateArticleId(articleIdStr)
+	if err != nil {
+		return
+	}
+
+	tx, err := pool.Begin(ctx)
+	if err != nil {
+		log.Err(err).Msg("Failed to add article to collections")
+		return
+	}
+
+	defer tx.Rollback(ctx)
+
+	collections, err = createCollectionArticles(ctx, tx, articleId, creatorId, collectionIds)
+	if err != nil {
+		return
+	}
+
+	if err = tx.Commit(ctx); err != nil {
+		log.Err(err).Msg("Failed to add article to collections")
+		return
+	}
+
+	return collections, nil
+}
+
 func getPublicCollections(ctx context.Context) (collections []*CollectionMetadata, err error) {
 	tx, err := pool.Begin(ctx)
 	if err != nil {

app/article/request.go

@@ -1,6 +1,9 @@
 package article
 
-import "gopkg.in/guregu/null.v4"
+import (
+	"github.com/oklog/ulid/v2"
+	"gopkg.in/guregu/null.v4"
+)
 
 type createArticleCategoryReq struct {
 	Name string `json:"name"`
@@ -71,3 +74,7 @@ type updateCollectionReq struct {
 	Name       null.String `json:"name"`
 	Visibility null.String `json:"visibility"`
 }
+
+type addArticleToCollectionsReq struct {
+	CollectionIds []ulid.ULID `json:"collection_ids"`
+}

app/article/router.go

@@ -39,9 +39,12 @@ func Router() *chi.Mux {
 
 	r.Get("/", getArticlesHandler)
 	r.Get("/{id}", getArticleByIdHandler)
-
+	
 	r.Group(func(r chi.Router) {
 		r.Use(auth.UserAuthMiddleware)
+
+		r.Get("/{articleId}/collection", getAddedCollectionsHandler)
+		r.Post("/{articleId}/collection", addArticleToCollectionsHandler)
 
 		r.Post("/collection/new", createCollectionHandler)
 		r.Put("/collection/{collectionId}", updateCollectionHandler)