1

internal/handlers/post_download.go

@@ -0,0 +1,110 @@
+package handlers
+
+import (
+	"context"
+	"net/http"
+	"strings"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+type postAttachmentDownloadInfo struct {
+	URL      string
+	Filename string
+	Mime     string
+}
+
+func loadPublishedPostAttachment(ctx context.Context, pool *pgxpool.Pool, postID, aid uuid.UUID) (postAttachmentDownloadInfo, error) {
+	var info postAttachmentDownloadInfo
+	err := pool.QueryRow(ctx, `
+		SELECT pa.url, COALESCE(NULLIF(TRIM(pa.filename), ''), 'download'), COALESCE(NULLIF(TRIM(pa.mime), ''), 'application/octet-stream')
+		FROM post_attachments pa
+		JOIN posts p ON p.id = pa.post_id
+		WHERE pa.id = $1 AND pa.post_id = $2
+			AND `+publicPostWhere, aid, postID,
+	).Scan(&info.URL, &info.Filename, &info.Mime)
+	if err != nil {
+		return info, err
+	}
+	info.URL = strings.TrimSpace(info.URL)
+	if info.URL == "" {
+		return info, pgx.ErrNoRows
+	}
+	return info, nil
+}
+
+func incrPostDownloadCount(ctx context.Context, pool *pgxpool.Pool, postID uuid.UUID) error {
+	cmd, err := pool.Exec(ctx, `
+		UPDATE posts SET download_count = download_count + 1, updated_at = NOW()
+		WHERE id = $1 AND `+publicPostWhere, postID)
+	if err != nil {
+		return err
+	}
+	if cmd.RowsAffected() == 0 {
+		return pgx.ErrNoRows
+	}
+	return nil
+}
+
+func handlePostAttachmentDownload(w http.ResponseWriter, r *http.Request, redirect bool) {
+	pool := poolFrom(r)
+	postID, err := uuid.Parse(chi.URLParam(r, "id"))
+	if err != nil {
+		http.Error(w, "bad id", http.StatusBadRequest)
+		return
+	}
+	aid, err := uuid.Parse(chi.URLParam(r, "aid"))
+	if err != nil {
+		http.Error(w, "bad attachment id", http.StatusBadRequest)
+		return
+	}
+	ctx := r.Context()
+	info, err := loadPublishedPostAttachment(ctx, pool, postID, aid)
+	if err != nil {
+		if err == pgx.ErrNoRows {
+			http.NotFound(w, r)
+			return
+		}
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if err := incrPostDownloadCount(ctx, pool, postID); err != nil {
+		if err == pgx.ErrNoRows {
+			http.NotFound(w, r)
+			return
+		}
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if redirect {
+		http.Redirect(w, r, info.URL, http.StatusFound)
+		return
+	}
+	writeJSON(w, map[string]any{
+		"ok":       true,
+		"url":      info.URL,
+		"filename": info.Filename,
+		"mime":     info.Mime,
+	})
+}
+
+// PostAttachmentDownload increments download_count and returns the attachment file URL for the client to open/save.
+func PostAttachmentDownload(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+	handlePostAttachmentDownload(w, r, false)
+}
+
+// GetPostAttachmentDownload increments download_count and redirects the browser to the attachment URL.
+func GetPostAttachmentDownload(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+	handlePostAttachmentDownload(w, r, true)
+}

internal/handlers/posts_public.go

@@ -93,30 +93,6 @@ func GetPost(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, dto)
 }
 
-func PostAttachmentDownload(w http.ResponseWriter, r *http.Request) {
-	pool := poolFrom(r)
-	postID, err := uuid.Parse(chi.URLParam(r, "id"))
-	if err != nil {
-		http.Error(w, "bad id", http.StatusBadRequest)
-		return
-	}
-	aid, err := uuid.Parse(chi.URLParam(r, "aid"))
-	if err != nil {
-		http.Error(w, "bad attachment id", http.StatusBadRequest)
-		return
-	}
-	cmd, err := pool.Exec(r.Context(), `
-		UPDATE posts SET download_count = download_count + 1, updated_at = NOW()
-		WHERE id = $1 AND status = 'published' AND is_public = TRUE
-			AND (published_at IS NULL OR published_at <= NOW())`, postID)
-	if err != nil || cmd.RowsAffected() == 0 {
-		http.NotFound(w, r)
-		return
-	}
-	writeJSON(w, map[string]any{"ok": true})
-	_ = aid
-}
-
 func listPostsQuery(w http.ResponseWriter, r *http.Request, searchMode bool) {
 	pool := poolFrom(r)
 	limit := postLimitDef(r, 20, 50)