feat: implement attachment preview

Signed-off-by: Sebastian <krupinski01@gmail.com>

src/components/reader/ReaderHeader.vue

@@ -61,7 +61,7 @@ const handleAttachmentClick = (attachment: MessagePartInterface, index: number):
 
 const handleViewerRetrieve = (item: AttachmentItem): Promise<Blob> => {
   if (!props.entity) return Promise.reject(new Error('No message selected'))
-  return mailUiStore.attachmentBlob(props.entity, item.meta.attachment)
+  return mailUiStore.attachmentPreviewBlob(props.entity, item.meta.attachment)
 }
 
 // Format date for display

src/stores/mailOperationsStore.ts

@@ -640,6 +640,20 @@ export const useMailOperationsStore = defineStore('mailOperationsStore', () => {
     return blob
   }
 
+  async function attachmentPreviewBlob(entity: EntityObject, part: MessagePartInterface): Promise<Blob> {
+    return entitiesStore.preview({
+      target: entity.identifier,
+      part: {
+        blobId: part.blobId ?? undefined,
+        partId: part.partId ?? undefined,
+        cid: part.cid ?? undefined,
+        type: part.type || 'application/octet-stream',
+        size: part.size ?? null,
+      },
+      variant: 'popover',
+    })
+  }
+
   // ── Exports ───────────────────────────────────────────────────────────────
 
   return {
@@ -681,6 +695,7 @@ export const useMailOperationsStore = defineStore('mailOperationsStore', () => {
     moveMessages,
     downloadMessage,
     attachmentBlob,
+    attachmentPreviewBlob,
     moveFolder,
     renameFolder,
     isServiceFolderLoading,

src/stores/mailUiStore.ts

@@ -714,6 +714,10 @@ export const useMailUiStore = defineStore('mailUiStore', () => {
     return mailOperationsStore.attachmentBlob(entity, part)
   }
 
+  function attachmentPreviewBlob(entity: EntityObject, part: Parameters<typeof mailOperationsStore.attachmentPreviewBlob>[1]) {
+    return mailOperationsStore.attachmentPreviewBlob(entity, part)
+  }
+
   return {
     sidebarVisible,
     settingsDialogVisible,
@@ -763,6 +767,7 @@ export const useMailUiStore = defineStore('mailUiStore', () => {
     moveMessages,
     downloadMessage,
     attachmentBlob,
+    attachmentPreviewBlob,
     messageSelectionModeActivate,
     messageSelectionModeDeactivate,
     messageSelectionToggleOne,